有效解除水平井段压差卡钻技术——在磨溪地区钻井中的应用

由于勘探工作的需要，目前国内各油气田水平井钻井数量越来越多，钻井中在水平井段出现的压差卡钻事故也经常发生，现场一般采用大吨位提拉活动钻具、反复震击、条件允许时替入足量的低密度钻井液降压差、在卡点附近浸泡解卡液、泡酸、爆炸松扣、套铣等方法处理此类事故，但很难奏效。为此，从水平井段发生压差卡钻的成因及解卡途径、SPJ解卡液研制与评价入手，摸索出解除水平井段压差卡钻的关键技术--SPJ解卡液技术。该技术在磨溪地区的应用表明，为解除水平井段发生的压差卡钻，用前置冲洗液降低井筒液柱压力和浸泡SPJ优质解卡液的综合手段十分有效。适合在类似磨溪地区的钻井中推广应用。

TECHNIQUES USED TO REMOVE PRESSURE STICKING IN HORIZONTAL WELLS AND ITS ACTUAL APPLICATION IN MOXI GASFIELD

More and more horizontal wells are now being drilled all over gas and oil fields in China due to the increasing need for oil and gas exploration and development. The pressure sticking has become a common problem during the drilling of horizontal section. Those previous measures normally used seemed helpless in many ways any more on fields, like high tonnage pull of drill string, repetitive jarring, injection of low density drilling fluid to reduce pressure differential if applicable, spotting sticking solution, acid spotting, thread backout with explosives, and milling, etc. Starting from study on differential sticking mechanism, how to solve this problem, and the development and evaluation of SPJ sticking solution, this paper introduced the critical techniques used to remove the pressure sticking problem in horizontal well, and how the SPJ solution remove pressure sticking effectively. Through its application in the Moxi gasfield, this study concluded that combining adopting preflush to reduce the hydraulic pressure of the fluid column in the wellbore and spotting of SPJ sticking solution effectively removed the pressure sticking in horizontal wells. This paper recommends this method to be widely applied in all drilling works similar to that in the Moxi gasfield.