CN-122016632-A - Simulation test device and method for observing deformation of well wall in gas drilling process of coal rock

CN122016632ACN 122016632 ACN122016632 ACN 122016632ACN-122016632-A

Abstract

The invention provides a simulation test device and a simulation test method for observing the deformation of a well wall in a gas drilling process, which belong to the technical field of gas drilling and comprise a base, a first hydraulic cylinder, a second hydraulic cylinder, a test box body, a coal and rock sample for test, a drilling fluid box, a controller, a lifter and an ultrasonic imaging control system; the coal and rock sample for test is positioned in the test box body; the coal rock sample for the test is internally provided with a simulated well drilling; the device truly simulates the drilling process, tests the deformation of surrounding rock of the well wall and provides a certain theoretical support for the prediction of the collapse period of the well wall and the optimal design of drilling fluid.

Inventors

ZHANG XIAOPING
GUO KANG
WANG JINGGUANG
DING LEI
XU CHAOYANG
JIA JUN
ZHAO HAIFENG
CHEN LEI
CAO HUI
SU HUAN

Assignees

中国石油天然气集团有限公司
中国石油集团川庆钻探工程有限公司

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (10)

1. The simulation test device for observing the deformation of the well wall in the coal and rock gas drilling process is characterized by comprising a base (1), a first hydraulic cylinder (3), a second hydraulic cylinder (4), a test box body (5), a coal and rock sample for test (6), a drilling fluid box (7), a controller (12), a lifter (13) and an ultrasonic imaging control system (14), wherein the coal and rock sample for test (6) is positioned in the test box body (5), and a simulation drilling well (21) is arranged in the coal and rock sample for test (6); The simulated drilling machine is characterized in that a simulated drilling rod (22) is arranged in the simulated drilling machine (21), an ultrasonic probe assembly is arranged in the simulated drilling rod (22), the ultrasonic probe assembly is electrically connected with an ultrasonic imaging control system (14) outside a test box body (5), the upper end of the ultrasonic probe assembly is connected with a lifter (13) outside the test box body (5), a gyrator (19) is arranged on the simulated drilling machine (21), the lifter (13) and the gyrator (19) are electrically connected with a controller (12), and the annular space between the simulated drilling rod (22) and the ultrasonic probe assembly and the annular space between the simulated drilling rod (22) and the simulated drilling machine (21) are communicated with a drilling fluid box (7); The test box body (5) is located above the base (1), two adjacent side faces and the bottom face of the test coal rock sample (6) are respectively provided with a horizontal direction pressure plate (23) and a vertical direction pressure plate (24), the horizontal direction pressure plate (23) and the vertical direction pressure plate (24) are respectively connected with the base (1) through a first hydraulic cylinder (3) and a second hydraulic cylinder (4) which are located outside the test box body (5) and correspond to each other, other faces of the test coal rock sample (6) are provided with fixing plates (28), and the base (1) is fixedly connected with the fixing plates (28) in the test box body (5) through fixing plate supports.
2. The simulation test device for observing the deformation of the well wall in the gas drilling process of coal and rock is characterized in that the ultrasonic probe assembly comprises an ultrasonic probe connecting pipe column (27) and an ultrasonic probe (25), the ultrasonic probe (25) is arranged at the inner bottom end of the ultrasonic probe connecting pipe column (27), and the ultrasonic probe (25) is electrically connected with an ultrasonic imaging control system (14) outside the test box body (5) through an ultrasonic probe cable (26) arranged in the ultrasonic probe connecting pipe column (27).
3. The simulation test device for observing the deformation of the well wall in the gas drilling process of the coal rock is characterized in that a lifting ring (17) is arranged at the top of the ultrasonic probe connecting pipe column (27), and the lifting ring (17) is connected with a lifter (13) outside the test box body (5).
4. The simulation test device for observing the deformation of the well wall in the gas drilling process of the coal rock is characterized in that the gyrator (19) is positioned above the coal rock sample (6) for testing and is fixed on a fixing plate (28) at the top through a gyrator bracket, a second bearing (20) is arranged on the contact surface of the simulation drill rod (22) and the fixing plate (28) at the top, and a first bearing (18) is arranged between the top of the simulation drill rod (22) and an ultrasonic probe connecting tubular column (27).
5. The simulation test device for observing the deformation of the well wall in the gas drilling process of the coal rock is characterized in that a heating device (16) is arranged in the test box body (5), and the heating device (16) is electrically connected with a temperature controller (15) positioned in the test box body (5).
6. The simulation test device for observing the deformation of the well wall in the gas drilling process of the coal rock is characterized in that an annular space between the ultrasonic probe assembly and the simulation drill rod (22) is communicated with a drilling fluid tank (7) through a drilling fluid injection pipeline (11), an annular space between the simulation drilling well (21) and the simulation drill rod (22) is communicated with the drilling fluid tank (7) through a flushing fluid outflow pipeline (9), a pump (10) is arranged on the drilling fluid injection pipeline (11), and a control valve (8) is arranged on the flushing fluid outflow pipeline (9).
7. The method for testing the simulation test device for observing the deformation of the well wall in the gas drilling process of any one of the coal rock according to the claims 1-6 is characterized by comprising the following specific steps: firstly, processing coal and rock for test into a coal and rock sample (6) for test, which meets the test requirement in standard specification, and opening a simulated drilling hole at the top of the coal and rock sample for test to form a simulated drilling hole (21), wherein the simulated drilling hole does not penetrate through the coal and rock sample (6) for test; placing the coal rock sample (6) for test in a pressure plate of a test box body (5), setting the pressures of a horizontal pressure plate (23) and a vertical pressure plate (24) according to actual stress, and lowering a simulation drill rod (22) with an ultrasonic probe assembly into a simulation drilling well (21) of the coal rock sample; Step three, well configuring drilling fluid for test in the drilling fluid box (7) and connecting a drilling fluid injection pipeline (11) with a flushing fluid outflow pipeline (9), and starting a heating device (16) to enable the temperature in the test box body (5) to be the same as the temperature of the original horizon of the coal rock; Step four, a pump (10) is opened to circulate drilling fluid, a gyrator (19) is opened to drive a simulation drill rod (22) to gyrate to simulate the drilling process, and meanwhile, the opening degree of a control valve (8) is adjusted, so that the circulating pressure of the drilling fluid is adjusted, and different drilling fluid pressures are simulated; Step five, after the setting time of the simulated drilling process, the simulated drill rod (22) stops rotating, drilling fluid stops circulating, the lifter (13) starts to lift the simulated drill rod (22) and the ultrasonic probe assembly in the well, ultrasonic imaging of surrounding rock of the well wall is completed in the lifting process, full well section imaging is completed after lifting to the position, and then the well section imaging is lowered to the initial position; step six, starting the pump (10) again to circulate drilling fluid, starting the gyrator (19) to drive the drill rod to revolve, and simulating the drilling process; Step seven, repeating the two-stage test process of the step five and the step six, so as to obtain the ultrasonic imaging data of the well wall with each interval of set time length; and step eight, after the test is finished, the data are exported and subjected to post-processing, so that the relation of the deformation of the surrounding rock of the well wall along with the time is obtained and is used for predicting the collapse period of the well wall.
8. The method for simulating the observation of the deformation of the well wall in the coal and rock drilling process according to claim 7, wherein the method is characterized in that the influence test of the performance parameter of the drilling fluid on the deformation of the well wall is obtained by using the drilling fluid without the performance parameter to conduct the test of the relation of the deformation of the well wall with time, so as to optimize the performance parameter of the drilling fluid.
9. The method for observing and simulating the deformation of the well wall in the coal and rock drilling process according to claim 7 is characterized in that the relation of the deformation of the well wall with time is tested by applying different ground stresses, the relation of the deformation of the well wall with time under different pressures is obtained, and the rule test of the influence of the stress on the deformation of the well wall is obtained.
10. The simulation test method for observing the deformation of the well wall in the coal and rock drilling process according to claim 7 is characterized in that the test of the relation of the deformation of the well wall along with time is carried out by setting different temperatures in an experimental box body (5), and the rule test method for the influence of the temperature on the deformation of the well wall is obtained.

Description

Simulation test device and method for observing deformation of well wall in gas drilling process of coal rock Technical Field The invention belongs to the technical field of downhole tools for sealing in drilling and completion in petroleum industry, and particularly relates to a simulation test device and a test method for observing borehole wall deformation in a gas drilling process. Background Along with the continuous increase of the development force of coal and rock gas, the drilling engineering of deep wells and complex wells is more and more. In the drilling process, drilling fluid is injected from the center of the drill rod, and plays roles of carrying rock scraps, cooling the drill bit, protecting the hole wall and the like from the annular gap between the drill rod and the well wall to the ground. In the process of circulating drilling fluid in a shaft, the drilling fluid entering the shaft can permeate into the shaft wall under the action of pressure, when the surrounding rock of the shaft wall has more water-absorbing minerals, the shaft wall can generate expansion deformation after absorbing water, particularly when the surrounding rock of the shaft wall has certain cracks, the invasion of the drilling fluid can cause the shaft wall to generate larger deformation, and the shaft wall can collapse when serious, so that the shaft wall is in a shaft accident, the shaft wall collapse can seriously influence the drilling efficiency, and larger manpower and material resource losses are caused. The deformation of the well wall under the action of the drilling fluid is continuous, and the deformation of the well wall under the action of different types of drilling fluids is different. Therefore, proper drilling fluid is selected according to different surrounding rock characteristics of the well wall, and it is important to reduce deformation of the well wall and avoid collapse of the well wall. The invention discloses a model test device and a test method for freezing a vertical shaft with cooperative and adjustable ground stress and water head, and relates to the field of model test in a manual freezing process, in particular to a model test device for freezing a vertical shaft with cooperative and adjustable ground stress and water head and a test method thereof, wherein the device comprises a model test box, a water head height-adjustable water source box, a small spiral freezer and a bidirectional loading device, and the concrete steps are as follows, S1, the test device is connected; S2, layering sample loading of a model test box, synchronous burying of a monitoring system, S3, installation of a small spiral freezer, S4, adjustment of a bidirectional loading device, S5, water supply, S6, starting of a freezing test, S7, application of external load, S8, stopping of the test when deformation of a shaft wall is overlarge or damage occurs, and simulation of deformation characteristics of the frozen shaft wall in the freezing construction process of a sandy stratum shaft is achieved through an indoor model test method. The existing device is single, can not accurately evaluate the well wall deformation in the drilling process, and can not simulate the real drilling working condition. Aiming at the situation, the invention designs an indoor test device capable of truly simulating the observation of the deformation of the well wall under the drilling condition, thereby obtaining the relation of the deformation of the well wall along with time, predicting the collapse period of the well wall, and optimizing a proper drilling fluid system to reduce the deformation of the well wall. Disclosure of Invention In order to solve the problems that the existing device is single and can not accurately evaluate the deformation of the well wall in the drilling process and can not simulate the real drilling working condition, the invention provides the simulation test device and the test method for observing the deformation of the well wall in the gas drilling process. The invention adopts the technical scheme that: the simulation test device for observing the deformation of the well wall in the coal gas drilling process comprises a base, a first hydraulic cylinder, a second hydraulic cylinder, a test box body, a coal and rock sample for test, a drilling fluid box, a controller, a lifter and an ultrasonic imaging control system, wherein the coal and rock sample for test is positioned in the test box body; the simulation drilling well is internally provided with a simulation drill rod, an ultrasonic probe assembly is arranged in the simulation drill rod, and the ultrasonic probe assembly is electrically connected with an ultrasonic imaging control system outside the test box body; the upper end of the ultrasonic probe assembly is connected with a lifter outside the test box body, the simulated drilling well is provided with a gyrator, and the lifter and the gyrator are both in electric signal connection with the co