Device for determining repairing effect information of micro annular space of cement sheath

Abstract

The embodiment of the invention provides a device for determining cement sheath micro annular space repairing effect information. The device comprises a device auxiliary system for guaranteeing the sealing performance of the device, a heating system, a pressurizing system, a sample inner cavity for placing a test sample, a micro annular space repairing system and a repairing effect evaluation system, the micro annular space repairing system is used for performing micro annular space filling repairing on the test sample based on the underground temperature environment simulated by the heating system and the stratum confining pressure environment simulated by the pressurizing system to obtain a repaired sample; the repairing effect evaluation system is used for obtaining first air tightness information of the test sample and second air tightness information of the repairing sample, repairing effect information is generated according to the first air tightness information and the second air tightness information, and the device is used for quantitatively representing the repairing effect of the micro-annulus through the repairing effect information.

Description

Technical Field

[0001] The present application relates to the field of oil and gas engineering cementing, and in particular to a device for determining information on the repair effect of a cement ring micro-annulus. Background Art

[0002] In oil and gas exploration and development, cementing cement ring will be affected by factors such as downhole temperature, pressure and various operations, causing micro cracks inside the cement ring and micro annulus at the cementing interface between the cement ring and casing (formation). Since the integrity of the cement ring has a significant impact on the productivity and production life of oil and gas wells, the repair of cement ring micro annulus has received more and more attention in the industry.

[0003] In the prior art, hydraulic pressure testing methods are often used to measure the repair effect of cement ring micro-annulus according to the anti-channeling capacity.

[0004] However, in actual operations, anti-gas channeling evaluation experiments are mostly qualitative observations, and the formation temperature and pressure environment are not taken into account, and it is impossible to provide reliable reference data for the construction site. Summary of the invention

[0005] An embodiment of the present application provides a device for determining the repair effect information of a cement ring micro-annulus, so as to quantitatively characterize the repair effect of the micro-annulus through the repair effect information.

[0006] In a first aspect, an embodiment of the present application provides a device for determining cement ring micro-annulus repair effect information, the device comprising:

[0007] The device auxiliary system, heating system, pressurizing system, sample inner cavity for placing test samples, micro-annulus repair system and repair effect evaluation system are used to ensure the sealing of the device; wherein the device auxiliary system is the outer layer of the device; the heating system is inside the device auxiliary system, which is the first layer of the device; the pressurizing system is connected with the heating system and the sample inner cavity, which is the second layer of the device; the sample inner cavity is connected with the pressurizing system, the micro-annulus repair system and the repair effect evaluation system, which is the third layer of the device; the micro-annulus repair system is connected with the sample inner cavity, which is the inner layer of the device; the repair effect evaluation system is connected with the sample inner cavity through a pipeline;

[0008] The micro-annulus repair system is used to fill and repair the micro-annulus in the test sample under the downhole temperature environment simulated by the heating system and the formation confining pressure environment simulated by the pressurization system to obtain the repaired sample;

[0009] The repair effect evaluation system is used to obtain the first airtightness information of the test sample and the second airtightness information of the repair sample, and generate the repair effect information according to the first airtightness information and the second airtightness information, wherein the repair effect information characterizes the repair effect of the micro-annular gap repair system on the test sample.

[0010] In a possible implementation, the inner cavity of the sample includes a first cement annulus, a second cement annulus, a first simulated casing, and a second simulated casing;

[0011] The first cement annulus is connected to the first simulated casing, and the second cement annulus is connected to the second simulated casing, so as to simulate the actual casing layer of the wellbore.

[0012] In a possible implementation, the sizes of the first cement annulus and the second cement annulus are respectively set according to actual sizes of the actual cement annulus.

[0013] In a possible embodiment, beeswax is applied to the first simulated casing and the second simulated casing. After cement slurry is poured into the first simulated casing and the second simulated casing, the beeswax melts, and the pore space occupied by the beeswax is used to simulate the micro-annulus of the cement annulus, wherein the thickness and area of ​​the application represent the width and area of ​​the simulated micro-annulus.

[0014] In one possible implementation, the device auxiliary system includes a top cover, a bottom cover, and a housing;

[0015] The top cover and the bottom cover are connected to the outer shell by screws respectively, and sealing members are arranged at the contact positions of the top cover and the bottom cover with the outer shell respectively.

[0016] In a possible implementation, the heating system includes: a heating tube, a temperature measuring couple, and a temperature controller;

[0017] The heating pipe is located inside the shell of the device auxiliary system and is used to stabilize the heating device and simulate the downhole temperature environment;

[0018] The temperature measuring couple is connected to the inner cavity of the sample to monitor the temperature of the first cement ring annulus and the second cement ring annulus in the test;

[0019] The temperature controller is connected to the heating tube and is used to control the temperature of the heating tube.

[0020] In a possible implementation, the pressurizing system includes: an annular pressure chamber, an annular pressure loading port, a hydraulic source, an annular rubber sleeve and a pressure gauge;

[0021] The annular pressure chamber is located outside the shell of the device auxiliary system and is used to transmit the pressure of the hydraulic source to the annular rubber sleeve to simulate the formation confining pressure environment;

[0022] The annular pressure loading port is connected to the annular pressure chamber and is used to apply the pressure of the hydraulic source to the annular pressure chamber;

[0023] The hydraulic source is connected to the ring pressure loading port to provide power for the hydraulic pressure;

[0024] The annular rubber sleeve is connected to the annular pressure chamber and is used to transmit the pressure of the annular pressure chamber to the inner cavity of the sample;

[0025] The pressure gauge is connected to the annular pressure loading port to determine the pressure value of the simulated formation confining pressure environment.

[0026] In one possible implementation, the micro-annulus repair system includes: a wellbore pressure loading port, a hydraulic loading fluid, an injected repair material, a perforation hole, and a fluid channel dead plug;

[0027] The wellbore pressure loading port is located above the top cover of the device auxiliary system and is used to inject hydraulic loading fluid into the device to simulate the squeeze pressure during actual operation;

[0028] The squeezed repair material is located below the hydraulic loading fluid and is used to fill and repair the micro-annuli of the first cement ring annulus and the second cement ring annulus under the pressure of the hydraulic loading fluid;

[0029] The perforated holes are located in the first wellbore annulus and the second wellbore annulus, and are used to inject the squeezed repair material into the first cement ring annulus and the second cement ring annulus respectively;

[0030] The dead plugging of the fluid channel and the bottom cover connection of the device auxiliary system are used to let the fluid in the inner cavity of the test sample flow out after the micro-annular gap of the test sample is repaired.

[0031] In a possible implementation, the repair effect evaluation system includes: a gas pressure loading port, a gas flow detection port, and a gas flow meter;

[0032] The air pressure loading port is located inside the bottom cover of the device auxiliary system and is used to inject air pressure into the first cement ring annulus and the second cement ring annulus respectively;

[0033] The gas flow detection port is located on the upper side of the top cover of the device auxiliary system and is used to monitor the gas pressure of the first cement ring annulus and the second cement ring annulus;

[0034] The gas flow meter is connected to the gas flow detection port to display the gas flow value.

[0035] In a possible implementation, the device further includes a computer system;

[0036] The computer system is connected to the temperature measuring couple, temperature controller, pressure gauge and gas flow meter for collecting data.

[0037] The device for determining the repair effect information of the micro-annulus of the cement ring provided in the embodiment of the present application is configured such that a test sample is loaded into the inner cavity of the sample, and after the device auxiliary system ensures its sealing, the downhole temperature environment and the formation confining pressure environment are simulated for the inner cavity of the sample through a heating system and a pressurizing system, and then the micro-annulus of the sample is filled and repaired by the micro-annulus repair system to obtain a repaired sample, and the first air tightness information of the test sample and the second air tightness information of the repaired sample are obtained through a repair effect evaluation system, and the repair effect information is generated according to the first air tightness information and the second air tightness information, so as to quantitatively characterize the repair effect of the micro-annulus repair system on the test sample through the repair effect information. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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.

[0039] Figure 1 A structural diagram of a device for determining the repair effect information of a cement ring micro-annulus provided in this application Figure 1 ;

[0040] Figure 2 A structural diagram of a device for determining the repair effect information of a cement ring micro-annulus provided in this application Figure 2 ;

[0041] Figure 3 A schematic diagram of the structure of a perforation hole of a device for determining information on the repair effect of a cement ring micro-annulus provided in the present application;

[0042] Figure 4 A schematic diagram of a casing wall area coated with beeswax in a device for determining information on the repair effect of a cement ring micro-annulus provided in the present application;

[0043] Figure 5 A flow chart of a method for determining cement ring micro-annulus repair effect information provided in this application.

[0044] Reference numerals:

[0045] 100-device auxiliary system; 101-top cover; 102-bottom cover; 103-housing;

[0046] 200-heating system; 201-heating tube; 202-temperature measuring couple; 203-temperature controller;

[0047] 300-pressurization system; 301-annular pressure chamber; 302-annular pressure loading port; 303-hydraulic source; 304-annular rubber sleeve; 305-pressure gauge;

[0048] 400 - sample cavity; 401 - first cement ring annulus; 402 - second cement ring annulus; 403 - first simulated casing; 404 - second simulated casing;

[0049] 500-micro-annulus repair system; 501-wellbore pressure loading port; 502-hydraulic loading fluid; 503-injected repair material; 504-perforation hole; 505-fluid channel dead blockage;

[0050] 600-repair effect evaluation system; 601-air pressure loading port; 602-gas flow detection port; 603-gas flow meter;

[0051] 700-Computer Systems.

[0052] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0054] In the embodiments of the present application, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have specific orientations, or to be constructed and operated in specific orientations. Moreover, in addition to being used to indicate orientations or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0056] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein.

[0057] In the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0058] Unless otherwise stated, the term "plurality" means two or more.

[0059] For the characterization of the repair effect of cement sheath, the existing test devices and methods mostly use hydraulic pressure test method to measure the anti-channeling ability. However, in actual operation, gas leakage usually occurs before liquid channeling occurs. Some existing anti-gas channeling evaluation experiments and methods are qualitative observations, and do not consider the formation temperature and pressure environment, and cannot provide reliable reference data for the site. The hydraulic pressure test method is mostly used. Therefore, the existing technology lacks a quantitative characterization test device for the micro-annulus repair of the cement sheath.

[0060] To solve the above problems, the present application provides a device for determining the repair effect information of a cement ring micro-annulus. The device loads a test sample into a sample inner cavity 400, and after the device auxiliary system 100 ensures its sealing, the heating system 200 and the pressurizing system 300 simulate the downhole temperature environment and the formation confining pressure environment of the sample inner cavity 400, and then the micro-annulus repair system 500 fills and repairs the micro-annulus of the sample to obtain a repaired sample, and the first air tightness information of the test sample and the second air tightness information of the repaired sample are obtained through the repair effect evaluation system 600, and the repair effect information is generated according to the first air tightness information and the second air tightness information, so as to quantitatively characterize the repair effect of the micro-annulus repair system on the test sample through the repair effect information.

[0061] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0062] Figure 1 A structural diagram of a device for determining the repair effect information of a cement ring micro-annulus provided in this application Figure 1 ,like Figure 1 As shown, the present embodiment provides a device for determining the repair effect information of a cement ring micro-annulus, comprising: a device auxiliary system 100 for ensuring the sealing of the device, a heating system 200, a pressurizing system 300, a sample cavity 400 for placing a test sample, a micro-annulus repair system 500 and a repair effect evaluation system 600; wherein the device auxiliary system 100 is the outer layer of the device; the heating system 200 is inside the device auxiliary system 100, which is the first layer of the device; the pressurizing system 300 is connected to the heating system 200 and the sample cavity, which is the second layer of the device; the sample cavity 400 is connected to the pressurizing system 300, the micro-annulus repair system 500 and the repair effect evaluation system 600, which is The third layer of the device; the micro-annulus repair system 500 is connected to the sample inner cavity 400, which is the inner layer of the device; the repair effect evaluation system 600 is connected to the sample inner cavity 400 through a pipeline; the micro-annulus repair system 500 is used to perform micro-annulus filling and repair in the test sample under the downhole temperature environment simulated by the heating system 200 and the formation confining pressure environment simulated by the pressurization system 300 to obtain a repaired sample; the repair effect evaluation system 600 is used to obtain the first air tightness information of the test sample and the second air tightness information of the repaired sample, and generate the repair effect information according to the first air tightness information and the second air tightness information, wherein the repair effect information characterizes the repair effect of the micro-annulus repair system on the test sample.

[0063] Exemplarily, the device for determining the repair effect information of the cement ring micro-annulus is a device simulating a wellbore, Figure 1 It is a cross-sectional view of the device, in which the device auxiliary system 100 is the outer layer of the device, the first layer inside the device is the heating system 200, the second layer is the pressurizing system 300, the third layer is the sample cavity 400, the inner layer of the device is the micro-annular gap repair system 500, and the repair effect evaluation system 600 is connected to the sample cavity 400 through a pipeline.

[0064] In this embodiment, the test sample is placed in the sample cavity 400, the auxiliary system 100 of the device ensures the sealing of the sample, the temperature and formation pressure environment downhole are simulated by the heating system 200 and the pressurizing system 300, and the micro-annulus repair system 500 is used to fill and repair the micro-annulus in the sample to obtain the repaired sample. The repair effect evaluation system 600 obtains the initial air tightness information of the test sample and the air tightness information of the repaired sample through measurement, and generates the repair effect information based on these two sets of air tightness information, thereby quantitatively characterizing the effect of the micro-annulus repair system in repairing the test sample.

[0065] Figure 2 A structural diagram of a device for determining the repair effect information of a cement ring micro-annulus provided in this application Figure 2 ,like Figure 2 As shown, in Figure 1On the basis of the embodiment shown, the device auxiliary system 100 includes a top cover 101, a bottom cover 102 and a shell 103; the top cover 101 and the bottom cover 102 are respectively connected to the shell 103 by screws, and the top cover 101 and the bottom cover 102 are respectively provided with seals at the contact positions with the shell 103, wherein the seals can maintain normal working performance under the simulated temperature environment, thereby ensuring a good sealing effect. The heating system 200 includes a heating pipe 201, a thermocouple 202 and a temperature controller 203; the heating pipe 201 is located inside the shell of the device auxiliary system, and is used to stabilize the heating device and simulate the downhole temperature environment; the thermocouple 202 is connected to the sample inner cavity 400 through a pipeline, and is used to monitor the temperature of the first cement ring annulus 401 and the second cement ring annulus 402; the temperature controller 203 is connected to the heating pipe 201, and is used to control the temperature of the heating pipe 201. The pressurizing system 300 includes an annular pressure chamber 301, an annular pressure loading port 302, a hydraulic source 303, an annular rubber sleeve 304 and a pressure gauge 305; the annular pressure chamber 301 is located on the outside of the outer shell 103 of the device auxiliary system 100, and is used to transfer the pressure of the hydraulic source 303 to the annular rubber sleeve 304 to simulate the formation confining pressure environment; the annular pressure loading port 302 is connected to the annular pressure chamber 301, and is used to apply the pressure of the hydraulic source 303 to the annular pressure chamber 301; the hydraulic source 303 is connected to the annular pressure loading port 302, and is used to provide power for the hydraulic pressure; the annular rubber sleeve 304 is connected to the annular pressure chamber 301, and is used to transfer the pressure of the annular pressure chamber 301 to the inner cavity of the sample; the pressure gauge 305 is connected to the annular pressure loading port 302, and is used to determine the pressure value of the simulated formation confining pressure environment. The heating system 200 and the pressurizing system 300 in the device of the present application simulate the downhole temperature environment and the formation confining pressure environment, so that the test samples are more in line with the actual working conditions, the simulation results are more accurate, and the simulation accuracy and applicability of the device of the present application are improved. The micro-annulus repair system 500 includes a wellbore pressure loading port 501, a hydraulic loading fluid 502, an injected repair material 503, a perforation hole 504 and a fluid channel plug 505; the wellbore pressure loading port 501 is located above the top cover 101 of the device auxiliary system 100, and is used to inject the hydraulic loading fluid 502 into the device to simulate the squeezing pressure during actual operation; the injected repair material 503 is located below the hydraulic loading fluid 502, and is used to respectively pressurize the first cement ring annulus 4 under the pressure of the hydraulic loading fluid 502. 01 and the second cement ring annulus 402 are filled and repaired; the squeezed repair material 503 is not limited to the use of ultrafine cement; the perforation hole 504 is located in the first cement ring annulus 401 and the second cement ring annulus 402, and is used to inject the squeezed repair material 503 into the first cement ring annulus 401 and the second cement ring annulus 402 respectively; the fluid channel dead plug 505 is connected to the bottom cover 102 of the device auxiliary system 100, and is used to make the fluid in the sample cavity flow out after the micro-annulus repair of the test sample is completed. The outflowing fluid includes the hydraulic loading fluid 502 and the remaining squeezed repair material 503.

[0066] For example, according to the size of the perforation hole to be simulated, a hole is drilled at a corresponding position of the steel pipe, and a cylindrical plastic mold of a corresponding size is prepared. The plastic mold is inserted when pouring cement slurry. After the cement slurry is poured, it is initially set. At this time, the cement slurry is shaped but has not yet had strength. The plastic mold is slowly pulled out to form a simulated perforation hole 504. The structural schematic diagram of the perforation hole 504 is shown in FIG. Figure 3 As shown, for the process of squeezing cement to repair micro-annulus of cement ring, the existing test device and method are limited to simulating the process of repair material entering micro-cracks of cement stone under vertical conditions. In actual operation, the repair material enters the annulus through the casing via the perforated holes, thereby completing the repair of the micro-annulus of cement ring of cementing. The present application adopts the method of perforating holes to fill the micro-annulus, so that the simulation device is more in line with the actual working conditions and more accurate simulation results can be obtained.

[0067] like Figure 2 As shown, in Figure 1 On the basis of the embodiment shown, the device also includes a repair effect evaluation system 600, which includes an air pressure loading port 601, a gas flow detection port 602 and a gas flow meter 603; wherein the air pressure loading port 601 is located inside the bottom cover 102 of the device auxiliary system 100, and is used to inject air pressure into the first cement ring annulus 401 and the second cement ring annulus 402 respectively; the gas flow detection port 602 is located on the upper side of the top cover 101 of the device auxiliary system 100, and is used to monitor the air pressure of the first cement ring annulus 401 and the second cement ring annulus 402; the gas flow meter 603 is connected to the gas flow detection port 602, and is used to display the numerical value of the gas flow. Through the repair effect evaluation system 600 in this device, the repair effect of the micro-annulus repair system on the test sample can be characterized by the repair effect information, and the repair effect of the micro-annulus in different annuli after repair can be evaluated by the air tightness. In addition, the device can also be used to quantitatively characterize the air tightness before and after the micro-annulus repair, so as to study the influence of factors such as the micro-annulus area, the type of repair material, and the size of the extrusion pressure on the repair effect.

[0068] Exemplarily, the device for determining the repair effect information of the cement ring micro-annulus also includes a computer system 700; the computer system 700 is connected to the temperature measuring couple 202, the temperature controller 203, the pressure gauge 305 and the gas flow meter 603 for collecting data. By recording the test process data in real time through the computer system 700, the difficulty of the test operation can be reduced, human errors can be reduced, and the accuracy of the test results can be improved.

[0069] Exemplarily, the present application provides a device for determining the repair effect information of cement ring micro-annulus, which also includes a sample inner cavity 400, and the sample inner cavity 400 includes a first cement ring annulus 401, a second cement ring annulus 402, a first simulated casing 403 and a second simulated casing 404; wherein the first cement annulus 401 is connected to the first simulated casing 403, and the second cement ring annulus 402 is connected to the second simulated casing 404, which are used to simulate the actual casing layer of the wellbore. The sizes of the first cement annulus 401 and the second cement annulus 402 can be set according to the actual sizes of the actual cement annuli. Optionally, before the test starts, a test sample is placed in the device sample inner cavity, and the sample is used to simulate the wellbore cement ring and casing combination. The test preparation includes the following processes: processing a mold of corresponding shape; replacing the casing with a steel pipe of the same steel material, and preparing cement slurry according to the simulated on-site formula; placing the steel pipe in the mold according to the size of the simulated casing-cement sheath assembly, and pouring cement slurry in the annulus; curing the casing-cement sheath assembly; demolding and removing the sample after curing. The existing simulated cement squeeze repair process and the device and method for evaluating the repair effect of the cement sheath micro-annulus do not consider the influence of the casing layer in the real wellbore. In actual applications, the pressure conditions of different casing annuli are different. The size of the cement sheath in the simulation device must be consistent with the size of the cement sheath in the actual wellbore. This includes key parameters such as the thickness and diameter of the cement sheath. Only accurate size simulation can ensure the reliability of the repair effect and the accuracy of the prediction. At the same time, the simulation device also needs to consider the hierarchical structure of the cement sheath. By simulating these hierarchical structures, the impact of the repair device on the wellbore performance can be more comprehensively evaluated. Therefore, it is necessary to accurately simulate the actual situation of the cement sheath and characterize the repair effect of different annuli.

[0070] For example, beeswax is applied to the first simulated casing 403 and the second simulated casing 404. After the cement slurry is poured into the first simulated casing 403 and the second simulated casing 404, the beeswax melts, and the pore space occupied by the beeswax is used to simulate the micro-annulus of the cement annulus. Specifically, the position where the beeswax is applied is as follows: Figure 4As shown, according to the principle of the lost wax method, the casing area where the micro-annulus needs to be simulated is first polished evenly with sandpaper, and then beeswax is evenly applied. The thickness and area of ​​the application represent the width and area of ​​the simulated micro-annulus. After the application is completed, ensure that it is attached to the casing, and then pour the cement slurry. After the initial setting of the cement slurry is completed, it is cured. Due to the low melting point of beeswax, the sample is placed in a temperature-controlled box during the curing process or after the curing is completed, and the beeswax is melted. The beeswax becomes a fluid and flows out, and the pore space occupied by it forms a micro-annulus. This application combines the characteristics of low melting point and strong operability of beeswax to use the beeswax method to make the micro-annulus of the cement ring. By adjusting the thickness, hardness and other parameters of the beeswax, the gap between the cement ring and the surrounding medium under different conditions can be simulated, so as to more accurately evaluate the impact of the micro-annulus on the integrity and sealing of the wellbore. At the same time, compared with other simulation methods, beeswax materials are relatively cheap and easy to obtain, and the experimental process is relatively simple, and does not require complex equipment and operations. This makes the beeswax method an economical and practical method for studying the micro-annulus of the cement ring.

[0071] Figure 5 A flowchart of a method for determining the repair effect information of a cement ring micro-annulus provided in this application, such as Figure 5 As shown, an embodiment of the present application provides a method for determining cement ring micro-annulus repair effect information, the method is used for repairing cement ring micro-annulus by cement squeezing process, and the method includes:

[0072] S501, prepare a first test sample, a second test sample and a third test sample respectively;

[0073] In this embodiment, the first test sample is not drilled and micro-annulus is not made. First, the casing layer and size of the test simulation are determined, and the steel pipe of the corresponding size is processed, but no drilling is performed; cement slurry is prepared according to the on-site cementing cement ring formula; the simulated casing is placed in the casting mold and the cement slurry is directly poured; after the cement slurry is initially set, the sample is taken out of the mold for curing; the second test sample is drilled and micro-annulus is made, and a steel pipe of the same size as the first test sample is processed, and a hole is drilled at the perforation hole position; the micro-annulus area on the casing to be simulated is carefully polished with sandpaper, and beeswax is evenly applied thereon; cement slurry is prepared according to the same formula as the first test sample; the simulated casing is placed in the casting mold, and then the plastic mold is inserted into the mold. Cement slurry is poured at the perforation holes; when the cement slurry is initially solidified, the hole-forming plastic mold is slowly pulled out to form a perforation hole; the sample is taken out of the mold for curing; after curing, it is placed in a temperature-controlled box to melt beeswax to form a micro-annulus; the third test sample is drilled but no micro-annulus is made, and a steel pipe of the same size as the first test sample is processed, but no drilling is performed; the micro-annulus area of ​​the casing is carefully polished with sandpaper, and the position is the same as that of the second test sample, and beeswax is evenly applied thereon; cement slurry is prepared according to the same formula as the first test sample; the simulated casing is placed in the casting mold, and cement slurry is directly poured; after the cement slurry is initially solidified, the sample is taken out of the mold for curing, and after curing, it is placed in a temperature-controlled box to melt beeswax to form a micro-annulus.

[0074] S502, placing the first test sample into the sample inner cavity, performing an annular sealing test on the first test sample according to the heating system and the pressurizing system; obtaining a first meter reading according to the gas flow meter;

[0075] In this embodiment, the top cover 101 of the device is opened, the first test sample is placed in the sample cavity, the casing is observed to be correctly positioned, the top cover is closed, all screws are tightened, and the device auxiliary system 100 is well sealed. The heating system is started, and the heating temperature of the heating pipe 201 is set to T according to the downhole temperature environment to be simulated. Fluid is injected into the annular pressure cavity 301 through the annular pressure loading port 302 to simulate the formation confining pressure Pc, and the indication of the pressure gauge 305 is observed to determine whether the pressure value is correct. Monitor the temperature value of the thermocouple 202. When the monitored value reaches the simulated wellbore temperature, apply air pressure to the first cement ring annulus 401 and the second cement ring annulus 402 through the nitrogen gas source. The pressure application value is set to Pseal with reference to the field sealing test standard. At the same time, monitor the readings of the gas flowmeter 603 corresponding to the different cement ring annuli above. Refer to the time tseal specified in the field test, stop pressurizing after applying pressure for tseal time, and record the reading of the air flowmeter 603 of the first cement ring annulus 401 as Avolume1, and the reading of the air flowmeter 603 of the second cement ring annulus 402 as Bvolume1. The test result is the air tightness test value under the complete sample.

[0076] S503, placing the third test sample into the sample inner cavity, repeating the step of S502 for the third test sample according to the heating system and the pressurizing system, obtaining a second meter reading according to the gas flow meter; determining whether the second meter reading is greater than the first meter reading, and if so, continuing the test;

[0077] In this embodiment, the top cover 101 of the device is opened, and the third test sample is placed in the inner cavity of the device. The casing is observed to be correctly positioned, and the top cover 101 is closed to ensure that all screws are tightened and the device auxiliary system 100 is well sealed. The heating system 200 is started, and the step S502 is repeated for the third test sample according to the heating system 200 and the pressurizing system 300. When the monitored value is the same as the temperature in S502, the gas pressure Pseal is applied to the first cement ring annulus 401 and the second cement ring annulus 402 respectively through the nitrogen gas source, and the gas flowmeter 603 corresponding to the different cement ring annuli above is monitored. After the tseal time, the pressurization is stopped, and it is recorded that the gas flowmeter 603 of the first cement ring annulus 401 shows Avolume2, and the gas flowmeter 603 of the second cement ring annulus 402 shows Bvolume2. Compare the values ​​of Avolume1 and Avolume2, and Bvolume1 and Bvolume2 respectively. When Avolume2 and Bvolume2 are both larger, it means that the micro-annulus prefabrication method is effective and subsequent tests can be continued.

[0078] S504, placing the second test sample into the sample inner cavity, repeating the step of S502 for the second test sample according to the heating system and the pressurizing system, performing micro-annulus repair on the second test sample according to the micro-annulus repair system, and determining the repaired sample;

[0079] In this embodiment, the second test sample is placed in the sample cavity 400, and the casing is observed to be correctly positioned. Then, the extruded repair material 503 is added. The amount added is required to be above the height of the perforation hole. Then, the top cover is tightly closed to ensure that all screws of the device are tightened and the device auxiliary system 100 is well sealed. Start the heating system 200 and set the heating temperature of the heating tube 201 to T. Inject fluid into the annular pressure cavity 301 through the annular pressure loading port 302, and set the pressure value to Pc. Monitor the temperature value of the thermocouple 202. When the monitored value is the same as the temperature in step S502, inject fluid through the wellbore pressure loading port 501 to apply hydraulic pressure. The pressure value and action time are both set to Pa and ta, respectively, with reference to the on-site cement squeezing process. After reaching the time ta, stop pressurizing the wellbore. Let it stand until the repair material is formed and has the strength to exert the plugging performance, and then proceed to the next test.

[0080] S505: Obtain a third count according to the repair effect evaluation system, and determine the repair effect information according to the first count, the second count, and the third count.

[0081] In this embodiment, the gas pressure Pseal is applied to the first cement ring annulus 401 and the second cement ring annulus 402 respectively through the nitrogen gas source, and the readings of the gas flowmeters 603 corresponding to the different cement ring annuli above are monitored. After the tseal time, the pressurization is stopped, and the reading of the gas flowmeter 603 of the first cement ring annulus 401 is recorded as Avolume3, and the reading of the gas flowmeter 603 of the second cement ring annulus 402 is recorded as Bvolume3. Compare the values ​​of Avolume3 with Avolume1 and Avolume2, and compare Bvolume3 with the values ​​of Bvolume1 and Bvolume2. When the values ​​of Avolume3 and Bvolume3 are respectively less than Avolume2 and Bvolume2, it means that the repair is effective, and the difference between Avolume3 and Avolume1, Bvolume3 and Bvolume1 can quantitatively characterize the quality of the repair effect.

[0082] Optionally, after the test of the repair effect evaluation system 600 is completed, the heating tube 201 is first turned off to stop heating the device, and then the fluid channel plug 505 below the device is opened to release the fluid in the simulated wellbore, and then the annular pressure loading system is turned off to drain the fluid in the annular pressure chamber 301, and the top cover 101 of the device is opened. After the sample temperature drops to room temperature, the sample is taken out and the test device is tidied up.

[0083] Optionally, the present application also provides a method for determining cement ring micro-annulus repair effect information, the method is used for repairing cement ring micro-annulus by a self-healing cement slurry system, and the method comprises:

[0084] Prepare samples S1 and S2, where sample S1 is not drilled or micro-annulus is made, and sample S2 is made of micro-annulus by beeswax method. The method for preparing samples S1 and S2 is the same as step S501. First, determine the casing layer and size of the test simulation, process the steel pipe of corresponding size, and prepare cement slurry according to the formula of self-healing cement slurry system; place the simulated casing in the casting mold and directly cast the cement slurry; after the cement slurry is initially set, take the sample out of the mold for curing; further place sample S1 in the sample cavity 400, and start the same as step S502. The heating system 200 repeats the step S502 for the sample S1 according to the heating system 200 and the pressurizing system 300. When the monitoring value is simulated to the wellbore temperature, the gas pressure Pseal is applied to the first cement ring annulus 401 and the second cement ring annulus 402 respectively through the nitrogen gas source, and the readings of the gas flowmeter 603 corresponding to the different cement ring annuli above are monitored. After tseal time, the pressurization is stopped, and it is recorded that the reading of the gas flowmeter 603 in the first cement ring annulus 401 is A1, and the reading of the gas flowmeter 603 in the second cement ring annulus 402 is B1. Further place the sample S2 in the sample cavity 400, and in the same manner as step S502, obtain the reading of the gas flowmeter 603 of the first cement ring annulus 401 corresponding to the sample 2 as meter A2, and the reading of the gas flowmeter 603 of the second cement ring annulus 402 as B2; perform secondary curing on the sample S2 according to the properties of the self-healing cement slurry system: if the self-healing cement slurry system triggers the healing function when it encounters water, it is allowed to stand in a container filled with water for a period of time so that the micro-annulus is fully in contact with the water; if the self-healing cement slurry system triggers the healing function when it encounters oil, it is allowed to stand in a container filled with oil for a period of time so that the micro-annulus is fully in contact with the oil. After the secondary curing is completed, take out the sample S2, and gently wipe off the liquid on the surface of the sample. Open the top cover 101 of the test device, place the sample S2 in the inner cavity of the device, observe whether the casing is correctly positioned, cover the top cover, ensure that all screws of the device are tightened, and the auxiliary system of the device is well sealed. Repeat step S502, start the heating system 200, monitor the temperature value of the thermocouple 202, and when the monitored value is the same as the temperature of the monitored value of sample 1, apply gas pressure Pseal to the first cement ring annulus 401 and the second cement ring annulus 402 through the nitrogen gas source, and monitor the readings of the gas flowmeter 603 corresponding to the different cement ring annuli above. Stop pressurization after tseal time, and record that the reading of the gas flowmeter 603 of the first cement ring annulus 401 is A3, and the reading of the gas flowmeter 603 of the second cement ring annulus 402 is B3. Compare the values ​​of A3 with A1 and A2, and compare B3 with the values ​​of B1 and B2. When the values ​​of A3 and B3 are respectively less than A2 and B2, it means that the repair is effective, and the difference between A3 and A1, B3 and B1 can quantitatively characterize the quality of the repair effect. After the test, the test device is arranged in the same way as step S505.

[0085] The present application provides a method for determining information on the repair effect of cement ring micro-annulus. A device for determining information on the repair effect of cement ring micro-annulus is used to simulate a process of repairing cement ring micro-annuli by a cement squeezing process under a real wellbore casing layer under a formation temperature and pressure environment, and a process of repairing cement ring micro-annuli by a self-healing cement slurry system. A method for characterizing cement ring micro-annuli is provided, and the air sealing effect of micro-annuli in different annuli after repair can be characterized. In addition, the device and method can also be used to quantitatively evaluate the air sealing before and after the micro-annulus repair to study the influence of factors such as micro-annulus area, type of repair material, and size of squeezing pressure on the repair effect.

[0086] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A device for determining cement ring micro-annulus repair effect information, characterized in that: The device comprises: A device auxiliary system, a heating system, a pressurizing system, a sample inner cavity for placing test samples, a micro-annulus repair system and a repair effect evaluation system are used to ensure the sealing of the device; wherein the device auxiliary system is the outer layer of the device; the heating system is inside the device auxiliary system and is the first layer of the device; the pressurizing system is connected to the heating system and the sample inner cavity and is the second layer of the device; the sample inner cavity is connected to the pressurizing system, the micro-annulus repair system and the repair effect evaluation system and is the third layer of the device; the micro-annulus repair system is connected to the sample inner cavity and is the inner layer of the device; the repair effect evaluation system is connected to the sample inner cavity through a pipeline; The micro-annulus repair system is used to fill and repair the micro-annulus of the test sample under the downhole temperature environment simulated by the heating system and the formation confining pressure environment simulated by the pressurization system to obtain a repaired sample; The repair effect evaluation system is used to obtain the first airtightness information of the test sample and the second airtightness information of the repair sample, and generate repair effect information based on the first airtightness information and the second airtightness information, wherein the repair effect information characterizes the repair effect of the micro-annular gap repair system on the test sample.

2. The device according to claim 1, characterized in that The sample inner cavity includes a first cement ring annulus, a second cement ring annulus, a first simulated casing and a second simulated casing; The first cement annulus is connected to the first simulated casing, and the second cement annulus is connected to the second simulated casing, so as to simulate the actual casing layer of the wellbore.

3. The device according to claim 2, characterized in that The sizes of the first cement annulus and the second cement annulus are respectively set according to the actual sizes of the actual cement annulus.

4. The device according to claim 3, characterized in that Beeswax is applied to the first simulated casing and the second simulated casing. After cement slurry is poured into the first simulated casing and the second simulated casing, the beeswax melts. The pore space occupied by the beeswax is used to simulate the micro-annulus of the cement annulus, wherein the applied thickness and applied area represent the width and area of ​​the simulated micro-annulus.

5. The device according to claim 1, characterized in that The device auxiliary system includes a top cover, a bottom cover and a housing; The top cover and the bottom cover are respectively connected to the outer shell by screws, and sealing members are provided at the contact positions of the top cover and the bottom cover with the outer shell.

6. The device according to claim 1, characterized in that The heating system comprises: a heating tube, a temperature measuring couple, and a temperature controller; The heating pipe is located inside the housing of the device auxiliary system and is used to heat the device stably to simulate the downhole temperature environment; The temperature measuring couple is connected to the inner cavity of the sample and is used to monitor the temperature of the first cement ring annulus and the second cement ring annulus in the test; The temperature controller is connected to the heating tube and is used to control the temperature of the heating tube.

7. The device according to claim 1, characterized in that The pressurizing system comprises: an annular pressure chamber, an annular pressure loading port, a hydraulic source, an annular rubber sleeve and a pressure gauge; The annular pressure chamber is located outside the housing of the device auxiliary system and is used to transmit the pressure of the hydraulic source to the annular rubber sleeve to simulate the formation confining pressure environment; The annular pressure loading port is connected to the annular pressure chamber and is used to apply the pressure of the hydraulic source to the annular pressure chamber; The hydraulic source is connected to the ring pressure loading port to provide power for the hydraulic pressure; The annular rubber sleeve is connected to the annular pressure chamber and is used to transmit the pressure of the annular pressure chamber to the inner cavity of the sample; The pressure gauge is connected to the annular pressure loading port and is used to determine the pressure value of the simulated formation confining pressure environment.

8. The device according to any one of claims 1 to 7, characterized in that The micro-annulus repair system comprises: a wellbore pressure loading port, a hydraulic loading fluid, an injected repair material, a perforation hole and a fluid channel dead plug; The wellbore pressure loading port is located above the top cover of the device auxiliary system and is used to inject the hydraulic loading fluid into the device to simulate the squeezing pressure during actual operation; The squeezed repair material is located below the hydraulic loading fluid and is used to fill and repair the micro-annuli of the first cement annulus and the second cement annulus under the pressure of the hydraulic loading fluid; The perforated holes are located in the first wellbore annulus and the second wellbore annulus, and are used to allow the squeezed repair material to be injected into the first cement ring annulus and the second cement ring annulus respectively; The fluid channel dead plug is connected to the bottom cover of the device auxiliary system, and is used to allow the fluid in the inner cavity of the sample to flow out after the micro-annular gap of the test sample is repaired.

9. The device according to any one of claims 1 to 7, characterized in that The repair effect evaluation system comprises: a gas pressure loading port, a gas flow detection port and a gas flow meter; The air pressure loading port is located inside the bottom cover of the device auxiliary system and is used to inject air pressure into the first cement ring annulus and the second cement ring annulus respectively; The gas flow detection port is located on the upper side of the top cover of the device auxiliary system, and is used to monitor the gas pressure of the first cement ring annulus and the second cement ring annulus; The gas flow meter is connected to the gas flow detection port and is used to display the numerical value of the gas flow.

10. The device according to any one of claims 1 to 7, characterized in that The apparatus also includes a computer system; The computer system is connected with the temperature measuring couple, the temperature controller, the pressure gauge and the gas flow meter for collecting data.

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