防漏堵漏低密度水泥浆室内研究与应用

Laboratory Study and Field Application of Leak-proof and Plugging Low Density Cement Slurry

涪陵焦石坝区块地质结构复杂,漏失严重。韩家店、小河坝、龙马溪等层位的裂缝性漏失尤为突出,固井作业过程中水泥浆漏失严重,导致水泥浆返高无法满足设计要求。为解决固井过程中水泥浆漏失问题,开发研制了一种防漏堵漏低密度水泥浆体系。室内评价结果显示,该水泥浆具有稳定性好、强度高、承压能力高的特性;在压差存在下,水泥浆体系能够快速形成致密薄韧的滤饼,有效阻止水泥浆向地层漏失。现场采用防漏堵漏低密度水泥浆封固直井段,现场固井施工顺利,水泥浆成功返出地面,72h候凝测井结果显示固井质量为优质,说明水泥浆有明显的防漏堵漏功能,具有推广应用空间。

The geological structure is complicated and the wells are severe leakage in Fuling Jiaoshiba Block.The fracture leakage is particularly severe in Hanjiadian,Xiaoheba and Longmaxi Formations.During the process of cementing operation,the leaking of cement slurry is serious,it results in return height of cement slurry,it can not meet the design requirements.In order to solve the problem of cement slurry loss during the cementing,a leak-proof and plugging low density cement slurry system is developed.The result of laboratory evaluation shows that the cement slurry has the characteristics of adjustable density,good stability,high strength,low water loss.Under pressure difference condition,it can quickly form a dense and thin tough filtercake,prevent the cement slurry loss in the formation effectively.The leak-proof and plugging slurry technology is applied in the oilfields,the result shows that the cement slurry has obvious leak-proof and plugging function leakage wells.It has broad space for popularization and application.