摘要
徐深气田登娄库组泥岩发育,井壁稳定性差;营城组井壁剥落易落碎块,井眼净化难;目的层裂缝发育,压稳气层与防漏堵漏矛盾突出,钻井液安全密度窗口窄;天然气中富含CO_(2),易造成地层伤害;在长水平段水平井施工中,钻井扭矩大、摩阻大。针对该气田的地质特点和作业要求,优选使用油基钻井液体系,并对其性能进行室内评价及现场应用效果分析。室内评价结果表明,油基钻井液体系性能稳定,破乳电压达到600V以上,高温高压滤失量不高于3mL,能够抗180℃高温,抗岩屑地层伤害能力强。现场起下钻作业顺利,未发生井壁失稳等复杂情况,机械钻速提升,套管一次下到位。在钻井液方面有效解决了深层气水平井井壁稳定性差、井眼净化难、地层易漏,以及CO_(2)对地层伤害和工程措施要求高等问题。
In Xushen gas field,there exists the following problems:the mudstone in Denglouku Formation was well developed leading to the poor wellbore stability;the wellbore of Yingcheng Formation was easy to collapse and debris falls,making it difficult to clean the wellbore;the fracture of Target Formation was well developed to produce the obvious contradictions between controlling gas reservoir pressure and preventing and plugging leakage,and the safety density window of drilling fluid was narrow.The CO_(2)was rich in natural gas,which was easy to cause pollution;the drilling operation has high torque and friction while drilling the horizontal wells with long horizontal section.According to the geological characteristics and operation requirements of the Xushen gas field,the oil-based drilling fluid system has been optimized,and its performance in laboratory was evaluated as well as the application effect at well site was analyzed.The results of laboratory evaluation showed that the oil-based drilling fluid has stable performance,the demulsification voltage was over 600V,the HTHP filtration loss was less than 3mL,and it could resist 180℃high temperature with strong resistance to rock cuttings pollution.Tripping was smooth in drilling operation,and the instability of wellbore and other complex problems were never happened.The mechanical drilling speed was increased and the casing was lowered once down in place.In the aspect of drilling fluid,the problems of poor wellbore stability,difficult wellbore cleaning,formation leakage,formation damage caused by CO_(2)and high engineering requirement were effectively solved.
作者
马金龙
陶丽杰
Ma Jinlong;Tao Lijie(Production Technology Institute of Daqing Oilfield Limited Company)
出处
《采油工程》
2024年第1期43-48,81-82,共8页
Oil Production Engineering
关键词
徐深气田
深层气
水平井
油基钻井液
钻井液性能
Xushen gas field
deep gas
horizontal well
oil-based drilling fluid
drilling fluid properties
