Split-flow automatic control system of coal bed methane horizontal branch well and process thereof

Abstract

The invention discloses a split-flow automatic control system of a coal bed methane horizontal branch well. The split-flow automatic control system of the coal bed methane horizontal branch well comprises a ground manifold structure and an automatic control system, the ground manifold structure comprises a first mud input pipeline (A), a second mud input pipeline (B), a mud outlet pipeline (C), an auxiliary mud outlet pipeline (D) and a gas injection pipeline (E), and the automatic control system comprises a field sensor, a field bus (26), an industrial control computer (27), a programmable logic controller PLC (29) and an electric actuating mechanism. The invention further discloses a well drilling process of the system. The split-flow automatic control system of the coal bed methane horizontal branch well and the well drilling process of the system have the advantages of being capable of eliminating pressure fluctuation in a shaft caused by a switch pump and capable of adjusting opening of a throttling valve automatically, guaranteeing that pressure in the shaft remains stable, being capable of guaranteeing that a gas phase and a liquid phase are mixed evenly in a coal bed methane horizontal branch well aerated underbalanced process, and preventing large displacement drilling fluid from flushing well walls while guaranteeing drilling fluid rock carrying efficiency of a high-inclination well section.

Description

technical field [0001] The invention relates to the technical field of coalbed methane horizontal branch well mining and its automation, in particular to an automatic control system and technology for coalbed methane horizontal branch well diversion for reducing the pressure fluctuation in the wellbore of the coalbed gas horizontal branch well. Background technique [0002] As a high-quality, high-efficiency and clean energy, coalbed methane has broad prospects for development and utilization. The main reasons restricting the large-scale development and utilization of coalbed methane are the low output and high cost of single wells of coalbed methane wells. The development of coalbed methane by horizontal branch wells is the solution to this problem. It is an important technical means, which can obtain high output at a lower cost and meet the requirements of industrial development. However, the use of horizontal wells to drill coal seams also poses higher challenges to drill...

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Problems solved by technology

[0009] The purpose of the present invention is to overcome the shortcomings of the prior art, make full use of drainage and production vertical wells, and provide an automatic control system and technology for the diversion of coalbed methane horizontal branch wells, which can effectively solve the downhole pressure that occurs in the existing coalbed methane horizontal branch well drilling. Large fluctuations, low rock-carrying efficiency, technical problems of erosion of the well wall, avoiding downhole accidents such as wellbore collapse and even lost circulation

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