Automatic control device of mud returning pipeline used for well drilling

Abstract

The invention relates to an automatic control device of a mud returning pipeline used for well drilling. The automatic control device of the mud returning pipeline used for well drilling comprises an open-loop control system, wherein the open-loop control system comprises a PLC, the front portion of the PLC is connected with a flow meter, a contactor is connected to the lower portion of the flow meter and is connected with an electromagnetic valve, and automatic control of the mud returning pipeline is achieved by opening and closing the electromagnetic valve. The automatic control device of the mud returning pipeline used for well drilling can be well applied to well drilling. When returned mud is reduced due to the fact that excessive solid components are contained in the returned mud and a vibration sieve is blocked, a bypass-valve is opened automatically in time to avoid waste of the mud.

Description

technical field [0001] The invention belongs to the field of oil and gas well engineering, and in particular relates to an automatic control device for a drilling mud return pipeline. Background technique [0002] Due to the structural characteristics of the drilling itself, serious sand production in the annular wellbore or complex accidents such as well collapse often occur during the drilling process. Along with the return of mud like this, the solid matter takes up the main body in the composition of mud. If there are too many solid components and the particles are large, when the mud flows through the vibrating screen, the solid components in it will directly block the screen cloth of the vibrating screen, which will cause the mud to go directly to the sewage tank without time for solid-liquid separation. Especially in formations where the geological cementation strength is not high, if the mud properties used are not very good, making this situation even worse. If th...

AI Technical Summary

Problems solved by technology

Although this can slow down the further blockage of the screen cloth, it has the following three defects: 1. The mud displacement is suddenly reduced, resulting in a reduction in the return speed of the mud in the borehole annular space, which increases the drilling speed. Risk of "grit" stuck drill

2 Due to the suspension of drilling, the progress of the project will slow down and the drilling cycle will increase a lot

3 Although it can reduce the further accumulation of solid matter on the vibrating screen cloth to a certain extent, it does not fundamentally solve the tendency of the vibrating screen cloth to continue to be blocked

But its disadvantages are: there must be special personnel to take care of the vibrating screen. Once the screen cloth is found to be blocked, the bypass valve will be manually opened, which consumes manpower and does not realize the automation of control.

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