Downhole fluid continuous detection device and drill collar

Abstract

The present invention relates to a downhole fluid continuous detection device, comprising: a body, wherein a first through hole and a second through hole are axially provided on the body; a fluid tube mounted on the outer wall of the body, wherein the fluid tube has a channel for fluid circulation, and the two ends of the channel are respectively connected to the first through hole and the second through hole; and a fluid detection device for detecting the fluid in the fluid tube. A rotating rod is provided in the channel, and a plurality of spiral blades are provided on the rotating rod so as to abut against the inner wall of the fluid tube. The spiral blades can be rotated by a driving device to achieve directional flow of the fluid in the channel.

Description

Technical Field

[0001] The invention relates to a downhole fluid continuous detection device and a drill collar comprising the downhole fluid continuous detection device. Background Art

[0002] During oil drilling, detection-while-drilling (MDD) technology has become a crucial tool for real-time monitoring of various downhole information. Testing downhole drilling fluid properties is a crucial component of MWD. ​​Testing downhole drilling fluid properties plays a crucial role in real-time oil and gas detection, accurate positioning of oil and gas reservoirs, understanding the wellbore temperature and pressure profile, early detection and accurate location of drilling anomalies such as kicks and lost circulation, ensuring drilling safety, and improving geosteering quality. To achieve downhole drilling fluid parameter testing, continuous sampling of the drilling fluid and ensuring that the drilling fluid meets specified quality standards are paramount.

[0003] At present, the status of downhole fluid sampling at home and abroad is as follows. In formation testers represented by Schlumberger, formation fluids are sampled. The main method is to push the support arm from the downhole formation tester instrument, push the instrument against the well wall, and extend the probe from the instrument into the well wall formation. The probe has a filter device that filters the fluid, and the piston pump is driven by the motor to extract the formation fluid and push the fluid into the sample tube for testing. The flow direction of the fluid is selected by the switch valve, that is, when the pump is extracting, the sampling valve is opened to extract the fluid; when the sampling valve is closed, the valve in the flow channel is opened to push the fluid into the sample tube. If fluid sampling is to be performed, the sampling valve is opened and fluid sampling is performed. This method can effectively extract and sample formation fluid samples, but the structure and control system are complex. It is used for sampling and testing of formation fluids, and is not used for downhole drilling fluid detection.

[0004] According to the currently available information in China, downhole drilling fluid testing and sampling uses a motor to drive the piston to suck and sample. The suction sampling can only be performed periodically at intervals, that is, a sample is taken for testing when the piston pump is extracted, and sampling is performed again after the sample is pushed out. The power motor also needs to be controlled to rotate forward and reverse to drive the sampling pump. This method cannot achieve continuous sampling of drilling fluid, so the detection is periodic and cannot be performed continuously. In addition, piston sampling requires the motor to have a considerable extension and retraction stroke, so the structure of the motor is relatively complex and the volume is large. In addition, piston sampling is in a space that the piston cannot reach, which easily forms a dead volume problem in the fluid circulation, affecting the detection accuracy, so it has strong limitations during downhole installation and testing. Summary of the Invention

[0005] To address the aforementioned technical issues, the present invention provides a downhole fluid continuous detection device. This device is compact and simple in structure, avoiding the dead volume problem associated with piston-type sampling. Furthermore, it enables continuous downhole fluid sampling, enhancing sampling reliability.

[0006] According to a first aspect of the present invention, there is provided a downhole fluid continuous detection device, comprising: a main body, on which a first through hole and a second through hole are axially arranged and pass through the main body; a fluid tube installed on the outer wall of the main body, wherein the fluid tube has a channel for fluid circulation, and the two ends of the channel are respectively connected to the first through hole and the second through hole; and a fluid detection device for detecting the fluid in the fluid tube.

[0007] A rotating rod is provided in the channel, and a plurality of spiral blades are provided on the rotating rod to abut against the inner wall of the fluid pipe. The spiral blades can be rotated by a driving device to achieve directional flow of the fluid in the channel.

[0008] In a preferred embodiment, the driving device is a DC motor, and the rotation direction of the DC motor is controlled so that the fluid has two different flow directions in the channel.

[0009] In a preferred embodiment, the DC motor is connected to the rotating rod through a dynamic sealing device.

[0010] In a preferred embodiment, a mounting bracket is provided on the outside of the fluid pipe in parallel with the fluid pipe, and the fluid detection device is mounted on the mounting bracket.

[0011] In a preferred embodiment, a gap is formed between the spiral blade and both ends of the rotating rod, and the fluid detection device extends into the gap to detect the fluid.

[0012] In a preferred embodiment, filters are provided in both the first through hole and the second through hole.

[0013] In a preferred embodiment, the filtering surface of the filter is substantially V-shaped.

[0014] In a preferred embodiment, the filter is a stainless steel sintered filter or a filter mesh, which is fixed in the first through hole and the second through hole through a connecting piece.

[0015] According to a second aspect of the present invention, there is provided a drill collar comprising a groove and the downhole fluid continuous detection device in the groove.

[0016] In a preferred embodiment, the body of the downhole fluid continuous detection device is constructed as a cover plate having the same arc as the outer surface of the drill collar, so that the body can seal the groove.

[0017] The downhole fluid continuous detection device described in this invention uses a motor-driven continuous spiral blade to transport fluid, enabling continuous and stable fluid flow within a fluid sampling channel. This not only enables continuous sampling, facilitating the acquisition of continuous and stable fluid data using the detection device, but also simplifies the device's structure and reduces its size, while also addressing the dead volume problem that traditional piston-type sampling devices often create within the fluid sampling channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described below with reference to the accompanying drawings.

[0019] Figure 1 A schematic diagram of a downhole fluid continuous detection device according to an embodiment of the present invention is shown.

[0020] Figure 2 Shows the Figure 1 Schematic diagram of the drill collar of the downhole fluid continuous detection device.

[0021] In this application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn to scale. DETAILED DESCRIPTION

[0022] The present invention will be described below with reference to the accompanying drawings.

[0023] Figure 1 FIG. 1 shows a schematic diagram of a downhole fluid continuous detection device according to an embodiment of the present invention. Figure 1 As shown, the detection device 100 includes a body 10, on which a first through hole 12 and a second through hole 14 are respectively provided along the axial direction. The first through hole 12 and the second through hole 14 penetrate the body 10, so that fluid can pass through the first through hole 12 and the second through hole 14 from one side of the body 10 to the other side of the body 10.

[0024] like Figure 1 As shown, a fluid tube 20 is provided on the outer wall of the body 10. The fluid tube 20 is a hollow tube, and defines a channel 30 for fluid circulation therein. The first end 32 and the second end 34 of the channel 30 are respectively connected to the first through hole 12 and the second through hole 14, so that fluid can flow into or out of the channel 30 through the first through hole 12 and the second through hole 14.

[0025] A rotating rod 35 is disposed within the channel 30, with its ends connected to the first end 32 and the second end 34 of the channel 30, respectively. A continuous spiral blade 38 is disposed on the outer wall of the rotating rod 35, abutting the inner wall of the fluid tube 20. Thus, when the rotating rod 35 rotates, thereby driving the continuous spiral blade 38 to rotate, the continuous spiral blade 38 can drive fluid to flow within the channel 30. For example, when the continuous spiral blade 38 rotates clockwise, it can drive fluid entering the channel 30 from the first end 32 to the second end 34 of the channel 30, that is, flowing into the first through-hole 12 and out of the second through-hole 14, thereby forming a continuous and stable liquid flow within the channel 30. Conversely, when the continuous spiral blade 38 rotates counterclockwise, it can drive fluid entering the channel 30 from the second end 34 to the first end 32 of the channel 30, that is, flowing into the second through-hole 14 and out of the first through-hole 12, thereby also forming a continuous and stable liquid flow within the channel 30. On the other hand, since both ends of the channel 30 are connected to the downhole space through the first through hole 12 and the second through hole 14 respectively, the pressure balance at both ends of the channel 30 can be ensured, which facilitates the rotation of the continuous spiral blades 38 to transport the fluid.

[0026] Although only one continuous spiral blade 38 is used as an example in this embodiment, it is easy to understand that more than one continuous spiral blade or several separately arranged spiral blades can also be provided on the rotating rod 35.

[0027] A mounting bracket 40 is provided parallel to the fluid tube 20 on a side of the fluid tube 20 that is away from the body 10. An annular space 45 is formed axially between the mounting bracket 40 and the fluid tube 20. Multiple fluid detection devices (not shown) can be installed in the annular space 45 according to detection needs. These detection devices may include, for example, various types of sensors. The sensor probes extend into the fluid tube 20, thereby contacting the fluid in the channel 30 and detecting data such as the fluid's density, viscosity, and pH value.

[0028] Essentially, to prevent the portion of the detection device extending into the fluid tube 20 from obstructing the rotation of the continuous spiral blade 38, the axial length of the continuous spiral blade 38 is shorter than the length of the rotating rod 35, thereby forming gaps 36 axially between the continuous spiral blade 38 and both ends of the rotating rod 35. Simultaneously, the sensor can extend into these gaps 36, thereby ensuring that the continuous spiral blade 38 rotates normally without interference.

[0029] like Figure 1As shown, the device 100 further includes a driving device disposed on a side of the body 10 near the fluid pipe 20, such as a motor 50. The motor 50 is connected to the rotating rod 35, so that the rotation of the motor 50 drives the rotating rod 35 and the continuous spiral blades 38 on the rotating rod 35 to rotate, thereby achieving the flow of fluid in the channel 30.

[0030] In a preferred embodiment, the motor 50 is also provided with a reducer 52. This allows the motor 50 to be decelerated to a preset value using the reducer 52 with varying conversion ratios, depending on actual needs. This allows the motor 50 to control the speed of the rotating rod 35 while also increasing the motor 50's output torque. Furthermore, a dynamic sealing device 55 is connected to the free end of the reducer's power output shaft 53, connecting the reducer 52 and the rotating rod 35 via the dynamic sealing device 55. Thus, the rotation of the motor 50 drives the reducer 52. The speed of the motor 50, adjusted by the reducer 52, drives the power output shaft 53, which in turn drives the dynamic sealing device 55, ultimately driving the rotating rod 35. During this process, the dynamic sealing device 55 seals the fluid tube 20. The reducer 52 and the dynamic sealing device 55 are well known to those skilled in the art, and a detailed description thereof is omitted herein.

[0031] like Figure 1 As shown, a filter 60 is disposed on each of the first through hole 12 and the second through hole 14. The filter 60 is secured within the first through hole 12 and the second through hole 14 via a connecting member, such as a spring clip or a thread. The filter 60 is used to filter impurities contained in the fluid entering the fluid pipe 20. The filter 60 may be, for example, a stainless steel sintered filter or filter mesh. Filters or filter meshes made of such materials have excellent corrosion resistance and are suitable for use in highly corrosive environments underground.

[0032] At the same time, in order to prevent the impurities in the fluid from clogging the filter 60 when the fluid flows into the fluid tube 20 through the filter 60 for a long time, the motor 50 is configured as a DC motor, and the direction of rotation of this DC motor can be artificially controlled. Thus, by setting the direction of the motor 50 to alternate, the flow direction of the fluid in the channel 30 is alternately converted. For example, in the first time period, the fluid flows from the first end 32 of the channel 30 to the second end 34, that is, flows in from the first through hole 12 and flows out from the second through hole 14. After the motor turns in the second time period, the fluid flows out from the second through hole 14 and flows in from the first through hole 12. In this way, while ensuring that there is always liquid flow in the channel 30 and does not affect the detection work, the fluid can backwash the filter 60, thereby avoiding the filter 60 from being blocked and improving the reliability of the device 100.

[0033] In a preferred embodiment, the filtering surface on the upper side of the filter 60 is configured in a substantially V-shape. As is readily understood, this configuration facilitates the cleaning of the filter 60 surface by the fluid, while also preventing the filter 60 from excessively contacting the well wall and causing damage.

[0034] Figure 2 Shows the Figure 1 Schematic diagram of the drill collar of the downhole fluid continuous detection device shown in FIG. Figure 2 As shown, a groove 75 is provided on the wall of the drill collar 70, and the downhole fluid continuous detection device 100 is installed in the groove 75. Preferably, the body 10 is constructed as a cover plate with the same arc as the outer surface of the drill collar 70, so that the body 10 is compatible with the groove 75. In this way, the device 100 can be embedded in the wall of the drill collar 70 as a whole, simplifying the structure of the device 100 and making it more suitable for the narrow environment downhole. On the other hand, the body 10 can seal the groove 75, thereby protecting the various components of the device 100 located on the side of the body 10 located on the fluid pipe 20.

[0035] The following briefly describes the use of the downhole fluid continuous detection device 100 according to the present invention.

[0036] The downhole fluid continuous detection device 100 of the present invention is installed in the drill collar 70 with the groove 75. After the motor 50 is turned on and the switching frequency of the motor direction is set, the device 100 is lowered into the well together with the drill collar 70.

[0037] When the device 100 is lowered to a predetermined position downhole along with the drill collar 70, fluid flowing through the body of the device 100 flows through the first through-hole 12 or the second through-hole 14 into the channel 30. Driven by the continuous spiral blades 38, a continuous and stable flow of fluid is formed within the channel 30. This allows the detection device embedded in the fluid pipe 20 to record downhole fluid detection data. This data can then be uploaded to the surface by a downhole data transmission device for real-time analysis and drilling guidance.

[0038] At the same time, after the device 100 is pulled out of the ground after the drilling is completed, all the detection data recorded in the detection device can be played back and the data can be analyzed again.

[0039] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A downhole fluid continuous detection device (100), comprising: A body (10) is arranged on the outer surface of the drill collar (70), wherein a first through hole (12) and a second through hole (14) are axially arranged on the body and penetrate the body; A fluid tube (20) is installed on the outer wall of the body, wherein the fluid tube has a channel (30) for fluid circulation, wherein both ends of the channel are connected to the first through hole and the second through hole, respectively, and filters (60) are provided in the first through hole and the second through hole; and a fluid detection device for detecting the fluid in the fluid pipe; A rotating rod (35) is provided in the channel, and a spiral blade (38) is provided on the rotating rod to abut against the inner wall of the fluid pipe. The spiral blade can be rotated by a driving device, thereby realizing continuous directional flow of the fluid in the channel. The driving device is a DC motor (50). By controlling the rotation direction of the DC motor, the fluid has two different flow directions in the channel, so that the fluid can flow into the channel from the first through hole and then flow out from the second through hole, or can flow into the channel from the second through hole and then flow out from the first through hole.

2. The downhole fluid continuous detection device according to claim 1, characterized in that: The DC motor is connected to the rotating rod via a dynamic sealing device (55).

3. The downhole fluid continuous detection device according to claim 1, characterized in that: A mounting frame (40) is provided on the outside of the fluid pipe (20) and parallel to the fluid pipe (20), and the fluid detection device is mounted on the mounting frame.

4. The downhole fluid continuous detection device according to claim 1, characterized in that: A gap (36) is formed between the spiral blade and the two ends of the rotating rod, and the fluid detection device extends into the gap to detect the fluid.

5. The downhole fluid continuous detection device according to claim 1, characterized in that: The filtering surface of the filter is configured as a "V" shape.

6. The downhole fluid continuous detection device according to claim 5, characterized in that: The filter is a stainless steel sintered filter or a filter mesh, which is fixed in the first through hole and the second through hole through a connecting piece.

7. A drill collar (70) comprising a groove (75) provided in an outer surface of the drill collar, and a downhole fluid continuous detection device according to any one of claims 1 to 6 installed in the groove.

8. The drill collar according to claim 7, characterized in that The body of the downhole fluid continuous detection device is constructed to have the same curvature as the outer surface of the drill collar.

Images