Bottom cone for detecting depth of ball seat

Abstract

The utility model relates to the technical field of auxiliary descending tools of separated layer water injection well testing instruments, in particular to a base cone for depth detection of a ball seat, which comprises a main body, a connector is arranged at one end of the main body and used for being connected with a downhole tool, and a cone body connected with the other end of the main body is eccentrically arranged. When the cone eccentrically arranged at the lower end of the main body is in contact with a ball seat at the bottom of a water injection well tubular column, the contact area between the cone and the surface of the ball seat is greatly reduced, and an attached sealing state is not formed under the action of pressure, so that the bottom cone can be smoothly separated from the ball seat when an instrument is lifted after ball seat depth detection is completed; the situation that the base cone falls into the ball seat and is sealed with the ball seat and is difficult to fall off from the ball seat during lifting operation is avoided, it is guaranteed that the ball seat depth detection operation is smoothly carried out, an underground tool can be put down to an accurate position in testing operation, and guarantee is provided for normal allocation of a separate layer water injection well and completion of flow measurement work.

Description

Technical Field

[0001] The utility model relates to the technical field of auxiliary downhole tools of layered water injection well testing instruments, in particular to a bottom cone for ball seat depth detection. Background Art

[0002] In the process of oil reservoir development, in order to supplement underground energy and improve crude oil recovery, it is necessary to inject water into the formation through water injection wells to maintain or restore oil layer pressure. This is an important development measure widely adopted to achieve high and stable production of oil reservoirs and improve recovery. In addition, in order to adjust interlayer conflicts, expand the scope of influence and improve water injection effects, more and more stratified water injection wells are being used. In actual production, stratified testing of water injection wells, casting and catching of water nozzles and other work should be carried out in a timely manner to ensure that the actual water injection volume meets geological requirements. During normal operations, instruments such as wire-suspended flow meters or bailers are required, and weighted rods are installed under the flow meters or bailers, and the bottom cone of the cone is lowered to an appropriate depth to accurately measure the downhole stratified flow or successfully cast and bailer. However, the steel wire used to hang the flow meter or the bailer is several thousand meters underground, and the stretching of the steel wire due to its elasticity and the wear of the metering wheel will cause an error between the depth displayed by the depth gauge of the well test winch and the actual depth of the well. This will directly lead to inaccurate test data or failure of the bailer, and it is also easy to cause abnormal phenomena such as obstruction and jamming, which seriously affects the normal stratified injection.

[0003] At present, for stratified water injection wells with a ball seat at the bottom of the injection well pipe, the depth of the ball seat is often explored first during field operations, and the downhole tool is lowered by wire. The actual depth of the downhole tool is compared with the depth of the depth meter and the error is determined, thereby determining the actual lowering depth and improving the accuracy of stratified testing and the success rate of casting and salving. However, since the outer diameter of the bottom cone in the downhole tool is similar to the ball seat, when the ball is not dropped as required in the water injection well, or when the eccentric water distributor temporarily does not allow the ball to be dropped, the bottom cone will sit on the ball seat during the ball seat exploration process. Moreover, since the gap between the bottom cone and the ball seat is very small after the bottom cone sits on the ball seat, a sealed state is easily formed. Under the water pressure operation in the oil pipe, the bottom cone falls into the ball seat and forms a seal with the ball seat. During the lifting operation, it is difficult for the bottom cone to escape from the ball seat, resulting in the inability to normally lift the instrument, which eventually leads to accidents such as the instrument being pulled out of the well. The well can only be repaired by a well repair team, and all the oil pipes and supporting instruments in the well must be removed, and the obstruction must be removed from the ground, and then all the oil pipes and supporting instruments in the well must be normally lowered into the well to resume normal production. This not only occupies a lot of equipment and is expensive, resulting in huge operating well repair expenses, but also takes a long time to operate, seriously affecting normal water injection production. Utility Model Content

[0004] The utility model aims to provide a bottom cone for ball seat depth detection, so as to solve the problem in the prior art that when detecting the ball seat at the bottom of the water injection well pipe column, the bottom cone is easy to fall into the ball seat and form a seal with the ball seat, and the bottom cone is difficult to escape from the ball seat during lifting operation, resulting in the instrument encountering obstruction and being unable to be lifted out normally.

[0005] To achieve the above purpose, the technical solution of the bottom cone for ball seat depth detection provided by the utility model is: it includes a main body, one end of the main body is provided with a joint for connecting with a downhole tool, and the cone connected to the other end of the main body is eccentrically set.

[0006] As a further improvement, two cones are connected side by side on the main body.

[0007] As a further improvement, the two cones have different heights.

[0008] As a further improvement, the cone is a circular cone.

[0009] As a further improvement, the base areas of the two cones are the same.

[0010] As a further improvement, two generatrixes on opposite sides of the cone are flush with two opposite side surfaces of the main body.

[0011] As a further improvement, the cone is detachably connected to the main body.

[0012] As a further improvement, the main body and the cone are threadedly connected via a screw hole and a stud.

[0013] As a further improvement, a flow passage is provided on the main body.

[0014] As a further improvement, the flow channel is an arc-shaped groove.

[0015] The beneficial effect is that the utility model provides a bottom cone for depth sounding with a ball seat which is improved on the basis of the bottom cone in the prior art. In on-site operations, the bottom cone for depth sounding with a ball seat is connected to the bottom of the weighted rod when the flow meter or the bailer is matched with the weighted rod through a joint, so that the well test winch lowers the flow meter or the bailer and other instruments along the oil pipe in the water injection well through the downhole wire. When the cone at the lower end of the main body contacts the ball seat at the bottom of the water injection well pipe column, the cone eccentrically connected to the lower end of the main body does not block the ball seat, but rests on one side of the ball seat, and there is a large gap between the cone and the surface of the ball seat. Compared with the prior art in which the bottom cone sits on the ball seat, the contact area between the cone and the surface of the ball seat in the utility model is greatly reduced, No close sealing state is formed under the action of pressure, so that when the instrument is lifted up after completing the depth detection of the ball seat, the bottom cone can be smoothly separated from the ball seat, avoiding the situation that the bottom cone falls into the ball seat and is difficult to get out of the ball seat during the lifting operation, thereby ensuring that the instrument can be lifted out normally, reducing the process of salvaging fallen objects caused by the instrument being pulled out, saving the additional well repair operation expenses caused by the inability of stratified water injection wells to produce normally, and at the same time enabling operators to obtain actual downhole data as soon as possible in order to determine specific errors, ensuring that downhole tools can be lowered to the correct position during operations such as stratified testing of water injection wells, verifying ball seat leakage, and salvaging and deployment, thereby ensuring the completion of normal water injection deployment, flow measurement, and other tasks in stratified water injection wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A front view of the bottom cone for ball seat depth detection provided by the utility model;

[0017] Figure 2 A side view of the bottom cone for ball seat depth detection provided by the utility model;

[0018] Figure 3 for Figure 1 A-A1 direction cross section;

[0019] Figure 4 for Figure 1 Middle B-B1 direction cross section;

[0020] In the figure: 1, main body; 21, left cone; 22, right cone; 3, arc groove; 4, joint; 5, screw hole. DETAILED DESCRIPTION

[0021] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0022] With the improvement of oil field development, stratified water injection is becoming more and more common. During the water injection process, a flow meter is needed to test the actual water injection volume of each layer. If the actual water injection volume does not meet the geological requirements, the water nozzle should be replaced and tested repeatedly to ensure that the water injection volume meets the geological requirements. During normal operation, it is necessary to use instruments such as wire-suspended flow meters or bailers, and lower them to the appropriate depth with bottom cones that have the functions of drag reduction, shock prevention, pressure division, and diversion, so as to accurately measure the underground stratified flow or successfully bailers. However, the wire used to suspend the flow meter or bailer is several thousand meters underground, and the wire is stretched due to its elasticity, and the wear of the metering wheel will cause errors between the depth displayed by the well test winch depth gauge and the actual underground lowering depth, which will directly lead to inaccurate test data or failure of bailing, and it is also easy to cause abnormal phenomena such as encountering resistance and jamming.

[0023] At present, for stratified water injection wells with a ball seat at the bottom of the water injection well pipe, the depth of the ball seat is often explored first during field operations, and the downhole tool is lowered by wire. The error is checked based on the actual depth of the downhole tool and the depth of the depth meter, so as to determine the actual lowering depth and improve the accuracy of stratified testing and the success rate of casting and fishing. However, since the outer diameter of the bottom cone in the downhole tool is similar to the ball seat, the bottom cone will sit in the ball seat during the ball seat exploration process, and fall into the ball seat under pressure and form a seal with the ball seat and cannot be pulled out normally. The well repair operation can only be carried out by the well repair team, which not only causes additional well repair expenses, but also takes a long time to operate, seriously affecting normal water injection production. Based on this, the present application improves on the basis of the bottom cone in the prior art and provides a bottom cone for ball seat depth exploration.

[0024] The overall design concept of the bottom cone for ball seat depth detection provided by the utility model is:

[0025] A ball seat depth probe bottom cone, such as Figure 1-4As shown, it includes a main body 1, one end of the main body 1 is provided with a joint 4, the main body 1 is connected to the bottom of the downhole tool through the joint 4, and the cone connected to the other end of the main body 1 is eccentrically arranged. In the field operation of the water injection well, the ball seat depth detection bottom cone provided by the utility model is connected to the bottom of the weighting rod when the flow meter or the bailer is matched with the weighting rod through the connecting thread provided on the joint 4, so that the well test winch lowers the flow meter or the bailer and other instruments along the oil pipe in the water injection well through the downhole steel wire, and keeps lowering at a uniform speed. In the process of lowering, the cone can remove part of the adhesion and scale in the oil pipe to ensure smooth lowering into the well. When the cone at the lower end of the main body 1 contacts the upper surface of the ball seat, compared with the prior art in which the contact surface between the bottom cone and the ball seat is larger and the cone is tightly attracted to sit firmly in the ball seat and is difficult to be removed, in the utility model, not only the cone eccentrically connected to the lower end of the main body 1 does not block the ball seat, but is against one side of the ball seat, and there is a large gap between the cone and the surface of the ball seat, so that under the action of pressure, the cone and the ball seat will not be tightly attracted to fall into the ball seat and form a seal with the ball seat, so that when the instrument is lifted up after completing the depth detection of the ball seat, the bottom cone can be smoothly separated from the ball seat , reducing the process of salvaging objects caused by instrument removal, saving additional well repair operation expenses caused by the inability of water injection wells to produce normally, and enabling operators to obtain actual downhole data as soon as possible in order to determine specific errors, ensuring that downhole tools can be lowered to the correct position during operations such as stratified testing of water injection wells, verifying ball seat leakage, and salvaging deployment, thereby improving the accuracy of stratified testing and the success rate of salvaging, thereby ensuring the completion of normal deployment and flow measurement of stratified water injection wells, with excellent use effects and significant economic benefits.

[0026] Based on the overall introduction of the present invention above, a more specific embodiment is provided below on the basis of the overall introduction:

[0027] like Figure 1-Figure 4 As shown, two cones are connected side by side on the main body 1, which is not only conducive to reducing drag and facilitating the lowering of the instrument, but also when it is lowered to the ball seat, the tops of the two eccentrically set cones are on both sides of the ball seat, and the contact surface between the two cones and the ball seat is greatly reduced. There is also a large gap between the two cones and the ball seat, and they will not fit together to form a sealed state. Therefore, when the instrument is lifted up after completing the depth detection of the ball seat, the bottom cone can be smoothly separated from the ball seat. In this embodiment, the heights of the two cones are the same. To further ensure that the bottom cone can be smoothly separated from the ball seat, the heights of the two cones are different in other embodiments. For the convenience of description, it is defined as Figure 1The two cones in the figure are the left cone 21 and the right cone 22, and taking the example that the height of the left cone 21 is greater than that of the right cone 22, when the bottom cone of the utility model is lowered to contact the ball seat, because the left cone 21 first rests on the ball seat, the downhole instrument will tilt to the right and lean against the oil pipe. At this time, the shorter right cone 22 basically does not contact the ball seat. Compared with the situation where the left cone 21 sits vertically on the ball seat, the contact area between the left cone 21 and the ball seat is further reduced when the left cone 21 is tilted to the right. The left cone 21 and the right cone 22 do not fit the ball seat but are sucked tightly under the action of pressure. Therefore, when the instrument is lifted after completing the depth detection of the ball seat, the bottom cone can be more smoothly separated from the ball seat, so that the instrument can be smoothly lifted out, which is convenient for the operator to carry out the next step. Of course, the eccentrically connected cones on the main body 1 are not limited to one or two, and three cones are also eccentrically set in other embodiments.

[0028] Furthermore, the two generatrixes on the opposite sides of the cone are flush with the two opposite sides of the main body 1, so that in the process of the downhole tool below, it can have a better guiding and drag reduction effect, and the process of going down the well is smoother and less likely to get stuck. In other embodiments, the two generatrixes on the opposite sides of the cone can also be on the inner side of the two opposite sides of the main body 1 to facilitate the downhole operation. At the same time, in order to avoid excessive impact on the ball seat when sitting on the ball seat and damaging the ball seat, preferably, the top of the cone is processed into a more rounded angle. Furthermore, the bottom area of ​​the cone is the same, which is convenient for manufacturing and improves the processing speed.

[0029] The cone can be a pyramid, such as a four-sided pyramid or other irregular pyramids. During the lowering process, impurities such as scale or other adhesions are attached to the inner wall of the oil pipe. In order to avoid too many impurities adhering to the edges and corners of the cone during the lowering, in other embodiments, the cone is a cone, which can to a certain extent avoid impurities adhering to the surface of the cone during the lowering process, ensure smooth entry into the well, and avoid the cone scraping off the scale on the inner wall of the oil pipe during the entry into the well, and the scale deposition causing the ball seat to be stuck.

[0030] In order to adapt to the increasing requirements of stratified water injection operations, the cone can be detachably connected to the main body 1, such as Figure 4 As shown, a screw hole 5 is provided at the bottom of the main body 1, and a matching stud is provided at the top of the cone, so that the main body 1 and the cone are threadedly connected through the screw hole 5 and the stud, which is convenient for processing and manufacturing. Of course, a connecting hole can also be provided on the cone, and a threaded hole can be provided on the main body 1, and the cone can be installed on the main body 1 through bolts; a plug hole can also be provided at the bottom of the main body 1, and a matching plug-in column can be provided at the top of the cone, so that the cone can be installed side by side on the main body 1 by inserting the plug-in column into the plug hole. At the same time, such a plug-in setting is convenient for regular maintenance. In the case that the cone is worn after multiple downhole operations, the cone can be quickly replaced to avoid affecting the normal operation of the water injection well.

[0031] Based on the overall introduction of the present invention above, or on the basis of the embodiments of the present invention introduced above, a more specific embodiment is provided below on the basis of the overall introduction:

[0032] This embodiment focuses on the detailed description of the flow channel.

[0033] like Figure 1-Figure 2 As shown, a flow channel is provided on the main body 1, and the flow channel can allow the water in the well to flow from the outside of the main body 1 to the inside of the main body 1, and finally flow out of the inside of the main body 1, so that the inside and outside of the main body 1 are connected. In the process of lifting the bottom cone, the flow channel can divert the pressure of the upper water column, which is conducive to the bottom cone to separate from the ball seat. In addition, the water resistance can be reduced, which is convenient for lowering downhole tools, and when approaching the ball seat, the water flow between the ball seat and the bottom cone can flow out through the flow channel, reducing the impact of the instantaneous water flow on the ball seat when the bottom cone is placed on the ball seat, so that the bottom cone can be placed on the ball seat more stably. In other embodiments, multiple flow channels are provided on the main body 1 to further reduce the resistance of the bottom cone to be lifted and lowered, and preferably, the flow channels are evenly distributed along the circumference of the main body 1 to facilitate stability during the lifting and lowering process.

[0034] Specifically, the flow channel is an arc groove 3, which can improve the smoothness of water flow and facilitate water flow guidance. In this embodiment, two arc grooves 3 are symmetrically opened on the main body 1 to allow the cone to sit more stably on the ball seat. In other embodiments, it can also be a long strip groove.

[0035] It should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0036] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. A ball seat bottom cone for deep exploration, comprising a main body, one end of which is provided with a joint for connecting with a downhole tool, characterized in that: The cone connected to the other end of the main body is set eccentrically.

2. The bottom cone for ball seat depth detection according to claim 1, characterized in that: Two cones are connected side by side on the main body.

3. The bottom cone for ball seat depth detection according to claim 2, characterized in that: The two cones are of different heights.

4. The bottom cone for ball seat depth detection according to claim 3, characterized in that: The cone is a cone.

5. The bottom cone for ball seat depth detection according to any one of claims 2 to 4, characterized in that: The base areas of the two cones are the same.

6. The bottom cone for ball seat depth detection according to any one of claims 1 to 4, characterized in that: The two generatrixes on the opposite sides of the cone are flush with the two opposite side surfaces of the main body.

7. The bottom cone for ball seat depth detection according to any one of claims 1 to 4, characterized in that: The cone is detachably connected to the main body.

8. The ball seat depth detection bottom cone according to claim 7, characterized in that: The main body and the cone are connected by screw holes and stud threads.

9. The ball seat depth detection bottom cone according to claim 1, characterized in that: A flow passage is provided on the main body.

10. The ball seat depth detection bottom cone according to claim 9, characterized in that: The flow passage is an arc-shaped groove.

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