Borehole annulus volume determination method and device

Abstract

The invention discloses a borehole annulus volume determination method and device, and belongs to the field of well drilling. The method comprises the steps that the first moment when drilling fluid is added into a first well is obtained, and the drilling fluid is mixed with a tracer agent; acquiring a second moment when the concentration of the tracer agent in the drilling fluid returned from the borehole annulus of the first well reaches a preset concentration, and detecting the concentration of the tracer agent in the drilling fluid returned from the borehole annulus by tracer agent detection equipment from filtrate of the drilling fluid returned from the borehole annulus; the well diameter of the first well is determined according to the time difference between the first moment and the second moment; a volume of a wellbore annulus of the first well is determined from a borehole diameter of the first well. According to the method, the accuracy of determining the volume of the wellbore annulus can be improved.

Description

Technical Field

[0001] The present application relates to the field of drilling, and in particular to a method and device for determining the volume of a wellbore annulus. Background Art

[0002] During the drilling process, casing is usually lowered into the well to support the well wall. The annular space between the well wall and the casing and the annular space between different casings in the well are all wellbore annulus. In order to protect the casing in the well, cement slurry needs to be injected into the wellbore annulus for cementing after drilling is completed. Before cementing, the volume of the wellbore annulus needs to be determined according to the well diameter, and the amount of cement slurry used for cementing needs to be determined according to the volume of the wellbore annulus.

[0003] However, for highly deviated wells (e.g., wells with a deviated angle between 46 and 85 degrees), long horizontal wells (horizontal wells with a long horizontal section), etc., it is difficult to lower the logging instrument into the well, resulting in greater difficulty in measuring the well diameters of these wells. Therefore, for highly deviated wells, long horizontal wells, etc., the volume of the wellbore annulus of the well is usually calculated based on the well diameters of the well's neighboring wells (i.e., wells adjacent to the well).

[0004] However, the difference between the wellbore diameter of the adjacent well and the wellbore diameter of the present well may be quite large, resulting in a large difference between the volume of the wellbore annulus of the present well calculated based on the wellbore diameter of the adjacent well and the actual volume of the wellbore annulus of the present well. Therefore, the current technical solutions for determining the volume of the wellbore annulus of highly deviated wells, long horizontal wells, etc. have low accuracy. Summary of the invention

[0005] The present application provides a method and device for determining the volume of a wellbore annulus, which can improve the accuracy of determining the volume of the wellbore annulus. The technical solution of the present application is as follows.

[0006] In a first aspect, a method for determining the volume of a wellbore annulus is provided, which is applied to a computer device, and the method comprises:

[0007] Acquiring a first moment of adding drilling fluid into a first well, wherein the drilling fluid is mixed with a tracer;

[0008] Acquiring a second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, wherein the concentration of the tracer in the drilling fluid returned from the wellbore annulus is detected by a tracer detection device from a filtrate of the drilling fluid returned from the wellbore annulus;

[0009] Determine the well diameter of the first well according to the time difference between the first moment and the second moment;

[0010] The volume of the wellbore annulus of the first well is determined according to the wellbore diameter of the first well.

[0011] Optionally, the wellbore annulus includes a first annular space between a first casing in the first well and a wellbore wall of the first well, and determining the wellbore diameter of the first well according to the time difference between the first moment and the second moment includes:

[0012] Determine a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid added to the first well, wherein the target displacement is the amount of the drilling fluid added to the first well per unit time;

[0013] The wellbore diameter of the first well is determined according to the first time duration, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

[0014] Optionally, the first casing includes a first pipe section and a second pipe section, the first annular space is an annular space between the first pipe section and the wellbore wall of the first well, the wellbore annulus also includes a second annular space between the second pipe section and a second casing in the first well, the first casing is lowered into the first well from the second casing, the second pipe section is in the second casing, and the first pipe section is outside the second casing;

[0015] The method further includes: determining a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement;

[0016] The method of determining the wellbore diameter of the first well according to the first time length, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment includes: determining the wellbore diameter of a first well section of the first well according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, and the time difference between the first moment and the second moment, the first well section being the well section where the first pipe section is located.

[0017] Optionally, the first time duration, the second time duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore diameter of the first well section satisfy a first relationship;

[0018] The wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship;

[0019] The first relationship is: △t = T1 + [π × [(D / 2) 2 -(d11 / 2) 2 ]×(H1-H2)] / Q+T2;

[0020] The second relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2;

[0021] Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, V represents the volume of the wellbore annulus, d 22 represents the inner diameter of the second sleeve.

[0022] Optionally, the first duration, the outer diameter of the first casing, the length of the first casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore of the first well satisfy a third relationship:

[0023] The well diameter of the first well and the volume of the wellbore annulus of the first well satisfy a fourth relationship;

[0024] The third relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×H1] / Q;

[0025] The fourth relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×H1;

[0026] Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, D represents the wellbore diameter of the first well, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, Q represents the target displacement, and V represents the volume of the wellbore annulus.

[0027] Optionally, the drilling fluid satisfies at least one of the following conditions:

[0028] The difference between the density of the drilling fluid and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid is obtained by adding the tracer to the initial drilling fluid;

[0029] The concentration of the tracer in the drilling fluid added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, and the concentration recovery rate is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid.

[0030] In a second aspect, a device for determining the volume of a borehole annulus is provided, which is applied to a computer device, and the device comprises:

[0031] A first acquisition module, used for acquiring a first moment of adding drilling fluid into a first well, wherein the drilling fluid is mixed with a tracer;

[0032] A second acquisition module is used to acquire a second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, and the concentration of the tracer in the drilling fluid returned from the wellbore annulus is detected by a tracer detection device from a filtrate of the drilling fluid returned from the wellbore annulus;

[0033] A first determination module, configured to determine a well diameter of the first well according to a time difference between the first moment and the second moment;

[0034] The second determination module is used to determine the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well.

[0035] Optionally, the wellbore annulus includes a first annular space between a first casing in the first well and a wellbore wall of the first well, and the first determining module is used to:

[0036] Determine a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid added to the first well, wherein the target displacement is the amount of the drilling fluid added to the first well per unit time;

[0037] The wellbore diameter of the first well is determined according to the first time duration, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

[0038] Optionally, the first casing includes a first pipe section and a second pipe section, the first annular space is an annular space between the first pipe section and the wellbore wall of the first well, the wellbore annulus also includes a second annular space between the second pipe section and a second casing in the first well, the first casing is lowered into the first well from the second casing, the second pipe section is in the second casing, and the first pipe section is outside the second casing; the first determining module is used to:

[0039] Determining a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement;

[0040] The wellbore of the first well section of the first well is determined according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, and the time difference between the first moment and the second moment, where the first well section is the well section where the first pipe section is located.

[0041] Optionally, the first time duration, the second time duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore diameter of the first well section satisfy a first relationship;

[0042] The wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship;

[0043] The first relationship is: △t = T1 + [π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)] / Q+T2;

[0044] The second relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2;

[0045] Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, d 11represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, V represents the volume of the wellbore annulus, d 22 represents the inner diameter of the second sleeve.

[0046] Optionally, the first duration, the outer diameter of the first casing, the length of the first casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore of the first well satisfy a third relationship:

[0047] The well diameter of the first well and the volume of the wellbore annulus of the first well satisfy a fourth relationship;

[0048] The third relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×H1] / Q;

[0049] The fourth relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×H1;

[0050] Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, D represents the wellbore diameter of the first well, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, Q represents the target displacement, and V represents the volume of the wellbore annulus.

[0051] Optionally, the drilling fluid satisfies at least one of the following conditions:

[0052] The difference between the density of the drilling fluid and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid is obtained by adding the tracer to the initial drilling fluid;

[0053] The concentration of the tracer in the drilling fluid added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, and the concentration recovery rate is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid.

[0054] In a third aspect, a device for determining the volume of a wellbore annulus is provided, comprising a memory and a processor;

[0055] The memory is used to store computer programs;

[0056] The processor is used to execute the computer program stored in the memory so that the device for determining the volume of the borehole annulus executes the method for determining the volume of the borehole annulus provided in the first aspect or any optional implementation of the first aspect.

[0057] In a fourth aspect, a computer device is provided, which may be a smart phone, a tablet computer, a laptop computer or a desktop computer, etc. The computer device includes a volume determination device for the wellbore annulus as provided in the second aspect or any optional implementation of the second aspect, or the computer device includes a volume determination device for the wellbore annulus as provided in the third aspect.

[0058] In a fifth aspect, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed, a method for determining the volume of a wellbore annulus as provided in the first aspect or any optional method of the first aspect is implemented.

[0059] In a sixth aspect, a computer program product is provided, the computer program product comprising a program or code, which, when executed, implements a method for determining the volume of a wellbore annulus as provided in the first aspect or any optional method of the first aspect.

[0060] The beneficial effects of the technical solution provided by this application are:

[0061] In the technical solution provided by the present application, the diameter of the first well is determined according to the time difference between the first moment when the drilling fluid mixed with the tracer is added to the first well and the second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, and then the volume of the wellbore annulus of the first well is determined according to the diameter of the first well. Compared with determining the volume of the wellbore annulus of the present well according to the diameter of the adjacent well, the present application directly determines the volume of the wellbore annulus of the first well according to the diameter of the first well, so the accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 It is a flow chart of a method for determining the volume of a wellbore annulus provided in an embodiment of the present application;

[0064] Figure 2 is a schematic diagram of a drilling method provided in an embodiment of the present application;

[0065] Figure 3 is a schematic diagram of a first well after casing is lowered into the well according to an embodiment of the present application;

[0066] Figure 4 is a schematic diagram of a first well provided in an embodiment of the present application;

[0067] Figure 5 is a schematic diagram of another first well provided in an embodiment of the present application;

[0068] Figure 6 is a schematic diagram of a wellbore annulus volume determination device provided in an embodiment of the present application;

[0069] Figure 7 It is a schematic diagram of another device for determining the volume of a wellbore annulus provided in an embodiment of the present application.

[0070] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0072] During the drilling process, casing is usually lowered into the well to support the well wall. The annular space between the well wall and the casing and the annular space between different casings in the well are all wellbore annuli. In order to protect the casing in the well, cement slurry needs to be injected into the wellbore annulus for cementing after drilling is completed. If the cement slurry injected into the wellbore annulus is insufficient, it is easy for the cement slurry to fail to return to the designed depth, affecting the cementing effect. If too much cement slurry is injected into the wellbore annulus, the excess cement slurry needs to be cleaned out, which is easy to cause pollution to the cemented well section, affecting the cementing effect, and the cleaned cement slurry needs to be processed, causing environmental pressure and increasing the construction process. Therefore, before cementing, it is necessary to accurately design the amount of cement slurry injected into the wellbore annulus. For example, before cementing, the volume of the wellbore annulus is determined according to the well diameter, and the amount of cement slurry used for cementing is determined according to the volume of the wellbore annulus. At present, the wellbore diameter of the well (that is, the well that currently needs cementing) can be measured by a logging instrument, and the volume of the wellbore annulus of the well can be calculated based on the wellbore diameter of the well measured by the logging instrument. However, it is difficult to lower the logging instrument into highly deviated wells, long horizontal wells, etc., which makes it difficult to measure the wellbore diameter of highly deviated wells, long horizontal wells, etc. Therefore, for highly deviated wells, long horizontal wells, etc., the volume of the wellbore annulus of the well is usually calculated based on the wellbore diameter of the neighboring wells of the well. The wellbore diameter of the neighboring well may differ greatly from the wellbore diameter of the well, resulting in a large difference between the volume of the wellbore annulus of the well calculated based on the wellbore diameter of the neighboring well and the actual volume of the wellbore annulus of the well, and the calculated volume of the wellbore annulus is less accurate.

[0073] The embodiment of the present application provides a method and device for determining the volume of a borehole annulus, and the method for determining the volume of a borehole annulus is executed by a device for determining the volume of a borehole annulus. In the technical solution provided by the embodiment of the present application, a tracer is mixed in the drilling fluid, and the device for determining the volume of the borehole annulus obtains a first moment when the drilling fluid mixed with the tracer is added to the first well and a second moment when the concentration of the tracer in the drilling fluid returned from the borehole annulus of the first well reaches a preset concentration, and the device for determining the volume of the borehole annulus determines the diameter of the first well according to the time difference between the first moment and the second moment, and then determines the volume of the borehole annulus of the first well according to the diameter of the first well. The embodiment of the present application determines the volume of the borehole annulus of the first well according to the diameter of the first well to be cemented, and compared with determining the volume of the borehole annulus of the present well (e.g., the first well) according to the diameter of the neighboring well (e.g., the well adjacent to the first well), the embodiment of the present application directly determines the volume of the borehole annulus of the first well according to the diameter of the first well, so the accuracy is higher. The embodiments of the present application are applicable to determining the volume of the wellbore annulus of various possible wells, and have a significant effect in particular on determining the volume of the wellbore annulus of highly deviated wells, long horizontal wells, etc.

[0074] The technical solution of the present application is introduced below, and first the method embodiment of the present application is introduced.

[0075] Please refer to Figure 1 , which shows a flow chart of a method for determining the volume of a borehole annulus provided in an embodiment of the present application. The method for determining the volume of a borehole annulus is executed by a device for determining the volume of a borehole annulus (hereinafter referred to as a volume determining device). The method for determining the volume of a borehole annulus includes the following steps S101 to S104.

[0076] S101. Obtain a first moment of adding drilling fluid into a first well, wherein the drilling fluid is mixed with a tracer.

[0077] The first moment may be the moment when the drilling fluid mixed with the tracer is started to be added into the first well, that is, the first moment is the start time of adding the drilling fluid mixed with the tracer into the first well. In the embodiment of the present application, the tracer mixed in the drilling fluid may be ammonium thiocyanate or sodium nitrite.

[0078] In an optional embodiment, the volume determination device obtains first time information, and the first time information is used to indicate the first moment of adding the drilling fluid mixed with the tracer into the first well, and the volume determination device determines the first moment of adding the drilling fluid mixed with the tracer into the first well according to the first time information. In one embodiment, the volume determination device includes a human-computer interaction component, and the staff inputs the first time information into the volume determination device through the human-computer interaction component, and the volume determination device obtains the first time information input by the staff. For example, when the drilling fluid pump starts to add the drilling fluid mixed with the tracer into the first well, the staff records the first moment when the drilling fluid pump starts to add the drilling fluid into the first well, and the staff inputs the first time information into the volume determination device according to the first moment. Among them, the human-computer interaction component includes but is not limited to a keyboard, a mouse, a touch screen, etc. In another embodiment, the volume determination device is connected to a drilling fluid pump for adding drilling fluid into the first well. The drilling fluid pump is an intelligent pump capable of communicating with the volume determination device. For example, the drilling fluid pump is an intelligent Internet of Things device. When the drilling fluid pump starts to add drilling fluid mixed with a tracer into the first well, the first time information is sent to the volume determination device, and the volume determination device receives the first time information sent by the drilling fluid pump. In another embodiment, a sensor is provided at the wellhead of the first well, and the volume determination device is connected to the sensor. The sensor can be used to sense whether drilling fluid flows into the first well through the wellhead of the first well. When the sensor senses that drilling fluid starts to flow into the first well through the wellhead of the first well, the sensor sends a sensing signal to the volume determination device, and the volume determination device obtains the first time information according to the sensing signal.

[0079] For example, Figure 2 Schematic diagram of a drilling well provided in an embodiment of the present application. Figure 2As shown, the drilling tool includes a drill pipe, a drill bit and a turntable. The drill bit and the turntable are arranged at both ends of the drill pipe. The drilling fluid tank is connected to the drilling tool through a first pipeline. A drilling fluid pump and a control valve are arranged on the first pipeline. The control valve is located between the drilling fluid pump and the drilling tool. The control valve is used to control the displacement of the drilling fluid added to the first well. The drilling fluid pump is used to apply pressure to the drilling fluid in the drilling fluid tank so that the drilling fluid enters the inside of the drilling tool through the first pipeline and enters the well through the drilling tool. During the drilling process, the rotation of the turntable drives the drill pipe and the drill bit to rotate, and the drill bit rotates underground to drill a wellbore. The wellbore continues to deepen as the drill pipe is lengthened and the drill bit rotates. At the same time, the drilling fluid pump applies pressure to the drilling fluid in the drilling fluid tank so that the drilling fluid enters the drill tool through the first pipeline and enters the first well through the drill tool. The drilling fluid that enters the first well fills the gap between the drill tool and the well wall of the first well and then returns upward from the gap between the drill tool and the well wall of the first well. The drilling fluid can cool the drill tool during its flow in the drill tool, and the drilling fluid that returns upward from the gap between the drill tool and the well wall of the first well can bring the debris generated during the drilling process out of the first well. After drilling (for example, after drilling a section), the drill tool can be removed from the first well, and casing can be lowered into the first well to support the well wall of the first well. For example, Figure 3 is a schematic diagram of a casing (such as a first casing) after being lowered into a first well provided by an embodiment of the present application, such as Figure 3 As shown, after the first casing is lowered into the first well, one end of the first casing is connected to the first pipeline, and the dosing tank for holding the tracer is connected to the drilling fluid tank through the second pipeline, and the tracer in the dosing tank can flow into the drilling fluid tank through the second pipeline to add the tracer to the drilling fluid in the drilling fluid tank, and the drilling fluid pump is used to apply pressure to the drilling fluid mixed with the tracer in the drilling fluid tank, so that the drilling fluid mixed with the tracer in the drilling fluid tank flows into the first well through the first pipeline, thereby realizing the addition of the drilling fluid mixed with the tracer into the first well. The first moment can be the moment when the drilling fluid pump starts to apply pressure to the drilling fluid mixed with the tracer in the drilling fluid tank, or it can be the moment when the drilling fluid mixed with the tracer in the drilling fluid tank starts to enter the first well from the wellhead of the first well, and the embodiment of the present application does not limit this.

[0080] S102. Obtain the second moment when the concentration of the tracer in the drilling fluid returned from the annulus of the first well reaches a preset concentration, and the concentration of the tracer in the drilling fluid returned from the annulus of the wellbore is detected by a tracer detection device from the filtrate in the drilling fluid returned from the annulus of the wellbore.

[0081] The second moment is the moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well after the drilling fluid mixed with the tracer is added to the first well reaches a preset concentration, which is set according to actual conditions, for example, the preset concentration is 0.0000837 mol / L. The concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well is detected by the tracer detection device from the filtrate in the drilling fluid returned from the wellbore annulus.

[0082] In an optional embodiment, the volume determination device obtains second time information, and the second time information is used to indicate the second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well after the drilling fluid mixed with the tracer is added to the first well reaches a preset concentration, and the volume determination device determines the second moment according to the second time information. In one embodiment, the volume determination device includes a human-computer interaction component, and the staff inputs the second time information to the volume determination device through the human-computer interaction component, and the volume determination device obtains the second time information input by the staff. For example, after the staff learns that the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches the preset concentration, the staff inputs the second time information to the volume determination device.

[0083] In an optional embodiment, after adding drilling fluid mixed with a tracer into the first well, the drilling fluid fills the annulus of the first well and then begins to return from the annulus of the first well. The drilling fluid returned from the annulus of the first well can be collected at regular intervals as a drilling fluid sample, and a filtering device is used to filter the drilling fluid sample to obtain a filtrate of the drilling fluid sample (for example, the filtrate of the drilling fluid sample is referred to as a filtrate sample). A tracer detection device is used to detect the concentration of the tracer in the filtrate sample until the concentration of the tracer detected in the filtrate of the drilling fluid sample collected at a certain moment reaches a preset concentration. The volume determination device determines the certain moment as the second moment when the concentration of the tracer in the drilling fluid returned from the annulus of the first well reaches the preset concentration. In one embodiment, a staff member collects drilling fluid samples, filters the collected drilling fluid samples using a filtering device, and detects the concentration of the tracer in the filtrate sample using a tracer detection device. After the staff member determines that the concentration of the tracer detected in the filtrate of the drilling fluid sample collected at a certain moment reaches a preset concentration, the staff member inputs the second time information into the volume determination device based on the certain moment.

[0084] In the embodiment of the present application, the time of collecting the drilling fluid sample corresponds to the concentration of the tracer in the filtrate of the drilling fluid sample detected by the tracer detection device. For example, the relationship between the time of collecting the drilling fluid sample and the concentration of the tracer in the filtrate of the drilling fluid sample detected by the tracer detection device is shown in Table 1.

[0085] Table 1

[0086] Time to collect drilling fluid samples Concentration of tracer in the filtrate of drilling fluid sample (mol / L) <![CDATA[t1]]> <![CDATA[C a ]]> <![CDATA[t2]]> <![CDATA[C b ]]> <![CDATA[t3]]> <![CDATA[C c ]]>

[0087] Referring to Table 1, time t2 is after time t1, time t3 is after time t2, and so on. According to Table 1, it can be determined that the concentration of the tracer detected by the tracer detection device from the filtrate of the drilling fluid sample collected at time t1 is C a The tracer detection equipment detects the tracer concentration C in the filtrate of the drilling fluid sample collected at time t2. b The tracer detection device detects the tracer concentration C in the filtrate of the drilling fluid sample collected at time t3. c Assume C a and C b are all less than the preset concentration, C c Greater than or equal to a preset concentration, for example, the preset concentration is 0.0000837 mol / L, C a is 0.0000037 mol / L, C b is 0.0000748 mol / L, C c It is 0.0000856 mol / L. The volume determination device determines that the second time when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches the preset concentration is time t3.

[0088] S103. Determine the well diameter of the first well according to the time difference between the first moment and the second moment.

[0089] The volume determination device first determines the time difference between the first moment and the second moment, and then determines the wellbore diameter of the first well according to the time difference between the first moment and the second moment. In an optional embodiment, a casing is inserted into the first well, and the wellbore annulus of the first well includes the annular space between the wellbore wall of the first well and the casing in the first well. The volume determination device determines the wellbore diameter of the first well according to the time difference between the first moment and the second moment, the parameters of the casing in the first well, and the target displacement of the drilling fluid mixed with the tracer added to the first well. The target displacement is the amount of drilling fluid mixed with the tracer added to the first well per unit time. The parameters of the casing include the length, inner diameter, outer diameter, etc. of the casing.

[0090] In the embodiment of the present application, the casing in the first well includes a first casing, and the wellbore annulus of the first well includes a first annular space between the first casing and the wellbore wall of the first well. Alternatively, the casing in the first well includes a first casing and a second casing, and the wellbore annulus of the first well includes a first annular space between the first casing and the wellbore wall of the first well and a second annular space between the first casing and the second casing. Depending on whether the casing in the first well includes the second casing, S103 includes the following two cases.

[0091] The first case: the casing in the first well includes a first casing and a second casing, the first casing is lowered into the first well from the second casing, the length of the first casing is greater than the length of the second casing, the first casing includes a first pipe section and a second pipe section, the first pipe section and the second pipe section are continuous and smoothly transitioned, the first pipe section and the second pipe section are an integral structure, the second pipe section is inside the second casing, and the first pipe section is outside the second casing, for example, the first end of the first casing is outside the second casing, and the second end of the first casing is inside the second casing and is flush with a section of the second casing. The wellbore annulus of the first well includes a first annular space between the first pipe section and the wellbore wall of the first well and a second annular space between the second pipe section and the second casing. The volume determination device determines a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well. The volume determination device determines a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement of the drilling fluid mixed with the tracer added to the first well. The volume determination device determines the well diameter of the first well section of the first well according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement and the time difference between the first moment and the second moment. The first well section is the well section where the first pipe section is located, and the length of the first well section is equal to the length of the first pipe section.

[0092] Optionally, the first time duration, the second time duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore of the first well section satisfy a first relationship, and the first relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)] / Q+T2. Wherein, △t represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, d 11 Represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, and the symbol " / " represents a division sign. The volume determination device substitutes the time difference between the first moment and the second moment, the first duration, the second duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, and the target displacement into the first relationship to calculate the wellbore diameter of the first well section. For example, the time difference between the first moment and the second moment is 112 minutes, the first duration is 31.6909 minutes, the second duration is 41.7500 minutes, the outer diameter of the first casing is 0.1397 meters, the length of the first casing is 5933 meters, the length of the second casing is 3410 meters, and the target displacement is 1.92m 3 / min (cubic meters per minute), the volume determination device substitutes the time difference, the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing and the target displacement into the first relationship to calculate that the well diameter of the first well section is 0.2385 meters.

[0093] In an optional embodiment, the volume determination device determines the volume of the first casing according to the inner diameter of the first casing and the length of the first casing, and the volume determination device determines the ratio of the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well as the first time required for the drilling fluid to fill the inner cavity of the first casing. For example, the volume determination device uses a first time formula to determine the first time required for the drilling fluid to fill the inner cavity of the first casing, and the first time formula is T1=[π×(d 12 / 2) 2 ×H1] / Q, where d 12 represents the inner diameter of the first casing, H1 represents the length of the first casing, Q represents the target displacement, and the symbol " / " represents a division sign. The volume determination device substitutes the inner diameter of the first casing, the length of the first casing and the target displacement into the first time length formula to calculate the first time length required for the drilling fluid to fill the inner cavity of the first casing. For an example, please refer to Figure 4 , which shows a schematic diagram of a first well provided by an embodiment of the present application, wherein a first casing 410 and a second casing 420 are run into the first well, and the first casing 410 is run into the first well through the second casing 420, the first casing 410 includes a first pipe section 411 and a second pipe section 412, the first end of the first casing 410 is outside the second casing 420, and the second end of the first casing 410 is inside the second casing 420 and flush with one end of the second casing 420. The wellbore annulus of the first well includes a first annular space 430 between the first pipe section 411 and the wellbore wall of the first well, and a second annular space 440 between the second pipe section 412 and the second casing 420. The inner diameter of the first casing 410 is 0.1143 meters, the outer diameter of the first casing 410 is 0.1397 meters, the length of the first casing 410 is 5933 meters, and the target displacement is 1.92m 3 / min, the volume determination device substitutes the inner diameter of the first sleeve 410, the length of the first sleeve 410 and the target displacement into the first duration formula to calculate the first duration to be 31.6909 minutes.

[0094] In an optional embodiment, the volume determination device determines the volume of the second annular space according to the length of the second casing, the outer diameter of the first casing and the inner diameter of the second casing, and the volume determination device determines the ratio of the volume of the second annular space and the target displacement of the drilling fluid mixed with the tracer added to the first well as the second time required for the drilling fluid to fill the second annular space. For example, the volume determination device uses a second time formula to determine the second time required for the drilling fluid to fill the second annular space, and the second time formula is T2=[π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2] / Q, where d 11 Indicates the outer diameter of the first casing, d 22 represents the inner diameter of the second casing, H2 represents the length of the second casing, Q represents the target displacement, and the symbol " / " represents a division sign. The volume determination device substitutes the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement into the second time length formula to calculate the second time length required for the drilling fluid to fill the second annular space. For example, please continue to refer to Figure 4 , which shows a schematic diagram of a first well provided by an embodiment of the present application, wherein the wellbore annulus of the first well includes a first annular space 430 between a first pipe section 411 and the wellbore wall of the first well and a second annular space 440 between a second pipe section 412 and a second casing 420. The outer diameter of the first casing 410 is 0.1397 meters, the inner diameter of the second casing 420 is 0.2224 meters, the length of the first casing 410 is 5933 meters, the length of the second casing 420 is 3410 meters, and the target displacement is 1.92m 3 / min, the volume determination device substitutes the outer diameter of the first sleeve 410, the inner diameter of the second sleeve 420, the length of the second sleeve 420 and the target displacement into the second duration formula to calculate the second duration to be 41.7500 minutes.

[0095] The second case: the casing in the first well includes the first casing but does not include the second casing, and the wellbore annulus of the first well includes the first annular space between the first casing and the wellbore wall of the first well. For example, please refer to Figure 5 , which shows a schematic diagram of another first well provided by an embodiment of the present application, wherein a first casing 510 is inserted into the first well, and the wellbore annulus of the first well includes a first annular space 520 between the first casing 510 and the well wall of the first well. The volume determination device determines the first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well, and the volume determination device determines the wellbore diameter of the first well according to the first time, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

[0096] In an optional embodiment, the first time duration, the outer diameter of the first casing, the length of the first casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore diameter of the first well satisfy a third relationship, and the third relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×H1] / Q. Wherein, △t represents the time difference between the first moment and the second moment, T1 represents the first time length, D represents the wellbore diameter of the first well section, d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, Q represents the target displacement, and the symbol " / " represents a division sign. The volume determination device determines the time difference between the first moment and the second moment, and the volume determination device substitutes the first time length, the outer diameter of the first casing, the length of the first casing, and the target displacement into the third relationship to obtain the wellbore of the first well. For example, the time difference between the first moment and the second moment is 112 minutes, the first time length is 31.6909 minutes, the outer diameter of the first casing is 0.1397 meters, the length of the first casing is 5933 meters, and the target displacement is 1.92m 3 / min, the volume determination device substitutes the time difference, the first time length, the outer diameter of the first casing, the length of the first casing and the target displacement into the third relationship and calculates that the well diameter of the first well is 0.2293 meters.

[0097] In an optional embodiment, the volume determination device determines the volume of the first casing according to the inner diameter of the first casing and the length of the first casing, and the volume determination device determines the ratio of the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well as the first duration. The specific implementation process can refer to the implementation method of the volume determination device determining the first duration in the first case, which will not be described in detail here.

[0098] S104. Determine the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well.

[0099] According to the description of S103, the wellbore annulus of the first well is different depending on whether the casing in the first well includes the second casing. According to the difference in the wellbore annulus of the first well, S104 includes the following two situations.

[0100] The first case (corresponding to the first case in S103): the wellbore annulus of the first well includes the first annular space between the first pipe section of the first casing and the wellbore wall of the first well and the second annular space between the second pipe section of the first casing and the second casing. The volume determination device determines the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well section. The first well section is the well section where the first pipe section of the first casing is located, and the length of the first well section is equal to the length of the first pipe section. In an optional embodiment, the wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship, and the second relationship is: V = π × [(D / 2)2 -(d 11 / 2) 2 ]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2. Where V represents the volume of the wellbore annulus of the first well, D represents the wellbore diameter of the first well section, and d 11 Indicates the outer diameter of the first casing, d 22 Represents the inner diameter of the second casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, and the symbol " / " represents a division sign. The volume determination device substitutes the wellbore diameter of the first well section, the outer diameter of the first casing, the inner diameter of the second casing, the length of the first casing and the length of the second casing determined in S103 into the second relationship to obtain the volume of the wellbore annulus of the first well. For example, the wellbore diameter of the first well section is 0.2385 meters, the outer diameter of the first casing is 0.1397 meters, the length of the first casing is 5933 meters, the length of the second casing is 3410 meters, and the inner diameter of the second casing is 0.2224 meters. The volume determination device substitutes the wellbore diameter of the first well section, the outer diameter of the first casing, the inner diameter of the second casing, the length of the first casing and the length of the second casing into the second relationship to obtain the volume of the wellbore annulus of the first well as 154.19m 3 (cubic meter).

[0101] The second case (corresponding to the second case in S103): the wellbore annulus of the first well includes the first annular space between the first casing and the wellbore wall of the first well, and the volume determination device determines the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well. In an optional embodiment, the wellbore diameter of the first well and the volume of the wellbore annulus of the first well satisfy a fourth relationship, and the fourth relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×H1. Where V represents the volume of the wellbore annulus of the first well, D represents the wellbore diameter of the first well, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, and the symbol " / " represents a division sign. The volume determination device substitutes the wellbore diameter of the first well, the outer diameter of the first casing, and the length of the first casing into the fourth relationship to obtain the volume of the wellbore annulus of the first well. For example, the wellbore diameter of the first well is 0.2293 meters, the outer diameter of the first casing is 0.1397 meters, and the length of the first casing is 5933 meters. The volume determination device substitutes the wellbore diameter of the first well, the outer diameter of the first casing, and the length of the first casing into the fourth relationship to obtain the volume of the wellbore annulus of the first well as 154.19m 3 (cubic meter).

[0102] In an optional embodiment, the volume determination device obtains the tracer concentration in the drilling fluid returned from the annulus of the first well before the second moment (i.e., before S102) reaches a preset concentration, and the volume determination device determines the predicted wellbore diameter of the first well. For example, the volume determination device determines the predicted wellbore diameter of the first well based on the wellbore diameters of the adjacent wells of the first well, or the volume determination device determines the wellbore diameter of the first well measured by the logging instrument as the predicted wellbore diameter of the first well, and the volume determination device determines the predicted return time of the drilling fluid from the annulus of the first well based on the predicted wellbore diameter of the first well. Optionally, the volume determination device determines the predicted wellbore diameter of the first well based on the wellbore diameter of an adjacent well of the first well, including: the volume determination device calculates the wellbore diameter expansion rate of the adjacent well based on the wellbore diameter of the adjacent well of the first well and the diameter of a drill bit (for example, called a first drill bit) used when drilling the adjacent well, the volume determination device determines the difference between the wellbore diameter of the adjacent well and the diameter of the first drill bit, the volume determination device determines the ratio of the difference to the diameter of the first drill bit as the wellbore diameter expansion rate of the adjacent well, the volume determination device determines the wellbore diameter expansion rate of the adjacent well as the wellbore diameter expansion rate of the first well, the volume determination device determines the product of the diameter of the drill bit (for example, called a second drill bit) used when drilling the first well and the wellbore diameter expansion rate of the first well as the amount by which the wellbore diameter of the first well increases compared with the diameter of the second drill bit, and the volume determination device determines the sum of the diameter of the second drill bit and the increased amount as the predicted wellbore diameter of the first well. The wellbore expansion rate of the first well refers to the percentage of the increase in the wellbore of the first well compared to the diameter of the second drill bit to the diameter of the second drill bit.

[0103] In the embodiment of the present application, according to the difference in the wellbore annulus of the first well, the volume determination device determines the predicted return time of the drilling fluid from the wellbore annulus of the first well according to the predicted wellbore diameter of the first well, including two cases. In the first case, the wellbore annulus of the first well includes a first annular space between a first pipe section of the first casing and the wellbore wall of the first well and a second annular space between a second pipe section of the first casing and the second casing. The volume determination device determines a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well. The volume determination device determines a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement of the drilling fluid mixed with the tracer added to the first well. The volume determination device determines a predicted return time of the drilling fluid from the wellbore annulus of the first well according to the first time, the second time, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the first time, the predicted wellbore diameter of the first well section and the above-mentioned first relationship. In the second case, the wellbore annulus of the first well includes a first annular space between the first casing and the wellbore wall of the first well, and the volume determination device determines a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid mixed with the tracer added to the first well, and the volume determination device determines a predicted return time of the drilling fluid from the wellbore annulus of the first well according to the first time, the outer diameter of the first casing, the length of the first casing, the target displacement, the first time, the predicted wellbore diameter of the first well and the above-mentioned third relationship.

[0104] In an embodiment of the present application, the drilling fluid mixed with the tracer satisfies at least one of the following conditions: the difference between the density of the drilling fluid mixed with the tracer and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid mixed with the tracer is obtained by adding the tracer to the initial drilling fluid; the concentration of the tracer in the drilling fluid mixed with the tracer added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection device to the concentration recovery rate of the tracer, and the concentration recovery rate of the tracer is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid. The minimum concentration that can be detected by the tracer detection device is also the detection accuracy of the tracer detection device. Since the difference between the density of the drilling fluid mixed with the tracer and the density of the initial drilling fluid is less than the preset difference, the difference between the density of the drilling fluid mixed with the tracer and the density of the initial drilling fluid is small, which can avoid the tracer affecting the performance of the drilling fluid. The concentration of the tracer in the drilling fluid mixed with the tracer added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, ensuring that the tracer detection equipment can detect the tracer in the drilling fluid returned from the wellbore annulus of the first well.

[0105] In an embodiment of the present application, a drilling fluid mixed with a tracer that meets the above conditions is prepared by a staff member. Optionally, the staff member selects the tracer to be added to the initial drilling fluid (that is, selects the tracer solute) according to the type of the initial drilling fluid, for example, a water-soluble tracer is selected when the initial drilling fluid is a water-based drilling fluid, and an oil-soluble tracer is selected when the initial drilling fluid is an oil-based drilling fluid. The staff member first mixes the tracer solute with the tracer solvent according to a first mixing ratio to obtain a tracer solution, and then mixes the tracer solution with the initial drilling fluid according to a second mixing ratio to obtain the drilling fluid mixed with a tracer that meets the above conditions required for drilling in the embodiment of the present application. The first mixing ratio and the second mixing ratio are determined according to the above conditions that the drilling fluid required for drilling in the embodiment of the present application (that is, the above-mentioned drilling fluid mixed with a tracer) needs to meet. Optionally, first determine the first mixing ratio based on the above conditions that the drilling fluid required for drilling in the embodiment of the present application (that is, the drilling fluid mixed with the tracer) needs to meet, and then determine the second mixing ratio based on the above conditions and the first mixing ratio.

[0106] In an optional embodiment, the concentration recovery rate of the tracer in the drilling fluid required for drilling in the embodiment of the present application (that is, the drilling fluid mixed with the tracer as mentioned above) is first determined. Specifically, firstly, a first volume of tracer solution sample is prepared, and the concentration of the tracer solution sample is k times the detection accuracy of the tracer detection device, where k is a positive integer, for example, k is greater than 10; then, the first volume of the tracer solution sample is added to the second volume of the initial drilling fluid sample to obtain a drilling fluid sample (i.e., a drilling fluid sample mixed with a tracer), and the first concentration of the tracer in the drilling fluid sample (i.e., the concentration of the tracer in the drilling fluid sample) is calculated; then, the drilling fluid sample is filtered using a filtering device to obtain a filtrate of the drilling fluid sample (hereinafter referred to as the drilling fluid filtrate sample), and the second concentration of the tracer in the drilling fluid filtrate sample (i.e., the concentration of the tracer in the drilling fluid filtrate sample) is detected using a tracer detection device; finally, the percentage of the second concentration to the first concentration is calculated, and the percentage is the concentration recovery rate of the tracer in the drilling fluid sample. That is, the concentration recovery rate of the tracer in the drilling fluid required for drilling in the embodiment of the present application. In one example, the concentration of the tracer solution sample is C1=k×C0, where C0 is the detection accuracy of the tracer detection device, the first volume is V1, the second volume is V2, and the first concentration C2=(V1×C 1) / (V1+V2), the second concentration is C3, then the concentration recovery rate of the tracer is F=C3 / C2.

[0107] Suppose the first mixing ratio of the tracer solute to the tracer solvent is m:1, and the second mixing ratio of the tracer solution to the initial drilling fluid is 1:n. In "m:1", "m" is the mass of the tracer solute in grams (g), "1" is the volume of the tracer solvent in liters. In "1:n", "1" is the volume of the tracer solution in liters, and "n" is the volume of the initial drilling fluid in liters.

[0108] The following describes the implementation process for determining the first mixing ratio and the second mixing ratio, that is, the implementation process for determining the values of m and n. In one embodiment, the density of the tracer solute is ρ1, the mass of the tracer solute is m, the density of the tracer solvent is ρ2, and the volume of the tracer solvent is 1 liter. The concentration of the tracer solution obtained after adding m grams of the tracer solute with density ρ1 to 1 liter of the tracer solvent with density ρ2 is C4, and the density is ρ4. That is, the concentration of the tracer solution obtained by mixing the tracer solute and the tracer solvent according to the first mixing ratio is C4, and the density is ρ4, C4 = m / (1 + m / ρ1), ρ4 = (ρ2×1 + m) / (1 + m / ρ1). In one embodiment, the density of the initial drilling fluid is ρ6, the volume of the initial drilling fluid is n liters, the density of the tracer solution is ρ4, and the volume of the tracer solution is 1 liter. The concentration of the tracer in the drilling fluid mixed with the tracer obtained after adding 1 liter of the tracer solution with density ρ4 to n liters of the initial drilling fluid with density ρ6 is C5, and the density of the drilling fluid mixed with the tracer is ρ5. That is, the concentration of the tracer in the drilling fluid mixed with the tracer obtained by mixing the tracer solution and the initial drilling fluid according to the second mixing ratio is C5, and the density of the drilling fluid mixed with the tracer is ρ5. To ensure that after adding the tracer solution to the initial drilling fluid, the tracer has little impact on the performance of the drilling fluid, it is necessary to satisfy ρ 5- ρ6 < E, where E is a constant. To ensure that the tracer detection device can detect the tracer in the drilling fluid returning from the wellbore annulus of the first well, it is necessary to satisfy C5 > C0 / F, where C0 is the detection accuracy of the tracer detection device, and F is the concentration recovery rate of the tracer in the drilling fluid mixed with the tracer. By联立计算 ρ 5- ρ6 < E and C5 > C0 / F, the value range of the mass m of the tracer solute and the value range of the volume n of the tracer solution are obtained. In practical applications, the first mixing ratio is determined according to the value range of m. For example, the ratio of any value in the value range of m to 1 is determined as the first mixing ratio. And, the second mixing ratio is determined according to the value range of n. For example, the ratio of 1 to any value in the value range of n is determined as the second mixing ratio.

[0109] In a specific embodiment, the density of the tracer solute is 0.8 g / cm 3, the mass of the tracer solute is m, and the density of the tracer solvent is 1.03 g / cm 3 , the volume of the tracer solvent is 1 liter, and the density of the m grams of tracer solute is 0.8 g / cm 3 is added to 1 liter of the tracer solvent with a density of 1.03 g / cm 3 . The concentration of the tracer solution obtained after adding is C4, and the density is ρ4. That is, the concentration of the tracer solution obtained by mixing the tracer solute and the tracer solvent according to the first mixing ratio is C4, and the density is ρ4. C4 = m / (1 + 0.00125m), ρ4 = (1030 + m) / (1000 + 1.25m). In one embodiment, the density of the initial drilling fluid is 1.56 g / cm 3 , the volume of the initial drilling fluid is n liters, the density of the tracer solution is ρ4, and the volume of the tracer solution is 1 liter. The concentration of the tracer in the drilling fluid mixed with the tracer obtained after adding 1 liter of the tracer solution with a density of ρ4 to n liters of the initial drilling fluid with a density of 1.56 g / cm 3 is C5, and the density of the drilling fluid mixed with the tracer is ρ5. That is, the concentration of the tracer in the drilling fluid mixed with the tracer obtained by mixing the tracer liquid and the initial drilling fluid according to the second mixing ratio is C5, and the density of the drilling fluid mixed with the tracer is ρ5, In one embodiment, the value of E is 0.02. In the embodiment of the present application, the concentration extraction rate of the tracer in the drilling fluid required for drilling is 85%, and the detection accuracy of the tracer detection device is 0.001 g / liter. In order to ensure that after adding the tracer solution to the initial drilling fluid, the influence of the tracer on the performance of the drilling fluid is small, it is necessary to satisfy ρ 5- ρ6 < 0.02. In order to ensure that the tracer detection device can detect the tracer in the drilling fluid returned from the wellbore annulus of the first well, it is necessary to satisfy C5 > 0.001 / 85%. Combining ρ 5- ρ6 < 0.02 and C5 > 0.001 / 85% and calculating simultaneously to obtain the value range of the mass m of the tracer solute and the value range of the volume n of the tracer solution. The specific calculation process is as follows:

[0110] That is Transforming (1) gives Transforming (2) gives From (3) and (4), it can be seen that f(m) < g(m), that is Solving gives That is, m > 3.1164×10 -8 grams. If m is determined to be 0.1, then according to (3) and (4), the value range of n can be calculated. According to (3), we can get According to (4), it can be obtained that By combining (5) and (6), the value range of n is obtained as 25.5 < n <8502338>5. In practical applications, the first mixing ratio is determined according to the value of m as 0.1. For example, the ratio of the value of m as 0.1 to 1 is determined as the first mixing ratio. And the second mixing ratio is determined according to the value range of n. For example, the ratio of 1 to any value within the value range of n is determined as the second mixing ratio.

[0111] In summary, in the method for determining the volume of the wellbore annulus provided by the embodiments of the present application, a tracer is mixed in the drilling fluid. The device for determining the volume of the wellbore annulus obtains the first moment when the drilling fluid mixed with the tracer is added into the first well and the second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration. The device for determining the volume of the wellbore annulus determines the well diameter of the first well according to the time difference between the first moment and the second moment, and then determines the volume of the wellbore annulus of the first well according to the well diameter of the first well. Compared with determining the volume of the wellbore annulus of this well according to the well diameter of the adjacent well, the present application directly determines the volume of the wellbore annulus of the first well according to the well diameter of the first well, so the accuracy is relatively high.

[0112] The following is the device embodiment of the present application, which can be used to execute the method embodiment of the present application. For the details not disclosed in the device embodiment of the present application, please refer to the method embodiment of the present application.

[0113] Please refer to Figure 6 , which shows a schematic diagram of a device 600 for determining the volume of a wellbore annulus provided by the embodiments of the present application. The device 600 for determining the volume of the wellbore annulus is used to execute Figure 1 the method for determining the volume of the wellbore annulus provided by the embodiment shown in Figure 6 As shown in , the device 600 for determining the volume of the wellbore annulus includes a first acquisition module 601, a second acquisition module 602, a first determination module 603, and a second determination module 604.

[0114] The first acquisition module 601 is configured to acquire the first moment when the drilling fluid is added into the first well, and the drilling fluid is mixed with a tracer;

[0115] The second acquisition module 602 is configured to acquire the second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration. The concentration of the tracer in the drilling fluid returned from the wellbore annulus is detected by the tracer detection device from the filtrate of the drilling fluid returned from the wellbore annulus;

[0116] The first determination module 603 is configured to determine the well diameter of the first well according to the time difference between the first moment and the second moment;

[0117] The second determination module 604 is used to determine the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well.

[0118] Optionally, the wellbore annulus includes a first annular space between a first casing in the first well and a wellbore wall of the first well, and the first determining module 603 is used to:

[0119] Determine a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid added to the first well, the target displacement being the amount of the drilling fluid added to the first well per unit time;

[0120] The wellbore diameter of the first well is determined according to the first time length, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

[0121] Optionally, the first casing includes a first pipe section and a second pipe section, the first annular space is an annular space between the first pipe section and the wellbore wall of the first well, the wellbore annulus also includes a second annular space between the second pipe section and a second casing in the first well, the first casing is lowered into the first well from the second casing, the second pipe section is in the second casing, and the first pipe section is outside the second casing; the first determining module 603 is used to:

[0122] Determine a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement;

[0123] The wellbore of the first section of the first well is determined according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement and the time difference between the first moment and the second moment. The first section is the section where the first pipe section is located.

[0124] Optionally, the first time duration, the second time duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore of the first well section satisfy a first relationship;

[0125] The wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship;

[0126] The first relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)] / Q+T2;

[0127] The second relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2;

[0128] Where △t represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, V represents the volume of the wellbore annulus, d 22 Indicates the inner diameter of the second casing.

[0129] Optionally, the first duration, the outer diameter of the first casing, the length of the first casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore of the first well satisfy a third relationship:

[0130] The wellbore diameter of the first well and the volume of the wellbore annulus of the first well satisfy a fourth relationship;

[0131] The third relationship is: △t=T1+[π×[(D / 2) 2 -(d 11 / 2) 2 ]×H1] / Q;

[0132] The fourth relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×H1;

[0133] Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, D represents the wellbore diameter of the first well, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, Q represents the target displacement, and V represents the volume of the wellbore annulus.

[0134] Optionally, the drilling fluid satisfies at least one of the following conditions:

[0135] The difference between the density of the drilling fluid and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid is obtained by adding the tracer to the initial drilling fluid;

[0136] The concentration of the tracer in the drilling fluid added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, and the concentration recovery rate is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid.

[0137] In summary, the technical solution provided by the embodiment of the present application determines the wellbore diameter of the first well according to the time difference between the first moment when the drilling fluid mixed with the tracer is added to the first well and the second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, and then determines the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well. Compared with determining the volume of the wellbore annulus of the present well according to the wellbore diameter of the adjacent well, the present application directly determines the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well, so the accuracy is higher.

[0138] An embodiment of the present application provides a device for determining the volume of a borehole annulus, comprising a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory so that the volume determination device executes the method for determining the volume of a borehole annulus provided in the above embodiment.

[0139] As an example, see Figure 7 , which shows a schematic diagram of another wellbore annulus volume determination device 700 provided in an embodiment of the present application. The volume determination device 700 is a computer device or a functional component deployed in a computer device. The computer device can be a smart phone, a tablet computer, a laptop computer, or a desktop computer. The volume determination device 700 is used to perform Figure 1 The method provided by the illustrated embodiment.

[0140] Typically, the volume determination device 700 includes a processor 701 and a memory 702 .

[0141] The processor 701 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 701 may be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor 701 may include but is not limited to a central processing unit (CPU). In some embodiments, the processor 701 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. The processor 701 may also include an artificial intelligence (AI) processor to handle computing operations related to machine learning.

[0142] The memory 702 includes one or more computer-readable storage media, which may be non-transitory. The memory 702 may also include a high-speed random access memory and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 702 is used to store at least one instruction, which is used to be executed by the processor 701 to implement the method for determining the volume of the wellbore annulus provided in the embodiment of the present application.

[0143] In some embodiments, the volume determination device 700 may further optionally include: a peripheral device interface 703 and at least one peripheral device. The processor 701, the memory 702 and the peripheral device interface 703 may be connected via a bus or a signal line. Each peripheral device may be connected to the peripheral device interface 703 via a bus, a signal line or a circuit board. The peripheral device may include: at least one of a radio frequency circuit 704, a display screen 705, a camera 706, an audio circuit 707, a positioning component 708 and a power supply 709.

[0144] The peripheral device interface 703 may be used to connect at least one peripheral device related to input / output (I / O) to the processor 701 and the memory 702. In some embodiments, the processor 701, the memory 702, and the peripheral device interface 703 are integrated on the same chip or circuit board; in some embodiments, any one or two of the processor 701, the memory 702, and the peripheral device interface 703 may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

[0145] The radio frequency circuit 704 is used to receive and transmit radio frequency (RF) signals, also known as electromagnetic signals. The radio frequency circuit 704 communicates with communication networks and other communication devices through electromagnetic signals. The radio frequency circuit 704 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals into electrical signals. Optionally, the radio frequency circuit 704 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, and the like. The radio frequency circuit 504 can communicate with other devices through at least one wireless communication protocol. The wireless communication protocol includes, but is not limited to: the World Wide Web, a metropolitan area network, an intranet, various generations of mobile communication networks (2G, 3G, 4G and 5G), and a wireless local area network, which is not limited in the embodiments of the present application.

[0146] The display screen 705 is used to display a user interface (UI). The UI may include graphics, text, icons, videos, and any combination thereof. When the display screen 705 is a touch display screen, the display screen 705 also has the ability to collect touch signals on the surface or above the surface of the display screen 705. The touch signal can be input to the processor 701 as a control signal for processing. At this time, the display screen 705 can also be used to provide virtual buttons and / or virtual keyboards, also known as soft buttons and / or soft keyboards. In some embodiments, the display screen 705 can be a flexible display screen. Even, the display screen 705 can also be set to a non-rectangular irregular shape, that is, a special-shaped screen. The display screen 705 can be a liquid crystal display (LCD), an organic light-emitting diode (OLED) display screen, etc.

[0147] The camera assembly 706 is used to capture images or videos. Optionally, the camera assembly 706 includes a front camera and a rear camera. Optionally, the computer device is a terminal device such as a smart phone or a tablet computer. Usually, the front camera is set on the front panel of the computer device, and the rear camera is set on the back of the computer device. In some embodiments, there are at least two rear cameras, which are any one of a main camera, a depth of field camera, a wide-angle camera, and a telephoto camera, so as to realize the fusion of the main camera and the depth of field camera to realize the background blur function, the fusion of the main camera and the wide-angle camera to realize panoramic shooting and virtual reality (VR) shooting function or other fusion shooting functions. In some embodiments, the camera assembly 706 may also include a flash. The flash can be a monochrome temperature flash or a dual-color temperature flash. A dual-color temperature flash refers to a combination of a warm light flash and a cold light flash, which can be used for light compensation at different color temperatures.

[0148] The audio circuit 707 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, and convert the sound waves into electrical signals and input them into the processor 701 for processing, or input them into the radio frequency circuit 704 to achieve voice communication. For the purpose of stereo acquisition or noise reduction, there can be multiple microphones, which are respectively arranged in different parts of the computer device. The microphone can also be an array microphone or an omnidirectional acquisition microphone. The speaker is used to convert the electrical signal from the processor 701 or the radio frequency circuit 704 into sound waves. The speaker can be a traditional film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can not only convert the electrical signal into sound waves audible to humans, but also convert the electrical signal into sound waves inaudible to humans for purposes such as ranging.

[0149] The positioning component 708 is used to locate the geographic location of the computer device to implement navigation or location based service (LBS). The positioning component 708 can be a positioning component based on the global positioning system (GPS), Beidou system or Galileo system.

[0150] The power supply 709 is used to supply power to various components in the computer device. The power supply 709 can be an alternating current, a direct current, a disposable battery, or a rechargeable battery. When the power supply 709 includes a rechargeable battery, the rechargeable battery can be a wired rechargeable battery or a wireless rechargeable battery. A wired rechargeable battery is a battery that is charged through a wired line, and a wireless rechargeable battery is a battery that is charged through a wireless coil.

[0151] In some embodiments, the volume determination device 700 further includes one or more sensors 710 , including but not limited to: a fingerprint sensor 711 , an optical sensor 712 , a proximity sensor 713 , a pressure sensor 714 , an acceleration sensor 715 , and a gyroscope sensor 716 .

[0152] The fingerprint sensor 711 is used to collect the user's fingerprint, and the processor 701 identifies the user's identity based on the fingerprint collected by the fingerprint sensor 711, or the fingerprint sensor 711 identifies the user's identity based on the collected fingerprint. When the user's identity is identified as a trusted identity, the processor 701 authorizes the user to perform relevant sensitive operations, which include unlocking the screen, viewing encrypted information, downloading software, paying, and changing settings. The fingerprint sensor 711 can be set on the front, back, or side of the computer device. When a physical button or manufacturer logo is set on the computer device, the fingerprint sensor 711 can be integrated with the physical button or manufacturer logo.

[0153] The optical sensor 712 is used to collect the ambient light intensity. In one embodiment, the processor 701 can control the display brightness of the display screen 705 according to the ambient light intensity collected by the optical sensor 712. Specifically, when the ambient light intensity is high, the display brightness of the display screen 705 is increased; when the ambient light intensity is low, the display brightness of the display screen 705 is reduced. In another embodiment, the processor 701 can also dynamically adjust the shooting parameters of the camera assembly 707 according to the ambient light intensity collected by the optical sensor 712.

[0154] The proximity sensor 713, also known as a distance sensor, is usually disposed on the front panel of the display screen 705 of the computer device. The proximity sensor 713 is used to collect the distance between the user and the display screen 705. In one embodiment, when the proximity sensor 713 detects that the distance between the user and the display screen 705 is gradually decreasing, the processor 701 controls the display screen 705 to switch from the screen-on state to the screen-off state; when the proximity sensor 713 detects that the distance between the user and the display screen 705 is gradually increasing, the processor 701 controls the display screen 705 to switch from the screen-off state to the screen-on state.

[0155] The pressure sensor 714 can be set on the side frame of the computer device and / or the lower layer of the touch display screen 705. When the pressure sensor 714 is set on the side frame of the computer device, it can detect the user's grip signal of the computer device, and the processor 701 performs left and right hand recognition or shortcut operation according to the grip signal collected by the pressure sensor 714. When the pressure sensor 714 is set on the lower layer of the touch display screen 705, the processor 701 controls the operability controls on the UI interface according to the user's pressure operation on the touch display screen 705. The operability controls include at least one of a button control, a scroll bar control, an icon control, and a menu control.

[0156] The acceleration sensor 715 can detect the magnitude of acceleration on the three coordinate axes of the coordinate system established by the computer device. For example, the acceleration sensor 715 can be used to detect the components of gravity acceleration on the three coordinate axes. The processor 701 can control the touch screen 705 to display the user interface in a horizontal view or a vertical view according to the gravity acceleration signal collected by the acceleration sensor 715. The acceleration sensor 715 can also be used for collecting game or user motion data.

[0157] The gyroscope sensor 716 can detect the body direction and rotation angle of the computer device, and the gyroscope sensor 716 can cooperate with the acceleration sensor 715 to collect the user's 3D actions on the computer device. The processor 701 can implement the following functions based on the data collected by the gyroscope sensor 712: motion sensing (such as changing the UI according to the user's tilt operation), image stabilization during shooting, game control, and inertial navigation.

[0158] Those skilled in the art will understand that Figure 7 The structure shown in the figure does not constitute a limitation on the volume determination device 700. The volume determination device 700 may include more or fewer components than those shown in the figure, or combine certain components, or adopt a different arrangement of components.

[0159] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed (for example, when executed by a computer device, a wellbore annulus volume determination device, one or more processors, etc.), all or part of the steps of the wellbore annulus volume determination method provided in the above embodiment are implemented.

[0160] An embodiment of the present application provides a computer program product, which includes a program or code. When the program or code is executed (for example, when executed by a computer device, a wellbore annulus volume determination device, one or more processors, etc.), all or part of the steps of the wellbore annulus volume determination method provided in the above embodiment are implemented.

[0161] It should be understood that the term "at least one" in this application refers to one or more, and "multiple" refers to two or more. The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate clear description, in this application, the words "first", "second", "third" and the like are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first", "second", "third" and the like do not limit the quantity and execution order.

[0162] The method embodiments and system embodiments provided in the embodiments of the present application can refer to each other, and the embodiments of the present application are not limited thereto. The sequence of operations of the method embodiments provided in the embodiments of the present application can be appropriately adjusted, and the operations can also be increased or decreased in response to the situation. Any technician familiar with the technical field can easily think of the method of change within the technical scope disclosed in the present application, and it should be included in the protection scope of the present application, so it will not be repeated.

[0163] In the corresponding embodiments provided in the present application, it should be understood that the disclosed system and the like can be implemented by other configuration methods. For example, the system embodiments described above are only illustrative, for example, the division of modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0164] The modules described as separate components may or may not be physically separate, and the components described as modules may or may not be physical modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0165] The above is only an exemplary embodiment of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for determining the volume of a wellbore annulus, characterized in that: Applied to a computer device, the method comprises: Acquire a first moment of adding drilling fluid into a first well, wherein the drilling fluid is mixed with a tracer; Acquiring a second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, wherein the concentration of the tracer in the drilling fluid returned from the wellbore annulus is detected by a tracer detection device from a filtrate of the drilling fluid returned from the wellbore annulus; Determine the well diameter of the first well according to the time difference between the first moment and the second moment; The volume of the wellbore annulus of the first well is determined according to the wellbore diameter of the first well.

2. The method according to claim 1, characterized in that The wellbore annulus includes a first annular space between a first casing in the first well and a well wall of the first well, and determining the well diameter of the first well according to the time difference between the first moment and the second moment includes: Determine a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid added to the first well, wherein the target displacement is the amount of the drilling fluid added to the first well per unit time; The wellbore diameter of the first well is determined according to the first time duration, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

3. The method according to claim 2, characterized in that The first casing includes a first pipe section and a second pipe section, the first annular space is an annular space between the first pipe section and the wellbore wall of the first well, the wellbore annulus also includes a second annular space between the second pipe section and a second casing in the first well, the first casing is lowered into the first well from the second casing, the second pipe section is in the second casing, and the first pipe section is outside the second casing; The method further includes: determining a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement; The method of determining the wellbore diameter of the first well according to the first time length, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment includes: determining the wellbore diameter of a first well section of the first well according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, and the time difference between the first moment and the second moment, the first well section being the well section where the first pipe section is located.

4. The method according to claim 3, characterized in that The first duration, the second duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore diameter of the first well section satisfy a first relationship; The wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship; The first relationship is: △t = T1 + [π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)] / Q+T2; The second relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2; Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, V represents the volume of the wellbore annulus, d 22 represents the inner diameter of the second sleeve.

5. The method according to any one of claims 1 to 4, characterized in that: The drilling fluid meets at least one of the following conditions: The difference between the density of the drilling fluid and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid is obtained by adding the tracer to the initial drilling fluid; The concentration of the tracer in the drilling fluid added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, and the concentration recovery rate is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid.

6. A device for determining the volume of a wellbore annulus, characterized in that: Applied to computer equipment, the device comprises: A first acquisition module, used for acquiring a first moment of adding drilling fluid into a first well, wherein the drilling fluid is mixed with a tracer; A second acquisition module is used to acquire a second moment when the concentration of the tracer in the drilling fluid returned from the wellbore annulus of the first well reaches a preset concentration, and the concentration of the tracer in the drilling fluid returned from the wellbore annulus is detected by a tracer detection device from a filtrate of the drilling fluid returned from the wellbore annulus; A first determination module, configured to determine a well diameter of the first well according to a time difference between the first moment and the second moment; The second determination module is used to determine the volume of the wellbore annulus of the first well according to the wellbore diameter of the first well.

7. The method according to claim 6, characterized in that The wellbore annulus includes a first annular space between a first casing in the first well and a well wall of the first well, The first determining module is used to: Determine a first time required for the drilling fluid to fill the inner cavity of the first casing according to the volume of the first casing and the target displacement of the drilling fluid added to the first well, wherein the target displacement is the amount of the drilling fluid added to the first well per unit time; The wellbore diameter of the first well is determined according to the first time duration, the outer diameter of the first casing, the length of the first casing, the target displacement, and the time difference between the first moment and the second moment.

8. The method according to claim 7, characterized in that The first casing includes a first pipe section and a second pipe section, the first annular space is an annular space between the first pipe section and the wellbore wall of the first well, the wellbore annulus also includes a second annular space between the second pipe section and a second casing in the first well, the first casing is lowered into the first well from the second casing, the second pipe section is in the second casing, and the first pipe section is outside the second casing; The first determining module is used to: Determining a second time required for the drilling fluid to fill the second annular space according to the outer diameter of the first casing, the inner diameter of the second casing, the length of the second casing and the target displacement; The wellbore of the first section of the first well is determined according to the first time length, the second time length, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, and the time difference between the first moment and the second moment, where the first section is the section where the first pipe section is located.

9. The device according to claim 8, characterized in that The first duration, the second duration, the outer diameter of the first casing, the length of the first casing, the length of the second casing, the target displacement, the time difference between the first moment and the second moment, and the wellbore diameter of the first well section satisfy a first relationship; The wellbore diameter of the first well section and the volume of the wellbore annulus of the first well satisfy a second relationship; The first relationship is: △t = T1 + [π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)] / Q+T2; The second relationship is: V = π × [(D / 2) 2 -(d 11 / 2) 2 ]×(H1-H2)+π×[(d 22 / 2) 2 -(d 11 / 2) 2 ]×H2; Wherein, Δt represents the time difference between the first moment and the second moment, T1 represents the first duration, T2 represents the second duration, D represents the wellbore diameter of the first well section, and d 11 represents the outer diameter of the first casing, H1 represents the length of the first casing, H2 represents the length of the second casing, H1-H2 represents the length of the first pipe section, Q represents the target displacement, V represents the volume of the wellbore annulus, d 22 represents the inner diameter of the second sleeve.

10. The device according to any one of claims 6 to 9, characterized in that The drilling fluid meets at least one of the following conditions: The difference between the density of the drilling fluid and the density of the initial drilling fluid is less than a preset difference, and the drilling fluid is obtained by adding the tracer to the initial drilling fluid; The concentration of the tracer in the drilling fluid added to the first well is greater than the ratio of the minimum concentration that can be detected by the tracer detection equipment to the concentration recovery rate of the tracer, and the concentration recovery rate is the percentage of the concentration of the tracer in the filtrate of the drilling fluid to the concentration of the tracer in the drilling fluid.

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