Downhole gas logging and drilling test device

Abstract

The present invention provides a downhole gas logging while drilling test device, comprising a hydraulic module, a gas detection module, a control module and a mud pulse generator. The piston in the hydraulic module moves to allow the annular drilling fluid to flow into the hydraulic module. The gas detection module measures the content of methane gas in the annular drilling fluid, and determines the concentration of methane gas in the formation based on the measured value, and transmits the gas concentration data to the control module. The control module processes the data transmitted by the gas detection module, and transmits the data to be uploaded to the ground system to the mud pulse generator. The mud pulse generator converts the data signal to be uploaded to the ground system into a mud pulse signal, and transmits it to the ground system. The ground system interprets the mud pulse signal to obtain the uploaded data. The downhole gas logging while drilling test device can realize downhole gas parameter detection in real time and online, and improve the accuracy of the test results.

Description

Technical Field

[0001] The invention relates to the field of oil and gas exploration and development, and in particular to an underground gas logging and drilling testing device. Background Art

[0002] Traditional gas logging technology collects gas (including methane, carbon dioxide, hydrogen sulfide and other mixtures) in the drilling fluid returned to the ground, measures its material components, and indirectly evaluates the formation. However, the drilling fluid needs to flow through a long annular pipeline (the length of the pipeline varies with the drilling depth, generally up to several thousand meters) from the target formation to the ground, and the information lags seriously, and it is impossible to reflect the relevant information at the drill bit downhole in real time; at the same time, during the flow of the drilling fluid back to the ground through the annular space, the temperature, pressure and other related environmental conditions change dynamically with the flow of the drilling fluid in the pipeline, and the dissolved gas in the drilling fluid may also be converted to a free state during the flow process. Some of the gas will enter the degasser with the drilling fluid for degassing, but some of the gas may be directly lost to the air through the liquid surface after the drilling fluid rises to the ground, affecting the accuracy of subsequent gas detection data.

[0003] In recent years, the requirements for drilling speed and efficiency have become higher and higher, and the requirements for gas analysis and safety have become more and more stringent. Traditional gas logging technology has been unable to meet the needs of oil and gas exploration and development. For this reason, we have invented a new downhole gas logging test device while drilling to solve the above technical problems. Summary of the invention

[0004] The purpose of the present invention is to provide a downhole gas logging and drilling testing device for online and real-time detection and analysis of gas dissolved in drilling fluid in a downhole high-temperature and high-pressure environment.

[0005] The purpose of the present invention can be achieved through the following technical measures: the downhole gas logging test device while drilling includes a hydraulic module, a gas detection module, a control module and a mud pulse generator. The annulus drilling fluid flows into the hydraulic module through the movement of the piston in the hydraulic module. The gas detection module is connected to the hydraulic module, measures the methane gas content in the annulus drilling fluid, and determines the concentration of methane gas in the formation based on the measured value, and transmits the gas concentration data to the control module. The control module is connected to the gas detection module, processes the data transmitted by the gas detection module, and transmits the data to be uploaded to the ground system to the mud pulse generator. The mud pulse generator is connected to the control module, converts the data signal to be uploaded to the ground system into a mud pulse signal, and transmits it to the ground system. The ground system interprets the mud pulse signal to obtain the uploaded data.

[0006] The purpose of the present invention can also be achieved by the following technical measures:

[0007] The downhole gas logging while drilling test device also includes a filter module, which is located below the hydraulic module to remove rock cuttings in the annular drilling fluid.

[0008] The downhole gas logging while drilling test device also includes a pressure compensation module, which is connected to the hydraulic module so that the oil tank pressure of the hydraulic module is slightly higher than the annular pressure and the oil tank pressure of the hydraulic module is automatically adjusted at different depths.

[0009] The downhole gas logging while drilling test device also includes a downhole power module, which is connected to the hydraulic module, the gas detection module, the control module and the mud pulse generator to provide power.

[0010] The downhole power module comprises a high-temperature battery pack and a mud turbine generator. The mud turbine generator is the main power supply of the downhole gas logging while drilling test device, and the high-temperature battery pack is a backup power supply.

[0011] The hydraulic module also includes a temperature sensor, a pressure sensor and a displacement sensor, and the temperature sensor, the pressure sensor and the displacement sensor collect downhole temperature, pressure and displacement data.

[0012] The downhole gas logging while drilling test device in the present invention can realize real-time and online detection of downhole gas parameters (such as methane, carbon dioxide, hydrogen sulfide and other gases), solve the information lag problem caused by traditional gas logging during ground detection, improve the accuracy of test results, and provide valuable guidance information for subsequent exploration and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of a specific embodiment of the downhole gas logging and drilling testing device of the present invention;

[0014] Figure 2 It is a schematic diagram of a downhole gas logging and testing device while drilling in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

[0016] like Figure 1 and Figure 2 As shown, Figure 1 This is a structural diagram of the downhole gas logging and drilling testing device of the present invention. Figure 2The schematic diagram of the downhole gas logging and mud logging test device while drilling is shown in FIG. The downhole gas logging and mud logging test device while drilling includes a mud pulse generator 1, a downhole power supply module 2, a control module 3, a pressure compensation module 4, a gas detection module 5, a hydraulic module 6, and a filter module 7.

[0017] The filter module 7 is used to remove the rock cuttings in the annular drilling fluid to prevent large particles from entering the hydraulic system and causing serious damage to the hydraulic cylinder and hydraulic valve. Since the downhole tool needs to have a trouble-free working time of 3 to 4 days, the filter module 7 is required to be able to filter continuously and normally for a long time, that is, it has the function of preventing the formation of mud cakes. The filter module 7 can be a filter screen or a centrifuge, and its feature is anti-clogging.

[0018] The hydraulic module 6 is connected to the filter module 7. The hydraulic module is the action execution mechanism of the device, which includes a hydraulic pump, a hydraulic integrated block, a hydraulic valve, a hydraulic cylinder, a temperature sensor, a pressure sensor, a displacement sensor, etc. Its main function is to perform mud suction, mud pressure reduction and mud discharge.

[0019] The gas detection module 5 is connected to the hydraulic module 6, and is connected to the downhole power supply module 2 and the control module 3 through the circuit. It is used to measure the content of methane and other gases in the annular drilling fluid, and determine the concentration of methane and other gases in the formation based on the measured value, and transmit the gas concentration data to the control module.

[0020] The pressure compensation module 4 is connected to the hydraulic module 6, one side of its piston is connected to the oil tank of the hydraulic module 6, and the other side is connected to the annular mud and the compression spring. The oil tank pressure of the hydraulic module can maintain a dynamic balance with the annular pressure and spring pressure at different well depths, so that the oil tank pressure of the hydraulic module 6 is slightly higher than the annular pressure, that is, only the hydraulic oil is allowed to leak unidirectionally to the annular space, and the drilling fluid in the annular space is not allowed to enter the hydraulic module 6. At the same time, as the depth of the test device changes, the module realizes automatic adjustment of the oil tank pressure of the hydraulic module 6 at different depths.

[0021] The control module 3 is connected to the pressure compensation module 4, and is connected to the mud pulse generator 1, the downhole power supply module 2, and the control module 3 through the circuit. It is used to receive the operation instructions transmitted from the ground system to the downhole, and then use the single-chip computer program to control the hydraulic module 6, collect, store, and process the status information of the sensors in the test device (including temperature sensors, pressure sensors, and displacement sensors in one example); process the data transmitted by the gas detection module 5, and transmit the data that needs to be uploaded to the ground system to the mud pulse generator 1.

[0022] The downhole power supply module 2 is connected to the mud pulse generator 1, the control module 3, the gas detection module 5 and the hydraulic module 6, and includes a high-temperature battery pack and a mud turbine generator. Since the present invention works for a long time underground, the mud turbine generator is used as the main power supply of the test device to supply energy to the oil-immersed motor, solenoid valve and other components with high power consumption in the hydraulic module 6; the high-temperature battery pack is used as a backup power supply to supply power to the mud pulse generator 1, the control module 3 and the gas detection module 5 to ensure that the test device is controlled normally when the mud turbine generator fails.

[0023] The mud pulse generator 1 is connected to the control module 3 and is connected to the downhole power supply module 2 through the circuit. The data signal to be uploaded to the ground system is converted into a mud pulse signal and transmitted to the ground system. The ground system interprets the mud pulse signal and obtains the uploaded data.

[0024] The outer cylinder of the test device is connected to the standard drill collar 9 through an adapter 8 and arranged near the drill bit 10;

[0025] Each module in the test device uses an electrical connection plug and a fluid connection joint to complete electrical coordination and fluid transmission between modules.

[0026] The operation process of the downhole gas logging and drilling testing device of the present invention is as follows:

[0027] In the first step, the piston in the hydraulic module 6 moves to increase the volume of the rodless chamber of the hydraulic cylinder from zero, a low pressure is formed inside the test device, and the annular drilling fluid flows into the rodless chamber of the hydraulic cylinder in the hydraulic module 6 through the hole 71. During the inflow process, the filter module 7 removes the cuttings in the drilling fluid.

[0028] In the second step, the control module 3 closes the stop valve in the hydraulic module 6, one end of which is connected to the annulus, and the other end is connected to the rodless chamber of the hydraulic cylinder. At the same time, the volume of the rodless chamber of the hydraulic cylinder continues to increase. Since the mass of the drilling fluid flowing into the rodless chamber of the hydraulic cylinder remains unchanged, but the volume of the drilling fluid increases, the drilling fluid quickly decreases from high pressure to low pressure, accompanied by gas precipitation. At this time, the gas detection module 5 can detect the precipitated gas in a low-pressure environment and send the data to the control module 3. After processing and analyzing the data, the control module 3 transmits the results to the ground system through the mud pulse generator 1.

[0029] In the third step, after the gas measurement is completed, the hydraulic module 6 opens the stop valve and pushes the piston back to discharge the drilling fluid in the hydraulic cylinder that has completed the test into the annulus. In one example, the drilling fluid is discharged from the test device through the hole 71 into the annulus. In another example, the drilling fluid is discharged from another small hole in the hydraulic module 6 that is connected to the annulus into the annulus.

[0030] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. Downhole gas logging and drilling testing device, characterized in that: The downhole gas logging and drilling test device comprises a hydraulic module, a gas detection module, a control module and a mud pulse generator. The piston in the hydraulic module moves to make the annular drilling fluid flow into the hydraulic module. The gas detection module is connected to the hydraulic module to measure the content of methane gas in the annular drilling fluid, and the concentration of methane gas in the formation is determined by the measured value, and the gas concentration data is transmitted to the control module. The control module is connected to the gas detection module to process the data transmitted by the gas detection module, and transmit the data to be uploaded to the ground system to the mud pulse generator. The mud pulse generator is connected to the control module to convert the data signal to be uploaded to the ground system into a mud pulse signal, and transmit it to the ground system. The ground system interprets the mud pulse signal to obtain the uploaded data. The hydraulic module is connected to the control module and performs mud suction, mud pressure reduction and mud discharge under the control of the control module; The downhole gas logging while drilling test device also includes a pressure compensation module, which is connected to the hydraulic module so that the oil tank pressure of the hydraulic module is slightly higher than the annular pressure and the oil tank pressure of the hydraulic module is automatically adjusted at different depths.

2. The downhole gas logging while drilling test device according to claim 1, characterized in that: The downhole gas logging while drilling test device also includes a filter module, which is located below the hydraulic module to remove rock cuttings in the annular drilling fluid.

3. The downhole gas logging while drilling test device according to claim 1, characterized in that: The downhole gas logging while drilling test device also includes a downhole power module, which is connected to the hydraulic module, the gas detection module, the control module and the mud pulse generator to provide power.

4. The downhole gas logging while drilling test device according to claim 3, characterized in that: The downhole power module comprises a high-temperature battery pack and a mud turbine generator. The mud turbine generator is the main power supply of the downhole gas logging while drilling test device, and the high-temperature battery pack is a backup power supply.

5. The downhole gas logging while drilling test device according to claim 1, characterized in that: The hydraulic module also includes a temperature sensor, a pressure sensor and a displacement sensor, and the temperature sensor, the pressure sensor and the displacement sensor collect downhole temperature, pressure and displacement data.

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