Single-pipe coring device for improving core recovery rate of superficial sand shale interbed area
By installing water-blocking plates in the drainage tube connected to the drill pipe and in the core tube to optimize the water inlet channel, the problem of low core recovery rate in the shallow sandstone and mudstone interbedded areas was solved, efficient core recovery and protection were achieved, and the simplicity and economy of the device were maintained.
Patent Information
- Application Number
- CN202422843964.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-11-21
AI Technical Summary
The core sampling rate in the shallow sandstone-mudstone interbedded area is low, mainly due to core damage caused by water erosion and external force impact.
A single-tube coring device was designed. By connecting multiple drainage tubes to the outside of the drill pipe and installing a water-blocking plate inside the core tube, the water inlet channel was optimized, the water flow was diverted to lubricate the core body, and the scouring of the core was reduced. The core was also easily removed by matching the difference in inner diameter of the drill bit and the core tube.
The core recovery rate is improved, the core integrity is ensured, the simplicity, convenience and low cost of the device are maintained, and the engineering needs are met.
Smart Images
Figure CN223469243U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the engineering drilling field especially relates to a single pipe coring device that improves shallow sand and mudstone interbedded area core recovery rate. BACKGROUND
[0002] Core recovery rate refers to the ratio of the total length of complete rock + broken rock taken out by drilling to the footage of the round, and is a key index for measuring the quality of drilling core taking. The main factors affecting core recovery rate include the construction device and process of drilling core taking, the integrity and softness of the rock-soil in the core taking section, the proportioning and use of circulating mud, and the operation method and process. The shallow layer is usually covered by the Quaternary System, and is mostly sand and mudstone interbedded area. The rock mass is mostly broken and soft, and the core recovery rate is generally low, usually 70%-80%, and only 30%-50% in special broken and soft sections, and even cannot take core.
[0003] There are many reasons for the low single pipe core recovery rate, but the main reasons are generally two aspects, one is that water enters the core pipe, causing the core to be eroded and soaked by water flow, and the other is that the core is damaged by external force knocking during the core taking process. UTILITY MODEL CONTENT
[0004] The utility model aims at solving the shortcomings in the prior art, and provides a single pipe coring device that improves shallow sand and mudstone interbedded area core recovery rate.
[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme: a single pipe coring device that improves shallow sand and mudstone interbedded area core recovery rate, including drill pipe, the side of drill pipe is fixedly connected with external drainage tube, the inside of external drainage tube is connected with the inside of drill pipe, the top of drill pipe is screwedly connected with core tube, the inside of core tube is connected with the inside of drill pipe, the top of core tube is screwedly connected with drill bit, the outer surface of drill bit is fixedly connected with reaming block.
[0006] Further description of the above technical scheme:
[0007] The number of external drainage tubes is multiple, and the multiple external drainage tubes are uniformly distributed on the outer surface of the drill pipe.
[0008] Further description of the above technical scheme:
[0009] The core tube comprises a core tube main body, a water blocking plate is fixedly connected to the inside of the core tube main body, and a through hole is formed in the inside of the water blocking plate.
[0010] Further description of the above technical scheme:
[0011] The top of the drill bit is provided with a drill tooth.
[0012] As a further description of the above technical solutions:
[0013] The length of the reaming block is greater than the outer wall of the external drainage tube.
[0014] As a further description of the above technical solutions:
[0015] The bottom of the drill rod is threadedly connected with a connecting head, and the inside of the connecting head is in communication with the inside of the drill rod.
[0016] As a further description of the above technical solutions:
[0017] The inner diameter of the drill bit is less than the inner diameter of the core tube.
[0018] As a further description of the above technical solutions:
[0019] The inner diameter of the external drainage tube is 4mm.
[0020] The utility model has the following beneficial effects:
[0021] 1、Compared with the prior art, the single-tube coring device for improving the core recovery rate in the superficial sand-shale interbedded area optimizes the water inlet channel, designs the water inlet channel into the inner hole of the drill rod after the water pump pumps water, at this time, a water stop plate is arranged inside the core tube, and drilling and shunting are performed on the core tube wall and the water stop plate. About 1% of the water body enters the core tube through the water stop plate fine hole to lubricate the inner wall of the core body and the core tube; more than 99% of the water body enters the inner hole through the core tube hole wall and reaches the drill bit position at the drilling surface through the drainage tube added to the outer wall, which plays a role of cooling, lubrication and carrying cuttings. Due to the optimization of the water flow channel, the water flow no longer enters the inner hole of the core tube, and the core recovery rate is ensured. At the same time, the advantages of simple and practical, portable, fast and low cost of single-tube coring are maintained, and the needs of engineering projects are better met.
[0022] 2、Compared with the prior art, single-tube coring needs external force to knock off the core body from the core tube, which often causes the core body to be difficult to fall off from the core tube due to the close contact between the core body and the inner wall of the core tube. The external force is too strong and easy to cause damage to the core body. The inner diameters of the drill bit and the core tube are well matched, the inner diameter of the drill bit is less than (about 1mm) the inner diameter of the core tube, and finally the outer diameter of the core body is slightly smaller than the inner diameter of the core tube, so that the core body can be easily and smoothly knocked off from the core tube. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 The utility model proposes a kind of overall structure schematic diagram of single-tube coring device for improving the core recovery rate in the superficial sand-shale interbedded area;
[0024] Figure 2 The utility model provides a single pipe coring device of improving shallow sand and mudstone interbedded area core recovery rate Figure 1 The structure enlarged view of A in the middle;
[0025] Figure 3 The utility model provides a single pipe coring device of improving shallow sand and mudstone interbeded area core recovery rate Figure 1 The structure enlarged view of B in the middle;
[0026] Figure 4 The utility model provides a single pipe coring device of improving shallow sand and mudstone interbeded area core recovery rate internal structure sectional view;
[0027] Figure 5 The utility model provides a single pipe coring device of improving shallow sand and mudstone interbeded area core recovery rate Figure 4 The structure enlarged view of C in the middle;
[0028] Figure 6 The utility model provides a single pipe coring device of improving shallow sand and mudstone interbeded area core recovery rate explosion drawing.
[0029] Legend:
[0030] 1, drill pipe, 2, external drainage tube, 3, core tube, 301, core tube main body, 302, water stop plate, 303, through -hole, 4, drill bit, 5, reamer, 6, connector. Specific implementation
[0031] Refer to Figures 1-6The utility model provides a kind of single pipe coring device of improving superficial sand shale interbedded area core recovery rate: including drill rod 1, the side of drill rod 1 is fixedly connected with external drainage tube 2, the inside of external drainage tube 2 is connected with the inside of drill rod 1, water flow reaches drill face position by passing through external drainage tube 2, can play the role of cooling, lubrication and carrying rock debris, the top of drill rod 1 is threadedly connected with core tube 3, and core tube 3 includes core tube main body 301, and the inside of core tube main body 301 is fixedly connected with water stop plate 302, and the inside of water stop plate 302 is provided with through-hole 303, by water stop plate 302, water flow is shunted after entering the inside of core tube 3, about 1% water body enters the other end of core tube main body 301 by through-hole 303 on water stop plate 302, to lubricate the inner wall of core body and core tube;More than 99% water body will enter external drainage tube 2, assist drilling, the inside of core tube 3 is connected with the inside of drill rod 1, and the top of core tube 3 is threadedly connected with drill bit 4, and the outer surface of drill bit 4 is fixedly connected with reaming block 5, and the bottom of drill rod 1 is threadedly connected with connector 6, and the inside of connector 6 is connected with the inside of drill rod 1, and drill rod 1, external drainage tube 2, core tube 3, drill bit 4 are all hollow structure, and the inside hollow structure of drill rod 1, external drainage tube 2, core tube 3, drill bit 4 forms water inlet channel.
[0032] The number of external drainage tube 2 is multiple, the number of external drainage tube 2 is 2-4, multiple external drainage tube 2 is evenly distributed on the outer surface of drill rod 1, and the inner diameter of external drainage tube 2 is 4mm.
[0033] The length of reaming block 5 is greater than the outer wall of external drainage tube 2, which can increase the drilling diameter under the action of reaming block 5, protect external drainage tube 2, the top of drill bit 4 is provided with drill teeth, the inner diameter of drill bit 4 is less than the inner diameter of core tube 3, the inner diameter of drill bit 4 is less than the inner diameter of core tube 3, so that the outer diameter of core body is less than the inner diameter of core tube 3, so that the core body falls off from core tube 3 smoothly.
[0034] Working principle: the water inlet channel is optimized, and the water inlet channel is designed into the inner hole of drill rod 1 after water pumping by water pump, at this time, in the inside of core tube 3, water stop plate 302 is arranged, and drilling and shunting are carried out on the wall of core tube and water stop plate 302.About 1% water body enters core tube 3 through through-hole 303 on water stop plate 302, to lubricate the inner wall of core body and core tube 3;More than 99% water body, by the hole wall of core tube 3 from inner hole to outer wall, through the outer wall of external drainage tube 2, reaches the position of drill bit 4 at drill face, plays the role of cooling, lubrication and carrying rock debris, due to the optimization of water flow channel, water flow no longer enters the inner hole of core tube 3, no longer washes and soaks core body, ensures core recovery rate.Meanwhile, maintain the advantages of simple and practical, portable, low cost of single pipe coring, better meet the needs of engineering project.
[0035] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application has been described in detail, for the skilled in the art, it still can be modified, or for part of the technical features of the equivalent replacement, the spirit and principles of the present application, made any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.
Claims
1. A single tube coring device for improving core recovery in shallow sand-shale interbedded zones, comprising a drill pipe (1), characterized in that: The side of the drill pipe (1) is fixedly connected with an external drainage tube (2), the inside of the external drainage tube (2) is communicated with the inside of the drill pipe (1), the top of the drill pipe (1) is threadedly connected with a core tube (3), the inside of the core tube (3) is communicated with the inside of the drill pipe (1), the top of the core tube (3) is threadedly connected with a drill bit (4), and the outer surface of the drill bit (4) is fixedly connected with a reaming block (5).
2. The single tube coring device for improving core recovery rate in the shallow sand and shale interbedded area according to claim 1, characterized in that: The number of the external drainage tubes (2) is multiple, and the multiple external drainage tubes (2) are uniformly distributed on the outer surface of the drill pipe (1).
3. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The core tube (3) comprises a core tube main body (301), the inside of the core tube main body (301) is fixedly connected with a water blocking plate (302), and the inside of the water blocking plate (302) is provided with a through hole (303).
4. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The top of the drill bit (4) is provided with a drill tooth.
5. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The length of the reaming block (5) is greater than the outer wall of the external drainage tube (2).
6. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The bottom of the drill pipe (1) is threadedly connected with a connecting head (6), the inside of the connecting head (6) is communicated with the inside of the drill pipe (1).
7. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The inner diameter of the drill bit (4) is less than the inner diameter of the core tube (3).
8. The single tube coring device for improving core recovery rate in the shallow sand-shale interbedded area according to claim 1, characterized in that: The inner diameter of the external drainage tube (2) is 4 mm.