Shoe for well logging instrument and method of operation

Abstract

The application provides a guide shoe for a well logging instrument, comprising a guide head, and an adjusting mechanism, the adjusting mechanism comprising a joint, a sliding sleeve arranged on one side of the guide head close to the joint, and a spring arranged between the joint and the sliding sleeve, wherein the guide shoe further comprises a steel cable concentrically arranged in the sliding sleeve, and two ends of the steel cable are fixedly connected with the joint and the guide head through fixing members respectively.

Description

Technical Field

[0001] This invention relates to the field of cable logging technology, specifically to a guide shoe for logging instruments and a construction method. Background Technology

[0002] Currently, in the exploration and development of ultra-deep drilling projects in the Tarim Basin, open-hole logging in the vertical well section during the intermediate completion stage generally uses wireline logging. If the well conditions are good, wireline + instrument string is used; if the well conditions are risky, wireline + instrument string + guide cone is used.

[0003] Currently, due to factors such as the long open-hole section, the crossing of multiple strata, the large differences in lithology between different strata, and the influence of drilling fluid, some sections of the open-hole section collapse to form large "belly" formations, and some sections have alternating soft and hard surfaces to form steps. The current wireline logging directional cone technology cannot effectively avoid obstruction, with no fewer than 18 wells encountering obstruction each year. After discussion, these wells are either switched to direct-push logging or the logging project is canceled, which seriously affects drilling efficiency and the rate of geological data acquisition.

[0004] Therefore, considering the shortcomings of current cable logging guide cones and the needs of oilfield development, it is desirable to provide a guide shoe for logging instruments to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to propose a guide shoe for logging instruments, which can compensate for the inadequacy of conventional cable logging guide cones and avoid logging obstruction caused by wellbore steps and large boreholes in the open hole section. It is of great significance for obtaining complete logging data and improving the understanding of regional reservoir geology.

[0006] According to a first aspect of the invention, a guide shoe for a logging instrument is provided, comprising a guide head.

[0007] Connectors are spaced apart from the guide head and are connected to logging instruments.

[0008] The sliding sleeve abuts against the guide head.

[0009] A mandrel is disposed at one end of the joint near the sliding sleeve, the free end of the mandrel being able to extend and penetrate into the sliding sleeve.

[0010] A spring, which is sleeved on the mandrel and abuts against the sliding sleeve and the connector respectively, and

[0011] The steel cables are concentrically arranged within the sliding sleeve and are fixedly connected to the guide head and the connector, respectively.

[0012] The joint is configured to descend under external force and compress the spring, thereby reducing the tension of the steel cable to allow the guide head to bend under the action of the well wall steps.

[0013] In one embodiment, both the guide head and the connector are provided with through holes adapted to the steel cable, and the through holes are constructed as Morse taper holes.

[0014] In one embodiment, a plurality of springs are arranged in a mating connection along the axial direction of the mandrel.

[0015] In one embodiment, the length of the sliding sleeve is greater than the compression stroke of the spring.

[0016] In one embodiment, the guide head is provided with a receiving chamber that allows the mandrel to enter.

[0017] In one embodiment, a plug for limiting the steel cable is provided inside the guide head.

[0018] In one embodiment, an inclined surface is formed on the upper end face of the slide sleeve to allow the guide head to bend.

[0019] In one embodiment, the connector is threadedly connected to the logging instrument.

[0020] According to a second aspect of the present invention, a construction method is provided, which utilizes a guide shoe for a logging instrument as described above, comprising the following steps:

[0021] S1. After assembling the guide shoe with the logging instrument, lower it into the well until the guide head encounters resistance in the well.

[0022] S2. Apply downward pressure to move the connector downward and compress the spring to reduce the tension of the steel cable, thereby allowing the guide head to bend under the action of the well wall step to pass over the well wall step.

[0023] In one embodiment, a preload stress is applied to the spring during assembly to keep the steel cable taut.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] Firstly, this invention can compensate for the shortcomings of conventional cable logging guide cones, and avoid logging obstruction caused by wellbore steps and large boreholes in the open hole section. It is of great significance for obtaining complete logging data and improving the understanding of regional reservoir geology.

[0026] In addition, this device features simple structure, easy operation, and good durability. Its application can improve the logging data acquisition rate and regional reservoir geology understanding, while also improving logging construction efficiency and economic benefits. It has a promising prospect for widespread application.

[0027] Secondly, this invention enables the guide head to bend, so as to smoothly cross the well wall steps and continue the diving operation.

[0028] Preferably, when the guide head encounters resistance in the well, the joint continues to descend under external pressure, thereby compressing the spring to further reduce the tension of the steel cable. At this time, the guide head will have greater freedom, thus making it easier to change its diving direction under the action of the well wall steps. That is, the guide head will bend and then cross the well wall steps to continue the diving operation. Attached Figure Description

[0029] The invention will now be described in detail with reference to the accompanying drawings, in which:

[0030] Figure 1 The schematic diagram illustrates the structure of the guide shoe for a well logging instrument according to the present invention.

[0031] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0032] The meanings of the reference numerals in the attached figures are as follows:

[0033] 10 seekers

[0034] 11 connectors

[0035] 111 spindle

[0036] 12 Sliding Sleeves

[0037] 13 springs

[0038] 14 steel cables

[0039] 141 First fastener

[0040] 142 Second fastener

[0041] 15-thread plug. Detailed Implementation

[0042] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0043] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0045] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] The invention will now be further described with reference to the accompanying drawings.

[0047] Figure 1 The schematic diagram shows the structure of the guide shoe 100 for a logging instrument according to the present invention.

[0048] like Figure 1 As shown, according to a first aspect of the present invention, a guide shoe 100 for a logging instrument is provided, which mainly includes a guide head 10 and an adjustment mechanism adapted to the guide head 10, wherein the adjustment mechanism includes a connector 11, a sliding sleeve 12, and a spring 13. Preferably, the connector 11 is fixedly connected to the upper logging instrument, thereby enabling the logging instrument to smoothly complete the diving operation; the sliding sleeve 12 is arranged at a distance from the connector 11 and is disposed at the end of the guide head 10 away from the connector 11; the spring 13 is disposed between the sliding sleeve 12 and the connector 11, thereby facilitating subsequent adjustment work, the details of which are described below.

[0049] Preferably, the guide head 10 is located at the foremost end of the guide shoe of the logging instrument, and its axial through hole is divided into four sections: a screw hole at the top, a Morse taper hole above that, a small round hole immediately following, and a large round hole near the sliding sleeve section. Preferably, a Morse taper hole adapted to the steel cable 14 is also provided on the connector 11.

[0050] In one embodiment of the present invention, such as Figure 1 As shown, the guide shoe 100 for the logging instrument also includes a steel cable 14 concentrically arranged within the sliding sleeve 12. Preferably, the first end of the steel cable 14 extends out of the sliding sleeve 12 to be fixedly connected to the connector 11, and the second end of the steel cable 14 extends out of the sliding sleeve 12 to be fixedly connected to the guide head 10.

[0051] In this invention, the degree of freedom of the guide head 10 can be adjusted by changing the tension of the steel cable 14, thereby helping to change the working state of the guide head 10 and providing technical support for the diving or bending guidance work of this device.

[0052] Preferably, such as Figure 1 As shown, the two ends of the steel cable 14 are fixedly connected to the connector 11 and the guide head 10 respectively by fasteners. Specifically, the first end of the steel cable 14 is fixedly connected to the connector 11 by the first fastener 141, and the second end of the steel cable 14 is fixedly connected to the guide head 10 by the second fastener 142. Therefore, by adjusting the relative position of the connector 11 and the sliding sleeve 12, the tension of the steel cable 14 can be changed, thereby further achieving the purpose of changing the working state of the guide head 10.

[0053] Preferably, the guide head 10 is provided with a receiving chamber that allows the mandrel 111 to enter.

[0054] In one embodiment, such as Figure 1 As shown, a receiving chamber is formed within the sliding sleeve 12. The adjusting mechanism also includes a mandrel 111 extending axially outward from the side end of the connector 11. Preferably, the mandrel 111 is configured to extend laterally into the receiving chamber, thereby enabling a sliding connection between the mandrel 111 and the sliding sleeve 12 during subsequent movements.

[0055] Preferably, the length of the mandrel 111 should be greater than the degree of freedom of the spring 13, and the length of the sliding sleeve 12 should be greater than the compression stroke of the spring 13. In this way, the mandrel 111 can always slide laterally along the receiving chamber of the sliding sleeve 12 during the compression of the spring 13, thereby ensuring the stability and reliability of the device throughout the guiding process.

[0056] In addition, this method can effectively prevent the spindle 111 from disengaging from the sleeve 12, thereby further improving the reset capability and reusability of the device.

[0057] In one embodiment of the present invention, the mandrel 111 is constructed as a hollow sleeve, and the steel cable 14 is concentrically arranged inside the mandrel 111. Thus, the steel cable 14, mandrel 111, and spring 13 in this device are arranged sequentially from the inside to the outside. Therefore, in this way, the mandrel 111 can provide good protection for the steel cable 14, thereby further improving the stability and reliability of the device.

[0058] In this invention, when the guide head 10 encounters resistance in the well, the joint 11 continues to descend under external pressure, thereby compressing the spring 13 to further reduce the tension of the steel cable 14. At this time, the guide head 10 will have greater freedom, thus making it easier to change its diving direction under the action of the well wall steps. That is, the guide head 10 will bend and then cross the well wall steps to continue the diving operation.

[0059] Preferably, the diameter of the seeker head 10 is much smaller than the diameter of the wellbore. This effectively increases the success rate of the seeker head 10 over wellbore steps.

[0060] In one embodiment, at least five springs 13 are arranged axially along the mandrel 111. Preferably, adjacent springs 13 are matingly connected to improve the overall strength and stiffness of the springs 13. Furthermore, the connector 11 can smoothly compress the springs 13 after descending under external force, thus providing a guarantee for reducing the tension of the steel cable 14 and allowing the guide head 10 to bend.

[0061] In this invention, the length of the steel cable 14 should be adjusted before entering the well to apply appropriate pre-tightening stress to the spring 13, thereby improving the mobility and response speed of the entire device, so as to ensure that the logging instrument can be quickly lowered under the action of the guide shoe 100, so as to further improve the logging efficiency and quality.

[0062] In one embodiment, such as Figure 1 As shown, a plug 15 is provided inside the guide head 10. Preferably, the plug 15 can not only effectively seal the guide head 10, but also cooperate with the second fixing member 142 to firmly install the second end of the steel cable 14 inside the guide head 10, so as to ensure that the guide head 10 can bend smoothly and thus smoothly cross the well wall step.

[0063] Preferably, a guide ramp is formed on the upper end face of the sliding sleeve 12. Therefore, when the tension of the steel cable 14 decreases and the degree of freedom of the guide head 10 is increased, the guide head 10 can bend more easily under the action of the guide ramp, thereby improving the efficiency of downhole operations while shortening downhole operation time.

[0064] Preferably, the bending angle of the guide head 10 is 0 to 180°.

[0065] According to a second aspect of the present invention, a construction method is provided, which utilizes a guide shoe for a logging instrument as described above, comprising the following steps:

[0066] First, after fixing the upper part of the connector 11 to the lower part of the logging instrument, lower it into the well until the guide head 10 encounters resistance in the well.

[0067] Then, the logging instrument applies downward pressure to make the connector 11 move downward. At the same time, the spring 13 will be compressed under the action of the connector 11 to further reduce the tension of the steel cable 14.

[0068] Preferably, since the force exerted by the steel cable 14 on the guide head 10 is reduced, the guide head 10 will have a greater degree of freedom.

[0069] Finally, the guide head 10 changes its descent direction under the action of the well wall steps, making it easier to bend and further cross the well wall steps to continue the descent.

[0070] In one embodiment of the present invention, the length of the steel cable 14 should be adjusted before entering the well to apply appropriate pre-tightening stress to the spring 13, thereby improving the mobility and response speed of the entire device, so as to ensure that the logging instrument can be quickly lowered under the action of the guide shoe 100, so as to further improve the logging efficiency and quality.

[0071] Compared with existing technologies, the advantages of this invention are:

[0072] Firstly, this invention can compensate for the shortcomings of conventional cable logging guide cones, and avoid logging obstruction caused by wellbore steps and large boreholes in the open hole section. It is of great significance for obtaining complete logging data and improving the understanding of regional reservoir geology.

[0073] In addition, this device features simple structure, easy operation, and good durability. Its application can improve the logging data acquisition rate and regional reservoir geology understanding, while also improving logging construction efficiency and economic benefits. It has a promising prospect for widespread application.

[0074] Secondly, the present invention enables the guide head 10 to bend, so as to smoothly cross the well wall steps and continue the diving operation.

[0075] Preferably, when the guide head 10 encounters resistance in the well, the joint 11 continues to descend under external pressure, thereby compressing the spring 13 to further reduce the tension of the steel cable 14. At this time, the guide head 10 will have greater freedom, thus making it easier to change its diving direction under the action of the well wall steps. That is, the guide head 10 will bend and then cross the well wall steps to continue the diving operation.

[0076] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present invention, and such changes or modifications should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A guide shoe for a well logging instrument, comprising: Guide head (10), A connector (11) is arranged at intervals from the guide head (10), and the connector (11) is connected to the logging instrument. Sliding sleeve (12), which abuts against the guide head (10), A mandrel (111) is disposed at one end of the connector (11) near the sliding sleeve (12), the free end of the mandrel (111) being able to extend into the sliding sleeve (12). Spring (13), which is sleeved on the mandrel (111) and abuts against the sliding sleeve (12) and the connector (11) respectively, and A steel cable (14) is concentrically arranged within the sliding sleeve (12) and fixedly connected to the guide head (10) and the connector (11), respectively. The joint (11) is configured to move downward under the action of an external force and compress the spring (13), thereby reducing the tension of the cable (14) to allow the guide head (10) to bend under the action of the well wall steps.

2. The guide shoe for a well logging instrument according to claim 1, characterized in that, Both the guide head (10) and the connector (11) are provided with through holes adapted to the steel cable (14), and the through holes are constructed as Morse taper holes.

3. The guide shoe for a well logging instrument according to claim 2, characterized in that, Multiple springs (13) are arranged in a cooperating connection along the axial direction of the spindle (111).

4. The guide shoe for a well logging instrument according to claim 3, characterized in that, The length of the sliding sleeve (12) is greater than the compression stroke of the spring (13).

5. The guide shoe for a well logging instrument according to claim 4, characterized in that, The guide head (10) is provided with a receiving chamber that allows the mandrel (111) to enter.

6. The guide shoe for a well logging instrument according to claim 5, characterized in that, A plug (15) for limiting the steel cable (14) is provided inside the guide head (10).

7. The guide shoe for a logging instrument according to any one of claims 1 to 4, characterized in that, An inclined surface is formed on the upper end face of the sliding sleeve (12) to allow the guide head (10) to bend.

8. The guide shoe for a logging instrument according to any one of claims 1 to 4, characterized in that, The connector (11) is threadedly connected to the logging instrument.

9. A construction method utilizing a guide shoe for a logging instrument according to any one of claims 1 to 8, comprising the following steps: S1. After assembling the guide shoe with the logging instrument, lower it into the well until the guide head (10) encounters resistance in the well. S2. Apply downward pressure to move the connector (11) downward and compress the spring (13) to reduce the tension of the cable (14), thereby allowing the guide head (10) to bend under the action of the well wall step to pass over the well wall step.

10. The guide shoe for a well logging instrument according to claim 9, characterized in that, During assembly, a preload stress needs to be applied to the spring (13) to keep the steel cable (14) taut.

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