Oil-based drilling fluid conversion degree detection method and equipment and storage medium

Abstract

The embodiment of the invention provides an oil-based drilling fluid conversion degree detection method and equipment and a storage medium, and belongs to the technical field of oil-gas exploration and development. The method comprises the following steps: a parameter detection value determination step: injecting prepared oil-based drilling fluid into a drilling fluid circulation system, and detecting return fluid parameters of the drilling fluid circulation system in the injection process to obtain detection values of the return fluid parameters; and a conversion starting point judgment step: comparing the detection value of the return liquid parameter with a preset parameter, and determining the conversion starting point of the oil-based drilling fluid according to a comparison result. The method is used for solving the problems that in an existing oil-based drilling fluid conversion degree detection method, effective distinguishing of an oil-based drilling fluid conversion starting point is lacked, and mixed slurry discharging cannot be accurately controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration and development, and particularly relates to a method for detecting conversion degree of oil-based drilling fluid, a device and a storage medium. BACKGROUND

[0002] With the development of exploration and development to complex deep and shale formations, oil-based drilling fluid plays a more and more important role due to its strong inhibition and good lubricity. In the field application process, the upper part of the wellbore is usually constructed by using low-cost water-based drilling fluid in relatively simple formations, and the oil-based drilling fluid with higher cost needs to be replaced when drilling complex deep formations. After the replacement of the slurry is completed, the performance of the oil-based drilling fluid is adjusted to meet the design requirements for drilling in new formations.

[0003] In the process of replacing the slurry, the existing method mainly determines the conversion degree of the oil-based drilling fluid by observation and displacement measurement. Since the observation and displacement measurement methods both have large errors and also have the potential problem of interruption during the replacement of the slurry, the existing method is difficult to accurately determine whether the oil-based drilling fluid is completely converted. If the end point is determined too early, a large amount of water-based drilling fluid will be mixed into the oil-based drilling fluid, which will seriously affect the performance of the oil-based drilling fluid and cause abnormal difficulty in maintenance and treatment in the later period, and the maintenance cost will be significantly increased. If the end point is determined too late, a large amount of oil-based drilling fluid will be discharged into the waste liquid pool, which will significantly increase the cost of the drilling fluid.

[0004] To solve the above problems, CN201410418228.2 discloses a method for detecting the conversion degree of oil-based drilling fluid. The method detects the demulsification voltage of the return fluid of the drilling fluid circulation system, then compares the detection value of the return fluid demulsification voltage with a preset parameter threshold, and determines the conversion degree of the oil-based drilling fluid according to the comparison result. The method can more accurately determine whether the drilling fluid circulation system completes the conversion of the oil-based drilling fluid, and is more convenient for the operation of the field staff. However, the method is mainly used to determine the end point of the conversion of the oil-based drilling fluid, and lacks effective discrimination of the start point of the conversion of the oil-based drilling fluid. Since the end point of the conversion of the oil-based drilling fluid is determined only by the demulsification voltage, and the change value of the demulsification voltage is relatively small, the detection of the conversion of the drilling fluid has a certain lag and inaccuracy, and under the condition of high displacement in the field, it is easy to cause the discharge of the mixed slurry to be unable to be accurately controlled. This is the deficiency of the prior art. SUMMARY

[0005] To solve the above problems of lacking effective discrimination of the conversion starting point of oil-based drilling fluid and being unable to accurately control the discharge of mixed slurry, in a first aspect, the present application provides a method for detecting the conversion degree of oil-based drilling fluid, comprising the following steps: a parameter detection value determination step, injecting prepared oil-based drilling fluid into a drilling fluid circulation system, and detecting the return fluid parameters of the drilling fluid circulation system during the injection process to obtain the detection value of the return fluid parameters; and a conversion starting point judgment step, comparing the detection value of the return fluid parameters with a preset parameter, and determining the conversion starting point of oil-based drilling fluid according to the comparison result.

[0006] Optionally, the return fluid parameter of the drilling fluid circulation system includes return fluid conductivity, and the preset parameter includes a preset conductivity, which is greater than the measured conductivity of the prepared oil-based drilling fluid.

[0007] Optionally, in the conversion starting point judgment step, when the detection value of the return fluid conductivity is less than the preset conductivity, it is judged that the drilling fluid circulation system starts the conversion of oil-based drilling fluid, otherwise it is judged that the drilling fluid circulation system does not start the conversion of oil-based drilling fluid.

[0008] Optionally, the method further comprises a conversion endpoint judgment step, comparing the return fluid demulsification voltage of the return fluid parameters with a preset demulsification voltage, and determining the conversion endpoint of oil-based drilling fluid according to the comparison result.

[0009] Optionally, in the conversion endpoint judgment step, after it is judged that the drilling fluid circulation system starts the conversion of oil-based drilling fluid, the detection of return fluid demulsification voltage is started, when the difference between the detection value of return fluid demulsification voltage and the demulsification voltage preparation value is less than the preset demulsification voltage, it is judged that the drilling fluid circulation system completes the conversion of oil-based drilling fluid, otherwise it is judged that the drilling fluid circulation system does not complete the conversion of oil-based drilling fluid, wherein the demulsification voltage preparation value is the measured demulsification voltage of the prepared oil-based drilling fluid, and the preset demulsification voltage is less than the measured demulsification voltage of the prepared oil-based drilling fluid.

[0010] Optionally, when the return fluid parameters of the drilling fluid circulation system are detected, the detection of return fluid conductivity is real-time detection, and the detection of return fluid demulsification voltage is detection once every interval of a first preset time length.

[0011] Optionally, in the parameter detection value determination step, before the oil-based drilling fluid is injected into the drilling fluid circulation system, a preset volume of spacer fluid is injected into the drilling fluid circulation system, and the spacer fluid is clear water or base oil of oil-based drilling fluid.

[0012] Optionally, when injecting the preset volume of spacer fluid into the drilling fluid circulation system, the detection of the demulsification voltage of the return fluid is performed once every first preset time interval, and after the injection of the spacer fluid is completed, the detection of the demulsification voltage of the return fluid is performed once every second preset time interval; the second preset time interval is less than the first preset time interval.

[0013] In a second aspect, the present application provides an oil-based drilling fluid conversion degree detection device, comprising a memory; and a processor configured to perform any of the oil-based drilling fluid conversion degree detection methods described above.

[0014] In a third aspect, the present application provides a machine-readable storage medium having instructions stored thereon for causing a machine to perform any of the oil-based drilling fluid conversion degree detection methods described above.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The present application detects the return fluid parameters of the drilling fluid circulation system and compares them with the preset parameters, which can quickly and accurately detect the oil-based drilling fluid conversion degree, and help to effectively identify the oil-based drilling fluid conversion starting point; and avoid the hysteresis and inaccuracy caused by only detecting the demulsification voltage to determine the conversion endpoint, thereby helping to accurately control the discharge of the mixed slurry and ensuring the stability of the oil-based drilling fluid performance.

[0017] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0019] Figure 1 is a flow chart for determining the opening of the oil-based drilling fluid conversion of an embodiment of the present application.

[0020] Figure 2 is a flow chart for determining the opening and completion of the oil-based drilling fluid conversion of an embodiment of the present application. DETAILED DESCRIPTION

[0021] The specific implementation of the embodiments of the present application will be described in detail below in conjunction with the drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application.

[0022] Embodiment one:

[0023] Figure 1 is a flow chart for determining the start of oil-based drilling fluid conversion. As shown in Figure 1 , the present application provides an oil-based drilling fluid conversion degree detection method, comprising the following steps:

[0024] S101: parameter detection value determination step, the prepared oil-based drilling fluid is injected into the drilling fluid circulation system, and the return fluid parameters of the drilling fluid circulation system are detected during the injection process to obtain the detection value of the return fluid parameters;

[0025] S102: conversion starting point determination step, the detection value of the return fluid parameters is compared with the preset parameters;

[0026] S103: according to the comparison result, the oil-based drilling fluid conversion starting point is determined, if the condition is met, it is judged that the oil-based drilling fluid conversion is started, if the condition is not met, it is judged that the oil-based drilling fluid conversion is not started, and returns to step S101 for continuous execution.

[0027] It can be understood that when setting the preset parameters, the configuration value of the oil-based drilling fluid needs to be referred to, so the parameter of the configuration value of the prepared oil-based drilling fluid needs to be measured before the parameter detection value determination step.

[0028] This embodiment is to convert the water-based drilling fluid of X1 well in the Taklimakan Desert into diesel-based drilling fluid, wherein the wellbore volume of X1 well is 350m 3 , and the total capacity of the ground drilling fluid circulation system is 400m 3 . In this embodiment, the volume of the prepared oil-based drilling fluid is 450m 3 . According to GB / T 16782 "Oil-based drilling fluid field test procedure", the basic performance parameters of the prepared oil-based drilling fluid are measured, especially the demulsification voltage of the oil-based drilling fluid, and the measured parameter value is taken as the configuration value of the oil-based drilling fluid parameter. Among them, the measured value of each oil-based drilling fluid parameter is as follows: the density is 1.45g / cm 3 ; funnel viscosity is 72s; plastic viscosity is 32mPa·s; dynamic shear force is 13Pa; demulsification voltage is 924V; conductivity is 0mS / cm.

[0029] The present application compares the detection value of the return fluid parameters with the preset parameters, and determines the conversion starting point of the oil-based drilling fluid according to the comparison result, so as to help solve the problem of lacking effective identification of the conversion starting point of the oil-based drilling fluid. After judging that the oil-based drilling fluid conversion is started, the outlet return gate valve of the drilling fluid circulation system can be adjusted in time, which helps to accurately control the discharge of the mixed slurry.

[0030] Figure 2 is a flow chart for determining the start of oil-based drilling fluid conversion. As shown inFigure 2 As shown, the return fluid parameter of the drilling fluid circulation system includes return fluid conductivity, and the preset parameter includes a preset conductivity, which is greater than the measured conductivity of the prepared oil-based drilling fluid. When judging the oil-based drilling fluid conversion start, the conductivity of the return fluid is detected to obtain a detection value of the return fluid conductivity.

[0031] In a specific implementation, after the conductivity and the demulsification voltage of the prepared oil-based drilling fluid are measured, step S2 is entered, and the outlet return valve of the drilling fluid circulation system is adjusted to ensure that the returned water-based drilling fluid flows into the recovery tank. The conductivity of the return fluid at the circulation outlet is detected in real time by using a conductivity detector to obtain a detection value of the conductivity.

[0032] The return fluid conductivity of the drilling fluid circulation system is detected and compared with the preset conductivity, which can quickly and accurately detect the oil-based drilling fluid conversion degree and further help to effectively identify the oil-based drilling fluid conversion start, thereby avoiding the hysteresis and inaccuracy caused by only using the demulsification voltage detection, and helping to accurately control the discharge of the mixed mud and ensure the stability of the oil-based drilling fluid performance.

[0033] Preferably, in the conversion start judgment step, when the detection value of the return fluid conductivity is less than the preset conductivity, it is judged that the drilling fluid circulation system starts the oil-based drilling fluid conversion, otherwise it is judged that the drilling fluid circulation system does not start the oil-based drilling fluid conversion.

[0034] Table 1 shows the detection values of the conductivity detected at each time in this embodiment.

[0035] Table 1

[0036]

[0037] When the oil-based drilling fluid is injected into the drilling fluid circulation system, the detection value of the conductivity a is continuously compared with the preset conductivity in step S3. If the detection value of the conductivity is less than the preset conductivity, it is judged that the oil-based drilling fluid conversion is started in step S4; otherwise, it is judged that the oil-based drilling fluid conversion is not started, and the process returns to step S2 to continue injecting the oil-based drilling fluid into the drilling fluid circulation system. In this embodiment, the preset conductivity is 0.5 mS / cm, but the present application is not limited thereto. In other embodiments of the present application, according to different oil-based drilling fluids used, the preset conductivity can also be selected as other reasonable values, such as values in the range of 0.5 mS / cm to 1 mS / cm.

[0038] It should be noted that the preset conductivity is greater than the measured conductivity of the prepared oil-based drilling fluid. When setting the preset conductivity, a preset conductivity threshold greater than the measured conductivity of the prepared oil-based drilling fluid can be set. In this embodiment, the preset conductivity threshold is 0.5 mS / cm, and the preset conductivity set on this basis is greater than or equal to the preset conductivity threshold.

[0039] It can be understood that the conductivity of the water-based drilling fluid is much higher than that of the oil-based drilling fluid. When the oil-based drilling fluid is injected into the drilling fluid circulation system, the conductivity of the mixed slurry gradually decreases, thereby gradually reducing the conductivity of the returned fluid. When the detected value of the conductivity of the returned fluid is less than the preset conductivity, it can be determined that the oil-based drilling fluid conversion of the drilling fluid circulation system is started.

[0040] According to the data shown in Table 1, it can be seen that the initial value of the detected value of the conductivity obtained in this embodiment is about 74.6 mS / cm. At 120 min, the conductivity detection value does not change significantly, which indicates that the drilling fluid returned from the outlet of the drilling fluid circulation system at this time is still the original water-based drilling fluid. At 126 min, the conductivity is significantly reduced to 12.2 mS / cm, which indicates that the returned drilling fluid at this time contains a small amount of oil-based drilling fluid. At 126.5 min, the conductivity is reduced to 0.4 mS / cm, which indicates that the returned drilling fluid at this time is a mixture of water-based drilling fluid and oil-based drilling fluid, and the content of oil-based drilling fluid increases. At this time, the detected value of the conductivity is less than the preset conductivity, that is, this is the starting point of the oil-based drilling fluid conversion, and the drilling fluid circulation system starts the oil-based drilling fluid conversion.

[0041] When it is determined that the oil-based drilling fluid conversion starts, the wellhead gate valve of the drilling fluid circulation system is adjusted, the discharge port is connected to the waste slurry tank, and the mixed slurry returned from the wellhead is smoothly introduced into the waste slurry tank, so as to avoid the returned drilling fluid from polluting the water-based drilling fluid in the original circulation system, thereby maintaining the performance stability of the water-based drilling fluid and processing the mixed slurry.

[0042] Please refer to Figure 2 The method further includes a conversion endpoint determination step of comparing the returned fluid demulsification voltage of the returned fluid parameter with a preset demulsification voltage, and determining the oil-based drilling fluid conversion endpoint according to the comparison result.

[0043] Preferably, in the conversion end point judging step, when judging that the drilling fluid circulation system starts the conversion of the oil-based drilling fluid, the demulsification voltage of the return fluid is detected, and when the difference between the detected value of the demulsification voltage of the return fluid and the demulsification voltage preparation value is less than the preset demulsification voltage, it is judged that the drilling fluid circulation system completes the conversion of the oil-based drilling fluid, otherwise it is judged that the drilling fluid circulation system does not complete the conversion of the oil-based drilling fluid, wherein the demulsification voltage preparation value is the measured demulsification voltage of the prepared oil-based drilling fluid, and the preset demulsification voltage is less than the measured demulsification voltage of the prepared oil-based drilling fluid.

[0044] In a specific implementation, after the oil-based drilling fluid conversion is started, step S5 is entered, and the demulsification voltage of the return fluid is detected by the electrical stability tester every first preset time interval, so as to obtain the detected value of the demulsification voltage. In this embodiment, the first preset time interval is 30s, but the present application is not limited thereto, and in other embodiments of the present application, the first preset time interval can also be other reasonable values according to actual needs, such as values in the range of 15s to 2min.

[0045] It can be understood that when the return fluid is detected, the conductivity detector is used for conductivity detection, and the electrical stability tester is used for demulsification voltage detection. The electrical stability tester needs manual operation every first preset time interval, which requires more work than the conductivity detector. The method of the present application starts to detect the demulsification voltage of the return fluid after the drilling fluid circulation system starts the conversion of the oil-based drilling fluid, which not only can timely and accurately determine the conversion end point, but also significantly reduces the detection frequency of the demulsification voltage of the return fluid and reduces the workload.

[0046] Table 2 shows the detected values of the demulsification voltage at each time in this embodiment.

[0047] Table 2

[0048]

[0049] When the oil-based drilling fluid continues to be injected into the drilling fluid circulation system, the detected value of the demulsification voltage of the return fluid is continuously compared with the preset demulsification voltage in step S6. If the difference between the detected value of the demulsification voltage of the return fluid and the demulsification voltage preparation value is less than the preset demulsification voltage, it is judged that the conversion of the oil-based drilling fluid is completed in step S7; otherwise, it is judged that the conversion of the oil-based drilling fluid is not completed, and the method returns to step S5 to continue to inject the oil-based drilling fluid into the drilling fluid circulation system.

[0050] It should be noted that the preset breaking voltage is less than the measured breaking voltage of the prepared oil-based drilling fluid. When the preset breaking voltage is set, a preset breaking voltage threshold less than the measured breaking voltage of the prepared oil-based drilling fluid can be set. In the embodiment, the preset breaking voltage threshold is 300 V, and the preset breaking voltage set on this basis is less than or equal to the preset breaking voltage threshold. In the embodiment, the preset breaking voltage is 300 V, but the present application is not limited thereto. In other embodiments of the present application, the preset breaking voltage can also be selected as other reasonable values according to different oil-based drilling fluids, for example, values in the range of 200 V to 300 V.

[0051] As can be seen from the data shown in Table 2, the initial value of the detected value of the breaking voltage obtained in the embodiment is about 67 V, and the detected value of the breaking voltage gradually increases as the oil-based drilling fluid is continuously injected, indicating that the content of the oil-based drilling fluid in the drilling fluid returned from the outlet of the drilling fluid circulation system gradually increases. At the 10th minute, the breaking voltage increases to 629 V, which indicates that the content of the oil-based drilling fluid in the returned drilling fluid is high at this time. At this time, the difference between the detected value and the preparation value of the breaking voltage is less than the preset breaking voltage, that is, this is the conversion endpoint of the oil-based drilling fluid, and the drilling fluid circulation system completes the conversion of the oil-based drilling fluid.

[0052] When it is determined that the conversion of the oil-based drilling fluid is completed, the wellhead gate valve of the drilling fluid circulation system is adjusted to ensure that the oil-based drilling fluid returned from the wellhead smoothly enters the drilling fluid circulation system. At the same time, the performance of the oil-based drilling fluid is adjusted, and drilling operation is started after the performance meets the construction requirements.

[0053] Preferably, in the parameter detection value determination step, a preset volume of spacer fluid is injected into the drilling fluid circulation system before the oil-based drilling fluid is injected into the drilling fluid circulation system, and the spacer fluid is clear water or base oil of the oil-based drilling fluid.

[0054] Preferably, when the preset volume of spacer fluid is injected into the drilling fluid circulation system, the detection of the breaking voltage of the returned fluid is performed once every interval of a second preset time length, and after the injection of the spacer fluid is completed, the detection of the breaking voltage of the returned fluid is performed once every interval of a first preset time length; the first preset time length is less than the second preset time length.

[0055] The spacer fluid is injected into the drilling fluid circulation system to ensure that the water-based drilling fluid and the oil-based drilling fluid can be effectively separated. In other embodiments of the present application, the spacer fluid can also be injected according to actual production conditions, and the present application is not limited thereto.

[0056] It's understandable that spacer fluid is cheaper than oil-based drilling fluid, and injecting it can reduce the cost of oil-based drilling fluid conversion. While spacer fluid is cheaper during injection, the oil-based drilling fluid conversion endpoint has not yet been reached. Therefore, selecting a longer interval for testing during the second preset duration helps reduce the number of times the return fluid demulsification voltage is tested, thus reducing workload.

[0057] Example 2:

[0058] This example is to convert the water-based drilling fluid of Well X2 in the Sichuan Basin into white oil-based drilling fluid, where the wellbore volume of Well X2 is 150m 3 The total capacity of the surface drilling fluid circulation system is 320m 3 .

[0059] Similar to the process of embodiment 1, Figure 2 As shown, in this embodiment, before the parameter detection value determination step, in step S1 , the parameters of the prepared oil-based drilling fluid are measured to obtain the measured conductivity and the measured demulsification voltage of the prepared oil-based drilling fluid.

[0060] In this embodiment, the volume of the prepared oil-based drilling fluid is 350m 3 According to GB / T 16782 "Oil-based Drilling Fluid Field Test Procedure", the basic performance parameters of the prepared oil-based drilling fluid are measured, especially the demulsification voltage of the oil-based drilling fluid, and the measured parameter values ​​are used as the prepared values ​​of the oil-based drilling fluid parameters. Among them, the measured values ​​of each oil-based drilling fluid parameter are as follows: density is 1.27g / cm 3 ; Funnel viscosity is 66s; plastic viscosity is 27mPa·s; dynamic shear force is 10Pa; demulsification voltage is 686V; conductivity is 0mS / cm.

[0061] like Figure 2 As shown, after measuring the conductivity and demulsification voltage of the prepared oil-based drilling fluid, the process proceeds to step S2 and adjusts the outlet gate valve of the drilling fluid circulation system to ensure that the returned water-based drilling fluid flows into the recovery tank. A conductivity meter is used to measure the conductivity of the fluid at the circulation outlet in real time to obtain a conductivity value.

[0062] Table 3 shows the conductivity values ​​detected at various times in this embodiment.

[0063] Table 3

[0064]

[0065] When the oil-based drilling fluid is injected into the drilling fluid circulating system, the detected value of the specific conductivity is continuously compared with the preset specific conductivity in step S3. If the detected value of the specific conductivity is less than the preset specific conductivity, it is determined that the oil-based drilling fluid conversion is started in step S4; otherwise, it is determined that the oil-based drilling fluid conversion is not started, and the oil-based drilling fluid is continuously injected into the drilling fluid circulating system in step S2. In this embodiment, the preset specific conductivity is 0.5 mS / cm, but the present application is not limited to this. In other embodiments of the present application, the preset specific conductivity can also be selected as other reasonable values, for example, values in the range of 0.5 mS / cm to 1 mS / cm, according to the different oil-based drilling fluids used.

[0066] According to the data shown in Table 3, it can be seen that the initial value of the detected value of the specific conductivity obtained in this embodiment is about 78.8 mS / cm. At the 40th minute, the detected value of the specific conductivity does not change significantly, which indicates that the drilling fluid returned from the outlet of the drilling fluid circulating system at this time is still the original water-based drilling fluid. At the 41st minute, the specific conductivity is significantly reduced to 10.7 mS / cm, which indicates that the returned drilling fluid at this time begins to contain a small amount of oil-based drilling fluid. At the 41.5th minute, the specific conductivity is reduced to 0.2 mS / cm, which indicates that the returned drilling fluid at this time is a mixed slurry of water-based drilling fluid and oil-based drilling fluid, and the content of oil-based drilling fluid increases. At this time, the detected value of the specific conductivity is less than the preset specific conductivity, that is, this time is the starting point of the oil-based drilling fluid conversion, and the drilling fluid circulating system starts to convert the oil-based drilling fluid.

[0067] When it is determined that the oil-based drilling fluid conversion starts, the wellhead gate valve of the drilling fluid circulating system is adjusted, the drainage port is connected to the waste slurry tank, and the mixed slurry returned from the wellhead is ensured to smoothly enter the waste slurry tank, so as to avoid the returned drilling fluid from polluting the water-based drilling fluid in the original circulating system, thereby maintaining the performance stability of the water-based drilling fluid and processing the mixed slurry.

[0068] After the oil-based drilling fluid conversion starts, step S5 is entered, and the demulsification voltage of the returned fluid is detected by the electrical stability tester every first preset time interval, so as to obtain the detected value of the demulsification voltage. In this embodiment, the first preset time interval is 30 s, but the present application is not limited to this. In other embodiments of the present application, the first preset time interval can also be other reasonable values, for example, values in the range of 15 s to 2 min, according to actual needs.

[0069] Table 4 shows the detected value of the demulsification voltage detected at each time in this embodiment.

[0070] Table 4

[0071]

[0072] When the oil-based drilling fluid continues to be injected into the drilling fluid circulation system, the detection value of the emulsion breaking voltage of the return fluid is continuously compared with the preset emulsion breaking voltage in step S6. If the difference between the detection value of the emulsion breaking voltage of the return fluid and the emulsion breaking voltage of the prepared oil-based drilling fluid is less than the preset emulsion breaking voltage, it is determined that the conversion of the oil-based drilling fluid is completed in step S7; otherwise, it is determined that the conversion of the oil-based drilling fluid is not completed, and the oil-based drilling fluid continues to be injected into the drilling fluid circulation system in step S5.

[0073] It should be noted that the preset emulsion breaking voltage is less than the measured emulsion breaking voltage of the prepared oil-based drilling fluid. When the preset emulsion breaking voltage is set, a preset emulsion breaking voltage threshold less than the measured emulsion breaking voltage of the prepared oil-based drilling fluid can be set. In this embodiment, the preset emulsion breaking voltage threshold is 200 V, and the preset emulsion breaking voltage is less than or equal to the preset emulsion breaking voltage threshold. In this embodiment, the preset emulsion breaking voltage is 200 V, but the present application is not limited thereto. In other embodiments of the present application, the preset emulsion breaking voltage threshold can also be selected as other reasonable values according to different oil-based drilling fluids used.

[0074] As can be seen from the data shown in Table 4, the initial value of the detection value of the emulsion breaking voltage obtained in this embodiment is about 48 V, and the detection value of the emulsion breaking voltage gradually increases as the oil-based drilling fluid continues to be injected. This indicates that the content of the oil-based drilling fluid in the drilling fluid returned from the outlet of the drilling fluid circulation system gradually increases. The emulsion breaking voltage increases to 489 V at 6.5 min, which indicates that the content of the oil-based drilling fluid in the returned drilling fluid is high at this time. At this time, the difference between the detection value and the preparation value of the emulsion breaking voltage is less than the preset emulsion breaking voltage, that is, this is the conversion endpoint of the oil-based drilling fluid, and the drilling fluid circulation system completes the conversion of the oil-based drilling fluid.

[0075] When it is determined that the conversion of the oil-based drilling fluid is completed, the wellhead gate valve of the drilling fluid circulation system is adjusted to ensure that the oil-based drilling fluid returned from the wellhead smoothly enters the drilling fluid circulation system. At the same time, the performance of the oil-based drilling fluid is adjusted, and drilling construction is started after the performance meets the construction requirements.

[0076] Compared with the existing test means, the oil-based drilling fluid conversion degree detection method provided by the embodiment of the present application can more scientifically and accurately determine whether the drilling fluid circulation system starts and completes the conversion of the oil-based drilling fluid compared with the existing method, and is convenient for field construction personnel to operate. At the same time, the present application does not need to increase additional supporting devices to realize the detection of the conversion degree of the oil-based drilling fluid, and the conversion starting point and endpoint can be determined by using the formation conductivity detector and the drilling fluid square electric stability tester, which has good timeliness, authenticity and reliability.

[0077] According to the embodiment of the present application, an embodiment of an oil-based drilling fluid conversion degree detection device is provided. The oil-based drilling fluid conversion degree detection device comprises a memory and a processor configured to execute the above-mentioned program units stored in the memory to realize corresponding functions.

[0078] The processor comprises a core, and the core retrieves corresponding program units from the memory. The core can be one or more, and the problem of lacking effective identification of the mixing point of the mixed mud and the problem of being unable to accurately control the discharge of the mixed mud can be solved by adjusting the core parameters.

[0079] The memory can include a non-permanent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory comprises at least one memory chip.

[0080] The embodiment of the present application provides a storage medium having a program stored thereon, and the program is executed by a processor to realize the oil-based drilling fluid conversion degree detection method.

[0081] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a device or a computer program product. Therefore, the present application can be in the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to a magnetic disk storage, a CD-ROM, an optical storage and the like) containing computer usable program code.

[0082] The present application is described with reference to flowcharts and / or block diagrams according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0083] These computer program instructions can also be stored in a computer readable memory capable of guiding the computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer readable memory produce a product comprising instruction means, which realizes the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocksFigure 1 the function(s) specified in the block or blocks.

[0084] These computer program instructions can also be loaded into computer or other programmable data processing devices to cause a series of operational steps to be performed on the computer or other programmable devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable devices provide steps for implementing the flowchart block(s) or flowchart flow(s) and / or portions thereof. Figure 1 Figure 1 the function(s) specified in the block or blocks.

[0085] In one typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0086] The memory can include non-persistent memory and / or volatile memory, such as random access memory (RAM) about which the computer stores information about an operating system, application software, and / or the like. Memory is an example of computer readable media.

[0087] Computer readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. According to the definition herein, computer readable media does not include transitory media, such as modulated data signals and carriers.

[0088] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices.

[0089] In the technical solution of the present application, the acquisition, transmission, storage, use, processing and the like of data comply with the relevant provisions of national laws and regulations.

[0090] ​It should be noted that in the embodiments of the present application, some software, components, models and the like in the prior art can be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility in the implementation of the technical scheme of the present application, but does not mean that the applicant has or will necessarily use the scheme.

[0091] The above merely illustrates the embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the present application. Any modification, equivalent replacement, improvement and the like within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for detecting the conversion degree of an oil-based drilling fluid, characterized by, The method comprises the following steps: a parameter detection value determination step of injecting the prepared oil-based drilling fluid into a drilling fluid circulation system, and detecting a return fluid parameter of the drilling fluid circulation system during the injection to obtain a detection value of the return fluid parameter; and a conversion starting point determination step of comparing the detection value of the return fluid parameter with a preset parameter, and determining a conversion starting point of the oil-based drilling fluid according to a comparison result.

2. The method of claim 1, wherein, The return fluid parameter of the drilling fluid circulation system comprises a return fluid conductivity, and the preset parameter comprises a preset conductivity, which is greater than a measured conductivity of the prepared oil-based drilling fluid.

3. The method of claim 2, wherein, In the conversion starting point determination step, when the detection value of the return fluid conductivity is less than the preset conductivity, it is determined that the drilling fluid circulation system starts the conversion of the oil-based drilling fluid, otherwise it is determined that the drilling fluid circulation system does not start the conversion of the oil-based drilling fluid.

4. The method of claim 2, wherein, The method further comprises: a conversion ending point determination step of comparing a return fluid demulsification voltage of the return fluid parameter with a preset demulsification voltage, and determining a conversion ending point of the oil-based drilling fluid according to a comparison result.

5. The method of claim 4, wherein, In the conversion ending point determination step, when it is determined that the drilling fluid circulation system starts the conversion of the oil-based drilling fluid, the detection of the return fluid demulsification voltage is started, and when a difference between the detection value of the return fluid demulsification voltage and a measured demulsification voltage of the prepared oil-based drilling fluid is less than a preset demulsification voltage, it is determined that the drilling fluid circulation system completes the conversion of the oil-based drilling fluid, otherwise it is determined that the drilling fluid circulation system does not complete the conversion of the oil-based drilling fluid, wherein the preset demulsification voltage is less than the measured demulsification voltage of the prepared oil-based drilling fluid.

6. The method of claim 4, wherein, When the return fluid parameter of the drilling fluid circulation system is detected, the detection of the return fluid conductivity is real-time detection, and the detection of the return fluid demulsification voltage is detection once every interval of a first preset time length.

7. The method of claim 1 wherein, In the parameter detection value determination step, before the oil-based drilling fluid is injected into the drilling fluid circulation system, a preset volume of spacer fluid is injected into the drilling fluid circulation system, and the spacer fluid is clear water or base oil of the oil-based drilling fluid.

8. The method of claim 7, wherein, When the preset volume of the spacer fluid is injected into the drilling fluid circulation system, the detection of the return fluid demulsification voltage is detection once every interval of a second preset time length, and after the injection of the spacer fluid is completed, the detection of the return fluid demulsification voltage is detection once every interval of the first preset time length; the first preset time length is less than the second preset time length.

9. An oil-based drilling fluid conversion degree detection apparatus characterized by comprising: The device comprises: a memory; and a processor configured to execute the method of any one of claims 1-8.

10. A machine-readable storage medium having instructions stored thereon for causing a machine to perform the method of any one of claims 1-8.

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