Testing Device and Method for Sedimentation Stability of Drilling Fluid at Multiple Angles under High Temperature and High Pressure Conditions

Abstract

The present invention discloses a device and method for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions. The testing device includes a gas cylinder, a high temperature and high pressure autoclave, a test container, a motor, a rotating rod, a power supply, and a computer. The gas cylinder is connected to the high temperature and high pressure autoclave through a connecting pipeline, and a pressure gauge one, a pressurizing valve, and a pressure gauge two are sequentially arranged on the connecting pipeline. The high temperature and high pressure autoclave includes a kettle body and a kettle cover that are detachably connected. An arc-shaped slide rail is arranged inside the kettle body, and the test container is slidably arranged on the arc-shaped slide rail. At least one group of pressure sensors is arranged on the test container. The motor is arranged on the kettle cover, and two ends of the rotating rod are respectively connected to the output end of the motor and the test container. The test container can rotate together with the rotating rod under the drive of the motor. The power supply is respectively connected to the motor and the computer, and the pressure sensor is connected to the computer through a data line. The present invention can test the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions, providing technical support for drilling and exploitation.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas drilling fluid engineering, and particularly relates to a device and method for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions. Background Art

[0002] With the continuous deepening of oil and gas exploration, the number of deep wells / ultra-deep wells is increasing, posing new challenges to drilling fluids. Especially under high temperature and high pressure conditions, the performance of drilling fluids will change greatly, and different well inclination angles will also cause uneven sedimentation of drilling fluids, resulting in the inability to carry out normal drilling operations. Therefore, the sedimentation under high temperature and high pressure and the reduction of drilling fluid density caused by well inclination angles are important factors leading to an increased well control safety risk.

[0003] Currently, the main methods for testing the sedimentation stability of drilling fluids include: static sedimentation test method, flow loop test method, viscometer sedimentation test method, Turbscan multiple light scattering method, etc. However, it is difficult to obtain accurate results of the sedimentation stability of indoor drilling fluids at multiple angles under high temperature and high pressure conditions by the above methods, nor can the dynamic change law of the sedimentation stability of drilling fluids in a high temperature and high pressure environment be described. Therefore, a new device and method for testing the sedimentation stability of drilling fluids at multiple angles under high temperature and high pressure conditions need to be proposed. Summary of the Invention

[0004] In view of the above problems, the present invention aims to provide a device and method for testing the sedimentation stability of drilling fluids at multiple angles under high temperature and high pressure conditions.

[0005] The technical solution of the present invention is as follows:

[0006] On the one hand, a device for testing the sedimentation stability of drilling fluids at multiple angles under high temperature and high pressure conditions is provided, including a gas cylinder, a high temperature and high pressure autoclave, a test container, a motor, a rotating rod, a power supply, and a computer;

[0007] The gas cylinder is connected to the high temperature and high pressure autoclave through a connecting pipeline, and a pressure gauge I, a pressurizing valve, and a pressure gauge II are sequentially arranged on the connecting pipeline;

[0008] The high temperature and high pressure autoclave includes a kettle body and a kettle cover that are detachably connected. An arc-shaped slide rail is arranged inside the kettle body, and the test container is slidably arranged on the arc-shaped slide rail. At least one group of pressure sensors is arranged on the test container, and a group of pressure sensors includes at least three pressure sensors arranged coaxially;

[0009] The motor is arranged on the kettle cover. One end of the rotating rod is connected to the output end of the motor, and the other end of the rotating rod passes through the kettle cover and is connected to the top of the test container through a universal joint. The test container can rotate together with the rotating rod under the drive of the motor;

[0010] The power supply is respectively connected to the motor and the computer, and the pressure sensor is connected to the computer through a data line.

[0011] Preferably, a heating protection sleeve is provided on the outer surface of the kettle body.

[0012] Preferably, the pressure sensors in the same group are arranged at equal intervals.

[0013] Preferably, when multiple groups of pressure sensors are provided, the pressure sensors in each group are evenly distributed in the radial direction of the test container.

[0014] Preferably, at least one group of pressure sensors is arranged on the surface of the test container where the included angle with the horizontal plane is the smallest after the test container is tilted.

[0015] On the other hand, a method for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions is also provided. The test is carried out by using the test device for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions described in any one of the above, and includes the following steps:

[0016] S1: Prepare the drilling fluid, pour the drilling fluid into the test container, and the liquid level of the drilling fluid is higher than the highest horizontal plane where the pressure sensor is located;

[0017] S2: Adjust the position of the test container on the arc-shaped slide rail so that the test container reaches a preset tilt angle;

[0018] S3: Conduct a simulated sedimentation test. During the simulated sedimentation test, keep the test container in a rotating state;

[0019] S4: End the simulated sedimentation test, and calculate the sedimentation stability coefficient of the drilling fluid according to the pressure sensor data obtained in the simulated sedimentation test;

[0020] S5: Judge the sedimentation stability of the drilling fluid according to the sedimentation stability coefficient. The greater the sedimentation stability, the more obvious the sedimentation.

[0021] Preferably, when only one group of pressure sensors is provided, and one group of pressure sensors includes a first pressure sensor, a second pressure sensor, and a third pressure sensor that are arranged in sequence from top to bottom on the surface of the test container where the included angle with the horizontal plane is the smallest after the test container is tilted, in step S4, the sedimentation stability coefficient is calculated by the following formula:

[0022]

[0023]

[0024]

[0025] Where: SF is the sedimentation stability coefficient of the drilling fluid; ρ 1-2 is the upper density of the drilling fluid after sedimentation between the first pressure sensor and the second pressure sensor; ρ 2-3 is the lower density of the drilling fluid after sedimentation between the second pressure sensor and the third pressure sensor; P1, P2, and P3 are the pressures measured by the first pressure sensor, the second pressure sensor, and the third pressure sensor respectively; g is the acceleration due to gravity; θ is the angle between the axis of the test container and the rotating rod; Δh is the distance between the sensors.

[0026] Preferably, if SF ≤ 0.5, there is no sedimentation of the drilling fluid; if SF > 0.5, sedimentation of the drilling fluid occurs.

[0027] Preferably, by changing the tilt angle of the test container and the temperature, pressure, curing and aging time, and static sedimentation time during the simulated sedimentation test, the sedimentation stability of the drilling fluid under different conditions can be obtained.

[0028] Preferably, by changing the drilling fluid system, the sedimentation stability of different drilling fluid systems can be obtained.

[0029] The beneficial effects of the present invention are as follows:

[0030] The present invention can test the sedimentation stability of the drilling fluid at different angles and under high temperature and high pressure conditions, and can provide technical support for drilling and exploitation. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is a schematic structural diagram of the device for testing the sedimentation stability of the drilling fluid at multiple angles under high temperature and high pressure conditions of the present invention.

[0033] Reference numerals in the figure: 1 - gas cylinder, 2 - pressure gauge 1, 3 - connecting pipeline, 4 - pressure regulating valve, 5 - pressure gauge 2, 6 - motor, 7 - heating protection sleeve, 8 - kettle cover, 9 - kettle body, 10 - rotating rod, 11 - arc-shaped slide rail, 12 - test container, 13 - first pressure sensor, 14 - second pressure sensor, 15 - third pressure sensor, 16 - power supply, 17 - computer. Detailed Embodiments

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. It should be pointed out that unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. As used in the disclosure of the present invention, words such as "including" or "comprising" and the like mean that the elements or items appearing before the word cover the elements or items listed after the word and their equivalents, without excluding other elements or items.

[0035] As Figure 1 shown, the present invention provides a device for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions, including a gas cylinder 1, a high temperature and high pressure autoclave, a test container 12, a motor 6, a rotating rod 10, a power supply 16, and a computer 17;

[0036] The gas cylinder 1 is connected to the high temperature and high pressure autoclave through a connecting pipeline 3, and a pressure gauge 2, a pressure regulating valve 4, and a pressure gauge 5 are successively arranged on the connecting pipeline 3;

[0037] The high temperature and high pressure autoclave includes a kettle body 9 and a kettle cover 8 that are detachably connected. An arc-shaped slide rail 11 is arranged inside the kettle body 9, and the test container 12 is slidably arranged on the arc-shaped slide rail 11. At least one set of pressure sensors is arranged on the test container 12, and a set of pressure sensors includes at least three pressure sensors arranged coaxially;

[0038] The motor 6 is arranged on the kettle cover 8. One end of the rotating rod 10 is connected to the output end of the motor 6, and the other end of the rotating rod 10 passes through the kettle cover 8 and is connected to the top of the test container 12 through a universal joint. The test container 12 can rotate together with the rotating rod 10 under the drive of the motor 6;

[0039] The power supply 16 is respectively connected to the motor 6 and the computer 17, and the pressure sensors are connected to the computer 17 through data lines.

[0040] In a specific embodiment, a heating protection sleeve 7 is arranged on the outer surface of the kettle body, and the internal environment of the high temperature and high pressure autoclave is heated and insulated through the heating protection sleeve 7 to meet different simulated temperature requirements.

[0041] In a specific embodiment, the pressure sensors in the same group are arranged at equal intervals. Optionally, the distance between adjacent two sensors is 3 cm. When multiple groups of pressure sensors are arranged, the pressure sensors in each group are evenly distributed in the radial direction of the test container, and at least one group of pressure sensors is arranged on the surface with the smallest included angle with the horizontal plane after the test container is tilted.

[0042] In a specific embodiment, the kettle body 9, the kettle lid 8, and the arc-shaped slide rail 11 of the present invention are all made of high-strength alloy steel, which can meet the airtight working pressure of 0 to 70 MPa and the standard working temperature of 0 to 200 °C; the rotating rod 10 is made of a metal rod; the test container 12 is made of corrosion-resistant alloy steel; the gas cylinder stores an inert gas, such as nitrogen. When using the present invention, the output power of the power supply can be controlled by a computer to adjust the motor speed and the temperature of the heating and insulation jacket, and various experimental related data can be read. The normal working temperature and pressure of the motor are the same as those of the high-temperature and high-pressure kettle, and both can work continuously for a long time in an environment of 0 to 200 °C.

[0043] It should be noted that the implementation scheme that can make the test container 12 both maintain the inclination angle and rotate together with the rotating rod 10 is the prior art, and many existing mechanical structures can meet this requirement. Therefore, the connection structures at the top and bottom of the test container 12 are not described herein.

[0044] On the other hand, the present invention also provides a method for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions. The method uses the device for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions described in any one of the above to perform the test, including the following steps:

[0045] S1: Prepare the drilling fluid, pour the drilling fluid into the test container 12, and the liquid level of the drilling fluid is higher than the highest horizontal plane where the pressure sensor is located.

[0046] In a specific embodiment, measure 500 ml of deionized water with a measuring cylinder and put it into a stirrer. Place the stirrer under a high-speed stirrer for high-speed stirring. While stirring, slowly add the weighed solid phase mass. After the solid phase is fully mixed, continue stirring for 30 minutes until the temperature of the drilling fluid is basically close to room temperature. In this way, the drilling fluid to be tested is obtained.

[0047] S2: Adjust the position of the test container 12 on the arc-shaped slide rail 11 so that the test container 12 reaches a preset inclination angle.

[0048] S3: Conduct a simulated sedimentation test. During the simulated sedimentation test, keep the test container 12 in a rotating state.

[0049] When conducting the simulated sedimentation test, open the pressure valve 4, the motor 6, and the heating and insulation jacket 7, maintain the test container 12 in a rotating state, and wait until the temperature and pressure in the high-temperature and high-pressure kettle reach the preset values to continuously cure and age the drilling fluid.

[0050] S4: End the simulated sedimentation test, and calculate the sedimentation stability coefficient of the drilling fluid according to the pressure sensor data obtained in the simulated sedimentation test.

[0051] S5: Determine the sedimentation stability of the drilling fluid according to the sedimentation stability coefficient. The greater the sedimentation stability, the more obvious the sedimentation.

[0052] In a specific embodiment, when only one set of pressure sensors is provided, and the set of pressure sensors includes a first pressure sensor 13, a second pressure sensor 14, and a third pressure sensor 15 that are sequentially arranged from top to bottom on the surface with the smallest angle with the horizontal plane after the test container 12 is tilted, in step S4, the sedimentation stability coefficient is calculated by the following formula:

[0053]

[0054]

[0055]

[0056] In the formula: SF is the sedimentation stability coefficient of the drilling fluid; ρ 1-2 is the upper density of the drilling fluid after sedimentation between the first pressure sensor and the second pressure sensor; ρ 2-3 is the lower density of the drilling fluid after sedimentation between the second pressure sensor and the third pressure sensor; P1, P2, and P3 are the pressures measured by the first pressure sensor, the second pressure sensor, and the third pressure sensor respectively; g is the acceleration due to gravity; θ is the angle between the axis of the test container and the rotating rod; Δh is the sensor spacing.

[0057] In a specific embodiment, the standard volume of the test container 12 is 500 ml. When 500 ml of the drilling fluid to be tested is filled, the three pressure sensors are just located in the upper, middle, and lower three regions of the measured drilling fluid. At this time, if SF = 0.5, the drilling fluid has no sedimentation; if SF > 0.5, the drilling fluid shows sedimentation; if SF > 0.52, the sedimentation of the drilling fluid is obvious.

[0058] In a specific embodiment, by changing the tilt angle of the test container and the temperature, pressure, curing and aging time, and static sedimentation time during the simulated sedimentation test, the sedimentation stability of the drilling fluid under different conditions is obtained; by changing the drilling fluid system, the sedimentation stability of different drilling fluid systems is obtained.

[0059] In a specific embodiment, the sedimentation stability test of the target drilling fluid is carried out by using the multi-angle drilling fluid sedimentation stability test method under high temperature and high pressure conditions of the present invention, which specifically includes the following steps:

[0060] (1) Prepare the target drilling fluid

[0061] Measure 500 ml of deionized water with a graduated cylinder and put it into a stirrer. Place the stirrer under a high-speed stirrer and stir at high speed. While stirring, slowly add the weighed solid phase mass (formula: KCL + KOH + PAC fluid loss reducer + SPNH high-temperature fluid loss reducer + MMH gelling agent + RH-3 lubricant + KPAM coating thickener). After the solid phase is fully mixed, continue stirring for 30 minutes until the temperature of the drilling fluid is basically close to room temperature.

[0062] (2) Prepare the experimental environment and conduct a simulated settlement test

[0063] Pour the prepared drilling fluid into the test container in the test device, ensuring that the liquid level is at the 500 ml graduation line. Adjust the inclination angle of the test container to 45° and fix it. Open the pressure valve, motor, and heating and insulation jacket, maintain the rotating state of the sample, and wait until the temperature and pressure in the high-temperature and high-pressure autoclave reach the experimental requirements (150 °C, 70 MPa). Continuously cure and age for 16 hours, stop the motor rotation, maintain the temperature stability in the high-temperature and high-pressure autoclave, let the drilling fluid stand and settle for 24 hours, and record the data of the three pressure sensors in the test container during the test.

[0064] (3) Calculate the settlement stability coefficient of the drilling fluid and obtain the settlement stability of the target drilling fluid

[0065] According to the pressure difference of the drilling fluid between the first pressure sensor and the second pressure sensor, combined with formula (2), calculate the upper density ρ of the drilling fluid after settlement 1-2 It is:

[0066]

[0067] Similarly, according to the pressure difference of the drilling fluid between the second pressure sensor and the third pressure sensor, combined with formula (3), calculate the lower density ρ of the drilling fluid after settlement 2-3 It is:

[0068]

[0069] According to formula (1), the settlement stability coefficient SF of the drilling fluid is calculated as:

[0070]

[0071] In this embodiment, the settlement stability coefficient SF of the target drilling fluid > 0.52. Therefore, the drilling fluid of this system will undergo obvious settlement after standing for 24 hours in a high-temperature and high-pressure environment of 70 MPa, 150 °C and a well deviation angle of 45°.

[0072] Observe the drilling fluid after the experiment. The visual result is consistent with the conclusion obtained from the calculation result of the present invention. It can be seen that obvious settlement has indeed occurred, indicating the accuracy of the test method described in the present invention.

[0073] In summary, the present invention can test the sedimentation stability of drilling fluids under various different conditions. Compared with the prior art, the present invention has made remarkable progress.

[0074] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A device for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions, characterized in that, It includes a gas cylinder, a high-temperature and high-pressure autoclave, a test container, a motor, a rotating rod, a power supply, and a computer; The gas cylinder is connected to the high-temperature and high-pressure autoclave through a connecting pipeline, and a pressure gauge one, a pressurizing valve, and a pressure gauge two are successively arranged on the connecting pipeline; The high-temperature and high-pressure autoclave includes a kettle body and a kettle cover that are detachably connected. An arc-shaped slide rail is arranged inside the kettle body. The test container is slidably arranged on the arc-shaped slide rail. At least one group of pressure sensors is arranged on the test container. A group of pressure sensors includes at least three pressure sensors arranged coaxially, and the pressure sensors in the same group are arranged at equal intervals; The motor is arranged on the kettle cover. One end of the rotating rod is connected to the output end of the motor, and the other end of the rotating rod passes through the kettle cover and is connected to the top of the test container through a universal joint. The test container can rotate together with the rotating rod under the drive of the motor; The power supply is respectively connected to the motor and the computer, and the pressure sensor is connected to the computer through a data line.

2. The device for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions according to claim 1, characterized in that A heating protection sleeve is arranged on the outer surface of the kettle body.

3. The high-temperature and high-pressure condition multi-angle drilling fluid sedimentation stability testing device according to claim 1, characterized in that When multiple groups of pressure sensors are set, the groups of pressure sensors are evenly distributed in the radial direction of the test container.

4. The high-temperature and high-pressure multi-angle drilling fluid sedimentation stability test device according to any one of claims 1-3, characterized in that At least one group of pressure sensors is arranged on the surface of the test container with the smallest angle with the horizontal plane after the test container is tilted.

5. A method for testing the sedimentation stability of drilling fluid at multiple angles under high temperature and high pressure conditions, characterized in that, Using the multi-angle drilling fluid settlement stability test device under the high-temperature and high-pressure conditions described in claim 1 or 2 for testing, includes the following steps: S1: Prepare the drilling fluid, pour the drilling fluid into the test container, and the liquid level of the drilling fluid is higher than the highest horizontal plane where the pressure sensor is located; S2: Adjust the position of the test container on the arc-shaped slide rail to make the test container reach a preset tilt angle; S3: Conduct a simulated settlement test. During the simulated settlement test, keep the test container in a rotating state; S4: End the simulated settlement test, and calculate the settlement stability coefficient of the drilling fluid according to the pressure sensor data obtained in the simulated settlement test; When only one group of pressure sensors is set, and a group of pressure sensors includes a first pressure sensor, a second pressure sensor, and a third pressure sensor that are successively arranged from top to bottom on the surface of the test container with the smallest angle with the horizontal plane after the test container is tilted, the settlement stability coefficient is calculated by the following formula: （1） （2） （3） Where: SF is the drilling fluid settlement stability coefficient; ρ 1-2 is the upper density of the settled drilling fluid between the first pressure sensor and the second pressure sensor; ρ 2-3 is the lower density of the settled drilling fluid between the second pressure sensor and the third pressure sensor; P1, P2, and P3 are the pressures measured by the first pressure sensor, the second pressure sensor, and the third pressure sensor respectively; g is the acceleration due to gravity; θ is the angle between the axis of the test container and the rotating rod; Δh is the pressure sensor spacing; S5: Judge the settlement stability of the drilling fluid according to the settlement stability coefficient. The greater the settlement stability, the more obvious the settlement.

6. The method for testing the sedimentation stability of a drilling fluid at multiple angles under high temperature and high pressure conditions according to claim 5, wherein, If SF ≤ 0.5, there is no settlement of the drilling fluid; if SF > 0.5, settlement of the drilling fluid occurs.

7. The method for testing the sedimentation stability of a drilling fluid at multiple angles under high temperature and high pressure conditions according to claim 5 or 6, characterized in that By changing the tilt angle of the test container and the temperature, pressure, curing and aging time, and static settlement time during the simulated settlement test, the settlement stability of the drilling fluid under different conditions is obtained.

8. The method for testing the sedimentation stability of a drilling fluid at multiple angles under high temperature and high pressure conditions according to claim 7, wherein By changing the drilling fluid system, the settlement stability of different drilling fluid systems is obtained.

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