A whole-section self-priming reverse circulation gas drilling system for oil and gas drilling

Abstract

The invention discloses a whole-section self-priming reverse circulation gas drilling system for oil and gas drilling, which comprises a ground manifold connection structure and a drilling tool assembly structure connected to the ground manifold connection structure. The structure includes: gas injection unit, pressure relief unit, flow meter, surface gas injection manifold, high-pressure gas injection hose, erosion-resistant gooseneck, high-pressure reverse circulation sand discharge hose, surface reverse circulation sand discharge pipeline and positive circulation gas drilling For the sand discharge pipeline, the whole well section of the present invention adopts double-wall drilling tools, which does not require the participation of conventional single-wall drilling tools, gas-water mixing joints and other tools. The whole well section uses air as the circulating medium, and does not require the participation of mud or other drilling fluids Reverse circulation can also be formed, especially suitable for well sections with severe water shortage, serious lost circulation or where gas lift reverse circulation cannot be implemented.

Description

technical field [0001] The invention relates to the technical field of oil and gas drilling, in particular to a full-section self-priming reverse circulation gas drilling system for oil and gas drilling. Background technique [0002] Gas drilling technology can greatly increase the ROP in difficult-to-drill formations such as volcanic rocks, gravel layers, clastic rocks, and carbonate rocks. It is applied in areas such as Sichuan and Chongqing, and the average ROP is increased by 4 to 15 times. However, when positive circulation gas is used to drill wells (especially large-diameter wells), equipment investment is large, land occupation is large, gas consumption is large, energy consumption is high, and cost is high. 3 / min or more, 17 1 / 2″ borehole required gas volume 300m 3 / min; when the stability of the borehole wall is poor, or the formation water yield is large, increasing the gas volume for gas drilling will intensify the erosion of the borehole wall and increase the ...

AI Technical Summary

Problems solved by technology

This method is mainly used for reaming drilling in the coal mine industry, and has high requirements on the formation. If the formation fractures develop, the annular pressure cannot be established, and the effect of reverse circulation formation will also be affected.

At the same time, the rock-breaking tool used in this construction method is a cluster DTH hammer. The structure of this tool is a bit complicated, and maintenance and replacement of drill bits are a bit cumbersome.

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