Underground gas cut monitoring system based on ultrasonic waves

Abstract

The invention belongs to the technical field of oil and gas drilling and particularly relates to an underground gas cut monitoring system based on ultrasonic waves. The monitoring system comprises anultrasonic gas cut monitoring device fixed on a drill rod and an annular gas-solid separation device located below the ultrasonic gas cut monitoring device; and the annular gas-solid separation devicecomprises a turbine and a gas-solid pre-separation device which are sequentially fixed on the drill rod from top to bottom. The underground gas cut monitoring system based on ultrasonic waves can effectively separate gas cut gas and rock debris in the well, eliminate the influence of the rock debris on gas cut monitoring, and also can enable the gas cut gas in the whole annular space to be concentrated in an effective monitoring window near the drill rod as far as possible, thereby solving the problem that a current underground gas cut monitoring method is limited by the space of the monitoring window and influenced by the rock debris, and greatly improving the timeliness, precision and reliability of gas cut monitoring.

Description

technical field [0001] The invention belongs to the technical field of oil and gas drilling, and in particular relates to an ultrasonic-based downhole gas invasion monitoring system. Background technique [0002] In the exploration and development of deep water and deep oil and gas resources, due to the lack of accurate prediction and monitoring information on the deep water environment, deep formations and working conditions, the risk of downhole complex accidents during the drilling process has increased significantly, among which blowout is a complex, A major accident that is extremely harmful and difficult to avoid and deal with once it occurs. Early monitoring of gas kick has become one of the key technical means to avoid blowout and implement effective well control. [0003] At present, the commonly used early monitoring methods for gas invasion and overflow are mainly the drilling fluid pool increment method and the outlet flow difference method, but for deep water a...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the defects of the existing downhole ultrasonic monitoring gas invasion method that it is difficult to grasp the gas fraction of the entire annular space due to the small ultrasonic monitoring information window and the monitoring results are affected by rock debris, resulting in low gas invasion monitoring accuracy and unreliable results. An ultrasonic-based downhole gas intrusion monitoring system, which can not only effectively separate downhole gas intrusion gas and cuttings, eliminate the impact of cuttings on gas intrusion monitoring, but also make the gas intrusion gas in the entire annulus as concentrated as possible The effective monitoring window near the drill pipe solves the problem that the current downhole monitoring method of gas intrusion is limited by the space of the monitoring window and the impact of cuttings, and greatly improves the timeliness, accuracy and reliability of gas intrusion monitoring

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