Novel core barrel with hole cleaning, sand gravel fishing and coring functions

Abstract

The invention discloses a novel core barrel with hole cleaning, sand gravel fishing and coring functions. The novel core barrel comprises a sand fishing segment, a coring segment and a core barrel connecting segment. An inner cavity pipe wall is arranged in the sand fishing segment so as to form a double-layer structure. The upper end of the inner cavity pipe wall is connected with a core barrel joint. The outline of the top of the sand fishing segment is in the shape of an arc streamline. A pair of sand inlets are formed in positions, close to the upper end, in the outer layer pipe wall of the sand fishing segment. A plurality of drain holes are formed in the positions close to the lower end of the sand fishing segment. An inner cavity pipe wall is arranged on the upper portion of the core barrel connecting segment so as to form a double-layer structure, and the lower portion of the core barrel connecting segment is of a single-layer structure. An annular sand separating plate is arranged in the middle portion of the core barrel connecting segment, so that a ladder shaped structure is formed. A gap in the double-layer structure of the sand fishing segment, a gap in the double-layer structure of the upper portion of the core barrel connecting segment and the sand separating plate define a sand storage chamber with an opening formed in the upper portion. The lower end of the core barrel connecting segment is connected with the coring segment, and a drill bit is arranged at the lower end of the coring segment. The novel core barrel further has the functions of fishing for sand gravel in various sand gravel and weathered clastic rock stratums besides a drill coring function.

Description

technical field [0001] The invention relates to the technical field of geological drilling, in particular to a novel core tube capable of clearing holes to fish for gravel and taking cores. Background technique [0002] In geotechnical engineering investigation, medium-coarse gravel, cohesive soil-containing gravel and weathered rock debris layers are often encountered. Coarse particles such as stones and weathered rock debris often cannot be discharged back to the hole with the circulating mud, resulting in increased sediment in the hole, cleaning the hole is not clean, and the core samples taken by the core tube are mostly disturbed sediment, resulting in Samples are often rarely taken, which affects the accurate division of stratigraphic layers, and also affects the accuracy and reliability of in-situ test data (standard penetration test and heavy-duty dynamic penetration test) of these coarse-grained soil layers. For these soil layers , in-situ test data (standard penet...

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Problems solved by technology

[0008] Through the analysis of the above four schemes, it can be seen that although the invention patent with the publication number of CN 103573202 A is mainly aimed at geotechnical engineering survey and geological survey, it is easy to bury and jam the drill due to the lateral oblique opening of the sand dredger. There are gaps between the sand drum and the sand drum and between the sand drum and the core tube. It is easy to cause large-grained gravel or rock debris to deposit in the gap and cause the equipment to stick, and it is easier to bury the drill. In actual use There are great limitations and construction risks; the utility model patent whose publication number is CN207048709 U is mainly used for sand settling, sand removal and anti-blocking in drilling, which is realized by reverse circulation while drilling, while drilling in geotechnical engineering investigation What generally all adopts is positive circulation; Publication No. is the utility model patent of CN 204492724 U to be used for the problem treatment of dredging sand of leaking oil and gas well on the oil field, does not return slurry, does not possess the effect of drilling into holes; Publication No. CN205876248 U is a utility model patent The new patent is to solve the problem of clear wellbore sand settling and downhole tool sand burial in oil wells, and it does not have the function of drilling holes

[0009] In addition, other unlisted inventions or utility model patents basically serve for sand fishing in oil production wells, and are not suitable or practical in geotechnical engineering investigation and geological exploration

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