水平井工程师法压井技术探索

EXPLORATION OF ENGINEER WELL-KILLING TECHNOLOGY FOR HORIZONTAL WELL

随着水平井应用范围日益扩大,水平井钻井井喷及井下事故的风险也随之增加。为有效避免井喷事故的发生,以工程师压井原理为基础,在水平井剖面上找出对应的井口、造斜点、稳斜点和钻头处四个关键点,并分别计算出这四个点的总循环立管压力,再将相邻两点以直线相连,计算出各段直线段的定冲压降值,制作成水平井压井数据控制表。从此表可看出当压井液到达稳斜点时,循环立管压力降至最小值;水平井段越长,其值越低。所以在整个压井期间,只要在不同井段控制不同的压降值作为循环立管压力控制的依据,就可实现水平井全井段井底常压法压井的目的,从而杜绝井喷、卡钻及井漏等事故的发生。

With the widely applications of horizontal wells,the risk of blowout and downhole accidents increases as well.In order to effectively avoid and put an end to the above accidents,in this paper,based on the killing principle of Engineer’s Method,four key points are found on the profile of horizontal well,i.e.the wellhead,the kick-off point,the holding point and the bit,and the total circulating standpipe pressure of these four points is calculated respectively.Then,the adjacent two points are connected in a straight line,and the fixed-stroke drop value of each straight line section is calculated,and the horizontal well killing data control table is made as the basis of circulating standpipe pressure control and well killing operation program.From this table,it can be seen that when the kill fluid reaches the holding point,the circulating standpipe pressure decreases to the minimum value.The longer the horizontal section,the lower the value.Therefore,during the whole killing period,as long as different pressure drop values are controlled in different well sections as the basis of circulating standpipe pressure control operation,the purpose of the constant bottom-hole pressure killing in the whole horizontal well section can be realized,so as to prevent blowout,sticking and lost circulation accidents.