Stiffness Evaluation Method and Application of BHA for Wiper Trip in Ultra-deep Well Based on Pipe
China's ultra-deep well drilling is in the rapid development stage,due to the influence of large hole size and depth,micro-deviation,borehole diameter expansion and shrinkage and wall step can easily occur in the drilling process,which leads to the difficulty of casing running,so the evaluation of wiper trip BHA is particular-ly important.At present,the evaluation methods used in the field often ignore the collision and deformation be-tween the pipe string and the wellbore in the process of RIH,resulting in unstable results of wiper trip.In order to assist the field operation,this paper proposes an evaluation method of wiper trip BHA based on the whole pipe string dynamic model and HHT-α numerical calculation method,which can simulate the dynamic running process of pipe string and consider the measured trajectory,the change of borehole diameter and running resistance,etc.Through case calculation and analysis of BHA prior to RIH casing of third section in an ultra-deep deep well,it is shown that the hole enlargement rate and the casing running resistance have great influence on wiper trip ability and casing running.When the hole enlargement rate is small and the casing string running resistance is large,the high stiffness wiper trip BHA with multi-centralizer should be used.This method can achieve more accurate stiff-ness comparison simulation under measured well conditions,and successfully guide the safe RIH of Ø486 mm cas-ing in this example.
NETL
NSTL
万方数据
维普
