多段压裂水平井拖动管柱找水关键技术

摘要

长庆油田长水平段水平井应用拖动管柱找水工艺时,存在配套的皮碗封隔器胶筒密封性变差和起钻时皮碗脱落的问题,为此对其进行了针对性研究.通过室内模拟井下环境,利用滚珠丝杠控制皮碗封隔器在套管内往复运动,得到每摩擦500.00 m时的皮碗磨损量,根据承压试验确定其最大下深为2500.00 m;通过改进Y211型拖动压裂封隔器结构、优选胶筒材料,研制了分别应用于单封和双封拖动管柱找水工艺的Y211-1型和Y211-2型封隔器;同时,研制了可在水平段重复坐封的新Y111型封隔器,以确保能够实施双封拖动管柱找水工艺.研究的新型封隔器和拖动管柱找水工艺已在长庆油田6口水平井应用,应用结果显示,1套封隔器可以完成2口井的找水作业,测试成功率由之前的91.3% 提高至100.0%,单井测试费用仅为皮碗封隔器拖动管柱找水的一半.研究结果表明,新型封隔器使拖动管柱找水工艺更简便、费用更低,在长水平段水平井中的应用效果良好.%In the application of water detection technology by dragging the pipe string in the long reach horizontal wells in the Changqing Oilfield,problems such as sealing property deterioration of the matched cup packer and cup dropping while POOH occurred.Therefore,the targeted studies were carried out. Through lab simulation of the downhole environment,ball screw was used to make the cup packer recipro-catingly move inside the casing to obtain the wear amount of each 500.0 m of friction.The maximum packer bearing setting depth of 2 500.0 m was also determined through bearing tests.By improving the structure of the Y211 dragging fracturing packer and by optimizing its rubber material,Y211-1 and Y211-2 packers suitable for single-packer and dual-packer water detection technology by dragging the pipe string were de-veloped respectively.Besides,a new Y111 packer that can be set repeatedly in the horizontal section was de-veloped to guarantee the implementation of dual-packer string dragging water detection technology.The new type packers and string dragging water detection technology were used in six horizontal wells of the Changqing Oilfield.The application results indicated that one set of packers was able to achieve water de-tection in two wells,and the testing success rate increased from 91.3% to 100.0%,while the cost of a sin-gle well test was only half of that with previous cup packer string dragging water detection.The research results show that the new packers make the water detection technology more convenient and economical, and they can obtain satisfying effect when applied in long horizontal wells.