A NEW BHA USED IN VERTICAL WELL DRILLING TO CONTROL DEVIATION

This article analyses the effective path to control bit side forces and shows the basic method of designing that providing theoretical basis for comprehensive analyzing BHA.Against the lack of pendulum and paced hole BHAs in controlling deviation,a new flexible BHA has been designed to control deviation in vertical well and the mechanics character has been analyzed by beam and column method.The test results have shown that new BHA can control hole deviation and increasing penetration rate.