Filtering device in crustal stress measurement process

Abstract

The utility model provides a filtering device in a crustal stress measurement process. The filtering device comprises a filtering rod and a reducing interface, the reducing connector comprises a precipitation cavity and a conical seat positioned below the precipitation cavity; the precipitation cavity is assembled in the drill rod and is close to the water outlet end; and a water path switching device is assembled and mounted outside the conical seat. The device is simple in structure, high in adaptability and high in practical degree, can be used for filtering test water in the hydraulic fracturing ground stress measurement process, and has important significance on hydraulic fracturing ground stress measurement.

Description

Technical Field

[0001] This utility model belongs to the technical field of geostress measurement equipment, and specifically relates to a filtering device in the geostress measurement process. Background Technology

[0002] In recent years, the commonly used methods for geostress measurement fall into two main categories: stress relief methods and hydraulic fracturing methods. Hydraulic fracturing, a type of in-situ geostress testing method, has been widely applied in earthquake mechanism research, deep resource development, and major engineering projects, yielding numerous research results. Hydraulic fracturing has relatively relaxed environmental requirements, can measure absolute stress states at considerable depths, and is the most direct measurement method. Furthermore, this method does not require knowledge or determination of the rock's elastic modulus, has a large spatial range for stress measurement, is less affected by local factors, has a simple testing process, and a high success rate. However, to ensure the high pressure required for the test, the water channel aperture in hydraulic fracturing equipment is typically small. Poor water quality leading to equipment blockage is one of the main reasons for failures in hydraulic fracturing geostress measurements. Moreover, hydraulic fracturing geostress measurements are usually conducted at the surface or within exploration adits, with test water primarily sourced from rivers near the drilling site. Water quality cannot be guaranteed, and even with filters installed at the water pipeline ports, it is difficult to prevent fine sediment from entering the testing equipment and causing blockages. Meanwhile, hydraulic fracturing is often used for deep hole stress measurement. The deeper the measurement point, the more drill rods are needed, and the test equipment is often clogged due to insufficient cleanliness of the drill rods. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a filtering device for the geostress measurement process, which can effectively solve the aforementioned problems.

[0004] The technical solution adopted in this utility model is as follows:

[0005] This utility model provides a filtration device for the geostress measurement process, including a filter rod (1) and a variable diameter interface (2); the variable diameter interface (2) includes a sedimentation cavity (2-1) and a conical seat (2-2) located below the sedimentation cavity (2-1);

[0006] The sedimentation cavity (2-1) is assembled inside the drill rod (3) and close to the water outlet; the water circuit switching device (4) is assembled on the outside of the conical seat (2-2); a filter rod connection port (2-2-1) communicating with the sedimentation cavity (2-1) is opened on the central axis of the conical seat (2-2); a water outlet (2-2-2) communicating with both the filter rod connection port (2-2-1) and the water circuit switching device (4) is opened below the filter rod connection port (2-2-1); the filter rod (1) is placed inside the drill rod (3); the bottom of the filter rod (1) passes through the sedimentation cavity (2-1) and is assembled to the filter rod connection port (2-2-1); the internal cavity of the filter rod (1) is connected to the water outlet (2-2-2).

[0007] Preferably, the filter rod (1) is a hollow cylindrical structure with a closed upper end and an open lower end.

[0008] Preferably, the bottom of the filter rod (1) has a first external thread (1-1), and the filter rod connection port (2-2-1) has an internal thread; the filter rod (1) and the filter rod connection port (2-2-1) are threaded together.

[0009] Preferably, the filter rod (1) has a plurality of filter holes (1-2) evenly distributed.

[0010] Preferably, the diameter of the filter holes (1-2) is 2-3 mm.

[0011] Preferably, the filter rod (1) is 50-70cm in length.

[0012] Preferably, the diameter of the filter rod (1) is the same as the diameter of the water outlet (2-2-2).

[0013] Preferably, the outer wall of the sedimentation cavity (2-1) has a second external thread (2-1-1) for connecting with the internal thread of the drill rod (3);

[0014] The outer wall of the conical seat (2-2) has a third external thread (2-2-3) for internal thread connection with the waterway switching device (4).

[0015] Preferably, the diameter of the sedimentation cavity (2-1) is larger than the diameter of the outlet (2-2-2).

[0016] Preferably, the diameter of the outlet (2-2-2) is smaller than the bottom diameter of the variable diameter interface (2).

[0017] The filtering device for the geostress measurement process provided by this utility model has the following advantages:

[0018] (1) The variable diameter interface in this utility model is a fixed accessory used to connect the test equipment and the drill rod during the hydraulic fracturing method for measuring in-situ stress. It has a high degree of fit with the test system and ensures that the test can be carried out smoothly.

[0019] (2) The structure of the filter rod in this utility model can effectively filter impurities in the water used in the test process, as well as rust, mud and sand in the drill rod, so as to avoid test failure due to equipment blockage.

[0020] (3) The combination of sedimentation cavity and drill rod of this utility model can provide a storage place for impurities filtered out by the filter rod, which is convenient for cleaning.

[0021] (4) This utility model has a simple structure, is easy to carry and process, and can be adapted to different models of drill rods, thus ensuring the progress of the test.

[0022] The device has a simple structure, high adaptability, and strong practicality. It can filter the test water during the hydraulic fracturing method for geostress measurement, which is of great significance for the hydraulic fracturing method for geostress measurement. Attached Figure Description

[0023] Figure 1 A schematic diagram of the structure of a filter device for measuring ground stress provided in an embodiment of this utility model;

[0024] Figure 2 A schematic diagram of the operation of a filter device for measuring ground stress provided in an embodiment of this utility model;

[0025] In the diagram: 1. Filter rod; 1-1 First external thread; 1-2 Filter hole; 2. Variable diameter interface; 2-1 Sedimentation cavity; 2-2 Conical seat; 2-1-1 Second external thread; 2-2-1 Filter rod connection port; 2-2-2 Water outlet; 2-2-3 Third external thread; 3. Drill rod; 4. Water circuit switching device. Detailed Implementation

[0026] The present invention will now be described clearly and completely with reference to the accompanying drawings.

[0027] Obviously, the embodiments described above represent only some implementations of this utility model, and not all of them. The implementation of this utility model is not limited to specific materials, structures, or steps, but can be adjusted and varied according to specific circumstances. For those skilled in the art, all other implementations obtained without inventive work, including various modifications and variations, are within the protection scope of this utility model, provided that such modifications and variations follow the basic principles of this utility model.

[0028] This utility model provides a filtering device for the geostress measurement process, used in geostress measurement equipment. It is a simple, highly adaptable, and practical filtering device for the geostress measurement process. (See reference) Figure 1 and Figure 2 It includes a filter rod 1 and a variable diameter interface 2; the variable diameter interface 2 includes a sedimentation cavity 2-1 and a conical seat 2-2 located below the sedimentation cavity 2-1;

[0029] The sedimentation cavity 2-1 is assembled inside the drill rod 3 and near the outlet end; the water circuit switching device 4 of the test equipment is assembled and installed on the outside of the conical seat 2-2; a filter rod connection port 2-2-1 communicating with the sedimentation cavity 2-1 is opened on the central axis of the conical seat 2-2; an outlet 2-2-2 communicating with both the filter rod connection port 2-2-1 and the water circuit switching device 4 is opened below the filter rod connection port 2-2-1; the filter rod 1 is placed inside the drill rod 3, the bottom of the filter rod 1 passes through the sedimentation cavity 2-1 and is assembled to the filter rod connection port 2-2-1, and the internal cavity of the filter rod 1 communicates with the outlet 2-2-2.

[0030] In one specific embodiment, the filter rod 1 is a hollow cylindrical structure with a closed upper end and an open lower end. The bottom of the filter rod 1 has a first external thread 1-1, and the filter rod connection port 2-2-1 has an internal thread; the filter rod 1 and the filter rod connection port 2-2-1 are threadedly connected, thereby realizing the assembly between the filter rod 1 and the variable diameter interface 2. The filter rod 1 has a plurality of filter holes 1-2 evenly distributed, specifically, the filter holes 1-2 are evenly distributed on the upper part of the filter rod 1. The diameter of the filter holes 1-2 is 2-3 mm. The length of the filter rod 1 is 50-70 cm. The diameter of the filter rod 1 is the same as the diameter of the outlet 2-2-2.

[0031] The outer wall of the sedimentation cavity 2-1 has a second external thread 2-1-1 for connecting with the internal thread of the drill rod 3; the outer wall of the conical seat 2-2 has a third external thread 2-2-3 for connecting with the internal thread of the water circuit switching device 4. The diameter of the sedimentation cavity 2-1 is larger than the diameter of the outlet 2-2-2. The diameter of the outlet 2-2-2 is smaller than the bottom diameter of the variable diameter interface 2.

[0032] This utility model also provides a method for using the filtering device in the above-mentioned geostress measurement process, comprising the following steps:

[0033] Step 1: Use a drilling rig to lower the hydraulic fracturing method geostress measurement equipment into the borehole, and fix the water path switching device 4 above the borehole opening.

[0034] Step 2: Connect the variable diameter port 2 of the filter device to the water circuit switching device 4.

[0035] Step 3: Connect the open end of filter rod 1 to the variable diameter interface 2.

[0036] Step 4: Pass drill rod 3 through filter rod 1 and connect it to the reducer interface 2.

[0037] Step 5: Determine the number of drill rods 3 according to the test requirements, connect them in sequence, and lower them to the required test depth using a drilling rig.

[0038] Test water enters the drill rod 3 and flows through the filter holes 1-2 into the inner cavity of the filter rod 1. The filtered water flows from the outlet 2-2-2 into the water switching device 4 for testing. Impurities blocked by the filter holes 1-2 are deposited in the sedimentation cavity 2-1. Therefore, after the test is completed, only the reducing port 2 needs to be removed to remove the impurities, thus cleaning the inside of the drill rod 3.

[0039] The filtering device for the geostress measurement process provided by this utility model has the following advantages:

[0040] (1) The variable diameter interface in this utility model is a fixed accessory used to connect the test equipment and the drill rod during the hydraulic fracturing method for measuring in-situ stress. It has a high degree of fit with the test system and ensures that the test can be carried out smoothly.

[0041] (2) The structure of the filter rod in this utility model can effectively filter impurities in the water used in the test process, as well as rust, mud and sand in the drill rod, so as to avoid test failure due to equipment blockage.

[0042] (3) The combination of sedimentation cavity and drill rod of this utility model can provide a storage place for impurities filtered out by the filter rod, which is convenient for cleaning.

[0043] (4) This utility model has a simple structure, is easy to carry and process, and can be adapted to different models of drill rods, thus ensuring the progress of the test.

[0044] The device has a simple structure, high adaptability, and strong practicality. It can filter the test water during the hydraulic fracturing method for geostress measurement, which is of great significance for the hydraulic fracturing method for geostress measurement.

[0045] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A filtering device for a geostress measurement process, characterized in that The variable diameter interface (2) comprises a sediment cavity (2-1) and a conical seat (2-2) below the sediment cavity (2-1). The sediment cavity (2-1) is fitted inside the drill pipe (3) near the water outlet end; the outside of the conical seat (2-2) is fitted with a waterway switching device (4); the central axis of the conical seat (2-2) is provided with a filter rod connecting port (2-2-1) communicating with the sediment cavity (2-1), and a water outlet (2-2-2) below the filter rod connecting port (2-2-1) communicates with the filter rod connecting port (2-2-1) and the waterway switching device (4); the filter rod (1) is placed inside the drill pipe (3), the bottom of the filter rod (1) passes through the sediment cavity (2-1) and is fitted into the filter rod connecting port (2-2-1), and the internal cavity of the filter rod (1) communicates with the water outlet (2-2-2).

2. A filtering device for a geostress measurement process according to claim 1, characterized in that The filter rod (1) is a hollow cylindrical structure with a closed upper end and an open lower end.

3. A filtering device for a geostress measurement process according to claim 1, characterized in that The bottom of the filter rod (1) has a first external thread (1-1), and the filter rod connecting port (2-2-1) has an internal thread; the filter rod (1) and the filter rod connecting port (2-2-1) are threadedly connected.

4. A filtering device for a geostress measurement process according to claim 1, characterized in that The filter rod (1) is uniformly provided with a plurality of filter holes (1-2).

5. A filtering device for a geostress measurement process according to claim 4, characterized in that The filter holes (1-2) have a diameter of 2-3mm.

6. A filtering device for a geostress measurement process according to claim 1, characterized in that The length of the filter rod (1) is 50-70cm.

7. A filtering device for a geostress measurement process according to claim 1, characterized in that The diameter of the filter rod (1) is consistent with the diameter of the water outlet (2-2-2).

8. A filtering device for a geo-stress measurement process according to claim 1, characterized in that, The outer wall of the sediment cavity (2-1) has a second external thread (2-1-1) for internal thread connection with the drill pipe (3); The outer wall of the conical seat (2-2) has a third external thread (2-2-3) for internal thread connection with the waterway switching device (4).

9. A filtering device for a geo-stress measurement process according to claim 1, characterized in that, The diameter of the sediment cavity (2-1) is greater than the diameter of the water outlet (2-2-2).

10. A filtering device for a geo-stress measurement process according to claim 1, characterized in that, The diameter of the water outlet (2-2-2) is smaller than the diameter of the bottom end of the variable diameter interface (2).

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