Well drilling tool face angle self-correction closed-loop control method

Abstract

The invention relates to the field of drilling and exploiting machines, and discloses a well drilling tool face angle self-correction closed-loop control method. The well drilling tool face angle self-correction closed-loop control method comprises the steps that firstly, input data and output data are collected; secondly, according to the input data and the output data, a CARMA model is established; thirdly, the CARMA model is converted into a least squares structure shown in the specification; fourthly, a gain matrix L(t) and a covariance matrix P(t) are set, parameter estimation is conducted, and identification parameters meeting the requirement are obtained; and fifthly, a control target function is established, a motor is controlled according to the control target function and the identification parameters, and the needled tool face angle is obtained. The CARMA model is adopted in the well drilling tool face angle self-correction closed-loop control method, the problems about established drilling tool system mathematic model variable uncertainty and model form uncertainty are solved; through the recursive least-squares method, dynamic parameter adjustment is conducted online,the C / A equation is introduced, and the prediction equation can be simplified; and real-time monitoring and automatic control on the tool face in the sliding drilling process are achieved.

Description

technical field [0001] The invention relates to the field of drilling and production machinery, in particular to a self-correcting closed-loop control method for the face angle of a drilling tool. Background technique [0002] In the process of directional well drilling, to ensure that the drilled well trajectory is close to the designed well trajectory, on-site engineering and technical personnel need to have rich experience. In the sliding mode, the drill string must first be lifted from the bottom of the hole and stop rotating, and then the directional driller can make the direction of the downhole motor elbow point to the direction required by the wellbore trajectory design by swinging the tool face. Swiveling the toolface needs to consider the torque of the drill bit, the reaction torque of the drill string and the friction between the drill string and the well wall, so the driller should slowly rotate the drill string on the surface, and then refer to the change of the...

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