复合空心玻璃微珠水泥浆体系在长庆定吴区块的应用

Application of composite hollow glass microsphere cement slurry system in Dingwu block of Changqing

长庆定吴区块洛河组下部及目的层延长组地层承压能力低,固井易发生压差性漏失,造成水泥返高不够及填充段固井质量差。为保证填充段固井质量,提高水泥浆返高,研发了一种复合空心玻璃微珠水泥浆体系,该体系浆体稳定、密度低、抗压强度高,并具有一定的自堵漏效果。进行水泥干混工艺优化设计,形成了一套适用于低压易漏水平井固井的防漏低密度水泥浆体系及混配工艺,5口井的现场试验显示,水泥浆返高满足设计要求,填充段固井质量合格率100%,满足定吴区块地低压易漏地层固井一次上返需要,为该区块水平井填充段固井质量提供了有力的技术支撑。

The lower part of Luohe formation and Yanchang formation in Dingwu block of Changqing have low pressure bearing capacity,which is easy to cause differential pressure leakage,resulting in insufficient cement return and poor cementing quality in filling section.In order to ensure the cementing quality of the filling section and ensure the return of cement slurry,a composite hollow glass microsphere cement slurry system was studied.The slurry is stable,low density,high compressive strength,and has certain self-plugging effect.Through the optimization design of cement dry mixing process,a set of anti-leakage low density cement slurry system and mixing technology suitable for cementing low pressure and easy lost circulation horizontal wells were formed.The field test of 5 wells shows that the return height of cement slurry meets the design requirements,and the qualified rate of cementing quality in filling section is 100%,which can meet the requirement of one-time cementing in low-pressure and easily lost circulation formation in Dingwu block,and provides a strong technical support for the improvement of cementing quality in the filling section of horizontal wells in this block.