CN204228981U - Hydraulic fracturing measures downhole data collecting device and the acquisition system of terrestrial stress - Google Patents

Abstract

The utility model provides an underground data acquisition device and an acquisition system for measuring ground stress by hydraulic fracturing. The underground data acquisition device (100) includes: an upper casing (101), a lower casing (102), a pressure acquisition A sensor (103) and a circuit board (104). The advantages are: (1) The water pressure of the fracturing test section can be directly collected, so there is no need to correct the water pressure value collected by the downhole data collection device 100, which not only improves the accuracy of the ground stress measurement result, but also reduces the The complexity of the in-situ stress calculation process; (2) The transformation of the existing hydraulic fracturing method in-situ stress measurement system is small, and does not occupy additional space in the fracturing test section, and has the advantages of simple structure, easy installation and use, and long working life advantage.

Description

Downhole data acquisition equipment and acquisition system for measuring ground stress by hydraulic fracturing

technical field

The utility model belongs to the technical field of ground stress measurement, in particular to an underground data acquisition device and a collection system for measuring ground stress by hydraulic fracturing.

Background technique

The use of hydraulic fracturing to measure in-situ stress has the following advantages: (1) Various in-situ stress parameters in the formation can be obtained without knowing the mechanical parameters of the rock mass; (2) It has simple equipment, convenient operation, and can be used at any depth It has the characteristics of continuous or repeated testing, fast measurement speed, intuitive measurement value, and large representative measurement value. Therefore, this method has broad application prospects.

The overall equipment of the traditional hydraulic fracturing stress measurement system is shown in Figure 1, including a first water delivery pipeline 4, a second water delivery pipeline 5, an upper packer 1, a lower packer 2, a connecting hose 3, Fracturing pipe 11, flow meter 9, water tank 10, return valve 11, first high-pressure pump 7 and second high-pressure pump 12; wherein, Figure 2 is a schematic diagram of the installation of the upper packer, lower packer and fracturing pipe ; The connecting hose 3 is connected between the upper packer and the lower packer, and the two ends of the connecting hose are respectively communicated with the cavities of the upper packer and the lower packer, and the upper packer's The water inlet communicates with the second water delivery pipeline 5, and the second water delivery pipeline 5 is connected to the water tank 10 through the second high-pressure pump 12; the fracturing tube is fixed between the upper packer and the lower packer, on the fracturing tube Several outlets are set, and the water inlet of the fracturing pipe is communicated with the first water delivery pipeline 4, and the first water delivery pipeline 4 is connected to the water tank 10 through the first high-pressure pump 7; The packer is placed downhole at the depth that needs to be measured, and a space is formed between the upper and lower packers through the support of the fracturing tube; then, since the upper packer and the lower packer are connected through a hose, the ground The second high-pressure pump 12 pumps water from the water tank 10, and simultaneously injects water into the upper and lower packers through the second water delivery pipeline 5, so that the upper and lower packers expand and make close contact with the hole wall, thereby forming an isolated space, that is, the fracturing test Section 6; then, the high-pressure pump 7 on the ground pumps water from the water tank 10, and continuously injects water into the fracturing pipe through the first water delivery pipeline, and the fracturing pipe continuously drains water to the isolated space through the drainage hole, so that the pressure of the isolated space The pressure sensor 8 is installed on the part of the first water delivery pipeline located on the ground, and the water delivery pressure value of the installed pipeline on the ground is recorded by the pressure sensor. The pressure value can be converted to obtain the pressure value of the sealed space, so , by analyzing the relationship between the pressure value collected by the pressure sensor and the change with time, the pressure record curve can be obtained. By analyzing the pressure record curve, the characteristic pressure parameters can be obtained, and then according to the corresponding theoretical calculation formula, the pressure at the measuring point can be obtained. Rock mechanical parameters such as the magnitude of the maximum and minimum horizontal principal stress and the tensile strength of the rock.

The main problem of the above measurement system is: the pressure sensor collects the water delivery pressure value of the surface pipeline, and due to the influence of parameters such as pipeline parameters, flow curve and depth of the measuring point, the pressure value collected by the pressure sensor will deviate from the underground pressure value. The water pressure carried by the cracks in the rock wall. Therefore, simply processing the pressure value collected by the pressure sensor approximately according to the water pressure carried by the cracks in the rock wall downhole will reduce the accuracy of the ground stress measurement results.

In order to solve the above problems, the pressure value collected by the pressure sensor can be corrected. However, in actual operation, the acquisition of pipeline parameters and flow curves depends on the field test conditions, and some parameters need to be obtained by guesswork or empirical values. Therefore, it is difficult to Accurate correction of the pressure value collected by the pressure sensor will still bring a large error to the final stress calculation result.

Utility model content

Aiming at the defects in the prior art, the utility model provides an underground data acquisition device and acquisition system for measuring ground stress by hydraulic fracturing, which can effectively solve the above problems.

The technical scheme that the utility model adopts is as follows:

The utility model provides a downhole data acquisition device for measuring ground stress by a hydraulic fracturing method. The downhole data acquisition device (100) comprises: an upper casing (101), a lower casing (102), a pressure acquisition sensor (103 ) and circuit board (104);

Wherein, the intersecting edges of the upper casing (101) and the lower casing (102) are sealed; the upper casing (101) has a first cavity (106), and the upper casing The shell wall of the body (101) is provided with several drainage holes (105) communicating with the first cavity (106), and the high-pressure water injected into the first cavity (106) passes through the drainage holes (105) ) is discharged into the fracturing test section;

The lower housing (102) has a sealed second cavity (107), the pressure acquisition sensor (103) and the circuit board (104) are fixed in the second cavity (107);

In addition, a through hole is provided between the first cavity (106) and the second cavity (107), through which the first cavity (106) and the second cavity are communicated body (107); the probe of the pressure acquisition sensor (103) is sealingly connected with the through hole, and the probe is located at the bottom of the first cavity (106) of the upper housing (101), so that the The probe directly collects the pressure value of the water injected into the first cavity (106).

Preferably, the upper casing (101) and the lower casing (102) are hermetically connected by threaded connection.

Preferably, the through hole has an internal thread; the probe of the pressure acquisition sensor (103) is provided with an external thread adapted to the internal screw; the probe of the pressure acquisition sensor (103) is threadedly connected to the Said through-hole sealed connection.

Preferably, the circuit board (104) includes: an input interface, a data acquisition circuit, a data memory and a power supply; one end of the input interface is electrically connected to the pressure acquisition sensor (103), and the other end of the input interface Connected to the input end of the data acquisition circuit, the output end of the data acquisition circuit is connected to the data memory; the power supply is respectively connected to the input interface, the data acquisition circuit, the data memory and the The pressure acquisition sensor (103) is electrically connected.

Preferably, the data acquisition circuit includes a preamplifier circuit, a low-pass filter circuit and a high-pass filter circuit connected in series.

Preferably, the circuit board further includes an output interface; the output interface is connected to the data storage.

Preferably, the output interface is a USB interface or an RS232 interface.

The utility model also provides a downhole data acquisition system, including the above-mentioned downhole data acquisition equipment for measuring ground stress by hydraulic fracturing, and also includes an upper packer, a lower packer and a fracturing tube; the downhole data acquisition The device includes an upper casing (101) and a lower casing (102);

The top end of the fracturing tube is fixedly connected to the bottom surface of the upper packer, the bottom end of the fracturing tube is fixedly connected to the top end of the upper shell (101), and the bottom of the lower shell (102) The bottom end is fixedly connected with the top surface of the lower packer.

The utility model also provides a downhole data acquisition system, including the above-mentioned downhole data acquisition equipment for measuring ground stress by hydraulic fracturing, and also includes an upper packer and a lower packer; the downhole data acquisition equipment includes an upper shell Body (101) and lower casing (102);

The top end of the upper casing (101) is fixedly connected with the bottom surface of the upper packer, and the bottom end of the lower casing (102) is fixedly connected with the top surface of the lower packer.

Preferably, the top end of the upper casing (101) is fixedly connected to the bottom surface of the upper packer through threaded connection, and the bottom end of the lower casing (102) is connected to the top surface of the lower packer. The connection is fixed by threaded connection.

The downhole data acquisition equipment and acquisition system for measuring ground stress by hydraulic fracturing provided by the utility model have the following advantages:

(1) The water pressure of the fracturing test section can be directly collected, so there is no need to correct the water pressure value collected by the downhole data acquisition device 100, which not only improves the accuracy of the ground stress measurement result, but also reduces the ground stress calculation the complexity of the process;

(2) The modification of the existing hydraulic fracturing method in-situ stress measurement system is small, does not occupy additional space in the fracturing test section, and has the advantages of simple structure, easy installation and use, and long working life.

Description of drawings

Fig. 1 is a schematic diagram of the overall equipment structure of a traditional hydraulic fracturing method ground stress measurement system;

Figure 2 is a schematic diagram of the installation of the upper packer, the lower packer and the fracturing tube in the traditional hydraulic fracturing method ground stress measurement system;

Fig. 3 is the installation diagram of upper packer, lower packer, fracturing tube and downhole data acquisition equipment provided by the utility model;

Fig. 4 is the decomposed state diagram of the downhole data acquisition equipment provided by the utility model;

Fig. 5 is a cross-sectional view of the downhole data acquisition equipment provided by the utility model.

Detailed ways

The utility model is described in detail below in conjunction with accompanying drawing:

The utility model provides a downhole data acquisition device for measuring ground stress by a hydraulic fracturing method, which can directly collect the hydraulic pressure of the fracturing test section. Therefore, the water pressure value collected by the downhole data acquisition device 100 does not need to be corrected. It not only improves the accuracy of the ground stress measurement results, but also reduces the complexity of the ground stress calculation process. Specifically, as shown in Figure 4, it is a schematic diagram of the decomposition state of the downhole data acquisition equipment; as shown in Figure 5, it is the downhole data Sectional view of the acquisition equipment; the downhole data acquisition equipment 100 includes: an upper housing 101, a lower housing 102, a pressure acquisition sensor 103 and a circuit board 104;

Wherein, the intersecting edges of the upper case 101 and the lower case 102 are in a sealed connection, for example, through a threaded connection; the upper case 101 has a first cavity 106, and the shell wall of the upper case 101 is provided with Several drainage holes 105 communicated with the first cavity 106, the high-pressure water injected into the first cavity 106 is discharged into the fracturing test section through the drainage holes 105;

The lower housing 102 has a sealed second cavity 107, and the pressure acquisition sensor 103 and the circuit board 104 are fixed in the second cavity 107;

In addition, a through hole is provided between the first cavity 106 and the second cavity 107, and the first cavity 106 and the second cavity 107 are communicated through the through hole; the probe of the pressure acquisition sensor 103 is sealed and connected with the through hole, and , the probe is located in the first cavity 106 of the upper housing 101 , so that the probe directly collects the pressure value of the water injected into the first cavity 106 . As a specific example, the through hole has an internal thread; the probe of the pressure acquisition sensor 103 is provided with an external thread adapted to the inner screw; the probe of the pressure acquisition sensor 103 is tightly connected to the through hole through a threaded connection.

Through the above structure, the pressure acquisition sensor 103 and the circuit board 104 are all fixed in the second cavity 107, and when the hydraulic fracturing experiment is carried out, since the second cavity 107 is a sealed cavity, it can effectively prevent fracturing. The high-pressure water enters the cavity of the lower shell and damages the circuit board and the pressure acquisition sensor; and because the probe of the pressure acquisition sensor is located at the bottom of the first cavity, during the fracturing test, the high-pressure water is injected into the first cavity, Therefore, the probe of the pressure acquisition sensor is in direct contact with the high-pressure water, and the purpose of the probe of the pressure acquisition sensor to directly measure the water pressure of the fracturing test section is achieved.

In the utility model, the main problems existing in the prior art can be solved through the above structure. As for the specific electronic devices included in the circuit board, those skilled in the art can flexibly configure them according to needs. Only introduce a kind of specific example of circuit board below, circuit board comprises: input interface, data acquisition circuit, data memory and power supply; One end of input interface is electrically connected with pressure acquisition sensor 103, and the other end of input interface is connected with data acquisition circuit The input end is connected, the output end of the data acquisition circuit is connected with the data memory; the power supply is electrically connected with the input interface, the data acquisition circuit, the data memory and the pressure acquisition sensor 103 respectively. The circuit board also includes an output interface; the output interface is connected with the data memory. The output interface is USB interface or RS232 interface.

Its working principle is: through the input interface and data acquisition circuit, the hydraulic pressure value of the fracturing test section collected by the pressure acquisition sensor is stored in the data memory; when the fracturing test is over, the downhole data Get the data memory, you can get the pressure record curve. Wherein, the data acquisition circuit may include a preamplifier circuit, a low-pass filter circuit and a high-pass filter circuit connected in series, for processing the original pressure value collected by the pressure acquisition sensor.

In the utility model, various forms can be adopted to fix the above-mentioned downhole data acquisition equipment to the fracturing test section. Two specific fixing methods are introduced below:

(1) Fixing method one

As shown in Figure 3, for a traditional hydraulic fracturing test system consisting of an upper packer, a lower packer and a fracturing tube; the downhole data acquisition equipment is matched with the fracturing tube, namely: downhole data acquisition The equipment includes an upper shell 101 and a lower shell 102; the top of the fracturing tube is fixedly connected to the bottom surface of the upper packer, such as screwed; the bottom end of the fracturing tube is fixedly connected to the top of the upper shell 101, such as screwed ; The bottom of the lower shell 102 is fixedly connected with the top surface of the lower packer, such as a screw connection; in this way, the series connection of the fracturing tube and the downhole data acquisition equipment is realized, that is, during the fracturing test, the ground High-pressure water is injected into the fracturing tube first, and then injected into the upper shell 101 from the fracturing tube. Then, the high-pressure water inside the fracturing tube and the upper shell 101 are both discharged to the fracturing test section to achieve the effect of fracturing. It can be seen that with this method, the downhole data acquisition equipment not only has the function of data acquisition, but also has the function of conventional fracturing tubes. Since the downhole data acquisition equipment is connected in series with the fracturing tubes, it will not occupy additional space in the fracturing test section. Space, the modification of the traditional hydraulic fracturing method test system is very small, and has the advantage of easy assembly.

(2) Fixing method 2

For the traditional hydraulic fracturing test system composed of upper packer, lower packer and fracturing tube; make the downhole data acquisition equipment completely replace the fracturing tube, that is, directly fix the downhole data acquisition equipment to the upper seal Between the packer and the lower packer, that is: the downhole data acquisition equipment includes an upper casing 101 and a lower casing 102; the top of the upper casing 101 is fixedly connected to the bottom surface of the upper packer, for example, a threaded connection can be used Fixed connection: the bottom end of the lower housing 102 is fixedly connected to the top surface of the lower packer, for example, it can be fixedly connected by threaded connection. In this fixing method, since the downhole data acquisition equipment is directly fixed between the upper packer and the lower packer, in addition to the hydraulic pressure acquisition function, the downhole data acquisition equipment also has the function of supporting the upper and lower packers, realizing The function of conventional fracturing tubes, therefore, will not occupy additional space in the fracturing test section, and the changes to the traditional hydraulic fracturing method test system are very small, which has the advantage of easy assembly.

In summary, the downhole data acquisition equipment and acquisition system for measuring ground stress by hydraulic fracturing provided by the utility model has the following advantages:

(1) The water pressure of the fracturing test section can be directly collected, so there is no need to correct the water pressure value collected by the downhole data acquisition device 100, which not only improves the accuracy of the ground stress measurement result, but also reduces the ground stress calculation the complexity of the process;

(2) The modification of the existing hydraulic fracturing method in-situ stress measurement system is small, does not occupy additional space in the fracturing test section, and has the advantages of simple structure, easy installation and use, and long working life.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made, these improvements and Retouching should also be considered within the protection scope of the present utility model.

Claims (10)

1. the downhole data collecting device of a hydraulic fracturing measurement terrestrial stress, it is characterized in that, described downhole data collecting device (100) comprising: upper shell (101), lower house (102), pressure acquisition sensor (103) and circuit board (104);

Wherein, the crossing edge of described upper shell (101) and described lower house (102) is for being tightly connected; Described upper shell (101) has the first cavity (106), and, the shell wall of described upper shell (101) offers several osculums (105) be communicated with described first cavity (106), and the water under high pressure being injected into described first cavity (106) is discharged in crushing test section by described osculum (105);

Packed second cavity (107) of described lower house (102) tool, described pressure acquisition sensor (103) and described circuit board (104) are all fixed in described second cavity (107);

In addition, between described first cavity (106) and described second cavity (107), be provided with through hole, by described through hole, be communicated with described first cavity (106) and described second cavity (107); Probe and the described through hole of described pressure acquisition sensor (103) are tightly connected, and, described probe is positioned at the bottom of first cavity (106) of described upper shell (101), described probe is directly gathered be injected into the force value of the water of described first cavity (106).

2. hydraulic fracturing according to claim 1 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described upper shell (101) and described lower house (102) mode of being threaded connection are tightly connected.

3. hydraulic fracturing according to claim 1 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described through hole has internal thread; The probe of described pressure acquisition sensor (103) is provided with the external thread with described inside screw adaptation; The probe of described pressure acquisition sensor (103) is threaded connection mode and described through hole is tightly connected.

4. hydraulic fracturing according to claim 1 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described circuit board (104) comprising: input interface, data acquisition circuit, data-carrier store and power supply; One end of described input interface is electrically connected with described pressure acquisition sensor (103), and the other end of described input interface is connected with the input end of described data acquisition circuit, and the output terminal of described data acquisition circuit is connected with described data-carrier store; Described power supply is electrically connected with described input interface, described data acquisition circuit, described data-carrier store and described pressure acquisition sensor (103) respectively.

5. hydraulic fracturing according to claim 4 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described data acquisition circuit comprises the pre-amplification circuit, low-pass filter circuit and the high-pass filtering circuit that are connected in series.

6. hydraulic fracturing according to claim 4 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described circuit board also comprises output interface; Described output interface is connected with described data-carrier store.

7. hydraulic fracturing according to claim 6 measures the downhole data collecting device of terrestrial stress, and it is characterized in that, described output interface is USB interface or RS232 interface.

8. a downhole data acquisition system, is characterized in that, the hydraulic fracturing comprised described in any one of claim 1-7 measures the downhole data collecting device of terrestrial stress, also comprises upper packer, lower packet and pressure break pipe; Described downhole data collecting device comprises upper shell (101) and lower house (102);

The top of described pressure break pipe is fixedly connected with the bottom surface of described upper packer, the bottom of described pressure break pipe is fixedly connected with the top of described upper shell (101), and the bottom of described lower house (102) is fixedly connected with the end face of described lower packet.

9. a downhole data acquisition system, is characterized in that, the hydraulic fracturing comprised described in any one of claim 1-7 measures the downhole data collecting device of terrestrial stress, also comprises upper packer and lower packet; Described downhole data collecting device comprises upper shell (101) and lower house (102);

The top of described upper shell (101) is fixedly connected with the bottom surface of described upper packer, and the bottom of described lower house (102) is fixedly connected with the end face of described lower packet.

10. downhole data acquisition system according to claim 9, it is characterized in that, the top of described upper shell (101) is fixedly connected with the underrun thread connecting mode of described upper packer, and the bottom of described lower house (102) is threaded connection mode with the end face of described lower packet and is fixedly connected with.