CN-122022439-A - High-pressure gas well integrity risk dynamic assessment method and related device

CN122022439ACN 122022439 ACN122022439 ACN 122022439ACN-122022439-A

Abstract

The invention belongs to the field of wellbore integrity risk assessment, and discloses a high-pressure gas well integrity risk dynamic assessment method and a related device, wherein the method comprises the steps of obtaining a B, C, D annular pressure control range of a high-pressure gas well; the method comprises the steps of checking performance parameters of all parts of an A annulus of a high-pressure gas well to obtain a maximum allowable zone pressure value and a minimum reserved working pressure value of all parts of the A annulus, obtaining an A annulus pressure control range chart according to the maximum allowable zone pressure value and the minimum reserved working pressure value of all parts of the A annulus, evaluating the well barrier state by utilizing the A annulus pressure control range chart and B, C, D annulus pressure control range and evaluating the integrity of stratum, a shaft and well mouth barrier parts respectively. The invention is beneficial to improving the safety and efficiency of gas well production, reducing the management cost and has important practical significance and application value.

Inventors

Kong Change
MA YAQIN
TU ZHIXIONG
YU XIAOTONG
WANG XUESONG
ZHOU XIAOJUN
ZHANG CHAO
LIU WENCHAO
LIU HONGTAO
ZENG NU
ZHANG BAO
JING HONGTAO
GENG HAILONG
WEI JUNHUI
YI JUN
ZHAO MIFENG

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (10)

1. The method for dynamically evaluating the integrity risk of the high-pressure gas well is characterized by comprising the following steps of: Acquiring an annulus pressure control range of the high-pressure gas well B, C, D; checking the performance parameters of all parts of the annular space A of the high-pressure gas well to obtain a maximum allowable belt pressure value and a minimum reserved working pressure value of all parts of the annular space A; obtaining a drawing plate of the control range of the annular pressure of the A annulus according to the maximum allowable belt pressure value and the minimum reserved working pressure value of each part of the A annulus; And evaluating the well barrier state by using the A annulus pressure control range chart and the B, C, D annulus pressure control range and adopting the list type evaluation to evaluate the integrity of stratum, shaft and wellhead barrier components respectively.
2. The method for dynamically assessing the integrity risk of a high-pressure gas well according to claim 1, wherein the step of obtaining the annulus pressure control range of the high-pressure gas well B, C, D comprises the steps of: B. c, D the maximum allowable working pressure of the annulus is the minimum of a) 80% of the minimum outward extrusion resistance intensity of the whole annulus inner sleeve, b) 80% of the minimum internal destruction strength of the whole annulus outer sleeve, c) 80% of the rated pressure value of the sleeve head corresponding to the annulus, and d) the fracture pressure of the stratum corresponding to the annulus; after B, C, D annular maximum allowable working pressure is obtained, taking the B, C, D annular maximum allowable working pressure value multiplied by 80% as the upper limit of recommended working pressure values; taking the minimum value of the four values of annulus hydraulic pressure subtracted from the corresponding casing head rated value of B, C, D annuluses, the minimum anti-extrusion intensity of the whole annulus inner layer casing, the minimum internal pressure intensity of the whole annulus outer layer casing and the corresponding stratum fracture pressure of the annuluses as the maximum limit pressure value of the annuluses; B. the minimum reserved pressure value of C, D annular space is 0.7MPa, and the recommended lower limit of the annular space pressure values of B and C, D is 1.4MPa.
3. The method of claim 2, wherein the calculation of the maximum allowable working pressure of B, C, D annulus comprises the steps of ① wellhead assembly, ② inner casing upper portion, ③ outer casing upper portion, ④ inner casing lower portion, ⑤ outer casing lower portion, and ⑥ formation.
4. The method for dynamically evaluating the integrity risk of a high-pressure gas well according to claim 1, wherein the step of obtaining the maximum allowable pressure value of each part of the annulus a by checking the performance parameters of each part of the annulus a of the high-pressure gas well comprises the following steps: Checking the tubing head, namely checking 80% of rated pressure value of the tubing head; checking the underground safety valve, namely ensuring that the maximum allowable pressure value of an annulus A corresponding to the safety of the underground safety valve is calculated in a simplified way by adopting the following steps: (1) wherein: -a maximum allowable working pressure of annulus MPa; -rated working pressure of the subsurface safety valve, MPa; -oil pressure, MPa; -the safety factor of rated working pressure of the subsurface safety valve takes a value of 1.0; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; j -downhole safety valve depth, m; Checking the packer, namely ensuring the maximum allowable zone pressure value of the annular space A corresponding to the safety of the packer, and adopting the following steps of: (2) wherein: -a maximum allowable working pressure of annulus MPa; -rated operating pressure of the packer, MPa; -oil pressure, MPa; -rated working pressure safety coefficient of the packer, which takes a value of 1.0; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -packer setting depth, m; Checking the oil pipe, namely checking the outward extrusion resistance strength and the triaxial stress strength of the oil pipe under the working conditions of open production and shut-in, respectively calculating the maximum allowable working pressure of an annulus A, and selecting the minimum one from the maximum allowable working pressure as the corresponding maximum allowable working pressure of the annulus A for checking the oil pipe strength; a) Calculating maximum allowable working pressure of annulus A through anti-extrusion strength of oil pipe : (3) Wherein: -a maximum allowable working pressure of annulus MPa; -the strength of the oil pipe against extrusion, MPa; -oil pressure, MPa; -the safety coefficient of the anti-extrusion strength of the oil pipe is 1.3; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -dangerous point depth, m; b) Calculating the maximum allowable working pressure of the annulus A through triaxial stress intensity check : Triaxial stress of tubing Represented by the formula: (4) Wherein: (5) (6) (7) In the above formula: -triaxial stress, MPa; -axial stress, MPa; -hoop stress, MPa; -radial stress, MPa; -external squeezing force of oil pipe, MPa; -internal pressure of the tubing, MPa; -outer radius of tubing, mm; -inner radius of tubing, mm; -initial axial load, N; Anti-extrusion force of oil pipe Represented by the formula: (8) wherein: -external squeezing force of oil pipe, MPa; -a annulus pressure, MPa; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -calculating the depth of the point, m; c) Judging the triaxial stress according to the Von-Mises yield strength criterion Whether the following formulas are satisfied, if all the formulas are satisfied, the safety state is realized, otherwise, the safety state is realized; (9) wherein: -triaxial stress, MPa; -oil pipe yield strength, MPa; -triaxial stress safety coefficient of oil pipe, 1.5; d) Calculating different A annulus pressure values until the formula (9) is met, wherein the maximum A annulus pressure which is met (9) is the maximum allowable working pressure of the A annulus obtained through triaxial stress check of the oil pipe; Checking the production casing, namely adopting a tie-back well cementation mode to finish the production casing, evaluating the abrasion condition of the production casing if a tail pipe is adopted, calculating the internal pressure resistance of the production casing according to the residual strength after abrasion, and calculating the maximum allowable working pressure of an annulus A through the internal pressure resistance of the production casing : (10) Wherein: -a maximum allowable working pressure of annulus MPa; -producing a casing having an internal pressure resistance strength, MPa; -producing a sleeve internal pressure strength safety factor of 1.25; Taking the worst well cementation environment density into consideration, wherein the density is 1.03g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -dangerous point depth, m; checking the liner hanger, and calculating the maximum allowable working pressure of the annulus A through the internal pressure resistance intensity of the liner hanger : (11) Wherein: -a maximum allowable working pressure of annulus MPa; -B annulus pressure, MPa; -liner hanger internal pressure resistance, MPa; -liner hanger internal pressure strength safety factor, 1.25; Taking the worst well cementation environment density into consideration, wherein the density is 1.03g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -dangerous point depth, m; checking the formation fracture pressure, namely calculating the maximum allowable working pressure of the annulus A according to the formation fracture pressure and the following formula : (12) Wherein: -a maximum allowable working pressure of annulus MPa; -formation fracture pressure, MPa; -stratum fracture pressure safety factor, value 1.25; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -formation depth, m; Tail pipe checking, namely calculating residual strength of the tail pipe according to the evaluated damage condition, and calculating the maximum allowable working pressure of the annulus A according to the internal pressure resistance strength of the tail pipe : (13) Wherein: -a maximum allowable working pressure of annulus MPa; -B annulus pressure, MPa; -internal pressure resistance of the tailpipe, MPa; -safety coefficient of internal pressure resistance of tail pipe, 1.25; Taking the worst well cementation environment density into consideration, wherein the density is 1.03g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; Dangerous point depth, m.
5. The method for dynamically evaluating the integrity risk of a high-pressure gas well according to claim 1, wherein the step of obtaining the minimum reserved working pressure value of each part of the annulus a by checking the performance parameters of each part of the annulus a of the high-pressure gas well comprises the following steps: checking the internal pressure resistance strength and the triaxial stress strength of the tubing string under the working conditions of open production and shut-in, respectively calculating the minimum reserved working pressure of the annulus A, and selecting the maximum working pressure as the minimum reserved working pressure of the annulus A; And checking the packer, namely ensuring that the minimum reserved working pressure value of the annular space A corresponding to the safety of the packer is calculated in a simplified way by adopting the following steps: (14) wherein: -a minimum pre-set working pressure in annulus MPa; -rated operating pressure of the packer, MPa; -oil pressure, MPa; -rated working pressure safety coefficient of the packer, which takes a value of 1.0; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -packer setting depth, m; Checking the underground safety valve, namely ensuring that the minimum reserved working pressure value of the annular space A corresponding to the safety of the underground safety valve is calculated in a simplified way by adopting the following steps: (15) wherein: -a minimum pre-set working pressure in annulus MPa; -rated working pressure of the subsurface safety valve, MPa; -oil pressure, MPa; -the safety factor of rated working pressure of the subsurface safety valve takes a value of 1.0; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; j -downhole safety valve depth, m; Checking the oil pipe, namely calculating the minimum reserved working pressure of the annular space A through the internal pressure resistance intensity of the oil pipe : (16) Wherein: -a minimum pre-set working pressure in annulus MPa; -oil pressure, MPa; -internal pressure resistance of the tubing, MPa; -safety coefficient of internal pressure resistance intensity of oil pipe, 1.3; -gas density in tubing, g/cm 3 ; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; Calculating minimum preset pressure value of A annulus through triaxial stress intensity check The minimum annular space A pressure meeting 16 is the minimum reserved working pressure of the annular space A obtained through triaxial stress check of the oil pipe; Checking the production sleeve, namely calculating the outward extrusion resistance strength of the production sleeve according to the residual strength after abrasion by adopting a tie-back well cementation mode of the production sleeve, and calculating the minimum reserved working pressure of the annular space A through the outward extrusion resistance strength of the production sleeve : (17) Wherein: -a minimum pre-set working pressure in annulus MPa; -producing the sleeve extrusion resistance strength, MPa; -producing a sleeve internal pressure strength safety factor of 1.125; -maximum mud density during drilling; -annulus protection fluid density, g/cm 3 ; -gravitational acceleration, m/s 2 ; -dangerous point depth, m; And checking the tail pipe and the tail pipe hanger, wherein the method for calculating the minimum reserved working pressure of the annulus A through the tail pipe and the tail pipe hanger is the same as that of the production casing.
6. The method for dynamically evaluating the integrity risk of a high-pressure gas well according to claim 1, wherein the obtaining an a-annulus pressure control range plate according to the maximum allowable band pressure value and the minimum reserved working pressure value of each part of the a-annulus comprises: Checking the tubing head, the downhole safety valve, the packer, the tubing string, the production casing, the liner hanger, the stratum and the liner to obtain the maximum allowable pressure value of the A annulus, and taking the minimum pressure value as the maximum allowable pressure value of the A annulus; Checking a downhole safety valve, a packer, a tubing string, a production sleeve, a tail pipe and a tail pipe hanger to respectively obtain a minimum reserved working pressure value of an A annulus, taking the maximum pressure value as the minimum reserved working pressure value of the A annulus, and obtaining a minimum reserved working pressure value curve of the A annulus according to different oil pressures under two working conditions of production and well closing; Obtaining an upper limit curve of recommended working pressure value of the annulus A by multiplying the maximum allowable zone pressure value of the annulus A by 80 percent, obtaining the maximum limit pressure value curve of the annulus A by the minimum value of the maximum allowable zone pressure value of the annulus A according to the calculated rated strength of each well barrier component of the annulus A; Obtaining an A annulus minimum reserved working pressure recommended lower limit value curve according to the larger of the A annulus minimum reserved working pressure value multiplied by 150% and 1.5MPa as the A annulus minimum reserved working pressure recommended lower limit value; and synthesizing the four curves to obtain the A annulus pressure control range plate under the production and well closing working conditions.
7. The method of claim 1, wherein the evaluating the well barrier status using a checklist evaluation using an a annulus pressure control range map and B, C, D annulus pressure control range, respectively evaluating the integrity of the formation, wellbore and wellhead barrier components, comprises: real-time monitoring A, B, C, D wellhead annular pressure numerical parameters; evaluating the well barrier state by a list type evaluation method according to the calculation result of the A, B, C, D annulus pressure control range, and respectively evaluating the integrity of stratum, shaft and wellhead barrier components; in the high wellhead pressure stage, if the oil pipe fails, the technical sleeve cannot be used as an independent well barrier because the oil pipe cannot bear high pressure, only one well barrier of the sleeve is produced, the risk is high, and the integrity grade of the marked evaluation well is high risk color; Along with the decrease of the formation pressure, the technical sleeve is used as a barrier to prevent oil gas leakage in the low wellhead pressure stage, two independent well barriers can be ensured, the risk is low, the high-risk color well meeting the conditions is degraded, and meanwhile, the original high-risk color well is restored to the well barrier through major repair, and the low-risk color is marked.
8. A high pressure gas well integrity risk dynamic assessment system, comprising: the pressure range acquisition module is used for acquiring the annular pressure control range of the high-pressure gas well B, C, D; the pressure range calculation module is used for obtaining a maximum allowable belt pressure value and a minimum reserved working pressure value of each part of the annulus A of the high-pressure gas well by checking the performance parameters of each part of the annulus A of the high-pressure gas well; obtaining a drawing plate of the control range of the annular pressure of the A annulus according to the maximum allowable belt pressure value and the minimum reserved working pressure value of each part of the A annulus; and the evaluation output module is used for evaluating the well barrier state by using the A annulus pressure control range chart and the B, C, D annulus pressure control range and adopting the inventory evaluation to evaluate the integrity of stratum, shaft and wellhead barrier components respectively.
9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of a high pressure gas well integrity risk dynamic assessment method according to any one of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of a method for dynamic evaluation of the integrity risk of a high pressure gas well according to any one of claims 1 to 7.

Description

High-pressure gas well integrity risk dynamic assessment method and related device Technical Field The invention belongs to the field of wellbore integrity risk assessment, and particularly relates to a high-pressure gas well integrity risk dynamic assessment method and a related device. Background The high-temperature and high-pressure gas well has the characteristics of deep well, high pressure and high temperature, has great challenge in well integrity management, has great risk of continuous production after the annular pressure of the high-temperature and high-pressure gas well is abnormal, and has the problems of high well repair cost and high operation difficulty if the well repair operation is fully carried out to remove potential safety hazards. Wellbore integrity management is a common management mode adopted by international oil companies, and is a solution for comprehensively applying technologies, operations and organization management to reduce risks of uncontrollable leakage of formation fluids from oil and gas wells in the whole life cycle. The core of well integrity management is well barrier and risk management, an orange well belongs to a medium-risk well, and production is monitored after risk reduction measures are adopted and emergency plans are formulated. However, as the field is developed, formation pressure decreases and risk decreases, and on-site management is still inconvenient according to the original integrity level. The essence of well integrity management is risk evaluation and management with well barrier components as cores, and risk dynamic management and control is to determine risk grades according to the current working conditions such as stratum pressure and the like by taking at least 2 independent barriers as a principle. Existing well barriers define a first well barrier that is limited to being composed of tubing, packers, etc., and a second well barrier that is composed of production casing, casing head, etc. According to the current well integrity classification principle, the failure of the oil pipe indicates the failure of the first well barrier, which is classified as orange, the actual pressure of the stratum is reduced, the oil pressure is reduced, and the risk of the gas well is dynamically changed. In the high wellhead pressure stage, after the oil pipe fails, the technical sleeve can not be used as an independent well barrier because the technical sleeve can not bear high pressure, only one barrier is produced, the risk is high, in the low wellhead pressure stage, the technical sleeve can be used as one barrier to prevent oil gas leakage, two independent well barriers can be ensured, the risk is low, degradation management can be realized, and the centralized strength on a production site is beneficial to well management of high risk. At present, well integrity management is basically static management, formation pressure is reduced along with gas field development, risk is reduced for an annular pressure abnormal well, and risk grade cannot be reasonably reduced according to original standard grading, so that the well integrity management does not accord with the actual situation of the site, and high-risk well management by concentrated force on the production site is not facilitated. Disclosure of Invention The invention aims to provide a dynamic evaluation method and a related device for the integrity risk of a high-pressure gas well, which are used for solving the problem of poor field management due to classification according to the original standard. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect, the present invention provides a method for dynamically evaluating the integrity risk of a high-pressure gas well, comprising: Acquiring an annulus pressure control range of the high-pressure gas well B, C, D; checking the performance parameters of all parts of the annular space A of the high-pressure gas well to obtain a maximum allowable belt pressure value and a minimum reserved working pressure value of all parts of the annular space A; obtaining a drawing plate of the control range of the annular pressure of the A annulus according to the maximum allowable belt pressure value and the minimum reserved working pressure value of each part of the A annulus; And evaluating the well barrier state by using the A annulus pressure control range chart and the B, C, D annulus pressure control range and adopting the list type evaluation to evaluate the integrity of stratum, shaft and wellhead barrier components respectively. Optionally, the obtaining the annulus pressure control range of the high-pressure gas well B, C, D includes: B. c, D the maximum allowable working pressure of the annulus is the minimum of a) 80% of the minimum outward extrusion resistance intensity of the whole annulus inner sleeve, b) 80% of the minimum internal destruction strength of the whole annulus outer sleeve,