Wall core positioning equipment and positioning method for side-wall coring instrument
By using sharp protrusions and sidewall marking technology in wellbore coring instruments, the problem of core positioning has been solved, enabling precise spatial positioning of the core within the well and improving the accuracy of geological research and reservoir evaluation.
Patent Information
- Application Number
- CN202410576343.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-10
- Publication Date
- 2025-11-11
AI Technical Summary
Existing wellbore coring technology lacks core location methods, resulting in insufficient accuracy in geological research and reservoir evaluation.
By setting a sharp protrusion at the head of the core push rod to mark the end and side wall of the core, and combining this with the side wall markings on the core length measuring rod, the spatial positioning of the core can be achieved.
Accurately locating the spatial orientation of core samples provides more precise stratigraphic and sedimentary information, supporting geological research and reservoir evaluation.
Smart Images
Figure CN120925784A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of well logging technology, specifically to a core positioning device and method for wellbore coring instruments. Background Technology
[0002] Currently, various wellbore coring technologies are widely used in major oilfields. Compared to drilling coring, wellbore coring is faster, more efficient, and less expensive. Because it obtains physical core samples of the formation, it allows for highly detailed analysis in the laboratory. Wellbore coring is typically used to confirm the lithology, oil-bearing properties, and the relationship between lithology and electrical properties of formations. However, it overlooks another crucial piece of information about geological sedimentation carried by the core itself: many cores contain textures or lithological interfaces formed by sedimentation. If the spatial location of the core when it was extracted from the formation can be reconstructed, it would not only allow for the determination of the sedimentary characteristics of the formation or the correction of formation dip data based on the textures and lithological interfaces on the core, but also allow for the repositioning of various formation parameters into three-dimensional space, providing more accurate evaluation criteria for geological research and reservoir assessment. Currently, however, no core positioning technology is used in wellbore coring instruments. Summary of the Invention
[0003] This invention provides a core positioning device and method for wellbore coring instruments, aiming to solve the problems in the prior art.
[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:
[0005] A method for core positioning in a wellbore coring instrument includes the following specific steps:
[0006] S1: The core pusher gradually pushes the core out of the drill bit. During this process, the sharp protrusion on the head of the core pusher marks the end of the core.
[0007] S2: The ejected core falls into the core extraction cylinder. Before entering the core extraction cylinder, the core passes through the core length measuring rod. The sharp edge of the core length measuring rod makes a side wall mark on the side wall of the core.
[0008] The beneficial effects of the present invention are as follows: During the positioning process, S1: the core pusher gradually pushes the core inside the drill bit out. During this process, the sharp protrusion of the core pusher head marks the end of the core. S2: the pushed-out core falls into the core barrel. Before the core enters the core barrel, it passes through the core length measuring rod. The sharp edge of the core length measuring rod head marks the side wall of the core. The spatial positioning of the core is achieved by using the double marks.
[0009] The method of this invention is simple and can accurately locate the spatial orientation of the core. After the core is collected, its true spatial orientation in the strata can be restored, providing more accurate stratigraphic and sedimentary information for geological research and reservoir evaluation.
[0010] Based on the above technical solution, the present invention can be further improved as follows.
[0011] Furthermore, S0 is included before S1: drilling the core using a drill bit.
[0012] The advantage of adopting the above-mentioned further solution is that it allows for easy core drilling, which facilitates subsequent positioning operations.
[0013] Furthermore, S0 includes the following specific steps:
[0014] S01: Obtain the core sample after the drill bit completes drilling while adhering to the well wall;
[0015] S02: The drill bit returns to its original position, carrying the core.
[0016] The advantages of adopting the above-mentioned further solution are that the steps are simple, the core can be obtained, and the drill bit can be used to drive the core back into position so that the core pusher can push the core in the subsequent operation, which is convenient.
[0017] Furthermore, in step S01, after the drill bit completes drilling along the well wall, the core is broken off to obtain the core.
[0018] The advantage of adopting the above-mentioned further solution is that the method is simple and can quickly obtain the core.
[0019] Furthermore, in step S02, the drill bit carrying the core rotates 90° to return to its original position.
[0020] The advantage of adopting the above-mentioned further solution is that the drill bit drives the core back into place, which facilitates subsequent operations.
[0021] Furthermore, in S1, the pressure at which the core pusher pushes the core is >800 psi.
[0022] The advantage of adopting the above-mentioned further solution is that the pressure value of the core pusher is set reasonably, ensuring that the core pusher can quickly push the core out of the drill bit.
[0023] Furthermore, S2 is followed by S3: removing the core from the core-retrieving cylinder and rinsing it clean.
[0024] The advantage of adopting the above-mentioned further solution is that core rinsing facilitates the clear identification of markings made on the core.
[0025] Furthermore, S3 also includes: reconstructing the spatial position of the core on the well wall when it was not drilled, by comparing the end marks and side wall marks on the core.
[0026] The advantage of adopting the above-mentioned further scheme is that the spatial position of the core in the well can be confirmed by using the end marks and sidewall marks on the core.
[0027] Furthermore, the end marks and sidewall marks on the core are scratches.
[0028] The advantage of adopting the above-mentioned further solution is that the scratches are clearly distinguishable, which facilitates the spatial positioning of the core.
[0029] The present invention also relates to a positioning device used in the core positioning method of the wellbore coring instrument as described above.
[0030] The beneficial effect of adopting the above-mentioned further solutions is that the present invention also provides a positioning device, which can accurately locate the spatial orientation of the core and return the core to its true spatial orientation in the strata after the core is collected, thus providing more accurate stratigraphic and sedimentary information for geological research and reservoir evaluation. Attached Figure Description
[0031] Figure 1 This is a flowchart of the present invention;
[0032] Figure 2 This is an assembly drawing of the wall core push rod in this invention;
[0033] Figure 3 This is an exploded view of the wall core push rod in this invention;
[0034] Figure 4 This is a schematic diagram of the protrusion on the core length measuring rod in this invention;
[0035] Figure 5 This is a schematic diagram of the structure of the first embodiment of the snap ring in this invention;
[0036] Figure 6 This is a schematic diagram of the second embodiment of the snap ring in this invention;
[0037] Figure 7 This is a schematic diagram of the drill bit structure in this invention.
[0038] The attached diagram lists the components represented by each number as follows:
[0039] 1. Core push rod; 2. Core length measuring rod; 3. Snap ring; 4. Drill bit. Detailed Implementation
[0040] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., 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. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0043] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0044] Example 1
[0045] like Figures 1 to 7 As shown, this embodiment provides a core positioning method for a wellbore coring instrument, including the following specific steps:
[0046] S1: The core pusher 1 gradually pushes the core out of the drill bit 4. During this process, the sharp protrusion at the head of the core pusher 1 marks the end of the core.
[0047] S2: The ejected core falls into the core extraction cylinder. Before entering the core extraction cylinder, the core passes through the core length measuring rod. The sharp edge of the core length measuring rod 2 makes a side wall mark on the side wall of the core.
[0048] During the positioning process, S1: The core pusher 1 gradually pushes the core out of the drill bit 4. During this process, the sharp protrusion of the core pusher head marks the end of the core. S2: The pushed-out core falls into the core barrel. Before entering the core barrel, the core passes through the core length measuring rod 2. The sharp edge of the core length measuring rod 2 marks the side wall of the core. The spatial positioning of the core is achieved by using the double marks.
[0049] In this embodiment, a tiny T-shaped sharp protrusion is placed at the head of the core push rod 1. When the push rod pushes the core, the push rod exerts a certain pressure on the surface of the core. Under this pressure, the sharp edge of the T-shaped protrusion will leave a T-shaped wound on the surface of the core. Based on the location of these T-shaped wounds, the specific position of the core on the well wall can be restored, and the core position will not be lost due to the rotation after the core is separated from the drill bit 4.
[0050] In addition, the aforementioned T-shaped sharp protrusion and the wall core push rod 1 are designed separately, and the T-shaped sharp protrusion can be bolted to the wall core push rod 1.
[0051] The method described in this embodiment is simple and can accurately locate the spatial orientation of the core. After the core is collected, its true spatial orientation in the strata can be restored, providing more accurate stratigraphic and sedimentary information for geological research and reservoir evaluation.
[0052] Example 2
[0053] Based on Example 1, in this example, S0 is included before S1: drilling the core using drill bit 4.
[0054] This method utilizes drill bit 4 to drill the core, which is convenient and facilitates subsequent positioning operations.
[0055] Example 3
[0056] Based on Example 2, in this example, S0 includes the following specific steps:
[0057] S01: After drilling with drill bit 4 attached to the well wall, the core sample is obtained;
[0058] S02: Drill bit 4 returns to its original position, carrying the core.
[0059] This step is simple, as it allows for the acquisition of the core and the use of drill bit 4 to return the core to its original position, facilitating subsequent core pusher 1 to move the core. This makes the operation convenient.
[0060] Example 4
[0061] Based on Example 3, in this example, after the drill bit 4 completes drilling by adhering to the well wall in S01, the core is broken off to obtain the core.
[0062] This method is simple and can quickly obtain the core.
[0063] Example 5
[0064] Based on any one of Embodiments 3 to 4, in this embodiment, the drill bit 4 carrying the core rotates 90° in S02 to return to its original position.
[0065] Drill bit 4 drives the core back into place, facilitating subsequent operations.
[0066] Example 6
[0067] Based on the above embodiments, in this embodiment, the pressure of the core pusher 1 pushing the core in S1 is >800psi.
[0068] The pressure value of the core pusher 1 is set reasonably to ensure that the core pusher 1 can quickly push the core out of the drill bit 4.
[0069] Preferably, in this embodiment, the pressure at which the core pusher 1 pushes the core in S1 is preferably 900 psi.
[0070] Preferably, in this embodiment, since a retaining spring 3 is installed inside the drill bit 4, and the inner wall of the retaining spring 3 is provided with a toothed structure, the toothed structure is used to increase the friction between the inner wall of the retaining spring 3 and the core wall, thereby increasing the thrust of the core wall push rod head on the core wall, increasing the indentation depth, and enhancing the clarity of the end mark.
[0071] In addition, the toothed structure on the aforementioned retaining ring 3 can be one or multiple, depending on the specific requirements.
[0072] Example 7
[0073] Based on the above embodiments, in this embodiment, S2 is followed by S3: removing the core from the core-taking cylinder and rinsing it clean.
[0074] Core rinsing facilitates clear identification of markings made on the core later.
[0075] Example 8
[0076] Based on Example 7, in this example, S3 further includes: restoring the spatial position of the core when it was not drilled on the well wall by comparing the end marks and side wall marks on the core.
[0077] This method uses end marks and sidewall marks on the core to determine the spatial location of the core within the well.
[0078] Example 9
[0079] Based on the above embodiments, in this embodiment, the end marks and side wall marks on the core are scratches.
[0080] The scratches are clearly visible, making it easy to locate the core material in space.
[0081] Example 10
[0082] Based on the above embodiments, this embodiment also provides a positioning device applied to the core positioning method of the wellbore coring instrument as described above.
[0083] This embodiment also provides a positioning device that can accurately locate the spatial orientation of the core and, after the core is retrieved, return to its true spatial orientation in the strata, providing more accurate stratigraphic and sedimentary information for geological research and reservoir evaluation.
[0084] The positioning steps of this invention are as follows:
[0085] S0: After drilling with drill bit 4 attached to the well wall, the drill bit is broken off to obtain the core; drill bit 4 rotates 90° with the core to return to its original position.
[0086] S1: The core pusher 1 gradually pushes the core out of the drill bit 4. During this process, the sharp protrusion at the head of the core pusher 1 marks the end of the core.
[0087] S2: The ejected core falls into the core extraction cylinder. Before entering the core extraction cylinder, the core passes through the core length measuring rod. The sharp edge of the core length measuring rod 2 makes a side wall mark on the side wall of the core.
[0088] S3: Remove the core from the core barrel and rinse it clean. Reconstruct the spatial position of the core on the well wall before it was drilled by comparing it with the end marks and side wall marks on the core.
[0089] The main objective of this invention is to accurately locate the spatial orientation of the core, enabling the core to be repositioned in its true spatial location within the strata after collection, thus providing more precise stratigraphic and sedimentary information for geological research and reservoir evaluation.
[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for core positioning in a wellbore coring instrument, characterized in that, The specific steps include the following: S1: The core pusher (1) gradually pushes the core inside the drill bit (4) out. During this process, the sharp protrusion at the head of the core pusher (1) marks the end of the core. S2: The ejected core falls into the core extraction tube and passes through the core length measuring rod (2) before entering the core extraction tube. The sharp edge of the core length measuring rod (2) makes a side wall mark on the side wall of the core.
2. The core positioning method for wellbore coring instruments according to claim 1, characterized in that, Before S1, there is also S0: drilling the core using drill bit (4).
3. The core positioning method for wellbore coring instruments according to claim 2, characterized in that, The S0 includes the following specific steps: S01: After the drill bit (4) completes drilling by adhering to the well wall, the core sample is obtained; S02: The drill bit (4) returns to its original position, carrying the core.
4. The core positioning method for wellbore coring instruments according to claim 3, characterized in that: In S01, after the drill bit (4) completes drilling along the well wall, the core is broken off to obtain the core.
5. The core positioning method for wellbore coring instruments according to claim 3, characterized in that: In S02, the drill bit (4) rotates 90° with the core to return to its original position.
6. The core positioning method for wellbore coring instruments according to any one of claims 1-5, characterized in that: The pressure exerted by the core pusher (1) in S1 on the core is >800 psi.
7. The core positioning method for wellbore coring instruments according to any one of claims 1-5, characterized in that, S2 is followed by S3: removing the core from the core-retrieving cylinder and rinsing it clean.
8. The core positioning method for wellbore coring instruments according to claim 7, characterized in that, The S3 further includes: restoring the spatial position of the core on the well wall when it was not drilled, by comparing the end marks and side wall marks on the core.
9. The core positioning method for wellbore coring instruments according to any one of claims 1-5, characterized in that: The end marks and side wall marks on the core are scratches.
10. A positioning device for use in the core positioning method of a wellbore coring instrument as described in any one of claims 1-9.