摘要
针对也门Abyed-2井大尺寸井眼灰岩裂缝性地层漏失、疏松砂泥岩井眼失稳等一系列钻井难题,确定了采用泡沫气基流体钻过灰岩地层、抑制性硬胶泡沫钻过不稳定砂泥岩地层、零滤失高效泡沫压井液保证起下钻安全的多套气体钻井施工方案。现场施工表明,空气/泡沫钻井工艺提高了灰岩地层的机械钻速,避免了裂缝性灰岩、疏松砂泥岩地层出现恶性漏失,能维持疏松砂泥岩地层的井眼稳定,有效缓解了严重缺水地区钻井施工对生产用水的依赖,降低了钻井成本。空气/泡沫钻井工艺在该井的成功应用,为也门1区块的优快钻井提供了借鉴。
In Well Abyed-2 in Yemen, the lithology in upper formation from surface to 260m is a hardy limestone and dolomite, formation from 260 to 700m is unconsolidated sand and sandy shale, and there is a water table in about 750m. Lost circulation and hole collapse were normally encountered in offset wells, therefore it is difficult to predict the pore pressure accurately. Geology required isolating formation above water table surface casing which puts higher requirements on drilling operation. Several plans were used to solve these problems encountered, including using foam to drill the limestone formation, using stiff foam to dill the unconsolidated sand formation, and using the high quality foam without fluid loss as kill mud to ensure the trip safety. Field applications indicate that air/foam drilling fluid improved the rate of penetration in limestone formation and avoided the loss circulation in fractured limestone formation and unconsolidated sandstone formation. Well stability can be maintain in unconsolidated sandstone formation and alleviate the dependent on water during drilling procedure in areas with problem of water shortage. The drilling cost was reduced. Air and foam drilling is the first valuable test to apply in serious loss and unconsolidated sandstone formation.
出处
《石油钻探技术》
CAS
北大核心
2009年第4期107-109,共3页
Petroleum Drilling Techniques
基金
国家重大专项"中东中亚复杂地层深井钻完井技术"专题2(编号:2008ZX05031-004-002)部分研究内容
