胜利油田高油气比地层欠平衡钻井技术

高油气比地层由于其气量较高,溢流激烈程度较高,欠平衡钻井的井控难度较大。胜利油田在渤深6区块的高油气比潜山油藏进行了十几口井的欠平衡钻井施工,通过对高油气比储层溢流特点以及施工中出现问题的分析,制定了一些有效的欠平衡钻井井控措施,并形成了一套适合高油气比储层的欠平衡钻井技术。防止油气在井底积聚,避免连续气枉的形成,是高油气比地层欠平衡钻井成功的关键;确定合理的钻井液密度,可实现无需节流控制;在地面处理系统中必须安装一个U形管,可增加液气分离器的水封高度,防止气体从液气分离器排液口间歇喷出。

Underbalanced Drilling Technology in High Gas/Oil Ratio Formations in the Shengli Oilfield

Being the high gas/oil ratio and severe overflow, it is difficult to control the well for underbalanced drilling such formations. Over ten wells are finished employing underbalanced drilling technology in Boshen 6 Block in the Shengli Oilfield. After analyzing overflow features of above reservoir and problems e-merged during drilling operations, some effective well control measures for underbalanced drilling are established, and then a series of underbalanced drilling techniques suitable for high gas/oil ratio are developed also. The key to successful underbalanced penetrating the high gas/oil ratio reservoir is to prevent the oil and gas from accumulating and forming continual gas column. Reasonable mud density can implement well control without choke. Installing an "U" style pipe in surface treating system can increase the "water seal" level of the liquid-gas separator to prevent the intermittently ejecting of gas from fluid outlets.