Device for sucking and discharging underground detection liquid

Abstract

The invention provides a device for sucking and discharging underground detection liquid, the device comprises a first hydraulic cavity, a second hydraulic cavity, a piston assembly for separating the first hydraulic cavity from the second hydraulic cavity and a sample cavity, the first hydraulic cavity and the second hydraulic cavity can be connected to an inner pipe, and the end face of the piston assembly forms the bottom surface of the sample cavity; the sample cavity is communicated with the space between the inner pipe and the outer pipe, and fluid in the inner pipe can enter the first hydraulic cavity and push the piston assembly to move towards the second hydraulic cavity, so that the internal pressure of the sample cavity is lower than the pressure of the space between the inner pipe and the outer pipe; fluid in the inner pipe can enter the second hydraulic cavity and push the piston assembly to move towards the first hydraulic cavity, so that the internal pressure of the sample cavity is higher than the pressure of the space between the inner pipe and the outer pipe. The internal and external pressure difference of the drill column during drilling fluid circulation is used as an energy source, so that underground detection fluid is sucked and discharged, and the power and electric energy loss of the whole system are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of drilling equipment, and in particular to a device for sucking and discharging downhole testing fluid. Background Art

[0002] During the drilling process, gas intrusion detection is mainly achieved through changes in the mud pool level and outlet flow rate on the ground. However, these two detection methods implemented on the ground are easily interfered by other factors, and the detection process and results are relatively delayed, which has a great impact on the later exhaust and underground safety. Therefore, downhole gas detection technology has become an effective method in the field of drilling and logging. Real-time, continuous and quantitative detection of formation hydrocarbons through downhole gas-liquid mixed fluid detection technology is an important part of drilling detection.

[0003] At present, downhole gas detection mainly relies on batteries as the power source, and uses an electric balance pump as an actuator to sample and discharge the detection fluid (also known as drilling fluid) between the inner tube and the outer tube. Under the high-pressure environment downhole, the electric balance pump has high operating power and high energy consumption, resulting in a huge battery load, which greatly increases the difficulty of battery selection and reduces the single-use time of the entire system. Summary of the invention

[0004] One purpose of the present invention is to provide a device for sucking and discharging downhole detection fluid, so as to realize the suction and discharge of downhole detection fluid by using the pressure difference between the inside and outside of the drill string when the drilling fluid circulates as an energy source, thereby greatly reducing the power and electric energy loss of the entire system.

[0005] According to the present invention, a device for absorbing and discharging downhole detection fluid includes a first hydraulic chamber, a second hydraulic chamber, a piston assembly separating the first hydraulic chamber from the second hydraulic chamber, and a sample chamber, wherein the first hydraulic chamber and the second hydraulic chamber can both be connected to an inner tube, the end surface of the piston assembly forms the bottom surface of the sample chamber, and the sample chamber is connected to the space between the inner tube and the outer tube, the fluid inside the inner tube can enter the first hydraulic chamber and push the piston assembly to move closer to the second hydraulic chamber, so that the pressure inside the sample chamber is lower than the pressure in the space between the inner tube and the outer tube; and the fluid inside the inner tube can enter the second hydraulic chamber and push the piston assembly to move closer to the first hydraulic chamber, so that the pressure inside the sample chamber is higher than the pressure in the space between the inner tube and the outer tube.

[0006] In a preferred embodiment, both the first hydraulic chamber and the second hydraulic chamber can be connected to the space between the inner tube and the outer tube, the fluid inside the inner tube can enter the first hydraulic chamber and at the same time the fluid in the space between the inner tube and the outer tube can enter the second hydraulic chamber; the fluid inside the inner tube can enter the second hydraulic chamber and at the same time the fluid in the space between the inner tube and the outer tube can enter the first hydraulic chamber.

[0007] In a preferred embodiment, the piston assembly includes a lower piston, an upper piston and a connecting rod connected between the lower piston and the upper piston, the top surface of the upper piston forms the bottom surface of the sample chamber, and the lower piston separates the first hydraulic chamber from the second hydraulic chamber.

[0008] In a preferred embodiment, the diameter of the lower piston is greater than the diameter of the upper piston.

[0009] In a preferred embodiment, the device for sucking and discharging downhole detection fluid further includes a sampling inlet tube and a sampling outlet tube connected to the sample cavity, and the sample cavity is connected to the space between the inner tube and the outer tube through the sampling inlet tube.

[0010] In a preferred embodiment, the sampling inlet pipe and the sampling outlet pipe are respectively provided with a first one-way valve and a second one-way valve.

[0011] In a preferred embodiment, the device for sucking and discharging downhole testing fluid further includes a plug and a limiter, the plug is arranged on the bottom surface of the lower hydraulic chamber, and the limiter is arranged on the upper surface of the plug.

[0012] In a preferred embodiment, the device for sucking and discharging downhole detection fluid also includes a first connecting pipe and a second connecting pipe, and the first hydraulic chamber is connected to the space between the inner pipe and the outer pipe and the interior of the inner pipe through the first connecting pipe and the second connecting pipe respectively.

[0013] In a preferred embodiment, the device for sucking and discharging downhole detection fluid also includes a third connecting pipeline and a fourth connecting pipeline, and the second hydraulic chamber is connected to the space between the inner tube and the outer tube and the interior of the inner tube through the third connecting pipeline and the fourth connecting pipeline respectively.

[0014] In a preferred embodiment, the first connecting pipeline, the second connecting pipeline, the third connecting pipeline and the fourth connecting pipeline are all provided with electric valves.

[0015] The present invention comprises a first hydraulic chamber, a second hydraulic chamber, a piston assembly separating the first hydraulic chamber from the second hydraulic chamber, and a sample chamber, wherein both the first hydraulic chamber and the second hydraulic chamber can be connected to an inner tube, the end surface of the piston assembly forms the bottom surface of the sample chamber, the sample chamber is connected to the space between the inner tube and the outer tube, and the fluid inside the inner tube can enter the first hydraulic chamber and push the piston assembly to move closer to the second hydraulic chamber, so that the pressure inside the sample chamber is lower than the pressure in the space between the inner tube and the outer tube, and the fluid inside the inner tube can enter the second hydraulic chamber and push the piston assembly to move closer to the first hydraulic chamber, so that the pressure inside the sample chamber is higher than the pressure in the space between the inner tube and the outer tube, so that the pressure difference between the inside and outside of the drill string during the circulation of the drilling fluid can be used as an energy source to realize the suction and discharge of the downhole detection fluid, thereby greatly reducing the power and electric energy loss of the entire system, and the entire pressure difference power system uses fewer mechanical components and has a simple structure.

[0016] The present invention enables the first hydraulic chamber and the second hydraulic chamber to be connected to the space between the inner tube and the outer tube, the internal fluid of the inner tube can enter the first hydraulic chamber, and the fluid in the space between the inner tube and the outer tube can enter the second hydraulic chamber, so as to push the piston assembly to move closer to the second hydraulic chamber, the internal fluid of the inner tube can enter the second hydraulic chamber, and the fluid in the space between the inner tube and the outer tube can enter the first hydraulic chamber, so as to push the piston assembly to move closer to the first hydraulic chamber, so as to use the fluid in the space between the inner tube and the outer tube to offset part of the pressure of the inner tube fluid, thereby avoiding system damage caused by excessive pressure difference between the first hydraulic chamber and the second hydraulic chamber, reducing the failure rate and improving the use.

[0017] The invention adopts the method of matching large and small I-shaped pistons through the lower piston and the upper piston, and uses the larger lower piston as the active piston and the smaller lower piston as the driven piston. Through the size difference between the lower piston and the upper piston, the effect of the pressure difference on the pressure generation is further amplified, thereby improving the efficiency of the pressure difference utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The schematic diagram schematically shows the overall structure of the device for sucking and discharging downhole testing fluid according to the present invention.

[0019] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as “bottom”, “top”, “inside”, “upper”, “lower”, “close to” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] In the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral or abutting connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1 As shown, the device 100 for sucking and discharging downhole detection fluid of the present invention comprises a first hydraulic chamber 7, a second hydraulic chamber 14, a piston assembly separating the first hydraulic chamber 7 from the second hydraulic chamber 14, and a sample chamber 5. The downhole detection fluid first flows in the inner tube (not shown in the figure), and then flows to the space between the inner tube and the outer tube (not shown in the figure) through the cut-off valve (not shown in the figure). The fluid pressure in the inner tube is greater than the fluid pressure in the space between the inner tube and the outer tube. The first hydraulic chamber 7 is located above the second hydraulic chamber 14. Both the first hydraulic chamber 7 and the second hydraulic chamber 14 can be connected to the inner tube. The end surface of the piston assembly forms the bottom surface of the sample chamber 5. The sample chamber 5 is connected to the space between the inner tube and the outer tube. The fluid inside the inner tube can enter the first hydraulic chamber 7 and push the piston assembly to move closer to the second hydraulic chamber 14. The cavity volume of the sample chamber 5 increases, so that the pressure inside the sample chamber 5 is lower than the pressure in the space between the inner tube and the outer tube, so that the fluid between the inner tube and the outer tube can be sucked into the sample chamber 5. The fluid inside the inner tube can enter the second hydraulic chamber 14 and push the piston assembly to move closer to the first hydraulic chamber 7. The volume of the sample chamber 5 is reduced so that the pressure inside the sample chamber 5 is higher than the pressure in the space between the inner tube and the outer tube, thereby enabling the fluid inside the sample chamber 5 to be discharged.

[0024] The present invention comprises a first hydraulic chamber 7, a second hydraulic chamber 14, a piston assembly separating the first hydraulic chamber 7 from the second hydraulic chamber 14, and a sample chamber 5, wherein both the first hydraulic chamber 7 and the second hydraulic chamber 14 can be connected to an inner tube, an end surface of the piston assembly forms a bottom surface of the sample chamber 5, the sample chamber 5 is connected to the space between the inner tube and the outer tube, and the fluid inside the inner tube can enter the first hydraulic chamber 7 and push the piston assembly to move closer to the second hydraulic chamber 14, so that the pressure inside the sample chamber 5 is lower than the pressure in the space between the inner tube and the outer tube, and the fluid inside the inner tube can enter the second hydraulic chamber 14 and push the piston assembly to move closer to the first hydraulic chamber 7, so that the pressure inside the sample chamber 5 is higher than the pressure in the space between the inner tube and the outer tube, so that the pressure difference between the inside and outside of the drill string during the circulation of the drilling fluid can be used as an energy source to realize the suction and discharge of the downhole detection fluid, thereby greatly reducing the power and electric energy loss of the entire system, and the entire pressure difference power system uses fewer mechanical components and has a simple structure.

[0025] In one or more embodiments, the first hydraulic chamber 7 and the second hydraulic chamber 14 can both be connected to the space between the inner tube and the outer tube, the fluid inside the inner tube can enter the first hydraulic chamber 7 and the fluid in the space between the inner tube and the outer tube can enter the second hydraulic chamber 14, and because the pressure of the fluid inside the inner tube is greater than the pressure of the fluid in the space between the inner tube and the outer tube, the pressure difference between the first hydraulic chamber 7 and the second hydraulic chamber 14 pushes the piston assembly to move closer to the second hydraulic chamber 14. The fluid inside the inner tube can enter the second hydraulic chamber 14 and the fluid in the space between the inner tube and the outer tube can enter the first hydraulic chamber 7, and the pressure difference between the first hydraulic chamber 7 and the second hydraulic chamber 14 pushes the piston assembly to move closer to the first hydraulic chamber 7, and by allowing the fluid in the space between the inner tube and the outer tube to offset part of the pressure of the fluid in the inner tube, it is possible to avoid system damage caused by excessive pressure difference between the first hydraulic chamber 7 and the second hydraulic chamber 14, reduce the failure rate and improve the use.

[0026] In one or more embodiments, the piston assembly includes a lower piston 13, an upper piston 6, and a connecting rod 12 connected between the lower piston 13 and the upper piston 6, the top surface of the upper piston 6 forms the bottom surface of the sample chamber 5, and the lower piston 13 separates the first hydraulic chamber 7 from the second hydraulic chamber 14. Optionally, the connecting rod 12 is perpendicular to the lower piston 13 and the upper piston 6. The fluid inside the inner tube enters the first hydraulic chamber 7 to push the lower piston 13 to move closer to the second hydraulic chamber 14, and the lower piston 13 drives the upper piston 6 to move downward together through the connecting rod 12, thereby increasing the volume of the sample chamber 5. The fluid inside the inner tube enters the second hydraulic chamber 14 to push the lower piston 13 to move closer to the first hydraulic chamber 7, and the lower piston 13 drives the upper piston 6 to move upward together through the connecting rod 12, thereby reducing the volume of the sample chamber 5.

[0027] In one or more embodiments, the diameter of the lower piston 13 is greater than the diameter of the upper piston 6. Optionally, the diameter of the lower piston 13 is 2 to 3 times the diameter of the upper piston 6.

[0028] The present invention adopts the method of matching large and small I-shaped pistons through the lower piston 13 and the upper piston 6, and uses the larger lower piston 6 as the active piston and the smaller lower piston 13 as the driven piston. Through the size difference between the lower piston 13 and the upper piston 6, the effect of the pressure difference on the pressure generation is further amplified, thereby improving the efficiency of the pressure difference utilization.

[0029] In one or more embodiments, the device 100 for absorbing and discharging downhole detection fluid described in the present invention further includes a sampling inlet tube 1 and a sampling outlet tube 3 connected to a sample chamber 5, and the sample chamber 5 is connected to the space between the inner tube and the outer tube through the sampling inlet tube 1.

[0030] In one or more embodiments, the sampling inlet pipe 1 and the sampling outlet pipe 5 are respectively provided with a first one-way valve 2 and a second one-way valve 4, and both the first one-way valve 2 and the second one-way valve 4 can be opened in response to pressure changes. The fluid inside the inner tube enters the first hydraulic chamber 7 and pushes the piston assembly to move closer to the second hydraulic chamber 14, and the cavity volume of the sample chamber 5 increases, so that the pressure inside the sample chamber 5 is lower than the pressure of the space between the inner tube and the outer tube. The first one-way valve 2 opens in response to the pressure change, so that the fluid between the inner tube and the outer tube can be sucked into the sample chamber 5 through the sampling inlet pipe 1. The fluid inside the inner tube enters the second hydraulic chamber 14 and pushes the piston assembly to move closer to the first hydraulic chamber 7, and the cavity volume of the sample chamber 5 decreases, so that the pressure inside the sample chamber 5 is higher than the pressure of the space between the inner tube and the outer tube. The second one-way valve 4 can be opened in response to the pressure change, so that the fluid inside the sample chamber 5 can be discharged outward through the sampling outlet pipe 5.

[0031] In one or more embodiments, the device 100 for sucking and discharging downhole detection fluid of the present invention further includes a plug 20 and a stopper 22, wherein the plug 20 is disposed on the bottom surface of the second hydraulic chamber 14, and the stopper 22 is disposed on the upper surface of the plug 20. The plug 20 can be installed in place through the mounting hole 21 and fixed by a screw.

[0032] In one or more embodiments, the device 100 for sucking and discharging downhole detection fluid of the present invention further includes a first connecting line 8 and a second connecting line 10, and the first hydraulic chamber 7 is connected to the space between the inner tube and the outer tube and the interior of the inner tube through the first connecting line 8 and the second connecting line 10. The first connecting line 8 and the second connecting line 10 are arranged near the top of the first hydraulic chamber 7, so as to ensure that when the upper piston 6 moves to the top of the sample chamber 5, the first connecting line 8 and the second connecting line 10 can still be connected to the inside and outside of the tube respectively.

[0033] In one or more embodiments, the device 100 for sucking and discharging downhole detection fluid described in the present invention also includes a third connecting pipeline 15 and a fourth connecting pipeline 17, and the second hydraulic chamber 14 is connected to the space between the inner tube and the outer tube and the interior of the inner tube through the third connecting pipeline 15 and the fourth connecting pipeline 17 respectively.

[0034] In one or more embodiments, the first connecting line 8, the second connecting line 10, the third connecting line 15 and the fourth connecting line 17 are all provided with electric valves, which can be opened and closed by a control system, thereby controlling the fluid to enter the second hydraulic chamber 14 and the first hydraulic chamber 7.

[0035] It should be noted that the length of the sample chamber 5 is slightly larger than the length of the second hydraulic chamber 14, and the third connecting line 15 and the fourth connecting line 17 are arranged close to the bottom of the second hydraulic chamber 14. When the plug 20 is installed, when the lower piston 13 moves to the bottom of the second hydraulic chamber 14, the end of the lower piston 13 is blocked by the limiter 22, thereby ensuring that the third connecting line 15 and the fourth connecting line 17 can still be connected with the inside and outside of the tube, and ensuring that the upper piston 6 is located in the sample chamber 5 and does not fall out during the entire movement of the piston assembly, thereby ensuring the separation of the sample chamber 5 from the first hydraulic chamber.

[0036] In one or more embodiments, the end surfaces of the lower piston 13 and the upper piston 6 are both provided with rubber pads, and piston rings and multiple sealing rings are arranged under the rubber pads, so as to ensure the sealing performance of the lower piston 13 and the upper piston 6. By providing the end surfaces of the lower piston 13 and the upper piston 6 with rubber pads, the piston displacement efficiency can be improved on the one hand, and the impact of the metal material can be buffered on the other hand.

[0037] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for sucking and discharging downhole testing fluid, comprising a first hydraulic chamber, a second hydraulic chamber, a piston assembly separating the first hydraulic chamber from the second hydraulic chamber, and a sample chamber, wherein the first hydraulic chamber and the second hydraulic chamber can both be connected to an inner tube, an end surface of the piston assembly forms a bottom surface of the sample chamber, and the sample chamber is connected to a space between the inner tube and an outer tube, The fluid inside the inner tube can enter the first hydraulic chamber and push the piston assembly to move closer to the second hydraulic chamber, so that the pressure inside the sample chamber is lower than the pressure in the space between the inner tube and the outer tube; and the fluid inside the inner tube can enter the second hydraulic chamber and push the piston assembly to move closer to the first hydraulic chamber, so that the pressure inside the sample chamber is higher than the pressure in the space between the inner tube and the outer tube.

2. The device for sucking and discharging downhole testing fluid according to claim 1, characterized in that: Both the first hydraulic chamber and the second hydraulic chamber can be connected to the space between the inner tube and the outer tube, the fluid inside the inner tube can enter the first hydraulic chamber and at the same time the fluid in the space between the inner tube and the outer tube can enter the second hydraulic chamber; the fluid inside the inner tube can enter the second hydraulic chamber and at the same time the fluid in the space between the inner tube and the outer tube can enter the first hydraulic chamber.

3. The device for sucking and discharging downhole testing fluid according to claim 2, characterized in that: The piston assembly includes a lower piston, an upper piston and a connecting rod connected between the lower piston and the upper piston. The top end surface of the upper piston forms the bottom surface of the sample chamber. The lower piston separates the first hydraulic chamber from the second hydraulic chamber.

4. The device for sucking and discharging downhole testing fluid according to claim 3, characterized in that: The diameter of the lower piston is greater than the diameter of the upper piston.

5. The device for sucking and discharging downhole testing fluid according to claim 2, characterized in that: It also includes a sampling inlet tube and a sampling outlet tube connected with the sample cavity. The sample cavity is connected with the space between the inner tube and the outer tube through the sampling inlet tube.

6. The device for sucking and discharging downhole testing fluid according to claim 5, characterized in that: The sampling inlet pipe and the sampling outlet pipe are respectively provided with a first one-way valve and a second one-way valve.

7. The device for sucking and discharging downhole testing fluid according to claim 2, characterized in that: It also includes a blocker and a stopper. The blocker is arranged on the bottom surface of the lower hydraulic chamber, and the stopper is arranged on the upper surface of the blocker.

8. The device for sucking and discharging downhole testing fluid according to claim 2, characterized in that: It also includes a first communicating pipeline and a second communicating pipeline, and the first hydraulic chamber is connected to the space between the inner tube and the outer tube and the interior of the inner tube through the first communicating pipeline and the second communicating pipeline respectively.

9. The device for sucking and discharging downhole testing fluid according to claim 8, characterized in that: It also includes a third communicating pipeline and a fourth communicating pipeline, and the second hydraulic chamber is connected to the space between the inner tube and the outer tube and the interior of the inner tube through the third communicating pipeline and the fourth communicating pipeline respectively.

10. The device for sucking and discharging downhole testing fluid according to claim 9, characterized in that: The first connecting pipeline, the second connecting pipeline, the third connecting pipeline and the fourth connecting pipeline are all provided with electric valves.

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