WO2022057947A1

WO2022057947A1 - Device and method for active measurement of cross-fault interface newton force in shale gas mining process

Info

Publication number: WO2022057947A1
Application number: PCT/CN2021/122372
Authority: WO
Inventors: 陶志刚; 施婷婷; 马高通; 明伟; 何满潮
Original assignee: 中国矿业大学(北京)
Priority date: 2021-04-26
Filing date: 2021-09-30
Publication date: 2022-03-24
Also published as: CN113187471B; LU501939B1; CN113187471A

Abstract

A device for active measurement of cross-fault interface Newton force in a shale gas mining process, comprising an NPR anchor cable (1) and at least one pair of measurement assemblies (2) symmetrically sleeved on the NPR anchor cable. The measurement assemblies comprise a platform mechanism (21), an squeezing mechanism (22), a constant resistance mechanism (23) and a sensing mechanism (24). Further disclosed is a method for active measurement of cross-fault interface Newton force in a shale gas mining process, the specific steps being: acquiring at least one pair of symmetrically arranged measurement assemblies and inserting same into a rock hole so that each pair of symmetrically arranged measurement assemblies are respectively located on two sides of a rock fault, and measuring in real time key parameters influencing fault stability. The device and the method for measurement is able to, for identified hazard faults, accurately and constantly collect in real time the key parameters influencing fault stability on the cross-fault interface in a fracturing process of the hazard fault, and thus providing data support for the prediction of disasters.

Description

Device and method for active measurement of Newtonian force across fault interface during shale gas production

technical field

The invention belongs to the field of shale gas exploitation and cross-fault interface Newton force monitoring, and in particular relates to an active measurement device and method for cross-fault interface Newton force in the process of shale gas exploitation.

Background technique

Hydraulic fracturing is an important method for the efficient development of shale gas with wide application prospects. When the velocity exceeds the absorption capacity of the oil layer, a very high pressure is formed on the bottom hole oil layer. When this pressure exceeds the fracture pressure of the oil layer rock near the bottom hole, the oil layer will be pushed open and fractures will occur. In the actual process of hydraulic fracturing, the microseismic monitoring of rock formations is very important, which is directly related to the fracturing effect of hydraulic fracturing. At the same time, earthquake disasters related to hydraulic fracturing have become more frequent in recent years. Different from the tectonic stable large plate shale gas in North America, my country's shale gas reserves are mainly concentrated in the Sichuan Basin, the Chongqing-Hubei-Hubei-Guizhou-Guangxi area and other complex mountainous areas in the south. Strong reformation, showing the obvious geological characteristics of "strong reformation, over-mature, high stress" mountain shale gas. Under the geological environment of mountain shale gas, the construction pressure of hydraulic fracturing is higher, resulting in more frequent and intense geological disasters such as earthquakes.

Therefore, accurate monitoring and early warning of earthquake disasters induced by hydraulic fracturing of mountainous shale gas is a key problem in the national shale gas energy strategy.

At present, the monitoring of earthquake disasters induced by shale gas hydraulic fracturing mostly adopts microseismic monitoring technology. Microseismic monitoring technology is a high-tech information-based dynamic monitoring technology for underground engineering. It collects and collects seismic wave signals emitted by rock mass failure or rock rupture through sensors, and at the same time processes and analyzes the seismic wave signals, so as to obtain the seismic signal. Information such as location, magnitude, energy, and seismic moment has become the preferred monitoring technology for underground geological structure detection.

However, since the microseismic monitoring sensors used in the existing microseismic monitoring system are all installed underground, the following problems exist in the actual use process:

1) The installation of the microseismic monitoring sensor is difficult, the installation method is complex, time-consuming and labor-intensive, and the installation cost is high;

2) The installation quality is difficult to guarantee, and the installed sensors are easy to fall off, which affects the normal monitoring process of the microseismic monitoring system;

3) Because the microseismic monitoring sensor is located below the ground, the long-distance transmission of its signal causes large signal attenuation, thus affecting the monitoring accuracy;

4) Microseismic monitoring lacks the monitoring of key factors such as stress and strain in the internal mechanism of fault activation and disaster generation, and the accuracy of disaster prediction is limited.

Therefore, how to make the active measurement of Newtonian force across the fault interface in shale gas production have low cost, high precision, good quality, and high accuracy of fault activation and disaster detection, which has become an important problem to be solved urgently.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an active measuring device for the Newton force across the fault interface in the process of shale gas exploitation, and a method for measuring the Newton force across the fault interface in the process of shale gas exploitation by using the device, so as to solve the problem in the prior art of shale gas exploitation. Among them, the active measurement of the Newtonian force across the fault interface has the technical problems of high cost, low accuracy, unguaranteed quality, and limited accuracy of fault-activated disaster-pregnancy detection.

In order to achieve the above purpose, the present invention provides the following technical solutions: an active Newtonian force measurement device across a fault interface in the process of shale gas exploitation, the measurement device includes an NPR anchor cable and at least a pair of measurement components symmetrically sleeved on the NPR anchor cable;

Measurement components include platform mechanism, extrusion mechanism, constant resistance mechanism and sensing mechanism;

A through hole is arranged in the vertical direction of the platform mechanism, and a hole is arranged on the side wall of the platform mechanism;

One side of the extrusion mechanism is fixedly connected with an elastic unit, the extrusion mechanism and the platform mechanism can be detached and connected through the elastic unit and the hole, and the other side of the extrusion mechanism is provided with a friction part with uneven surface;

The constant resistance mechanism includes an NPR constant resistance body and a sleeve; a chuck with a through hole is fixed in the middle of the sleeve, and the NPR constant resistance body is movably connected to the sleeve above the chuck; the NPR anchor cable passes through the NPR constant resistance body It is anchored with the NPR constant resistance body, and the constant resistance mechanism is fixedly connected to the inside of the through hole of the platform mechanism through the sleeve;

The sensing mechanism is fixedly sleeved outside the sleeve below the chuck; the platform mechanism is fixedly sleeved outside the sleeve through the through hole; the platform mechanism is located below the sensing mechanism, and the sensing mechanism is located between the chuck and the platform mechanism.

The active measurement method of the Newton force across the fault interface in the process of shale gas production, the steps are as follows:

S1, drill a hole in the rock, and drill through both sides of the cross-fault interface;

S2, insert the measuring device into the borehole, and arrange the measuring components symmetrically sleeved on the NPR anchor cable on both sides of the rock cross-fault interface, and the sensing mechanism in the measuring device detects the influence of the active fault sliding in real time A key parameter of fault stability.

Beneficial effects:

1. The cross-fault interface Newtonian force active measuring device of the present invention is provided with a friction component, and the protrusion matches the inner diameter of the first hole or the second hole, so that the extrusion mechanism, the platform mechanism and the hole wall of the rock hole are three There is no relative slip between them, which lays the foundation for accurate and precise measurement of the Newton force across the fault interface in shale gas production.

2. The measurement method of the present invention can accurately collect the key parameters (ie Newton force) affecting the stability of the fault on the cross-fault interface during the fracturing process for the identified dangerous faults, so as to predict the disaster. Provide data support.

Description of drawings

1 is a schematic structural diagram of an active measuring device for Newtonian force across a fault interface in shale gas exploitation in Example 1;

Fig. 2 is the structural representation of the measuring assembly in the embodiment 1;

Fig. 3 is the structural representation of the platform mechanism in the embodiment 1;

FIG. 4 is a schematic structural diagram of the extrusion mechanism in Example 1

5 is a schematic structural diagram of a constant resistance mechanism in Embodiment 1;

6 is a schematic cross-sectional structure diagram of the constant resistance mechanism in Embodiment 1;

7 is a schematic structural diagram of the NPR anchor cable and one of the measurement assemblies in Embodiment 1;

8 is a schematic diagram of the position of the measurement component in Example 2 when actively measuring the Newton force across the fault interface in shale gas production;

FIG. 9 is a schematic diagram of the position structure without relative slip when the Newton force across the fault interface is actively measured during shale gas production in Example 2. FIG.

In the figure: 1. NPR anchor cable, 2. Measuring assembly, 21, Platform mechanism, 22, Extrusion mechanism, 23, Constant resistance mechanism, 24, Sensing mechanism, 211, Through hole, 212, First hole, 213, The second hole, 221, protrusion, 222, friction part, 2221, elastic unit, 231, NPR constant resistance body, 232, sleeve, 2321, chuck, 3, fault, 4, rock, 5, hole wall.

detailed description

Example 1:

As shown in Figure 1 to Figure 9, the active Newton force measurement device across the fault interface in the process of shale gas production is shown in Figure 1:

The measuring device comprises NPR anchor cable 1 and a pair of measuring components 2 symmetrically sleeved on the NPR anchor cable 1;

As shown in FIG. 2 , the measurement assembly 2 includes a platform mechanism 21 , a pressing mechanism 22 , a constant resistance mechanism 23 and a sensing mechanism 24 ;

As shown in FIG. 3 , the platform mechanism 21 is provided with a through hole 211 in the vertical direction, the left portion of the platform mechanism 21 is provided with a first hole 212, and the right portion of the platform mechanism 21 is provided with a second hole 213; The two holes 213 are both cylindrical holes, and the size and length of the two holes are equal.

As shown in FIG. 4 , a protrusion 221 is fixed on one side of the extrusion mechanism 22, and a burr-shaped friction member 222 is fixed on the other side. The friction member 222 is made of rubber or metal (such as iron or steel), so that the friction member 222 has a certain friction force and ensures that the friction part 222 has a certain degree of wear resistance. The contact surface of the friction part 222 and the hole wall 5 adopts super friction material, which can ensure that the extrusion mechanism 22 and the hole wall do not have relative displacement; bulge 221 is fixedly connected with an elastic unit 2221; the elastic unit 2221 is a spring; there are two extrusion mechanisms 22, and the two extrusion mechanisms 22 are symmetrically arranged on both sides of the platform mechanism 21, specifically, the two springs are located in the first In the hole 212 and the second hole 213, and the spring is in a pre-compressed state, the setting of the pre-compressed spring is convenient for placing the Newton force measuring device into the hole, and cooperates with the extrusion mechanism 22 to tightly connect the Newton force measuring device with the surrounding rock. .

The protrusion 221 matches the inner diameter of the first hole 212 or the second hole 213, and the length of the protrusion 221 is smaller than the inner length of the first hole 212 or the second hole 213, so that the spring fixed on the protrusion 221 is in a predetermined position. compressed state.

The two sides of the platform mechanism 21 are symmetrically connected to the pressing mechanism 22 detachably, and the protrusion 221 is inserted into the first hole 212 or the second hole 213; At the end of the hole (that is, the end away from the orifice of the hole); the extrusion mechanism 22 and the platform mechanism 21 do not slide up and down; specifically, one end of a high-strength elastic unit 2221 (such as a spring) is installed on the protrusion 221 , and one end is compressed against the end of the first hole 212 or the second hole 213 to ensure that the pressing mechanism 22 and the platform mechanism 21 do not slide up and down.

As shown in FIG. 5 and FIG. 6 , the constant resistance mechanism 23 includes an NPR constant resistance body 231 and a sleeve 232 . Specifically, the NPR constant resistance body 231 is a truncated cone-shaped constant resistance body with a through hole, and the size of the through hole is the same as that of the NPR. The thickness of the anchor cable 1 is matched to prevent the NPR anchor cable 1 from shaking in the through hole; the sleeve 232 is fixedly provided with a chuck 2321 with a through hole, and the NPR constant resistance body 231 is detachably connected to the sleeve 232. Above chuck 2321.

As shown in FIG. 7 , the NPR anchor cable 1 passes through the through hole of the NPR constant resistance body 231 and is anchored to the NPR constant resistance body 231 , so that the NPR anchor cable 1 and the through hole of the NPR constant resistance body 231 are always fixedly connected, preventing the The relative displacement of its sound; the sensing mechanism 24 is fixedly sleeved under the chuck 2321 outside the sleeve 232. Specifically, the sensing mechanism 24 is a group of extruding static force sensors, which can convert the Newton generated after the chuck 2321 is stressed. The force is remotely transmitted by the static force sensor group; the platform mechanism 21 is fixedly sleeved outside the sleeve 232 through the through hole 211 ; the platform mechanism 21 is located below the sensing mechanism 24 .

Example 2:

Adopt the Newton force active measuring device of embodiment 1 to measure the Newton force across the fault interface in shale gas exploitation, and the specific steps are as follows:

S2, insert the measuring device into the borehole, and arrange the measuring components symmetrically sleeved on the NPR anchor cable on both sides of the rock cross-fault interface, and the sensing mechanism in the measuring device detects the influence of the active fault sliding in real time Newtonian force for fault stability.

Specifically, in shale gas exploitation, holes are opened in advance for the identified dangerous faults, and the pairs of symmetrically arranged measurement components 2 of Example 1 are connected in series on an NPR anchor cable 1, and the symmetrically arranged measurement components are connected in series. 2. Make the orientation of the measuring components 2 different, so as to prevent the constant resistance mechanism 23 from acting on the measuring components 2 with the same orientation, so as to improve the measurement accuracy; insert them into the pre-opened holes of the rock, as shown in FIG. The symmetrically arranged measurement components 2 are located on both sides of the fault 3 respectively; the Newton force can be collected in real time without interruption, and the series method has the advantage of point domain monitoring.

As shown in FIG. 9 , the friction member 222 of the extrusion mechanism 22 is brought into contact with the wall surface of the hole wall 5 of the hole on the rock 4. Since the contact surface between the friction member 222 and the hole wall 5 is made of super friction material, and the protrusion 221 and the first The inner diameter of the hole 212 or the second hole 213 is matched, and there is no relative sliding between the pressing mechanism 22 , the platform mechanism 21 and the hole wall 5 of the hole.

When a disaster occurs, the active fault 3 slides, which in turn drives the NPR constant resistance body 231 anchoring the NPR anchor cable 1 to displace in the sleeve 232. When the NPR constant resistance body 231 is subjected to the sliding of the active fault 3, the Newton force ( When the tension force) is greater than the friction force between it and the sleeve 232, the NPR anchor cable 1 slides along the sleeve 232 with the NPR constant resistance body 231 or displaces in the sleeve 232; then the NPR constant resistance body 231 squeezes the chuck 2321 is subjected to force, and the variable force is transmitted remotely by the sensing mechanism 24, and the measurement is completed.

To sum up, the friction member 222 is provided in the active Newtonian force measurement device of the present invention, and the protrusion 221 matches the inner diameter of the first hole 212 or the second hole 213, so that the extrusion mechanism 22, the platform mechanism 21 and the rock There is no relative sliding between the hole walls 5 of the holes, which lays the foundation for accurate and accurate measurement of the Newton force across the fault interface in shale gas exploitation; the Newton force active measurement device of the present invention can continuously collect the Newton force generated by the displacement of the active fault 3 in real time. The method in which multiple pairs of symmetrically arranged measurement components 2 are connected in series on one NPR anchor cable 1 has the advantages of point domain monitoring.

Claims

In the process of shale gas exploitation, an active measurement device for cross-fault interface Newtonian force is characterized in that, the measurement device comprises an NPR anchor cable and at least a pair of measurement components symmetrically sleeved on the NPR anchor cable;

The measurement assembly includes:

a platform mechanism, the vertical direction of the platform mechanism is provided with a through hole, and the side wall of the platform mechanism is provided with a hole;

A pressing mechanism, one side of the pressing mechanism is fixedly connected with an elastic unit, the pressing mechanism is detachably connected to both sides of the platform mechanism through the elastic unit and the hole, and the other side of the pressing mechanism is One side is provided with friction parts with uneven surface;

A constant resistance mechanism, the constant resistance mechanism includes an NPR constant resistance body and a sleeve; a chuck with a through hole is fixed in the middle of the sleeve, and the NPR constant resistance body is movably connected above the chuck In the sleeve, the NPR anchor cable passes through the NPR constant resistance body and is anchored with the NPR constant resistance body, and the constant resistance mechanism is fixedly connected to the inside of the through hole of the platform mechanism through the sleeve;

a sensing mechanism, the sensing mechanism is fixedly sleeved outside the sleeve below the chuck; the platform mechanism is fixedly sleeved outside the sleeve through the through hole, and the platform mechanism is located at Below the sensing mechanism, the sensing mechanism is located between the chuck and the platform mechanism.
The device for active measurement of Newtonian force across a fault interface during shale gas exploitation according to claim 1, wherein a protrusion is provided on one side of the extrusion mechanism, and an elastic unit is fixedly connected to the protrusion.
The device for active measurement of Newtonian force across a fault interface during shale gas production as claimed in claim 2, wherein there are two extrusion mechanisms, and a first hole is provided on the left side wall of the platform mechanism , the right side wall of the platform mechanism is provided with a second hole, and the two extrusion mechanisms are detachably connected to the first hole and the second hole respectively through the elastic unit.
The device for active measurement of Newtonian force across a fault interface during shale gas production as claimed in claim 3, wherein the bulge matches the inner diameter of the first hole or the second hole, and the length of the bulge matches the inner diameter of the first hole or the second hole. smaller than the inner length of the first hole or the second hole.
The device for active measurement of Newtonian force across a fault interface during shale gas production according to claim 3, wherein the protrusion is inserted into the first hole or the second hole, and the free end of the elastic unit is is located at the end of the first hole or the second hole.
The device for active measurement of Newtonian force across a fault interface during shale gas production as claimed in claim 1, wherein the friction member is burr-shaped.
The device for active measurement of Newtonian force across a fault interface during shale gas production according to claim 1, wherein the elastic unit is a spring or rubber.
The active measurement method of Newton force across the fault interface in shale gas production, the steps are as follows:

S1, drill a hole in the rock, and the drill hole runs through both sides of the cross-fault interface;

S2, insert the measuring device into the borehole, and arrange the measuring components symmetrically sleeved on the NPR anchor cable on both sides of the rock cross-fault interface, and detect the active fault in real time by the sensing mechanism in the measuring device Slip-generated key parameters affecting fault stability.
The method for actively measuring the Newtonian force across a fault interface during shale gas production according to claim 8, wherein the measuring device is a cross-fault interface during shale gas production according to any one of claims 1 to 7. Newtonian force active measuring device.
The method for active measurement of Newtonian force across a fault interface in shale gas production according to claim 8, wherein the key parameter is Newtonian force.