The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 2026
Filed:
Jan. 12, 2026
Hunan University of Science and Technology, Xiangtan, CN;
Buyan Wan, Xiangtan, CN;
Yongping Jin, Xiangtan, CN;
Xiangyang Dong, Xiangtan, CN;
Jialiang Wang, Xiangtan, CN;
Hunan University of Science and Technology, Xiangtan, CN;
Abstract
Provided are a forward and reverse circulation assembly for core drilling tools and a coring operation method using the same. The forward and reverse circulation assembly includes an outer tube body and an inner receiving body arranged inside it, defining a downward drilling fluid channel between the two, at least one longitudinal fluid acceleration groove is formed on an outer peripheral wall of the inner receiving body. During operation, the drilling fluid is rapidly accelerated as it flows through the acceleration groove, thereby forming a stable negative pressure zone downstream. The negative pressure zone is formed by a reverse circulation channel, which draws fluid and rock cores upwards from a rock core inlet, thereby creating a protective local reverse circulation. A mainstream drilling fluid that does not participate in a reverse circulation continues to flow downwards, thereby forming a forward circulation for chip removal and cooling.