沧东凹陷页岩油水平井不压井作业技术

Technologies for Snubbing Services in Horizontal Shale Oil Wells in the Cangdong Sag

王栋 赖学明 唐庆 周俊杰

WANG Dong LAI Xueming TANG Qing ZHOU Junjie

中国石油大港油田分公司采油工艺研究院，天津 300280

Oil Production Technology Research Institute, Petrochina Dagang Oilfield Company, Tianjin, 300280, China

沧东凹陷孔二段页岩油储层属于特低孔、特低渗储层，泥质含量高，作业过程中极易因压井液等外来流体侵入造成污染。针对这一问题，对页岩油井常用的有杆泵、电动潜油泵举升工艺及其生产管柱和井下工具进行优化设计，形成了由预制内防喷工具不压井作业技术、可控桥塞暂闭井筒完井技术和敷缆连续油管带压下泵技术等组成的沧东凹陷页岩油水平井不压井作业技术。现场应用结果表明，不压井作业技术可以解决有杆泵井内衬油管无法有效密封、电动潜油泵井无法带压作业等问题，作业后储层零污染，无需等待完全泄压结束再下泵投产。

The shale oil reservoir in the Kong-2 member of the Cangdong Sag has ultra-low porosity, ultra-low permeability and high shale content, and thus, it is prone to be contaminated by invasion of fluids including killing fluid during operations. Regarding this problem, the sucker rod pumps, the lift technology of electric submersible pumps, and the associated production string and downhole tools commonly used in shale oil wells were optimized. Then, the technologies for snubbing services in the horizontal shale oil wells in the Cangdong Sag were formed with snubbing service with prefabricated inner blowout preventers, completion with controllable bridge plugs that can temporarily close wellbore, and under-pressure pumping-down operation with cable-laying coiled tubing. Field applications showed that this technologies could successfully address the problems such as lined tubing sealing failures of sucker rod pumps and under-pressure operation failures of electric submersible pumps,etc. After the operations, the reservoir was not contaminated and the pumping-down operation were free from waiting for complete pressure relief.

https://doi.org/10.11911/syztjs.2021077