摘要
南堡凹陷高柳区块沙三3段V油组属于典型的砂泥薄互层致密油藏,因多年压裂注水开发导致地层压力系统复杂、人工缝网分布密集,水平井钻井过程中井漏、油水侵与井壁垮塌复杂情况同时存在、矛盾突出。结合高柳区块地层特征阐述了水平井安全钻井技术难点,明确了钻井液漏失、井壁垮塌原因,优选纳微米级乳化防塌剂、石墨微球与微米级柔性封堵剂、超细钙构建了封堵承压井壁稳定油基钻井液体系,该体系有效降低滤液对泥岩地层的侵入,对泥岩强度保持能力提高5倍以上,使中高渗砂岩封堵承压能力达到18 MPa;针对油基钻井液漏失问题提出了油基桥接堵漏技术与油基固化堵漏技术。现场试验解决了高柳区块复杂压力系统致密油藏水平井安全钻井难题,十余口应用井无井壁垮塌情况发生,漏失井堵漏后漏失层承压能力提高5.4 MPa,满足后续钻井施工要求。
The Sha-3 member V reservoir in the Gaoliu block,Nanpu sag is a typical interlayered thin sandstone and thin claystone tight reservoir with complex formation pressure systems and densely distributed artificial fractures resulted from many years of fracturing and injection operations.Horizontal drilling in this area is faced with problems such as mud losses,oil and water kicks as well as collapse of borehole walls.This paper describes,based on the formation characteristics of the Gaoliu block,the technical difficulties in horizontal drilling,and points out the causes of mud losses and borehole wall collapse.To solve these problems,an oil based drilling fluid was formulated with a nanometer/micrometer sized emulsified borehole wall collapse preventing agent,graphite microspheres,a micrometer flexible plugging agent and calcium carbonate of ultrafine particles,which render the drilling fluid capacities such as plugging,high pressure bearing and borehole wall stabilizing.The oil based drilling fluid has low filtration rate and has the ability of maintaining the strengths of the claystones that is 5 times higher than other drilling fluids.With this drilling fluid,the pressure bearing capacity of the sandstones of medium and high permeability can be increased to 18 MPa.Bridging and solidification mud loss control techniques were used to control mud losses.Using this drilling fluid,horizontal drilling through the tight reservoirs in the Gaoliu block was safely performed and no borehole wall collapse was encountered during drilling in more than ten wells.In formations where mud losses were encountered,the mud losses were controlled and the pressure bearing capacity of the formation was increased by 5.4 MPa,satisfying the requirement of subsequent drilling.
作者
吴晓红
李云峰
周岩
阚艳娜
李然
罗成
WU Xiaohong;LI Yunfeng;ZHOU Yan;KAN Yanna;LI Ran;LUO Cheng(Jidong Oilfield Company of PetroChina,Tangshan,Hebei 063004)
出处
《钻井液与完井液》
CAS
北大核心
2024年第1期45-52,共8页
Drilling Fluid & Completion Fluid
基金
中石油重大科技专项“低渗/致密油藏大幅度提高采收率关键技术研究”(2023ZZ17)
冀东油田公司重大项目“高深北区高5断块Ⅴ油组致密油效益开发关键技术研究与矿场试验”(KF2022A02)。
关键词
致密油藏
复杂压力系统
水平井
坍塌
井漏
油水侵
Tight reservoir
Complex pressure system
Horizontal well
Collapse
Mud loss
Oil and water kick
