Deep rock quality assurance coring device and coring method thereof

Abstract

The present disclosure relates to the field of scientific drilling technology and provides a deep rock quality assurance coring device and coring method thereof. The deep rock quality assurance coring device comprises a drilling tool, a drilling bit, a central rod and a core storage body, wherein the drilling bit is mounted at the lower end of the drilling tool, the lower end of the central rod is connected to the core storage body, and the central rod is capable of driving the core storage body to move in the drilling tool in an axial direction of the drilling tool, a reservoir chamber having a lower end opening is arranged in the central rod, a core storage chamber having a lower end opening is arranged in the core storage body.

What is claimed is: 
     
         1 . A deep rock quality assurance coring device comprising a drilling tool, a drilling bit, a central rod and a core storage body for storing a rock core, wherein the drilling bit is mounted at the lower end of the drilling tool, the lower end of the central rod is connected to the core storage body, and the central rod is capable of driving the core storage body to move in the drilling tool in an axial direction of the drilling tool, a reservoir chamber having a lower end opening is arranged in the central rod, a core storage chamber having a lower end opening is arranged in the core storage body, a first valve controlling communication or blocking of the reservoir chamber and the core storage chamber is mounted on the upper end of the core storage body, a second valve closing or opening the lower end opening of the core storage chamber is mounted on the inner wall of the drilling tool;
 before the deep rock quality assurance coring device extracts the rock core, a first liquid is stored in the reservoir chamber, and the lower end opening of the reservoir chamber is closed by closing the first valve, so as to block the reservoir chamber and the core storage chamber, a second liquid is stored in the core storage chamber and the lower end opening of the core storage chamber is closed by a membrane. 
 
     
     
         2 . The deep rock quality assurance coring device of  claim 1 , wherein the inner wall of the core storage body is provided with a liquid flow path, and when the first valve is opened, the reservoir chamber communicates with the core storage chamber through the liquid flow path. 
     
     
         3 . The deep rock quality assurance coring device of  claim 2 , wherein the liquid flow path comprises a plurality of branching paths and a plurality of openings communicating with each other, and when the first valve is opened, the reservoir chamber, the branching path, the opening and the core storage chamber are sequentially connected. 
     
     
         4 . The deep rock quality assurance coring device of  claim 3 , wherein the plurality of branching paths extend in an axial direction of the core storage body. 
     
     
         5 . The deep rock quality assurance coring device of  claim 4 , wherein the plurality of branching paths are evenly distributed along a circumferential direction of the core storage body. 
     
     
         6 . The deep rock quality assurance coring device of  claim 5 , wherein the plurality of openings are arranged at equal intervals along the axial direction of the core storage body. 
     
     
         7 . The deep rock quality assurance coring device of  claim 1 , wherein the first valve is an electronically controlled valve and the second valve is a flap valve. 
     
     
         8 . The deep rock quality assurance coring device of  claim 1 , wherein the inner wall of the lower end of the drilling tool is provided with a claw for clamping the rock core. 
     
     
         9 . The deep rock quality assurance coring device of  claim 1 , wherein the first liquid is water, and the second liquid is a solution formed by mixing hydroxyl terminated polydimethylsiloxane, crosslinking agent, catalyst and fillers. 
     
     
         10 . A coring method of the deep rock quality assurance coring device of  claim 1 , comprising the following steps:
 firstly, after the first liquid is stored in the reservoir chamber, the first valve is closed so as to block the reservoir chamber and the core storage chamber, and then the second liquid is stored in the core storage chamber and the lower end opening of the core storage chamber is closed by the membrane to prevent the second liquid from flowing out;   the drilling tool is started, and the drilling tool drives the drilling bit to perform rock breaking work; in the process of rock core extraction, the rock core breaks through the membrane and starts to enter into the core storage chamber, at this time, the second liquid in the core storage chamber starts to be discharged due to the entry of the rock core; in the process of the rock core entering the core storage chamber, the second liquid always wraps the rock core to avoid contamination of the rock core caused by other liquids; and   after the rock core enters the core storage chamber, the coring process is finished, the drilling tool stops working, the second valve is closed, so that the second valve covers the lower end opening of the core storage chamber, and then the first valve is opened to make the reservoir chamber and the core storage chamber communicate with each other, so that the first liquid in the reservoir chamber enters the core storage chamber and contacts with the second liquid around the rock core to trigger in-situ curing and form a sealing film to wrap the rock core, and isolate the rock core from the outside.