CN-122020966-A - Method, device and storage medium for determining cause of well wall damage

CN122020966ACN 122020966 ACN122020966 ACN 122020966ACN-122020966-A

Abstract

The embodiment of the application provides a method, a device and a storage medium for determining a well wall damage reason, and belongs to the technical field of exploration drilling. The method comprises the steps of obtaining total radial normal stress, total circumferential normal stress and total axial normal stress according to temperature difference additional normal stress, seepage additional normal stress, hydration additional normal stress and preset initial normal stress, obtaining maximum well Zhou Zhu stress and minimum well Zhou Zhu stress according to total radial normal stress, total circumferential normal stress, total axial normal stress and preset initial axial-circumferential tangential stress, and determining damage reasons of a well wall according to maximum well Zhou Zhu stress, minimum well Zhou Zhu stress, total radial normal stress, total circumferential normal stress, total axial normal stress and initial axial-circumferential tangential stress. The application can improve the accuracy of the judgment result of the damage reason of the well wall.

Inventors

ZHANG HUI
Lv Kunhong
LI JUN
An Jintao
WANG XINRUI
YANG HONGWEI
LIAN WEI
ZHANG GENG

Assignees

中国石油大学(北京)

Dates

Publication Date: 20260512
Application Date: 20251226

Claims (10)

1. A method for determining a cause of a borehole wall failure, the method comprising: under the condition that a well wall is damaged, obtaining temperature difference additional normal stress of the well wall under the action of temperature difference, seepage additional normal stress under the action of seepage of drilling fluid and hydration additional normal stress under the action of hydration of the drilling fluid; Obtaining total normal stress according to the temperature difference additional normal stress, the seepage additional normal stress, the hydration additional normal stress and the preset initial normal stress of the well wall, wherein the total normal stress comprises total radial normal stress, total circumferential normal stress and total axial normal stress; Obtaining the maximum well Zhou Zhu stress of the well wall and the minimum well Zhou Zhu stress of the well wall according to the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the preset initial axial-circumferential tangential stress of the well wall; determining a failure cause of the borehole wall based on the maximum well Zhou Zhu stress, the minimum well Zhou Zhu stress, the total radial normal stress, the total circumferential normal stress, the total axial normal stress, and the initial axial-circumferential tangential stress.
2. The method of claim 1, wherein the predetermined initial normal stresses comprise a predetermined initial radial normal stress, a predetermined initial circumferential normal stress, and a predetermined initial axial normal stress, wherein the differential additional normal stresses comprise a differential radial normal stress, a differential circumferential normal stress, and a differential axial normal stress, wherein the additional normal stresses comprise a hydration radial normal stress, a hydration circumferential normal stress, and a hydration axial normal stress, wherein the total normal stress is derived from the differential additional normal stress, the additional normal stress, and the predetermined initial normal stress of the borehole wall, and wherein the method comprises: Determining a sum of the predetermined initial radial normal stress, the differential radial normal stress, the seepage radial normal stress and the hydration radial normal stress to obtain the total radial normal stress; Determining a sum of the predetermined initial circumferential normal stress, the differential circumferential normal stress, the seepage circumferential normal stress and the hydration circumferential normal stress to obtain the total circumferential normal stress; and determining the sum of the predetermined initial axial normal stress, the temperature difference axial normal stress, the seepage axial normal stress and the hydration axial normal stress to obtain the total axial normal stress.
3. The method of claim 1, wherein deriving the maximum well Zhou Zhu stress for the borehole wall and the minimum well Zhou Zhu stress for the borehole wall from the total radial normal stress, the total circumferential normal stress, the total axial normal stress, and a predetermined initial axial-circumferential tangential stress for the borehole wall comprises: obtaining a first normal stress, a second normal stress and a third normal stress according to the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the initial axial-circumferential tangential stress; And determining the maximum value and the minimum value of the first positive stress, the second positive stress and the third positive stress to obtain the maximum well Zhou Zhu stress of the well wall and the minimum well Zhou Zhu stress of the well wall respectively.
4. A method according to claim 3, wherein deriving the first, second and third normal stresses from the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the initial axial-circumferential tangential stress comprises determining according to the following formula: Wherein, the For the first positive stress to be present, For the second positive stress to be present, For the third positive stress to be present, For the total circumferential positive stress to be described, For the total circumferential positive stress to be described, For the total axial positive stress, alpha is a preset effective stress coefficient, In order to achieve the formation pore pressure, Is said initial axial-circumferential tangential stress.
5. The method of claim 1, wherein the determining a cause of the damage to the borehole wall based on the maximum well Zhou Zhu stress, the minimum well Zhou Zhu stress, the total radial normal stress, the total circumferential normal stress, the total axial normal stress, and the predetermined initial axial-circumferential shear stress comprises: Acquiring weak face dip angles and weak face trends corresponding to a plurality of weak faces of rock around a well wall respectively; Obtaining an upper limit included angle and a lower limit included angle between each weak face trend and the maximum well Zhou Zhu stress according to the maximum well Zhou Zhu stress and the minimum well Zhou Zhu stress, wherein the upper limit included angle and the lower limit included angle form a weak face included angle interval; Respectively obtaining actual weak face included angles between each weak face tendency and the maximum well Zhou Zhu stress according to the initial axial-circumferential tangential stress, the total circumferential normal stress, the total axial normal stress and a plurality of weak face inclination angles; and obtaining the damage reason of the well wall according to the actual weak face included angles respectively corresponding to the weak face trends and the weak face included angle intervals respectively corresponding to the weak face trends.
6. The method according to claim 5, wherein the obtaining the damage cause of the well wall according to the actual weak face included angles respectively corresponding to the weak face tendencies and the weak face included angle intervals respectively corresponding to the weak face tendencies includes: and under the condition that at least one actual weak face included angle exists in the actual weak face included angles and is located in the corresponding weak face included angle interval, determining that the damage of the well wall is caused by weak face shearing damage of rocks around the well wall.
7. The method according to claim 5, wherein the obtaining the damage cause of the well wall according to the actual weak face included angles respectively corresponding to the weak face tendencies and the weak face included angle intervals respectively corresponding to the weak face tendencies includes: And under the condition that no actual weak face included angle exists in the actual weak face included angles and is located in the corresponding weak face included angle interval, determining that the damage of the well wall is caused by the shearing damage of the body of rock around the well wall.
8. An apparatus for determining the cause of a borehole wall failure, comprising: A memory configured to store instructions, and A processor configured to invoke the instructions from the memory and when executing the instructions is capable of implementing the method for determining a cause of borehole wall damage according to any of claims 1 to 7.
9. A machine-readable storage medium having stored thereon instructions for causing a machine to perform the method for determining the cause of a borehole wall failure according to any of claims 1 to 7.
10. A computer program product comprising a computer program, characterized in that the computer program, when executed by a processor, implements the method for determining the cause of a borehole wall failure according to any of claims 1 to 7.

Description

Method, device and storage medium for determining cause of well wall damage Technical Field The invention relates to the technical field of exploration drilling, in particular to a method, a device and a storage medium for determining a well wall damage reason. Background The special engineering geological conditions lead the well wall damage of coal and rock to become a worldwide technical problem, and the problems are mainly manifested in collapse or spalling of the well wall, further pressure holding and drill sticking, even the scrapping of the well engineering is caused when serious, and huge economic loss is caused. At present, the prior art mainly carries out judgment of the damage reason of the well wall by establishing a ground stress calculation model and a three-dimensional finite element numerical simulation means of the well wall crack, however, most of parameters used in the actual modeling process are preset values, the actual working condition is not considered, and the accuracy of the judgment result of the damage reason of the well wall can be reduced. Therefore, the prior art has the problem that the accuracy of the judgment result of the damage reason of the well wall is not high. Disclosure of Invention An object of the embodiments of the present application is to provide a method, an apparatus, a storage medium and a computer program product for determining a cause of a borehole wall damage, so as to solve the problem of inaccurate determination of the cause of the borehole wall damage in the prior art. To achieve the above object, an embodiment of a first aspect of the present application provides a method for determining a cause of a wall damage, the method including: Under the condition that the well wall is damaged, obtaining temperature difference additional normal stress of the well wall under the action of temperature difference, seepage additional normal stress under the action of seepage of drilling fluid and hydration additional normal stress under the action of hydration of the drilling fluid; obtaining total normal stress according to the temperature difference additional normal stress, the seepage additional normal stress, the hydration additional normal stress and the pre-determined initial normal stress of the well wall, wherein the total normal stress comprises total radial normal stress, total circumferential normal stress and total axial normal stress; obtaining the maximum well Zhou Zhu stress of the well wall and the minimum well Zhou Zhu stress of the well wall according to the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the initial axial-circumferential tangential stress of the well wall which are predetermined; And determining the damage reason of the well wall according to the maximum well Zhou Zhu stress, the minimum well Zhou Zhu stress, the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the initial axial-circumferential tangential stress. In the embodiment of the application, the pre-determined initial normal stress comprises a pre-determined initial radial normal stress, a pre-determined initial circumferential normal stress and a pre-determined initial axial normal stress, the temperature difference additional normal stress comprises a temperature difference radial normal stress, a temperature difference circumferential normal stress and a temperature difference axial normal stress, the seepage additional normal stress comprises a seepage radial normal stress, a seepage circumferential normal stress and a seepage axial normal stress, the hydration additional normal stress comprises a hydration radial normal stress, a hydration circumferential normal stress and a hydration axial normal stress, the total normal stress is obtained according to the temperature difference additional normal stress, the seepage additional normal stress, the hydration additional normal stress and the pre-determined initial normal stress of a well wall, the total normal stress is obtained by determining the sum of the pre-determined initial radial normal stress, the temperature difference radial normal stress, the seepage radial normal stress and the hydration radial normal stress to obtain the total radial normal stress, the total circumferential normal stress, the sum of the temperature difference normal stress, the seepage circumferential normal stress and the hydration circumferential normal stress to obtain the total circumferential normal stress, and the total normal stress. In the embodiment of the application, the maximum well Zhou Zhu stress of the well wall and the minimum well Zhou Zhu stress of the well wall are obtained according to the total radial normal stress, the total circumferential normal stress, the total axial normal stress and the initial axial-circumferential tangential stress of the well wall, the first normal stress, the second normal stress a