Reverse circulation drilling circulation channel switching short section

Abstract

The invention provides a reverse circulation drilling circulation channel switching short section, and belongs to the field of drilling tools and comprises an upper joint, a rubber plug and a reversing mandrel; the upper joint is provided with a first end and a second end which are oppositely arranged; the rubber plug is sleeved on the outer side of the upper joint, a discharge annular space is formed between the first end and the rubber plug, and an inflow annular space is formed between the second end and the rubber plug; a flow guide space communicating with a drilling fluid supply channelis arranged in the upper joint; the reversing mandrel is arranged in the flow guide space, and the flow guide space is separated into an inflow channel between the reversing mandrel and the inner wallof the flow guide space and an outflow channel inside the reversing mandrel; and the inflow channel, the inflow annular space, the outflow channel and the discharge annular space are communicated insequence. The reverse circulation drilling of an open hole section can be realized, ground equipment does not need to be changed and adjusted, the conventional drilling construction process is not influenced, the open hole section at the bottom of a well is free of rock debris, the drilling friction resistance is reduced, the speed is increased, the cost is reduced, and the drilling safety is guaranteed.

Description

technical field [0001] The invention relates to the field of drilling tools, in particular to a reverse circulation drilling circulation channel switching nipple. Background technique [0002] Reverse circulation drilling technology is a drilling technology developed to solve the drilling problems of low pressure, low permeability and easy leakage oil and gas reservoirs, reduce drilling friction, protect reservoirs and improve drilling safety. This technology generally uses double-walled drill pipe. By injecting circulating medium into the drill pipe annulus, after cleaning the drill bit and carrying cuttings at the bottom of the hole, the drilling fluid carrying cuttings flows into the inner channel of the drill pipe and returns to the ground. During the drilling process , Broken cuttings do not enter the drill pipe and borehole annulus, the annulus is purified drilling fluid with stable performance and stable pressure, which can effectively protect the reservoir, keep the ...

AI Technical Summary

Problems solved by technology

However, due to the high cost and production difficulty of double-walled drill pipes, equipment and tools such as surface rotary head blowout preventers, downhole reverse circulation motors, well deviation monitoring tools, downhole blowout preventers and drill bits are also required to match double-wall drill pipes. , which limits the application of the technique

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