伊拉克AHDEB油田钻井液完井液技术研究与应用

伊拉克AHDEB油田0～1100m井段为强水敏泥页岩。1100～1500m存在大段石膏层、盐层及盐水层．1780~2050m为燧石结核灰岩．地层渗透率较高；油田平面分布多个天然溶洞．溶洞内有不致密充填．溶洞及天然裂缝中存在炭化沥青。钻井过程中极易发生漏失和坍塌。通过室内研究，在现场采用聚磺混油钻井液体系及屏蔽暂堵完井液．实现了钻井液性能稳定与井眼稳定．完井液岩心渗透率恢复值达90％以上，钻井速度大幅提高，其中水平井提高了2．21倍。直井提高了2．52倍，定向井提高了2．47倍，同时钻井液成本降低了50％以上。

Research and Application of Drilling Completion Fluid Technology in AHDEB Oilfield of Iraq

There was high water sensitivity mud shale in well section of 0~1100 m in Iraqi AHDEB Oil- field,large section of plaster layer,salt layer and saline aquifers in well section of 1100~1500 m,chert nodules limestone,higher formation permeability in well section of 1780---2050 m, multiple natural caves filled incom- pactly were distributed in the oilfield plane and there was charring asphalt in caves and natural fractures which collapsed and leakaged easily. Through the indoor research, using polysulfonate mix oil drilling fluid and tempo- rary blocking completion fluid in field applications,we could keep drilling fluid properties and borehole stable and the recovery value of completion fluid core permeability could reach up to 90%, the drilling speed was greatly improved,which increased 2. Z1 times in horizontal wells,2.52 times in vertical wells and 2.47 times in directional wells,meanwhile,the cost of drilling fluid was reduced by more than 50%