Method and device for calculating mud shale collapse pressure, electronic equipment and storage medium

Abstract

The application provides a shale collapse pressure calculation method and device, electronic equipment and a storage medium. The method comprises the following steps: obtaining shale mineral component content of a completed well and shale water after the shale in the formation of the completed well. According to the shale mineral component content and the shale water, a first functional relationship between the shale mineral component content and the shale water is obtained. According to the first functional relationship, the rock mechanics parameters of the shale water are calculated. According to the rock mechanics parameters of the shale water, the shale collapse pressure is calculated. In the process of calculating the ground stress for calculating the collapse pressure, the influence of the physical and chemical effects, i.e. the influence of the water content of the shale water after the formation, is fully considered, and the accuracy of the obtained collapse pressure is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration, and provides a shale collapse pressure calculation method and device, an electronic device and a storage medium. BACKGROUND

[0002] 75% of the formations encountered in drilling are composed of shale, and 90% of the wellbore instability occurs in the shale section. If the reasonable collapse pressure of the shale formation is predicted, and the appropriate drilling fluid density is used to obtain mechanical stability during drilling, the invasion of the drilling fluid filtrate into the formation can be avoided, and the complex situations such as sticking and resistance can be avoided.

[0003] At present, the existing technology is to calculate the rock mechanical property parameters, to calculate the ground stress according to the obtained rock mechanical parameters, and to further calculate the wellbore collapse pressure. In the process of obtaining the rock mechanical parameters of the formation, the present ground stress, and the wellbore collapse pressure, the logging curve logging compressional wave slowness, logging density, and logging shear wave slowness are used from the pure mechanical point of view.

[0004] However, only from the pure mechanical point of view, the collapse pressure is not accurate enough, which will cause many complex situations in the drilling process. SUMMARY

[0005] The present application provides a shale collapse pressure calculation method and device, an electronic device and a storage medium, to solve the problem that the collapse pressure obtained from the mechanical point of view is not accurate enough.

[0006] In a first aspect, the present application provides a shale collapse pressure calculation method, which comprises:

[0007] obtaining the shale mineral component content of the drilled well and the shale filtrate invasion amount in the formation after the drilled well is hydrated;

[0008] obtaining the first functional relationship between the shale mineral component content and the shale filtrate invasion amount according to the shale mineral component content and the shale filtrate invasion amount;

[0009] calculating the rock mechanical parameters after the shale is hydrated according to the first functional relationship;

[0010] calculating the shale collapse pressure according to the rock mechanical parameters after the shale is hydrated.

[0011] Optionally, the method further comprises:

[0012] obtaining the second functional relationship between the shale filtrate invasion amount and the rock mechanical parameters after the shale is hydrated according to the shale filtrate invasion amount of the drilled well in the preset area and the rock mechanical parameters after the shale is hydrated;

[0013] According to the second function relationship, a correction coefficient of the predicted collapse pressure of a newly deployed well in the same area, the same formation and the same structure is obtained.

[0014] Optionally, the mud filtrate invasion amount in the shale formation after the drilling well is hydrous is obtained, including:

[0015] The initial water content and the saturated water content of the shale are measured;

[0016] The water absorption expansion coefficient of the shale is obtained, and the water absorption diffusion coefficient is related to the mud performance;

[0017] The mud filtrate invasion time of the formation after the wellbore is drilled and the size away from the well wall are obtained;

[0018] According to the initial water content, the saturated water content, the water absorption expansion coefficient, the mud filtrate invasion time of the formation after the wellbore is drilled and the size away from the well wall, the mud filtrate invasion amount of the shale is obtained.

[0019] Optionally, according to the shale mineral component content and the mud filtrate invasion amount, a first function relationship between the shale mineral component content and the mud filtrate invasion amount is obtained, including:

[0020] A two-dimensional relationship diagram is established, in which the abscissa represents the shale mineral component content and the ordinate represents the mud filtrate invasion amount;

[0021] The shale mineral component content and the mud filtrate invasion amount are filled into the two-dimensional relationship diagram to obtain a mapping relationship between the shale mineral component content and the mud filtrate invasion amount;

[0022] According to the mapping relationship, the first function relationship is obtained.

[0023] Optionally, according to the first function relationship, the rock mechanics parameters after the shale is hydrous are calculated, including:

[0024] According to the first function relationship, a Young's modulus formula after the shale is hydrous is calculated; and / or,

[0025] According to the first function relationship, a Poisson's ratio formula after the shale is hydrous is calculated; and / or,

[0026] According to the first function relationship, a cohesion formula after the shale is hydrous is calculated; and / or,

[0027] According to the first function relationship, an internal friction angle formula after the shale is hydrous is calculated;

[0028] According to the Young's modulus formula, the Poisson's ratio formula, the cohesion formula and the internal friction angle formula, the Young's modulus, the Poisson's ratio, the cohesion and the internal friction angle of the shale after the shale is hydrous are obtained.

[0029] Optionally, the shale collapse pressure is calculated according to the shale rock mechanics parameters after hydration, including:

[0030] According to the area, formation and structure of the drilled well, a preset ground stress model is selected;

[0031] The shale collapse pressure is calculated using the shale rock mechanics parameters after hydration and the preset ground stress model.

[0032] The shale collapse pressure is calculated using the shale rock mechanics parameters after hydration and the preset ground stress model.

[0033] Optionally, the shale rock mechanics parameters after hydration at least include: Young's modulus, Poisson's ratio, cohesion, internal friction angle, shear modulus, bulk modulus and compressive strength.

[0034] In a second aspect, the present application provides a shale collapse pressure calculation device, which comprises:

[0035] The obtaining module is configured to obtain the shale mineral component content of the drilled well and the shale mud filtrate invasion amount in the shale formation after hydration of the drilled well;

[0036] The processing module is configured to obtain a first functional relationship between the shale mineral component content and the shale mud filtrate invasion amount according to the shale mineral component content and the shale mud filtrate invasion amount;

[0037] The processing module is further configured to calculate the shale rock mechanics parameters after hydration according to the first functional relationship.

[0038] The processing module is further configured to calculate the shale collapse pressure according to the shale rock mechanics parameters after hydration.

[0039] In a third aspect, the present application provides an electronic device, which comprises a memory and a processor.

[0040] The memory is configured to store the executable instructions / programs of the processor.

[0041] The processor is configured to implement the shale collapse pressure calculation method according to the executable instructions / programs stored in the memory.

[0042] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer executable instructions / programs, and the computer executable instructions / programs are used to implement the shale collapse pressure calculation method according to the first aspect and the optional solutions when executed by the processor.

[0043] In a fifth aspect, the present application provides a computer program product, which comprises instructions, and the instructions are used to implement the shale collapse pressure calculation method according to the first aspect and the optional solutions when executed by the processor.

[0044] The present application provides a shale collapse pressure calculation method, device, electronic equipment and storage medium. In the method provided in the present embodiment, the shale mineral component content of a completed well and the mud filtrate invasion amount in the shale formation after hydration of the completed well are obtained, the first functional relationship between the shale mineral component content and the mud filtrate invasion amount is obtained according to the shale mineral component content and the mud filtrate invasion amount, the shale rock mechanics parameters after hydration are calculated according to the first functional relationship, and the shale collapse pressure is calculated according to the shale rock mechanics parameters after hydration. The influence of the physical and chemical effects, i.e. the influence of the water content in the shale formation after hydration, is fully considered in the process of calculating the ground stress for calculating the collapse pressure, and the accuracy of the calculated collapse pressure is improved. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 A flowchart of a shale collapse pressure calculation method according to an exemplary embodiment of the present application is shown;

[0046] Figure 2 A flowchart of a shale collapse pressure calculation method according to an exemplary embodiment of the present application is shown;

[0047] Figure 3 A functional relationship diagram of the shale mineral component content and the mud filtrate invasion amount according to the present embodiment is shown;

[0048] Figure 4 A functional relationship diagram of the mud filtrate invasion amount and the Young's modulus according to the present embodiment is shown;

[0049] Figure 5 A functional relationship diagram of the mud filtrate invasion amount and the Poisson's ratio according to the present embodiment is shown;

[0050] Figure 6 A functional relationship diagram of the mud filtrate invasion amount and the internal friction angle according to the present embodiment is shown;

[0051] Figure 7 A functional relationship diagram of the mud filtrate invasion amount and the uniaxial compressive strength according to the present embodiment is shown;

[0052] Figure 8 A comparison diagram of the rock mechanics parameter calculation results considering the mud filtrate invasion amount according to the present embodiment is shown;

[0053] Figure 9 A comparison diagram of the collapse pressure calculation results considering the mud filtrate invasion amount according to the present embodiment is shown;

[0054] Figure 10 A structural diagram of a shale collapse pressure calculation device according to an exemplary embodiment of the present application is shown;

[0055] Figure 11Fig. 1 is a schematic diagram of a hardware structure of an electronic device according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions will be described in detail below with reference to the accompanying drawings of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0057] The technical solutions of the present application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and some embodiments can not be described again for the same or similar concepts or processes.

[0058] The wellbore instability problem is a big problem universally existing in many oil fields in the world, which has been puzzling the petroleum industry. The causes of the wellbore instability are complex, and ultimately result from the instability of the wellbore mechanics. The mud shale contains water-sensitive clay minerals. When the mud shale is in contact with the drilling fluid, the mud shale and the drilling fluid interact, the mud shale hydration and expansion not only change the stress distribution around the wellbore, but also change the performance parameters of the mud shale due to water absorption. The chemical action of the drilling mud on the mud shale can ultimately be attributed to the change of the mechanical performance parameters, strength parameters of the wellbore rock and the stress state around the wellbore. 75% of the formations encountered during drilling are composed of mud shale, and 90% of the wellbore instability occurs in the mud shale section. If the reasonable collapse pressure of the mud shale formation is predicted, and the appropriate drilling fluid density is used to achieve mechanical stability during drilling, the complex situations such as sticking and resistance caused by the collapse of the wellbore due to the invasion of the drilling fluid filtrate into the formation can be avoided.

[0059] At present, the existing technology is to calculate the mechanical performance parameters of the rock, and then calculate the ground stress according to the obtained mechanical parameters of the rock, and further calculate the collapse pressure of the wellbore. In the process of obtaining the mechanical parameters of the formation rock, the present ground stress and the collapse pressure of the wellbore, the logging curve logging compressional wave slowness, logging density and logging shear wave slowness are used from the pure mechanical point of view.

[0060] However, only considering from the pure mechanical point of view, the collapse pressure obtained is not accurate enough, which will cause many complex situations during drilling.

[0061] In view of the above problems, the present application proposes a mud shale collapse pressure calculation method considering the invasion amount of the mud filtrate, and the main purpose is to quantitatively take into account the influence of the physical and chemical factors in the process of optimizing the obtained collapse pressure, so as to improve the accuracy of the obtained collapse pressure.

[0062] Figure 1 A flowchart of a shale collapse pressure calculation method according to an exemplary embodiment of the present application is shown. As shown in the flowchart, the shale collapse pressure calculation method provided by the present embodiment includes the following steps: Figure 1

[0063] S101, obtaining the shale mineral component content of a completed well and the shale mud filtrate invasion amount in the shale formation after hydration of the completed well.

[0064] More specifically, the completed well refers to a drilled well, and the completed well also has mud filtrate invasion. For the present embodiment, the collapse pressure is calculated according to the corresponding historical data (such as the calculated rock mechanical parameters of the shale after hydration) obtained from a completed well in the same region, same formation and same structure. The historical data and the finally calculated collapse pressure provide a better data reference value for predicting the collapse pressure of a new well deployed in the same region, same formation and same structure.

[0065] In the present embodiment, the mud filtrate invades in the well, the shale hydrates, and the clay mineral components of the shale formation at this time are obtained.

[0066] In the present embodiment, the shale mud filtrate invasion amount can be calculated by data experiments, comprehensively considering the initial water content of the shale, the saturated water content of the shale, the water absorption expansion coefficient of the shale, the mud filtrate invasion time of the formation after the borehole is drilled, and the size from the well wall.

[0067] S102, obtaining a first functional relationship between the shale mineral component content and the mud filtrate invasion amount according to the shale mineral component content and the mud filtrate invasion amount.

[0068] More specifically, the water absorption changes the mechanical properties of the shale, such as the decrease of strength and cohesion, the decrease of elastic modulus, and the increase of Poisson's ratio, which makes the wellbore instability problem of the shale formation more serious. In order to consider the influence of the mud filtrate invasion amount on the rock mechanical parameters, the first functional relationship between the mineral component content after hydration of the shale and the mud filtrate invasion amount is established in advance in the present embodiment, and the rock mechanical parameters after hydration of the shale are calculated according to the first functional relationship.

[0069] S103, calculating the rock mechanical parameters after hydration of the shale according to the first functional relationship.

[0070] More specifically, the rock mechanical parameters can be divided into two categories: rock mechanical elastic parameters and strength parameters. The rock mechanical elastic parameters include Poisson's ratio v, elastic modulus E, shear modulus G, bulk modulus K, and boits coefficient. The rock mechanical strength parameters include compressive strength ucs, cohesion Fc, and internal friction angle ​Tensile strength λ, etc. According to the rock elastic wave theory, the dynamic elastic parameters of the rock can be derived from the geometric equation, stress-strain equation and wave equation of the isotropic linear elastic body. The dynamic elastic parameters: reflect the mechanical properties of the formation under instantaneous loading.

[0071] The existing rock mechanics parameter calculation formula is based on pure mechanical effect and does not involve the influence of the chemical effect caused by the mud filtrate content of the penetrated formation and the clay minerals. Therefore, the embodiment improves the existing rock mechanics parameter calculation formula, and introduces the first function relationship obtained in the step S102 into the process of calculating the rock mechanics parameters of the hydrated shale.

[0072] S104, calculating the shale collapse pressure according to the rock mechanics parameters of the hydrated shale.

[0073] More specifically, in the embodiment, the rock mechanics parameters of the hydrated shale are used to preferentially perform the in-situ stress quantitative calculation, and the following formulas (1) and (2) can be used:

[0074]

[0075]

[0076] Wherein, T z is the vertical stress, the unit is Mpa; biot is the rock parameter, the biot coefficient is dimensionless; P p is the formation pore pressure, the unit is Mpa; x, y are the tectonic strain coefficients along the maximum horizontal principal stress direction and the minimum principal stress direction, respectively, and the unit is dimensionless.

[0077] Further, the rock mechanics parameters of the hydrated shale are used to calculate the collapse pressure, and the following formulas (3) and (4) can be used:

[0078]

[0079]

[0080] Wherein, a is the stress nonlinear correction coefficient, the unit is dimensionless.

[0081] In the embodiment, the rock mechanics parameters of the hydrated shale are used to participate in the calculation, the influence of the mud filtrate invasion amount on the borehole wall stability parameters is considered, the relationship between the mud filtrate invasion amount and the rock physical parameters and the mechanical parameters is used, and is applied to the quantitative calculation formula. In particular, the mechanical parameters such as the modulus, the strength and the Poisson's ratio of the rock and the in-situ stress quantitative calculation results can be more accurately obtained, so as to improve the quantitative calculation precision of the borehole wall collapse pressure.

[0082] In the method provided in the embodiment, the shale mineral component content of the completed well and the mud filtrate invasion amount in the shale formation after hydration of the completed well are obtained, the first functional relationship between the shale mineral component content and the mud filtrate invasion amount is obtained according to the shale mineral component content and the mud filtrate invasion amount, the shale rock mechanics parameter after hydration is calculated according to the first functional relationship, and the shale collapse pressure is calculated according to the shale rock mechanics parameter after hydration. Compared with the prior art, the embodiment fully considers the influence of the physical and chemical effects, i.e. the influence of the water content of the shale formation after hydration, in the process of calculating the ground stress for calculating the collapse pressure. The embodiment quantifies the mechanical effect caused by the chemical action of the mud filtrate in the formation and the clay mineral, combines the mechanical effect with the pure mechanical effect, and integrates the mechanical effect into the calculation formula of the rock mechanics parameter of the formation, and then the ground stress is calculated by using the rock mechanics parameter of the shale after hydration, and the collapse pressure is further calculated, thereby improving the accuracy of calculating the collapse pressure.

[0083] Figure 2 The flowchart of the shale collapse pressure calculation method according to an exemplary embodiment of the present application is shown in FIG. 1. As shown in FIG. 1, the shale collapse pressure calculation method provided in the embodiment includes the following steps: Figure 2

[0084] S201, obtaining the shale mineral component content of the completed well.

[0085] More specifically, the Schlumberger multi-mineral model is used to analyze and evaluate the shale content and mineral composition of the formation of the completed well, and the shale mineral component content of the completed well in the same region, the same formation and the same structure is obtained.

[0086] S202, obtaining the mud filtrate invasion amount in the shale formation after hydration of the completed well.

[0087] More specifically, the initial water content and the saturated water content of the shale are measured, the water absorption expansion coefficient of the shale is obtained, the water absorption diffusion coefficient is related to the mud performance, the mud filtrate invasion time of the formation after the wellbore is drilled and the size away from the well wall are obtained, and the mud filtrate invasion amount of the shale is obtained according to the initial water content, the saturated water content, the water absorption expansion coefficient, the mud filtrate invasion time of the formation after the wellbore is drilled and the size away from the well wall. The following formula (5) can be used:

[0088]

[0089] wherein, is an error compensation function; W0 is the initial water content of the shale, in %; W s is the saturated water content of the shale, in %; C f is the water absorption diffusion coefficient of the shale, related to the mud performance, in cm 2 ​ / h; t is the time for the mud filtrate to soak the formation after the wellbore is drilled, in hours (h); x is the distance from the wellbore, in centimeters (cm); W is the amount of mud filtrate that penetrates the shale, in percent (%).

[0090] S203. Based on the mineral component content of shale and the amount of mud filtrate intrusion, the first functional relationship between the mineral component content of shale and the amount of mud filtrate intrusion is obtained.

[0091] More specifically, a two-dimensional relationship diagram is established, where the horizontal axis represents the mineral composition content of shale and the vertical axis represents the amount of mud filtrate intrusion. By filling the two-dimensional relationship diagram with the mineral composition content of shale and the amount of mud filtrate intrusion, the mapping relationship between the mineral composition content of shale and the amount of mud filtrate intrusion is obtained. Based on this mapping relationship, the first functional relationship is derived. Figure 3 This is a graph showing the functional relationship between the content of shale mineral components and the amount of mud filtrate intrusion provided in this embodiment. Figure 3 As shown, the units of the horizontal and vertical axes are both %, and the final fitting formula is formula (6), with a fitting degree of 0.9727, as follows:

[0092] Fitting formula: 9.0972×x-0.1956; R-squared value: 0.9727, formula (6)

[0093] It should be noted that, in this Figure 3 The mapping relationship between the content of multiple mineral components and the amount of mud filtrate intrusion can be seen, such as Figure 3 In the shaded area, by fitting multiple mapping relationships into a linear function, and then using the linear function to describe the relationship between mineral components and mud filtrate intrusion, the above multiple mapping relationships are summarized and simplified. Therefore, when using this linear function relationship to subsequently calculate the rock mechanical parameters of shale after hydration, it is not only convenient to process, but the fitted linear function relationship will not affect the accuracy of the calculated rock mechanical parameters of shale after hydration.

[0094] S204. Calculate the rock mechanical parameters of shale after hydration based on the first functional relationship.

[0095] In this embodiment, the first functional relationship between mineral component content and mud filtrate intrusion amount is substituted into experimental data to construct formulas for calculating rock mechanical parameters of shale after hydration. Specifically, the main formulas for Young's modulus, Poisson's ratio, cohesion, and internal friction angle of shale after water splashing are described in detail below:

[0096] Based on the first functional relationship, the formula for calculating the Young's modulus of shale after water splashing is as follows:

[0097]

[0098] Based on the first functional relationship, the formula for calculating the Poisson's ratio after water dissipation in shale is as follows:

[0099] V w =V a +V b ×(a×vcl-b) Formula (8)

[0100] Based on the first functional relationship, the formula for calculating the cohesion of shale after water splashing is given.

[0101] Fc w =Ks×[(a×vcl-b)-W b ] Formula (9)

[0102] Formula for calculating the internal friction angle of shale after water splashing, based on the first functional relationship.

[0103]

[0104] Among them, E a E b V a V b , Ks is a regional empirical coefficient, in dimensionless units; Ks is a coefficient, in dimensionless units; W b VCL represents the initial water content increment, in %; VCL represents the clay content, in %; a and b are the coefficients relating the mud filtrate intrusion amount to the clay content (e.g., ...). Figure 3 As shown, a is 9.0972 and b is -0.1956, with units being dimensionless.

[0105] In this embodiment, the Young's modulus, Poisson's ratio, cohesion, and internal friction angle of shale after hydration are obtained based on the Young's modulus formula, Poisson's ratio formula, cohesion formula, and internal friction angle formula of shale after hydration.

[0106] Optionally, the rock mechanical parameters of hydrated mudstone and shale include at least: Young's modulus, Poisson's ratio, cohesion, internal friction angle, shear modulus, bulk modulus, and compressive strength.

[0107] Therefore, in addition to Young's modulus, Poisson's ratio, cohesion, and internal friction angle, rock mechanics parameters include at least other parameters. The method provided in this embodiment also includes: calculating other parameters of shale after water splashing based on Young's modulus, Poisson's ratio, cohesion, and internal friction angle of shale.

[0108] It should be noted that in the present embodiment, it has been stated that the rock mechanics parameters include not only the Young's modulus formula, the Poisson's ratio formula, the cohesion formula and the internal friction angle formula, but also the four rock mechanics parameters are the core parameters of shale hydration. In addition, the existing calculation formula used for calculating other parameters often uses one or more of the four parameters as intermediate calculation data. Therefore, for the present embodiment, the calculation formula of the four parameters is mainly constructed, which is sufficient to consider the influence of shale hydration on the change of rock mechanics parameters.

[0109] For the present embodiment, based on the selected in-situ stress model and the different wellbore collapse pressure calculation formula, the rock mechanics parameters required for model or formula calculation are obtained in advance, mainly the Young's modulus, Poisson's ratio, cohesion and internal friction angle of shale after hydration. If other parameters are also needed, it is necessary to see whether the four parameters are needed to support the calculation of other parameters. If so, the four parameters after shale hydration are used to perform related calculations.

[0110] S205, calculating the shale collapse pressure according to the rock mechanics parameters after shale hydration.

[0111] More specifically, according to the area, formation and structure of the completed well, a preset in-situ stress model is selected, which means that the Huang's model is mainly selected in the flat structure area, and the combined spring model is suitable for the high and steep structure area, etc. The rock mechanics parameters after shale hydration and the selected preset in-situ stress model are used to calculate the formation triaxial stress, which can be calculated by using formulas (1) and (2). The rock mechanics parameters after shale hydration and the formation triaxial stress are used to calculate the wellbore collapse pressure, which can be calculated by using formulas (3) and (4).

[0112] S206, obtaining a second functional relationship between the mud filtrate invasion amount and the rock mechanics parameters after shale hydration according to the mud filtrate invasion amount of the completed well in the preset area and the rock mechanics parameters after shale hydration.

[0113] More specifically, a second functional relationship between the mud filtrate invasion amount and the Young's modulus after shale hydration is obtained according to the mud filtrate invasion amount of the completed well in the preset area and the Young's modulus after shale hydration. A second functional relationship between the mud filtrate invasion amount and the Poisson's ratio after shale hydration is obtained according to the mud filtrate invasion amount of the completed well in the preset area and the Poisson's ratio after shale hydration. A second functional relationship between the mud filtrate invasion amount and the internal friction angle after shale hydration is obtained according to the mud filtrate invasion amount of the completed well in the preset area and the internal friction angle after shale hydration.

[0114] Figure 4 The mud filtrate invasion amount and Young's modulus functional relationship diagram provided for the present embodiment is as follows: Figure 4As shown in the figure, the second function relationship formula is obtained as formula (11), and the fitting degree is 0.9367.

[0115] Fitting formula: 71832.5160*exp(-0.5416x), R square value: 0.9367, formula (11)

[0116] Figure 5 The mud filtrate invasion amount and Poisson ratio function relationship graph provided for this embodiment is shown in the figure. Figure 5 As shown in the figure, the second function relationship formula is obtained as formula (12), and the fitting degree is 0.9003.

[0117] Fitting formula: 0.0187*x+0.2714, R square value: 0.9003, formula (12)

[0118] Figure 6 The mud filtrate invasion amount and internal friction angle function relationship graph provided for this embodiment is shown in the figure. Figure 6 As shown in the figure, the second function relationship formula is obtained as formula (13), and the fitting degree is 0.9452.

[0119] Fitting formula: -5.1754*x+43.7180, R square value: 0.9452, formula (13)

[0120] Figure 7 The mud filtrate invasion amount and uniaxial compressive strength function relationship graph provided for this embodiment is shown in the figure. Figure 7 As shown in the figure, the second function relationship formula is obtained as formula (14), and the fitting degree is 0.5083.

[0121] Fitting formula: -11.7495*x+168.1621, R square value: 0.5083, formula (14)

[0122] It should be noted that the existing calculation formula for calculating uniaxial compressive strength (rock mechanics parameters) is as follows:

[0123] ucs=[0.0045*(1-vcl)+0.008*vcl]*E*7.031*10 -3 Formula (15)

[0124] Wherein, vcl is the formation shale content, unit is %; E is Poisson's ratio, ucs is uniaxial compressive strength, and in the formula (15), Poisson's ratio is intermediate data, so for this embodiment, after the mud shale is hydrated, the Poisson's ratio changes, and then the calculated uniaxial compressive strength also changes, that is, the rock mechanics parameters also change, so a fitting function relationship between the mud filtrate invasion amount and the uniaxial compressive strength can also be established, which is also valuable reference data for deploying new wells.

[0125] Furthermore, in this embodiment, the fitting operation used has different requirements for obtaining different functional relationships. Different fitting degree coefficients can be preset. Then, for each fitting operation, it can be determined whether the fitting degree corresponding to the fitting operation is greater than the preset threshold. If not, the current fitting operation is discarded, indicating that the functional relationship of the current fitting is insufficient to represent the relationship between the two being fitted, so the operation is repeated.

[0126] S207. Based on the second functional relationship, obtain the correction coefficient for predicting the collapse pressure of newly deployed wells in the same region, the same stratum, and the same structure.

[0127] In this embodiment, multiple completed wells in the same region, strata, and structure are taken as the object. The second functional relationship between the mud filtrate intrusion and rock mechanical parameters is obtained. This provides better and more valuable reference data for deploying new wells in the same strata and structure in this region, and thus serves as a correction coefficient for predicting the collapse pressure of the newly deployed wells.

[0128] Furthermore, the specific application scenarios of this embodiment are described below:

[0129] Example Scenario 1: Taking a well in an oil field as an example, the evaluation well section is composed of clastic rock with a high content of mudstone and shale. Figure 8 A comparison chart of rock mechanical parameter calculation results considering mud filtrate intrusion volume is provided for this embodiment. (See figure) Figure 8 As shown, the comparison of rock mechanical parameter calculation results considering mud filtrate intrusion includes five data points. The mud filtrate intrusion rate is calculated to be between 1% and 5% (the curve shown in the first left corner of the image represents the mud filtrate intrusion rate). The following four curves compare the rock mechanical parameter calculation results without considering mud filtrate intrusion (red curve) and with considering the influence of mud filtrate intrusion (blue curve). It should be noted that because a grayscale image was submitted, for... Figure 8 The red and blue curves in the diagram are used to illustrate the following: In the second test, the blue curve is on the left and the red curve is on the right; in the third test, the red curve is on the left and the blue curve is on the right; in the fifth test, the blue curve is on the left and the red curve is on the right.

[0130] Figure 9 This is a comparison chart showing the calculation results of collapse pressure after considering the amount of mud filtrate intrusion in this embodiment. Figure 9As shown, since the submitted is a gray scale image, the calculated results under the conditions of not considering the mud filtrate invasion amount (red curve) and considering the mud filtrate invasion amount (blue curve) are illustrated in the figure. The curve in the first lane is the mud filtrate invasion amount, the red curve is on the left and the blue curve is on the right in the second lane, the red curve is on the left and the blue curve is on the right in the third lane, and the red curve is on the left and the blue curve is on the right in the fourth lane. Through comparative analysis, it can be known that the ground stress increases (expansion stress) when the mud filtrate invasion amount in the formation increases (the second and third lanes on the left of the figure); the collapse pressure increases (the fourth lane on the left of the figure). Compared with the actual drilling results, the collapse pressure gradient considering the mud filtrate invasion amount is about 0.1-0.3SG higher than that not considering the mud filtrate invasion amount, the well wall is more stable, and no complex situation occurs in the drilling process.

[0131] In the specific application scenario provided in the embodiment, the analysis values obtained in Figure 8 and 9 are obtained through experimental data, which are not specifically stated here.

[0132] Figure 10 FIG. 1 is a structural schematic diagram of a shale collapse pressure calculation device according to an example embodiment of the present application. As shown in Figure 10 , the present application provides a shale collapse pressure calculation device 40, which comprises:

[0133] The acquisition module 41 is configured to acquire the shale mineral component content of the drilled well and the mud filtrate invasion amount in the formation after the shale of the drilled well is hydrated;

[0134] The processing module 42 is configured to obtain a first functional relationship between the shale mineral component content and the mud filtrate invasion amount according to the shale mineral component content and the mud filtrate invasion amount;

[0135] The processing module 42 is further configured to calculate the rock mechanics parameters after the shale is hydrated according to the first functional relationship;

[0136] The processing module 42 is further configured to calculate the shale collapse pressure according to the rock mechanics parameters after the shale is hydrated.

[0137] Specifically, the embodiment can refer to the above-mentioned method embodiment, which has similar principles and technical effects, and will not be described here.

[0138] Figure 11 FIG. 2 is a hardware structure schematic diagram of an electronic device according to an example embodiment of the present application. As shown in Figure 11 , the electronic device 50 of the embodiment comprises a processor 51 and a memory 52; wherein,

[0139] The memory 52 is configured to store the memory of the processor executable instructions.

[0140] The processor 51 is configured to execute the instructions stored in the memory to implement the shale collapse pressure calculation method in the above embodiments. Details can be referred to the related description in the method embodiments.

[0141] Optionally, the memory 52 can be independent or integrated with the processor 51.

[0142] When the memory 52 is independent, the electronic device 50 further includes a bus 53 for connecting the memory 52 and the processor 51.

[0143] The present application also provides a computer readable storage medium, which stores computer instructions. The computer instructions are executed by a processor to implement the method provided in the above embodiments.

[0144] The computer readable storage medium can be a computer storage medium or a communication medium. The communication medium includes any medium that facilitates the transfer of computer program from one place to another. The computer storage medium can be any available medium that can be accessed by a general or special purpose computer. For example, the computer readable storage medium is coupled to the processor, so that the processor can read information from the computer readable storage medium and write information to the computer readable storage medium. Of course, the computer readable storage medium can also be an integral part of the processor. The processor and the computer readable storage medium can be located in an application specific integrated circuit (ASIC). In addition, the ASIC can be located in a user equipment. Of course, the processor and the computer readable storage medium can also exist as discrete components in a communication device.

[0145] The computer readable storage medium can be realized by any type of volatile or non-volatile storage devices or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read only memory (EEPROM), erasable programmable read only memory (EPROM), programmable read only memory (PROM), read only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk. The storage medium can be any available medium that can be accessed by a general or special purpose computer.

[0146] The application also provides a computer program product, which includes execution instructions stored in a computer readable storage medium. At least one processor of the device can read the execution instructions from the computer readable storage medium, and the execution of the execution instructions by the at least one processor causes the device to implement the method provided by the various embodiments described above.

[0147] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for calculating the collapse pressure of mudstone and shale, characterized in that, The method includes: The mineral composition of the mudstone and shale after drilling was obtained, as well as the amount of mud filtrate intrusion into the formation after the mudstone and shale hydration of the well was completed. Based on the content of the shale mineral components and the amount of mud filtrate intrusion, a first functional relationship between the content of the shale mineral components and the amount of mud filtrate intrusion is obtained; The calculation of the rock mechanical parameters of the shale after hydration based on the first functional relationship includes: substituting the first functional relationship into experimental data to construct a calculation formula for the rock mechanical parameters of the shale after hydration; and obtaining the rock mechanical parameters of the shale after hydration based on the calculation formula. The collapse pressure of the shale was calculated based on the rock mechanical parameters after hydration.

2. The method according to claim 1, characterized in that, The method further includes: Based on the amount of mud filtrate intrusion in the completed wells within the preset area and the rock mechanical parameters of the shale after hydration, a second functional relationship between the amount of mud filtrate intrusion and the rock mechanical parameters of the shale after hydration is obtained. Based on the second functional relationship, a correction coefficient is obtained for predicting the collapse pressure of newly deployed wells in the same region, the same stratum, and the same structure.

3. The method according to claim 1, characterized in that, Obtaining the amount of mud filtrate intrusion in the formation after hydration of the shale and mudstone in the completed well includes: The initial water content and saturated water content of the mudstone and shale were measured; The water absorption expansion coefficient of the mudstone is obtained, and the water absorption expansion coefficient is related to the mud properties; Obtain the formation soaking time and distance from the wellbore of the mud filtrate after drilling; The amount of mud filtrate intrusion into the shale is obtained based on the initial water content, the saturated water content, the water absorption expansion coefficient, the formation soaking time of the mud filtrate after drilling, and the distance from the well wall.

4. The method according to claim 3, characterized in that, The step of obtaining a first functional relationship between the shale mineral component content and the mud filtrate intrusion amount based on the shale mineral component content and the mud filtrate intrusion amount includes: Establish a two-dimensional relationship diagram, where the horizontal axis represents the mineral composition content of the mudstone and shale, and the vertical axis represents the amount of mud filtrate intrusion; The content of the shale mineral components and the amount of mud filtrate intrusion are filled into the two-dimensional relationship diagram to obtain the mapping relationship between the content of the shale mineral components and the amount of mud filtrate intrusion. Based on the mapping relationship, the first functional relationship is obtained.

5. The method according to claim 4, characterized in that, The step of substituting the first functional relationship into experimental data to construct a formula for calculating the rock mechanical parameters of shale after hydration includes: Based on the first functional relationship, calculate the Young's modulus formula for the shale after water splashing; and / or, Based on the first functional relationship, calculate the Poisson's ratio formula after water dissipation in the shale; and / or, Based on the first functional relationship, calculate the cohesion formula for the shale after water splashing; and / or, Based on the first functional relationship, calculate the formula for the internal friction angle of the mudstone and shale after water splashing; The process of obtaining the rock mechanical parameters of shale after hydration according to the calculation formula includes: Based on the Young's modulus formula, the Poisson's ratio formula, the cohesion formula, and the internal friction angle formula, the Young's modulus, Poisson's ratio, cohesion, and internal friction angle of mudstone and shale after water splashing are obtained.

6. The method according to claim 5, characterized in that, The calculation of the shale collapse pressure based on the rock mechanical parameters after hydration includes: Based on the region, formation, and structure of the completed well, a preset geostress model is selected; Using the rock mechanics parameters of the hydrated mudstone and the preset geostress model, the triaxial stress of the formation is calculated. The collapse pressure of the shale was calculated using the rock mechanics parameters after hydration and the triaxial stress of the formation.

7. The method according to claim 1, characterized in that, The rock mechanical parameters of the hydrated mudstone and shale include at least: Young's modulus, Poisson's ratio, cohesion, internal friction angle, shear modulus, bulk modulus, and compressive strength.

8. A device for calculating the collapse pressure of mudstone and shale, characterized in that, The device includes: The acquisition module is used to acquire the mineral composition content of the mudstone and shale after drilling and the amount of mud filtrate intrusion in the formation after the mudstone and shale hydration of the completed well. The processing module is used to obtain a first functional relationship between the mineral component content of the shale and the intrusion amount of the mud filtrate, based on the mineral component content of the shale and the intrusion amount of the mud filtrate. The processing module is also used to calculate the rock mechanical parameters of the shale after hydration based on the first functional relationship, including: substituting the first functional relationship into experimental data to construct a calculation formula for the rock mechanical parameters of the shale after hydration; and obtaining the rock mechanical parameters of the shale after hydration based on the calculation formula. The processing module is also used to calculate the collapse pressure of the shale based on the rock mechanical parameters of the shale after hydration.

9. An electronic device, characterized in that, include: Memory, processor; Memory, used to store the processor-executable instructions / programs; A processor is configured to implement the shale collapse pressure calculation method as described in any one of claims 1 to 7, based on executable instructions / programs stored in the memory.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions / programs, which, when executed by a processor, are used to implement the shale collapse pressure calculation method as described in any one of claims 1 to 7.

11. A computer program product, comprising instructions, characterized in that, When executed by the processor, this instruction implements the method for calculating the collapse pressure of mudstone and shale as described in any one of claims 1 to 7.

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