A device for controlling the volume of formation fluids extracted from oil and gas wells and its usage method.

Abstract

This invention discloses a device and its method for controlling the volume of formation fluid extracted from oil and gas wells, belonging to the field of open-hole logging technology in oil and gas exploration and development. The device utilizes a motor-reducer assembly to drive a piston within the fluid chamber. Precise control of the speed of the motor-reducer assembly, the stroke of the piston, and the output power ensures accurate control of the required fluid chamber volume. This avoids the risks of tool jamming and wasted time due to an excessively large chamber volume, and the possibility of false "dry" layers appearing in measurements due to an excessively small chamber volume. The device precisely controls the rotational speed of the stepper motor within the motor-reducer assembly, thereby controlling the piston's movement speed and extraction rate. This solves the technical problem of existing methods that cannot accurately measure formation pressure in oil and gas layers with different permeability in a single well run.

Description

Technical Field

[0001] This invention belongs to the field of open-hole logging technology in oil and gas exploration and development, specifically relating to a device for controlling the volume of fluid extracted from the formation in oil and gas wells and its usage method. Background Technology

[0002] In the process of oil and gas field exploration and development, after drilling to uncover the target layer, in order to quickly obtain the formation pressure of a certain layer in the oil and gas well and calculate the formation permeability, thereby quickly identifying and determining the oil, gas and water interface, and discovering and evaluating oil and gas layers, a formation testing instrument is usually lowered into the target layer by cable for measurement. Currently, domestic cable formation testing instruments are designed with one (20cc) or two (10cc) fixed volume spaces. After the formation testing instrument is anchored at a certain layer, the probe passes through the well mud and extends into the formation. The formation fluid fills the volume space through the internal pipeline of the instrument. At the same time, the pressure value is obtained by measuring the pressure drop generated when the volume space is filled, which is called the formation pressure. Meanwhile, the permeability of the formation is calculated by measuring the pressure drop flow rate generated when the volume space is filled.

[0003] Currently, existing domestic cable formation testing tools require a considerable amount of time to fill their fixed volume when the formation permeability is low, often leading to tool jamming risks and wasted time during downhole measurements. If the volume is designed too small during instrument manufacturing, it will be unable to accurately measure the pressure values ​​of high-permeability formations, while if the volume is too large, it will be unable to measure the pressure values ​​of extremely low-permeability formations, resulting in a "dry" layer in the measurement results, when in reality the formation may have pressure. Furthermore, a single oil and gas well typically contains multiple oil and gas layers, each with different lithology, permeability, and porosity. Therefore, existing domestic cable formation testing tools cannot accurately complete pressure measurements of all target formations in a single well run. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a device and method for controlling the volume of formation fluid extracted from oil and gas wells, which solves the technical problem that the cavity volume of existing cable formation tester tools is uncontrollable and cannot complete the measurement of different oil and gas layers in one well run.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention discloses a device for controlling the volume of formation fluid extracted from oil and gas wells, comprising a fluid cavity valve body and a motor reducer pressure bearing cylinder; the fluid cavity valve body and the motor reducer pressure bearing cylinder are connected; within the fluid cavity valve body, a fluid pipeline, a fluid cavity, a fluid cavity piston, a planetary screw, a planetary screw nut, and a combined bearing are arranged concentrically in sequence; one end of the fluid cavity is connected to one end of the fluid cavity piston, and the other end of the fluid cavity is connected to one end of the fluid pipeline; the other end of the fluid cavity piston is connected to one end of the planetary screw; the other end of the planetary screw passes through the interior of the planetary screw nut and the combined bearing, and is connected to both the planetary screw nut and the combined bearing; the motor reducer pressure bearing cylinder contains a motor reducer assembly, and the other end of the planetary screw is connected to the motor reducer assembly; a lever positioner is also provided within the fluid cavity valve body, and the lever positioner is connected to the planetary screw nut.

[0007] Furthermore, the central axes of the fluid cavity valve body and the pressure bearing cylinder of the motor reducer coincide.

[0008] Furthermore, the other end of the fluid pipeline is connected to the formation fluid inlet pipeline.

[0009] Furthermore, buffer springs are fixedly installed at both ends of the planetary screw nut.

[0010] Furthermore, the fluid cavity is cylindrical in shape; the motor reducer assembly includes a stepper motor; the motor reducer assembly is also connected to a circuit control system, the circuit control system is also connected to ground software, and the ground software is connected to information acquisition software.

[0011] Furthermore, the fluid cavity valve body is also provided with a fluid cavity outer sleeve, which is fitted over the outside of the fluid cavity.

[0012] Furthermore, the other end of the planetary screw is connected to the motor reducer assembly via a coupling; one end of the coupling is connected to the other end of the planetary screw, and the other end is connected to the motor reducer assembly.

[0013] Furthermore, a bearing locking nut is provided at one end of the combined bearing near the motor reducer assembly.

[0014] Furthermore, the bearing lock nut is located between the combined bearing and the coupling.

[0015] The present invention also discloses a method for using the above-mentioned device for controlling the volume of formation fluid extracted from oil and gas wells, comprising the following steps: first, confirming that the volume of the fluid cavity is zero; then, setting the target volume of the fluid cavity to be obtained according to the formation permeability characteristics; controlling the motor reducer assembly to drive the planetary screw to move, which in turn drives the piston of the fluid cavity to move, so that the volume of the fluid cavity reaches the target volume; at the same time, the lever positioner records the movement distance of the piston of the fluid cavity, thereby obtaining the volume of the extracted formation fluid.

[0016] The volume of the extracted formation fluid is calculated using the following formula:

[0017] V = πxR 2 xL;

[0018] Where V is the volume of the formation fluid in m³, R is the radius of the fluid cavity in cm, and L is the travel distance of the piston in the fluid cavity in cm.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses a device for controlling the volume of formation fluid extracted from oil and gas wells. It utilizes a motor-reducer assembly to drive a piston within the fluid chamber. Precise control of the motor-reducer assembly's speed, the piston's stroke, and output power ensures accurate control of the required fluid chamber volume. This avoids the problems associated with oversized chambers requiring excessive time to fill their fixed volume, which can lead to tool jamming and wasted time in downhole measurements. Conversely, undersized chambers can result in false "dry" formations. The device features a modular design for easy assembly and disassembly, facilitating maintenance and repair during operation. A linear potentiometer connected to the planetary screw nut measures the position of the planetary screw, yielding the piston's movement distance (L). Software control and real-time calculations then allow for precise control of the extracted formation fluid volume.

[0021] Furthermore, by employing a stepper motor, the movement of the motor can be precisely controlled; the motor reducer assembly is also connected to a circuit control system, which is further connected to ground software on the surface, and the ground software on the surface is connected to information acquisition software, which can solve the existing technical problem of not being able to accurately complete formation pressure measurement of oil and gas layers with different permeability in a single well run.

[0022] This invention also discloses a method for using the aforementioned device for controlling the volume of formation fluid extracted from oil and gas wells. By setting different volume values ​​(0cc-50cc) of the cavity and adjusting the suction rate (0.1cc / sec-2cc / sec) in real time through ground software, and issuing corresponding instructions to the pre-designed circuit control system of the downhole instrument, the rotational speed of the stepper motor in the motor reducer assembly can be precisely controlled, thereby controlling the speed of the piston movement in the fluid cavity and the suction rate. At the same time, the distance the piston movement in the fluid cavity is accurately measured by the lever positioner, and this information is fed back to the ground information acquisition software in real time for calculation and monitoring. This solves the technical problem that existing methods cannot accurately measure the formation pressure of oil and gas layers with different permeability in a single well run. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of a device for controlling the volume of oil and gas well fluid extraction according to the present invention.

[0024] Wherein: 1-Fluid pipeline; 2-Fluid cavity; 3-Fluid cavity piston; 4-Planetary screw; 5-Buffer spring; 6-Planetary screw nut; 7-Combined bearing; 8-Coupling; 9-Motor reducer assembly; 10-Pulse rod potentiometer; 11-Fluid cavity valve body; 12-Motor reducer pressure cylinder; 13-Fluid cavity outer sleeve; 14-Bearing lock nut. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings:

[0028] See Figure 1 As shown, this invention discloses a device for controlling the volume of formation fluid extracted from oil and gas wells. The specific component connections from left to right are as follows: the fluid chamber valve body 11 is connected to the motor reducer pressure cylinder 12, and the central axes of the fluid chamber valve body 11 and the motor reducer pressure cylinder 12 coincide; within the fluid chamber valve body 11, a fluid pipeline 1, a cylindrical fluid chamber 2, a fluid chamber piston 3, a planetary screw 4, a planetary screw nut 6, and a combined bearing 7 are arranged concentrically; one end of the fluid pipeline 1 is connected to the formation fluid inlet pipeline, and the other end of the fluid pipeline 1 is connected to one end of the fluid chamber 2; the other end of the fluid chamber 2 is connected to one end of the fluid chamber piston 3, and the other end of the fluid chamber piston is connected to one end of the planetary screw 4; the other end of the planetary screw 4... The end of the planetary screw nut 6 and the combined bearing 7 are connected to each other respectively; the buffer spring 5 is fixed at both ends of the planetary screw nut 6 to provide buffering; the other end of the planetary screw 4 is connected to one end of the coupling 8, and the other end of the coupling 8 is connected to the motor reducer assembly 9. The motor reducer assembly 9 is located inside the pressure cylinder 12 of the motor reducer; the pull rod potentiometer 10 is connected to the lower part of the planetary screw nut 6 to measure the movement distance of the fluid chamber piston 3, and the pull rod potentiometer 10 is located inside the fluid chamber valve body 11; the fluid chamber outer sleeve 13 is installed at the center of the fluid chamber valve body 11, and the bearing locking nut 14 is fixed on the planetary screw to prevent the combined bearing 7 from loosening; at the same time, in order to ensure precise control of the required chamber volume, a stepper motor is used.

[0029] The device disclosed in this invention, which allows for controllable volume extraction of formation fluids from oil and gas wells, has an outer diameter of 120 mm, a length of 2500 mm, a temperature resistance of 175℃, and a pressure resistance of 138 MPa. First, the position of the piston 3 in the fluid chamber is confirmed using surface acquisition software. Figure 1The fluid cavity 2 is positioned at its leftmost position, with a volume of 0. Next, the volume (0cc-50cc) and pumping rate (0.1cc / sec-2cc / sec) of the fluid cavity 2 are set according to the formation permeability characteristics. Then, corresponding commands are sent to the pre-designed circuit control system of the downhole instrument. When the stepper motor rotates clockwise, the planetary screw 4 rotates with it, and the planetary screw nut 6 and the connected fluid cavity piston 3 move to the right under the influence of the planetary screw nut 4, forming a cavity volume V. Conversely, when the stepper motor rotates counterclockwise, the planetary screw nut 6 and the connected fluid cavity piston 3 move to the left, reducing the cavity volume, thus achieving the desired, real-time adjustable, and precisely controllable fluid volume.

[0030] Formula for calculating fluid chamber volume: V = πxR 2 xL

[0031] Wherein, V is the volume of the formation fluid in m; R is the radius of the fluid cavity 2 in cm; and L is the movement distance of the fluid cavity piston 3 in cm.

[0032] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A device for controlling the volume of formation fluid extracted from oil and gas wells, characterized in that, The system includes a fluid chamber valve body (11) and a motor reducer pressure cylinder (12); the fluid chamber valve body (11) and the motor reducer pressure cylinder (12) are connected; a fluid pipeline (1), a fluid chamber (2), a fluid chamber piston (3), a planetary screw (4), a planetary screw nut (6), and a combined bearing (7) are arranged concentrically inside the fluid chamber valve body (11); one end of the fluid chamber (2) is connected to one end of the fluid chamber piston (3), and the other end of the fluid chamber (2) is connected to one end of the fluid pipeline (1); the fluid chamber piston... (3) The other end is connected to one end of the planetary screw (4); the other end of the planetary screw (4) passes through the interior of the planetary screw nut (6) and the combined bearing (7), and is connected to the planetary screw nut (6) and the combined bearing (7) respectively; the motor reducer pressure cylinder (12) is equipped with a motor reducer assembly (9), and the other end of the planetary screw (4) is connected to the motor reducer assembly (9); the fluid cavity valve body (11) is also equipped with a lever position counter (10), and the lever position counter (10) is connected to the planetary screw nut (6); The planetary screw nut (6) is fixedly provided with buffer springs (5) at both ends; the fluid cavity (2) is cylindrical in shape; the motor reducer assembly (9) includes a stepper motor; the motor reducer assembly (9) is also connected to a circuit control system, the circuit control system is also connected to ground software on the ground, and the ground software on the ground is connected to information acquisition software. The fluid cavity valve body (11) is also provided with a fluid cavity outer sleeve (13), which is fitted on the outside of the fluid cavity (2); the other end of the planetary screw (4) is connected to the motor reducer assembly (9) through a coupling (8); one end of the coupling (8) is connected to the other end of the planetary screw (4), and the other end is connected to the motor reducer assembly (9); a bearing locking nut (14) is provided at the end of the combined bearing (7) near the motor reducer assembly (9).

2. The device for controlling the volume of oil and gas well fluid extraction according to claim 1, characterized in that, The central axes of the fluid cavity valve body (11) and the motor reducer pressure cylinder (12) coincide.

3. The device for controlling the volume of oil and gas well fluid extraction downhole according to claim 1, characterized in that, The other end of the fluid pipeline (1) is connected to the formation fluid inlet pipeline.

4. The device for controlling the volume of oil and gas well fluid extraction according to claim 1, characterized in that, The bearing locking nut (14) is located between the combined bearing (7) and the coupling (8).

5. The method of using the device for controlling the volume of oil and gas well fluid extraction as described in claim 1, characterized in that, The process includes the following steps: First, confirm that the volume of the fluid cavity (2) is zero. Then, set the target volume of the fluid cavity (2) to be obtained according to the formation permeability characteristics. Control the motor reducer assembly (9) to drive the planetary screw (4) to move, which in turn drives the fluid cavity piston (3) to move, so that the volume of the fluid cavity (2) reaches the target volume. At the same time, the lever positioner (10) records the movement distance of the fluid cavity piston (3) to obtain the volume of the extracted formation fluid. The volume of the extracted formation fluid is calculated using the following formula: V=π x R 2 x L; Wherein, V is the volume of the formation fluid in m; R is the radius of the fluid cavity (2) in cm; L is the movement distance of the fluid cavity piston (3) in cm; and π is the circumference ratio.

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