Well cementation interface micro-annular gap opening degree evaluation method and device, electronic equipment and medium

Abstract

The invention relates to a well cementation interface micro-annulus opening degree evaluation method and device, electronic equipment and a medium, and belongs to the technical field of petroleum drilling and completion engineering, the method is applied to an indoor small-size shaft device, and the device comprises a kettle body with an annulus and a cement sheath contained in the annulus of the kettle body. The method comprises the following steps: acquiring pressure values of an upper interface and a lower interface of a cement sheath after any fluid is pumped into an annulus in each round of pressure loading and unloading circulation; judging whether the cement sheath generates a micro annular gap or not based on a preset judgment condition; if yes, fluid parameters of fluid are obtained; based on fluid parameters, the length of the device and the pressure values of the upper interface and the lower interface of the cement sheath, evaluating the opening degree of the micro-annulus. The technical problem that in the prior art, due to the fact that the change trend of the opening degree of the well cementation interface after pressure increasing and releasing of each turn under the cyclic load working condition is ignored, the precision of the opening degree calculation result of the micro-annular gap needs to be improved is effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum drilling and completion engineering, and in particular to a method, a device, an electronic device and a medium for evaluating the micro-annular gap opening at a cementing interface. Background Art

[0002] As the scale of unconventional oil and gas resource exploitation continues to expand, multi-stage fracturing has become an important means to increase oil and gas production. The alternating loads generated by multi-stage fracturing cause great damage to the quality of the original cementing, especially the integrity of the cement ring cannot be guaranteed, and annular pressure in the wellbore often occurs. Under the condition of alternating loads in fracturing, the cement ring gradually changes from elastic to plastic after fatigue. When the cement ring undergoes plastic deformation, it cannot be fully restored and there is residual strain. As the fracturing load continues to cycle, the plastic deformation gradually increases, the interface between the cement ring and the casing and the formation peels off, the interface bonding is damaged, and micro-annuli appear at the cementing interface. The appearance of micro-annuli at the cementing interface is one of the main reasons for the failure of the wellbore sealing integrity. Micro-annuli can cause a series of problems such as annular pressure and crossflow, which seriously endangers subsequent production operations.

[0003] After multi-stage fracturing operations in the wellbore, micro-annuli appear at the cementing interface. Since the acoustic logging instrument is greatly affected by the micro-annuli, the logging evaluation results at this time reflect that the cementing quality has deteriorated and subsequent operations cannot be carried out. In fact, the micro-annuli opening is very small, and the crossflow resistance is very large. In the wellbore that is several thousand meters long, the fluid will not crossflow, and the impact on subsequent operations is small. Therefore, it is very necessary to accurately calculate the micro-annuli opening value corresponding to different fracturing cycles.

[0004] Although the current technical solutions provide methods for calculating the size of the micro-annulus opening, they only study how to calculate the opening of the micro-annulus at the cementing interface, and do not pay attention to the changing trend of the micro-annulus opening at the cementing interface after each round of pressure increase and decompression under cyclic loading conditions. Summary of the invention

[0005] In view of this, it is necessary to provide a method, device, electronic equipment and medium for evaluating the micro-annulus opening of the cementing interface, so as to solve the technical problem that the accuracy of the micro-annulus opening calculation results needs to be improved due to the prior art ignoring the changing trend of the micro-annulus opening of the cementing interface after each round of pressure increase and unloading under cyclic load conditions.

[0006] In order to solve the above problems, the present invention provides a method for evaluating the micro-annulus opening of a cementing interface, which is applied to an indoor small-sized wellbore device. The device comprises: a kettle with an annulus and a cement ring contained in the annulus of the kettle. The method comprises: Obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; Determine whether micro-annulus occurs in cement sheath based on preset judgment conditions; If so, the fluid parameters of the fluid are obtained; The opening of the microannulus is evaluated based on the fluid parameters, the length of the device, and the pressure values ​​of the upper and lower interfaces of the cement sheath.

[0007] In a possible implementation, the determination condition includes: Whether the pressure values ​​of the upper and lower interfaces of the cement sheath in the current round are lower than the pressure values ​​of the upper and lower interfaces of the cement sheath in the previous round.

[0008] In a possible implementation, judging whether a micro-annulus is generated in the cement sheath based on a preset judgment condition includes: If the pressure value of the upper and lower interfaces of the cement sheath in the current round is lower than the pressure value of the upper and lower interfaces of the cement sheath in the previous round, it is determined that a micro-annulus is generated in the cement sheath; Otherwise, it is determined that the cement ring does not produce a micro-annular gap.

[0009] In a possible implementation, in each round of pressure loading and unloading cycles, the initial pressure difference and viscosity of the fluid pumped into the annulus are different.

[0010] In a possible implementation, the fluid parameters include: flow coefficient, viscosity and flow velocity of the fluid.

[0011] In a possible implementation, the evaluation of the opening of the micro-annulus based on the fluid parameters, the length of the device, and the pressure values ​​of the upper and lower interfaces of the cement sheath includes: The pressure difference between the upper and lower interfaces of the cement sheath is calculated based on the pressure values ​​of the upper and lower interfaces of the cement sheath; The opening of the microannulus is evaluated based on the fluid parameters, the length of the device, and the pressure difference.

[0012] In a possible implementation, the evaluating the opening of the micro-annulus based on the fluid parameter, the length of the device, and the pressure difference includes: Substituting the fluid parameters, the length of the device, and the pressure difference into the first formula to obtain an evaluation result; Wherein, the first formula includes:

[0013] In the formula, n represents the flow coefficient; k Represents viscosity, in Pa∙s; L Indicates the length of the device in m; W It indicates the micro-annulus opening of cementing interface, in m; h It represents the circumference of cementing interface, in m;q Indicates flow velocity in m 3 / s.

[0014] The present invention also provides a cementing interface micro-annular gap opening evaluation device, comprising: A data acquisition module is used to obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; A condition determination module is used to determine whether a micro-annulus is generated in the cement sheath based on a preset determination condition, and if so, to obtain fluid parameters of the fluid; The opening evaluation module is used to evaluate the opening of the micro-annulus based on the fluid parameters, the length of the device and the pressure values ​​of the upper and lower interfaces of the cement sheath.

[0015] The present invention also provides an electronic device, comprising: Memory, used to store programs; A processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the method for evaluating the micro-annular gap opening at the cementing interface described in any one of the above method items.

[0016] This aspect also provides a medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps of the cementing interface micro-annular gap opening assessment method described in any one of the above method items.

[0017] The beneficial effects of the present invention are as follows: the present invention provides a method for evaluating the micro-annulus opening of a cementing interface, firstly obtaining the pressure values ​​of the upper and lower interfaces of the cement ring after any fluid is pumped into the annulus in each round of pressure loading and unloading cycles, then judging whether the cement ring generates a micro-annulus, if so, obtaining the fluid parameters of the fluid, and finally evaluating the opening of the micro-annulus based on the fluid parameters, the length of the experimental device and the pressure values ​​of the upper and lower interfaces of the cement ring. Compared with the prior art which only studies how to calculate the opening of micro-annuli appearing at the cementing interface, but does not pay attention to the changing trend of the opening of the micro-annuli at the cementing interface after each round of pressure loading and unloading under cyclic load conditions, the present invention can evaluate the opening of the micro-annuli more accurately, thereby effectively solving the technical problem that the accuracy of the micro-annulus opening calculation result needs to be improved due to ignoring the changing trend of the opening of the micro-annuli at the cementing interface after each round of pressure loading and unloading under cyclic load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A method flow chart of an embodiment of a method for evaluating micro-annular gap opening at a cementing interface provided by the present invention; Figure 2 A schematic structural diagram of an embodiment of an indoor small-size shaft device provided by the present invention; Figure 3for Figure 1 A method flow chart of an embodiment of step S105; Figure 4 A structural schematic diagram of an embodiment of a device for evaluating micro-annular gap opening at a cementing interface provided by the present invention; Figure 5 A schematic structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0020] Before showing the embodiments, the following terms are explained: In the description of the embodiments of the present invention, unless otherwise specified, "multiple" means two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone.

[0021] The descriptions of "first", "second", etc. involved in the embodiments of the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the technical features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] In order to solve the above problems, Figure 1 As shown, the present invention provides a method for evaluating the micro-annulus opening of a cementing interface, which is applied to an indoor small-sized wellbore device. The device comprises: a kettle body with an annulus and a cement ring contained in the annulus of the kettle body. The method comprises: S101, obtaining the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; In a possible implementation, in each round of pressure loading and unloading cycles, the initial pressure difference and viscosity of the fluid pumped into the annulus are different.

[0024] S102, judging whether a micro-annulus is generated in the cement sheath based on a preset judgment condition; In a possible implementation, the determination condition includes: whether the pressure values ​​of the upper and lower interfaces of the cement sheath in the current round are lower than the pressure values ​​of the upper and lower interfaces of the cement sheath in the previous round.

[0025] Further step S102 includes: If the pressure value of the upper and lower interfaces of the cement sheath in the current round is lower than the pressure value of the upper and lower interfaces of the cement sheath in the previous round, it is judged that a micro-annulus is generated in the cement sheath; Otherwise, it is judged that no micro-annulus is produced in the cement sheath.

[0026] S103, if yes, obtaining fluid parameters of the fluid; In a possible implementation, the fluid parameters include: flow coefficient, viscosity and flow velocity of the fluid.

[0027] S104, evaluating the opening of the micro-annulus based on the fluid parameters, the length of the device, and the pressure values ​​of the upper and lower interfaces of the cement sheath.

[0028] like Figure 2 In a possible implementation, step S105 includes: S201, calculating the pressure difference between the upper and lower interfaces of the cement sheath based on the pressure values ​​of the upper and lower interfaces of the cement sheath; S202, evaluating the opening of the micro-annulus based on fluid parameters, device length, and pressure difference.

[0029] In a possible implementation, step S202 includes: Substituting the fluid parameters, the length of the device, and the pressure difference into the first formula, the evaluation result is obtained; Among them, the first formula includes: (1) In formula (1), n represents the flow coefficient; k Represents viscosity, in Pa∙s; L Indicates the length of the device in m; W It indicates the micro-annulus opening of cementing interface, in m; h It represents the circumference of cementing interface, in m; q Indicates flow velocity in m 3 / s.

[0030] Specifically, Figure 3As shown, the indoor small-size wellbore device 30 is composed of the following parts: 1-constant flow pump, 2-kettle body, 3-casing, 4-acoustic logging instrument, 5-cement ring, 6-lower end pressure sensor, 7-upper end pressure sensor, 8-acoustic wave transmitting probe, 9-acoustic wave receiving probe, 10-confining pressure pump, 11-rubber sleeve, 12-cementing interface 1, 13-cementing interface 2, 14-internal pressure pump.

[0031] Furthermore, when the above-mentioned device 30 is used to implement the method provided by the present invention, it is first necessary to prepare cement slurry according to the ratio requirements, pour it into the annulus of the test kettle body 2, and perform cement stone curing according to the on-site formation temperature and time of the oil field. Then, according to the actual conditions of different reservoir ground stresses and on-site construction pressures, simulate the casing external squeeze and casing internal pressure during the fracturing process, calculate the corresponding radial stress using finite element software, and calculate the corresponding casing internal pressure and casing confining pressure under indoor experimental conditions based on the standard of equal radial stress, determine the indoor experimental parameters, simulate the cement sheath interface peeling failure, and generate micro-annulus.

[0032] The confining pressure pump 10 can be used to load the outer side of the rubber sleeve 11 with confining pressure, and the internal pressure pump 14 can be used to load the inner side of the casing 3 with internal pressure to simulate the stress environment in the wellbore during the fracturing process. After reaching the set maximum load, the pressure is maintained for 5 minutes and then the pressure is released. After the pressure is released to the specified load, the pressure is maintained for 5 minutes and then the pressure is continued.

[0033] Each time the pressure is added or unloaded, the cementing quality is measured once with an acoustic logging instrument 4 (the logging instrument 4 is always in the kettle body 2 for pressure logging), and the acoustic amplitude or attenuation rate is obtained to evaluate the cementing quality, mainly to analyze the damage of the cementing interface.

[0034] Specifically, SBT sector logging can be used to analyze whether the first interface has peeled off, and VDL variable density logging can be used to analyze whether the cementing second interface has been damaged.

[0035] In addition, in order to eliminate the influence of the damage of the cement sheath body causing the change of the logging acoustic radiation, acoustic probes are installed at the upper and lower ends of the kettle body of the simulated wellbore, and the acoustic wave transmitting probe 8 is used to transmit acoustic waves to the acoustic wave receiving probe 9 to analyze the change of wave velocity to analyze whether the cement sheath body is damaged.

[0036] When the cement sheath is subjected to pressure loading and unloading cycles, a constant flow rate is set using a constant flow pump 1, and liquids of different viscosities and pressure differences are pumped into the annulus through the liquid inlet hole at the bottom sealing end of the device. At the same time, pressure sensors 6 and 7 (initial pressure difference 0.5 MPa) are installed between the top and bottom of the device. The pressure at the liquid inlet end is maintained at 0.5 MPa (if it is too small, it can be increased appropriately), and the fluid flow parameters under different initial pressure differences and different fluid viscosities in each cycle are recorded.

[0037] When the values ​​of sensors 6 and 7 decrease for the first time, it means that the cement sheath cementing interface begins to be damaged. After the initial damage of the cement sheath, the corresponding micro-annulus opening is calculated. After each cycle, different displacements and different viscosities are changed, and the micro-annulus opening after each cycle is calculated to correct the theoretical model.

[0038] like Figure 4 The present invention also provides a cementing interface micro-annular gap opening evaluation device 40, comprising: The data acquisition module 410 is used to obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; The condition determination module 420 is used to determine whether the cement sheath has micro-annulus based on the preset determination conditions, and if so, to obtain the fluid parameters of the fluid; The opening evaluation module 430 is used to evaluate the opening of the micro-annulus based on the fluid parameters, the length of the device, and the pressure values ​​of the upper and lower interfaces of the cement sheath.

[0039] like Figure 5 The present invention further provides an electronic device 50, comprising: A memory 510, used for storing programs; The processor 520 is coupled to the memory 510 and is used to execute the program stored in the memory 510 to implement the steps in the cementing interface micro-annulus opening assessment method described in any one of the above method items.

[0040] Figure 5 Only some of the components of the electronic device 50 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0041] In some embodiments, the processor 520 may be a central processing unit (CPU), a microprocessor or other data processing chip, which is used to run the program code or process data stored in the memory 510, such as the cementing interface micro-annulus opening evaluation method of the present invention.

[0042] In some embodiments, the processor 520 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 520 may be local or remote. In some embodiments, the processor 520 may be implemented in a cloud platform. In one embodiment, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0043] In some embodiments, the memory 510 may be an internal storage unit of the electronic device 50, such as a hard disk or memory of the electronic device 50. In other embodiments, the memory 510 may also be an external storage device of the electronic device 50, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 50.

[0044] Furthermore, the memory 510 may include both an internal storage unit of the electronic device 50 and an external storage device. The memory 510 is used to store application software installed in the electronic device 50 and various data.

[0045] In one embodiment, when the processor 520 executes the cementing interface micro-annulus opening evaluation program in the memory 510, the following steps may be implemented: Obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; Determine whether micro-annulus occurs in cement sheath based on preset judgment conditions; If so, the fluid parameters of the fluid are obtained; The opening of the microannulus is evaluated based on the fluid parameters, the length of the device, and the pressure values ​​at the upper and lower interfaces of the cement sheath.

[0046] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 50 mentioned, and the electronic device 50 may be a portable device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable devices include but are not limited to portable devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable devices may also be other portable devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 50 may not be a portable device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0047] This aspect also provides a medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps of the cementing interface micro-annular gap opening assessment method described in any one of the above method items.

[0048] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer storage medium, wherein the computer storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0049] The above is a detailed introduction to the cementing interface micro-annular gap opening evaluation method, device, electronic equipment and medium provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be modifications in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for evaluating the micro-annulus opening of a cementing interface, applied to an indoor small-sized wellbore device, the device comprising: A kettle body with an annulus and a cement ring contained in the annulus of the kettle body, characterized in that the method comprises: Obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; Determine whether micro-annulus occurs in cement sheath based on preset judgment conditions; If so, the fluid parameters of the fluid are obtained; The opening of the microannulus is evaluated based on the fluid parameters, the length of the device, and the pressure values ​​of the upper and lower interfaces of the cement sheath.

2. The method for evaluating the micro-annulus opening of cementing interface according to claim 1, characterized in that: The determination conditions include: Whether the pressure values ​​of the upper and lower interfaces of the cement sheath in the current round are lower than the pressure values ​​of the upper and lower interfaces of the cement sheath in the previous round.

3. The method for evaluating the micro-annular gap opening at the cementing interface according to claim 2, characterized in that: The method of judging whether a micro-annulus is generated in the cement sheath based on a preset judgment condition includes: If the pressure value of the upper and lower interfaces of the cement sheath in the current round is lower than the pressure value of the upper and lower interfaces of the cement sheath in the previous round, it is determined that a micro-annulus is generated in the cement sheath; Otherwise, it is determined that the cement ring does not produce a micro-annular gap.

4. The method for evaluating the micro-annulus opening of cementing interface according to claim 1, characterized in that: In each round of pressure loading and unloading cycle, the initial pressure difference and viscosity of the fluid pumped into the annulus are different.

5. The method for evaluating the micro-annulus opening of cementing interface according to claim 1, characterized in that: The fluid parameters include: flow coefficient, viscosity and flow velocity of the fluid.

6. The method for evaluating the micro-annular gap opening at the cementing interface according to claim 5, characterized in that: The micro-annulus opening is evaluated based on the fluid parameters, the length of the device and the pressure values ​​of the upper and lower interfaces of the cement sheath, including: The pressure difference between the upper and lower interfaces of the cement sheath is calculated based on the pressure values ​​of the upper and lower interfaces of the cement sheath; The opening of the microannulus is evaluated based on the fluid parameters, the length of the device, and the pressure difference.

7. The method for evaluating the micro-annular opening of a cementing interface according to claim 6, characterized in that: The micro-annulus opening evaluation based on the fluid parameters, the length of the device and the pressure difference includes: Substituting the fluid parameters, the length of the device, and the pressure difference into the first formula to obtain an evaluation result; Wherein, the first formula includes: In the formula, n represents the flow coefficient; k Represents viscosity, in Pa∙s; L Indicates the length of the device in m; W It indicates the micro-annulus opening of cementing interface, in m; h It represents the circumference of cementing interface, in m; q Indicates flow velocity in m 3 / s.

8. A device for evaluating the micro-annular gap opening at a cementing interface, characterized in that: include: A data acquisition module is used to obtain the pressure values ​​of the upper and lower interfaces of the cement sheath after any fluid is pumped into the annulus in each round of pressure loading and unloading cycle; A condition determination module is used to determine whether a micro-annulus is generated in the cement sheath based on a preset determination condition. If so, the fluid parameters of the fluid are obtained, and the pressure value is obtained again until the determination condition is met; The opening evaluation module is used to evaluate the opening of the micro-annulus based on the fluid parameters, the length of the device and the pressure values ​​of the upper and lower interfaces of the cement sheath.

9. An electronic device, characterized in that: include: Memory, used to store programs; A processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the cementing interface micro-annular gap opening evaluation method described in any one of claims 1 to 7.

10. A medium, characterized in that Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps of the cementing interface micro-annular gap opening evaluation method described in any one of claims 1 to 7 above.

Images