阅读说明：本技术 一种冻土层钻井过程中温度变化的监测装置及监测方法 (Monitoring device and monitoring method for temperature change in frozen soil layer drilling process ) 是由 王磊 柯珂 李莅临 杨进 张辉 张东清 徐东升 于 2019-09-20 设计创作，主要内容包括：本发明提供了一种冻土层钻井过程中温度变化的监测装置及方法,该装置包括低温恒温试验箱,其内铺设预设含水率的砂土/粘土,用于形成冻土模拟层；双层循环管,至少部分位于低温恒温试验箱内；钻井液循环系统,与双层循环管相连,用于使预设温度的钻井液在双层循环管循环；温度测量系统,设置在低温恒温试验箱内,用于监测整个钻井循环过程中低温试验箱内的冻土层的温度变化情况。该方法包括：在低温恒温试验箱内制备冻土模拟地层；在冻土模拟地层内通过双层循环管进行钻井液循环,并对冻土模拟地层进行温度动态监测。本发明采用低温恒温试验箱内制备冻土模拟地层,可以完整监测整个钻井循环过程中低温试验箱内冻土层的温度变化情况。(The invention provides a device and a method for monitoring temperature change in a frozen soil layer drilling process, wherein the device comprises a low-temperature constant-temperature test box, wherein sandy soil/clay with preset water content is paved in the low-temperature constant-temperature test box and is used for forming a frozen soil simulation layer; the double-layer circulating pipe is at least partially positioned in the low-temperature constant-temperature test chamber; the drilling fluid circulating system is connected with the double-layer circulating pipe and is used for circulating the drilling fluid at the preset temperature in the double-layer circulating pipe; and the temperature measuring system is arranged in the low-temperature constant-temperature test box and is used for monitoring the temperature change condition of the frozen soil layer in the low-temperature test box in the whole drilling circulation process. The method comprises the following steps: preparing a frozen soil simulation stratum in a low-temperature constant-temperature test box; and (3) circulating drilling fluid in the frozen soil simulation stratum through a double-layer circulating pipe, and dynamically monitoring the temperature of the frozen soil simulation stratum. The frozen soil simulation stratum is prepared in the low-temperature constant-temperature test box, so that the temperature change condition of the frozen soil layer in the low-temperature test box in the whole drilling circulation process can be completely monitored.)

1. A device for monitoring temperature change in a frozen soil layer drilling process is characterized by comprising:

the low-temperature constant-temperature test box is internally paved with sandy soil/clay with preset water content and used for forming a frozen soil simulation layer;

the double-layer circulating pipe is at least partially positioned in the low-temperature constant-temperature test chamber;

the drilling fluid circulating system is connected with the double-layer circulating pipe and is used for circulating drilling fluid at a preset temperature in the double-layer circulating pipe;

and the temperature measuring system is arranged in the low-temperature constant-temperature test box and is used for monitoring the temperature change condition of the frozen soil layer in the low-temperature test box in the whole drilling circulation process.

2. The device for monitoring the temperature change in the permafrost drilling process according to claim 1, wherein the low-temperature constant-temperature test chamber is externally sheathed with water.

3. The device for monitoring the temperature change in the frozen soil layer drilling process according to claim 1, wherein the double-layer circulating pipe comprises an inner pipe and an outer pipe sleeved outside the inner pipe, a drilling fluid inlet is formed in the inner pipe, and a drilling fluid return outlet is formed in the outer pipe.

4. The device for monitoring temperature change in the process of drilling in the frozen soil layer according to claim 3, wherein the drilling fluid circulating system comprises:

the drilling fluid container is connected with the drilling fluid return outlet;

one end of the constant-speed constant-pressure pump is connected with the drilling fluid inlet, and the other end of the constant-speed constant-pressure pump is connected with the drilling fluid container;

and the drilling fluid temperature controller is connected with the drilling fluid container and is used for enabling the temperature of the drilling fluid in the drilling fluid container to reach a preset value.

5. The device for monitoring the temperature change in the permafrost drilling process according to claim 3, wherein the bottom of the outer pipe is provided with a metal screen.

6. The device for monitoring temperature change in the permafrost drilling process according to claim 1, wherein the temperature measuring system comprises a plurality of needle-shaped temperature sensors vertically inserted upwards from the bottom end of the cryostat chamber.

7. The device for monitoring the temperature change in the permafrost drilling process according to claim 6, wherein 3 to 8 temperature measurement points are arranged on the needle-shaped temperature sensor.

8. The device for monitoring the temperature change in the permafrost drilling process according to claim 6, wherein the number of the needle-shaped temperature sensors is 12-48.

9. A method for monitoring temperature change in a frozen soil layer drilling process is characterized by comprising the following steps:

s1, preparing a frozen soil simulation stratum in the low-temperature constant-temperature test box;

s2, circulating drilling fluid in the frozen soil simulation formation through a double-layer circulating pipe;

and S3, dynamically monitoring the temperature of the frozen soil simulation stratum in the circulation process of the drilling fluid.

10. The method for monitoring temperature variation during drilling of the permafrost according to claim 9, wherein the step S1 comprises:

compacting the sandy soil/clay layer with preset water content in the low-temperature constant-temperature test box;

inserting the double circulation tube into the sandy soil/clay;

the cryostat was lowered through a low temperature water bath to a preset temperature and left to stand for 4 to 6 hours.

Technical Field

The invention belongs to the petroleum drilling industry, and particularly relates to a temperature change monitoring device in a frozen soil layer drilling process.

Background

The shallow stratum of the arctic and subarctic cryogenic regions is widely distributed with a large area of permafrost, and the permafrost covers the land and the sea and has a thickness of tens of meters to hundreds of meters. However, the drilling of the frozen soil layer is difficult and serious, and one important problem is that in the drilling process, because the circulating media such as drilling fluid and the like exchange heat with the stratum and the cutting friction between the drill bit and the stratum generates heat, pore ice in the frozen soil is melted, and the bearing capacity of the frozen soil is greatly reduced. Some wells in the Russian Siberian gas field sink at the well mouth due to the thawing of the frozen soil layer, and the maximum sinking depth is over 3m, so that monitoring the temperature change in the frozen soil layer drilling process has important significance for low-temperature frozen soil layer drilling.

The research on the aspect of drilling the frozen soil layer in China is basically in a blank state, and the device for simulating drilling in the frozen soil zone is disclosed in CN108104716A, is mainly used for simulating the drilling process of the frozen soil layer, comprises a drill bit, a drill stem and a circulating device, and also comprises a drilling fluid circulating device, but still has the problems that the experiment precision is influenced by the external temperature environment, and the dynamic temperature change condition of the frozen soil layer cannot be monitored.

Disclosure of Invention

Features and advantages of the invention will be set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the invention.

In order to overcome the problems of the prior art, the invention provides a device for monitoring temperature change in a frozen soil layer drilling process, which comprises:

the low-temperature constant-temperature test box is internally paved with sandy soil/clay with preset water content and used for forming a frozen soil simulation layer;

the double-layer circulating pipe is at least partially positioned in the low-temperature constant-temperature test chamber;

the drilling fluid circulating system is connected with the double-layer circulating pipe and is used for circulating drilling fluid at a preset temperature in the double-layer circulating pipe;

and the temperature measuring system is arranged in the low-temperature constant-temperature test box and is used for monitoring the temperature change condition of the frozen soil layer in the low-temperature test box in the whole drilling circulation process.

Optionally, the low-temperature constant-temperature test chamber is externally wrapped with a water jacket.

Optionally, the double-layer circulating pipe comprises an inner pipe and an outer pipe sleeved outside the inner pipe, the inner pipe is provided with a drilling fluid inlet, and the outer pipe is provided with a drilling fluid outlet.

Optionally, the drilling fluid circulation system comprises:

the drilling fluid container is connected with the drilling fluid return outlet;

one end of the constant-speed constant-pressure pump is connected with the drilling fluid inlet, and the other end of the constant-speed constant-pressure pump is connected with the drilling fluid container;

and the drilling fluid temperature controller is connected with the drilling fluid container and is used for enabling the temperature of the drilling fluid in the drilling fluid container to reach a preset value.

Optionally, the bottom of the outer pipe is provided with a metal screen.

Optionally, the temperature measurement system includes a plurality of needle-shaped temperature sensors inserted vertically upward from a bottom end of the cold constant temperature test chamber.

Optionally, 3 to 8 temperature measurement points are provided on the needle-like temperature sensor.

Optionally, the needle-shaped temperature sensors are 12-48.

The invention provides a method for monitoring temperature change in a frozen soil layer drilling process, which comprises the following steps:

s1, preparing a frozen soil simulation stratum in the low-temperature constant-temperature test box;

s2, circulating drilling fluid in the frozen soil simulation formation through a double-layer circulating pipe;

and S3, dynamically monitoring the temperature of the frozen soil simulation stratum in the circulation process of the drilling fluid.

Optionally, the step S1 includes:

compacting the sandy soil/clay layer with preset water content in the low-temperature constant-temperature test box;

inserting the double circulation tube into the sandy soil/clay;

the cryostat was lowered through a low temperature water bath to a preset temperature and left to stand for 4 to 6 hours.

According to the device and the method for monitoring the temperature change in the drilling process of the frozen soil layer, the drilling fluid circulation process of the polar region frozen soil zone is simulated through the low-temperature constant-temperature test box, and the dynamic temperature change of the frozen soil layer in the drilling fluid circulation process is monitored.

Drawings

FIG. 1 is a schematic structural diagram of a device for monitoring temperature change during a frozen soil layer drilling process according to an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a cold constant temperature test chamber and a double circulation pipe according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the distribution of needle-like temperature sensors in the cold constant temperature test chamber according to the embodiment of the present invention;

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

as shown in fig. 1 to 3, the present invention provides a device for monitoring temperature change during a frozen soil layer drilling process, comprising: the system comprises a low-temperature constant-temperature test box 10, a double-layer circulating pipe 20, a drilling fluid circulating system 30, a temperature measuring system 40 and a data acquisition system 50.

The temperature in the low-temperature constant-temperature test box 10 can be controlled by a low-temperature constant-temperature water bath, the temperature control range is-15-90 ℃, and the control precision is 0.5 ℃. More specifically, the low-temperature constant-temperature test box 10 is externally wrapped by a water jacket 11, cold water circulation can be carried out in the water jacket 11, the temperature in the low-temperature constant-temperature test box 10 is controlled by controlling the temperature of cold water, the low-temperature constant-temperature test box 10 is used for simulating the low-temperature environment of the polar region frozen soil zone, sandy soil/clay with preset water content is paved in the test box during the experiment, and the simulated frozen soil stratum is manufactured by using water bath cooling. In practice, a cover (not shown) is also included to seal the cryostat chamber 10. In one embodiment of the present invention, the sealed cryostat 10 may be provided with a circular observation window for observing the freezing condition of the fill after the test is sealed.

In this embodiment, the cold constant temperature test chamber 10 is a cylindrical container having an inner diameter of 0.5m, a height of 1.5m, and an effective volume of 295L. It should be noted that the cryostat 10 may have other dimensions, and the present invention is not limited thereto.

The double-layer circulating pipe 20 is a double-layer stainless steel pipe and comprises an inner pipe 21 and an outer pipe 22 sleeved outside the inner pipe 21, and an annular space 23 is formed between the inner pipe 21 and the outer pipe 22. The outer pipe 22 is provided with a drilling fluid return port 25, the inner pipe 21 is provided with a drilling fluid inlet 24, and the drilling fluid inlet 24 penetrates through the outer wall of the outer pipe 22. During the test, the double-layer circulating pipe 20 is inserted into the low-temperature constant-temperature test box from the top to simulate a drilling casing pipe and a drilling rod. The distance between the bottom of the inner tube and the bottom of the outer tube is 150 mm and 300mm, for example 200 mm. Sealing rubber can be used between the test chamber and the double-layer tube to realize sliding sealing.

The drilling fluid circulation system 30 comprises a constant speed and constant pressure pump 31, a drilling fluid container 32, a drilling fluid temperature controller (not shown in the figure); a drilling fluid temperature controller is coupled to the drilling fluid reservoir and is capable of directly controlling the drilling fluid temperature, such as by heating with a hot wire or by directly increasing or decreasing the temperature of the drilling fluid with refrigeration from a cold machine. The drilling fluid inlet 24 is connected with a constant-speed constant-pressure pump 31 through a first connecting pipe 26, the constant-speed constant-pressure pump 31 is connected with a drilling fluid container 32 through a connecting hard pipe 28, and the drilling fluid outlet 25 is connected with the drilling fluid container 32 through a second connecting pipe 27. Go into the drilling fluid to inner tube 21 pump through constant speed constant pressure pump 31, make the drilling fluid in the annular space 23 between the outer tube including to circulation simulation drilling in-process's drilling fluid circulation process, when concrete implementation, double-deck socle portion installation metal mesh screen 29, metal mesh screen can install the bottom at the outer tube, and the setting of metal mesh screen can guarantee that the drilling fluid invades frozen soil layer and prevents simultaneously that sand from getting into intraductal annular space jam circulating pump.

The temperature measuring system 40 includes a plurality of needle temperature sensors 41 vertically inserted upward from the bottom end of the cryostat, and the needle temperature sensors 41 may be arranged in an array. The number of the needle-shaped temperature sensors 41 may be 12-48, in this embodiment, there are 24 needle-shaped temperature sensors 41, and the array distribution is shown in fig. 3. The needle temperature sensors 41 may be used to monitor the temperature changes in the permafrost during drilling, with each sensor having 3 to 8 temperature measurement points, for example 6, arranged at intervals of 10cm from the bottom up. When 24 needle-shaped temperature sensors are adopted and 6 temperature measuring points are arranged at each temperature measuring point, 144 temperature measuring points are counted, and the temperature change condition of the frozen soil layer in the low-temperature test box in the whole drilling circulation process can be completely monitored.

The data acquired by all needle-shaped temperature sensors are collected and stored by a computer data acquisition system.

The invention provides a monitoring method for temperature change in a frozen soil layer drilling process, which can be implemented by adopting the monitoring device for temperature change in the frozen soil layer drilling process, and comprises the following steps:

s1, preparing a frozen soil simulation stratum in the low-temperature constant-temperature test box;

selecting sandy soil or clay with specified particle size and uniformly mixing with water to prepare sandy soil/clay with preset water content, then layering and compacting in a low-temperature constant-temperature test box, then inserting a double-layer circulating pipe into a soil body in the low-temperature constant-temperature test box from a through hole at the top and sealing, reducing the preset temperature of a low-temperature water bath of the low-temperature constant-temperature test box, wherein the preset temperature can be a very low fixed temperature, for example, setting the temperature to be 10 ℃ below zero for rapid cooling, reducing the temperature in the low-temperature constant-temperature test box to below 0 ℃, standing for 4 to 6 hours, and then entering step S2.

S2, circulating drilling fluid in the frozen soil simulation formation;

and opening a constant-speed constant-pressure pump of the drilling fluid circulating system to pump drilling fluid into an inner tube drilling fluid inlet of the double-layer circulating pipe, circulating in the annular space of the inner tube and the outer tube, returning out from a drilling fluid return outlet of the outer tube, arranging a metal screen at the bottom of the double-layer circulating pipe to organize soil particles in a frozen soil layer to enter the inside of the double-layer circulating pipe, and adjusting the temperature of the drilling fluid by a drilling fluid temperature controller of a drilling fluid container.

And S3, dynamically monitoring the temperature in the circulation process of the drilling fluid.

And a plurality of needle-shaped temperature sensors are vertically and upwards inserted into the bottom end of the low-temperature constant-temperature test chamber to measure the three-dimensional temperature field distribution inside the low-temperature constant-temperature test chamber, and data acquisition and processing are carried out through a data acquisition system. During processing, the temperature of each point can be drawn into a cloud by software.

The device and the method for monitoring the temperature change in the drilling process of the frozen soil layer provided by the invention have the advantages that the frozen soil simulation stratum is prepared in the low-temperature constant-temperature test box, and the drilling fluid circulation process and the temperature dynamic monitoring are carried out. The low-temperature constant-temperature environment of the polar region frozen soil zone can be simulated, sandy soil/clay with preset water content is paved in the test box during the experiment, and the simulated frozen soil stratum is prepared by cooling in a water bath; a plurality of needle-shaped temperature sensors are vertically and upwards inserted from the bottom end of the low-temperature constant-temperature test box and used for monitoring the temperature change of a frozen soil layer in the drilling process, and a plurality of temperature measuring points are arranged on each sensor, so that the temperature and pressure change conditions of the frozen soil layer in the low-temperature test box in the whole drilling circulation process can be completely monitored.

The invention is mainly applied to the research of the field of drilling the frozen soil layer in the low-temperature area, the temperature in the test box is controlled through water bath to form the frozen soil layer, the circulation test is carried out after the frozen soil layer is formed, the temperature of the water bath is kept unchanged in the circulation process, and the temperature of the drilling fluid is controlled by a drilling fluid temperature controller; thereby realizing three-dimensional dynamic monitoring of low-temperature environment, drilling fluid circulation and temperature; the device fills the blank of the research in the field of drilling of the frozen soil layer in China, and has important significance for researching the interaction mechanism of the drilling fluid and the frozen soil layer and the property change of the frozen soil layer under the condition of large temperature change.

The above-described embodiment is only one embodiment of the present invention, and it will be apparent to those skilled in the art that various modifications and variations can be easily made based on the application and principle of the present invention disclosed in the present application, and the present invention is not limited to the method described in the above-described embodiment of the present invention, so that the above-described embodiment is only preferred, and not restrictive.