伊拉克艾哈代布油田快速钻井技术

艾哈代布油田可采储量丰富,但新近系-古近系地层存在易蠕变的大段盐膏层、易坍塌的大段泥岩和泥质灰岩,盐膏层段和下白垩系地层可钻性较差,造成钻井过程中复杂情况频出、机械钻速低,从而导致钻井周期长。为了提高艾哈代布油田的整体开发进程,进行了钻井技术集成,形成了艾哈代布油田快速钻井技术。根据地层压力剖面优化水平井井身结构;根据地质特征、开发要求及钻井工艺水平,将水平井设计为双增剖面、中曲率半径的水平井;采用统一防碰设计进行井眼轨道整体设计;根据室内综合评价结果优选出了抑制性强的、抗盐钙侵的聚磺钻井液;将利用地层可钻性剖面优选出的PDC钻头与螺杆钻具配合进行复合导向钻进;丛式井组利用滑轨整体移动技术进行钻机搬迁安装。现场应用表明,快速钻井技术有效控制了缩径、阻卡等复杂情况,各井型机械钻速提高1倍以上,钻井周期平均缩短近50%。该快速钻井技术为艾哈代布油田高效开发提供了工程技术保障。 

Rapid Drilling Technology in Ahdeb Oilfield

Ahdeb Oilfield in Iraq contains abundant recoverable reserves.However,drilling problems have occurred frequently due to the existence of long interval easily-creeping anhydrite formation,easily-collapsing mudstone and argillaceous limestone in Tertiary,and less-drillable anhydrite and lower Cretaceous formations.To accelerate development of the field,several drilling techniques were integrated to a fast drilling technologyy suitable for the oilfield.The technology contains the following aspects: horizontal well structure optimization based on formation pressure profile,profile of horizontal wells optimization to a double build-up with medium curvature radius according to geological characteristics,development requirement and available drilling technology,well trajectory design with unified anti-collision,salt/calcium resisting sulphonated polymer mud with good inhibition capacity optimization through laboratory evaluation,PDC bit selection according to formation drillability profile and PDC bitalong with motor to realize steerable drilling,and slide rail rig move technique in cluster well drilling.Field application shows that tight hole and tight pull are mitigated with the technology,average ROP increase more than 100%,and average drilling period decreased by nearly 50%.Therefore,the fast drilling technology provides effective engineering support for capacity construction in Ahdeb Oilfield.