Full-well-section self-suction type reverse circulation gas drilling system for oil and gas drilling

Abstract

The invention discloses a full-well-section self-suction type reverse circulation gas drilling system for oil and gas drilling. The full-well-section self-suction type reverse circulation gas drilling system for oil and gas drilling comprises a ground manifold connecting structure and a drilling assembly structure connected with the ground manifold connecting structure; and the ground manifold connecting structure comprises a gas injection unit, a pressure relief unit, a flowmeter, a ground gas injection manifold, a high-pressure gas injection hose, an erosion-resistant gooseneck, a high-pressure reverse circulation sand discharging hose, a ground reverse circulation sand discharging pipeline and a normal circulation gas drilling sand discharging pipeline. Double-wall drilling rigs are used in a full well section, conventional tools such as single-wall drilling rigs and gas and water mixing joints are omitted, air serves as a circulatory medium in the full well section, and reverse circulation can be implemented without mud or other drilling fluid. The full-well-section self-suction type reverse circulation gas drilling system for oil and gas drilling is particularly suitable for well sections with serious water shortage, serious well leakage or incapability of implementing air lift reverse circulation drilling.

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, 171 / 2″ borehole required gas volume of 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 th...

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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