Research On An Intelligent Control Method Of Eccentric Vector In The Steering Drilling

The rotary steering drilling system with controllable eccentralizer can adjust the well trajectory by controlling the eccentric vector.Eccentric vector control is the core of drilling guidance control.In this paper,the fuzzy logic combined with neural network algorithm is used to study the method of intelligent control for the eccentric vector.The main work is as follows:The definition and characterization parameters of trajectory's deviation on the normal plane are introduced.And the calculation method of the deviation is explained.The spatial stress analysis of controllable eccentralizer rotary steering system's BHA is carried out,also the discussion of effccts on bit inclination force which caused by bias force and wellbore curvature is given.By means of the mechanical analysis and mathematical calculation for the three wing rib's force of guide tool,the scheme for eccentric vector control is obtained.And the combination of the three wing rib's force keeping the eccentric vector invariant in the rotation of the outer sleeve is also analyzed.It designs an eccentric vector fuzzy controller based on the trajectory deviation and the simulation process of the controller's parameters adjustment.A way to optimize the controller using neural network algorithm is put forward.Finally,an indoor experimental platform for the eccentric vector control is built.Through the platform,a large number of related experiments are carried out and good results are achieved.The conclusions are as follows: the eccentric vector control algorithm is effective;the maximum speed of the outer sleeve's rotation which the eccentric vector can follow is about 20r/h.