Hydraulic pressure type coring tool

Abstract

The invention discloses a hydraulic pressure type coring tool which comprises a safe joint, a hydraulic pressurizing device, an outer cylinder assembly, an inner cylinder assembly and a core catcher assembly. The safe joint is of a big-end-up cone shape, the bottom and the top of the safe joint are opened, the middle of the safe joint is connected with the outer cylinder assembly through threads, the lower portion of the safe joint is connected with the hydraulic pressurizing device through threads, the inner cylinder assembly is hung below the hydraulic pressurizing device through a hanging device, the core catcher assembly is arranged on the lower side of the inner cylinder assembly, and the hydraulic pressurizing device, the inner cylinder assembly and the core catcher assembly are located in the outer cylinder assembly. After the hydraulic pressurizing device exerts hydraulic pressure, the hanging device falls off, the inner cylinder assembly and the core catcher assembly fall along with the hanging device, and the core catcher assembly clamps under the action of hydraulic pressure to achieve the aim of completely wrapping a smashing core. When plastic deformation of a core sealing sleeve reaches a certain degree, drilling fluid is discharged from a gap between the core sealing sleeve and a connection sleeve, so that the core can not be compressed excessively, and integrity of the core is guaranteed.

Description

technical field [0001] The invention belongs to the field of drilling and coring, and in particular relates to a hydraulic pressurized coring tool. Background technique [0002] In the coring operation of soft and broken formations, there are mainly the following problems: the low strength of formation cement makes it difficult for the core to form and it is difficult to enter the coring tool. When the core cement has strong water sensitivity, the bearing capacity of the core is reduced under the erosion of water-based drilling fluid, and it is easy to collapse and break, resulting in core plugging and core grinding, thereby affecting the core technical indicators. During the coring process of loosely cemented and heterogeneous pebble-containing glutenite, the vibration of the core drill bit and tools can easily cause the core to break and break. During the core extraction process, due to changes in the stress state of the core column, the core is easily collapsed and broke...

AI Technical Summary

Problems solved by technology

The coring tools used in coring operations for soft and broken strata in the prior art are still relatively backward, and the average coring yield is extremely low, which has a negative impact on geological exploration

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