自愈合水泥在塔里木油田碎屑岩固井中的应用

The Application of Self-Healing Cement in Tarim Clastic Rock Well

塔里木LN油田、ST油田碎屑岩井储层多为中孔、中渗储层,水层多而薄、底水活跃,对层间封固质量要求高,固井过程中易发生油气水窜,水泥环易出现微间隙,后期开采含水率高。自愈合水泥具有自修复功能,并兼具一定的微膨胀效果,能有效防止窜流,改善界面胶结。针对碎屑岩固井难点,结合自愈合水泥特点,研究出一套适用于该区块的自愈合水泥浆体系。该水泥浆体系具有流动性好、抗压强度高、静胶凝过渡时间短等良好的工程性能。室内实验和4口井的现场成功应用表明:自愈合水泥浆体系能满足该区块碎屑岩井的固井施工作业,提高固井质量,储层段固井优质率达到70以上,2口实验井采油含水率0,为后续老油田稳产增效提供有力保障。

Generally, clastic rock reservoirs in LN oilfield and ST oilfield in Tarim Basin are of middle porosity and middle permeability, the thin aqueous layers occur frequently and bottom water are active, high quality of zonal isolation is required.In the process of cementing, fluid communication is easy to occur, and micro gaps are easily to appear to cement annulus, also lead to high moisture in the future oil and gas production.Self healing cement has self repairing function, and has a certain micro expansion effect, which can effectively prevent the channeling flow and improve the interfacial bond.Considering the difficulties in clastic rock cementing, combining with the characteristics of self-healing cement, we developed a self-healing cement slurry for this block.The cement slurry has good liquidity, high compressive strength, short transition time in static gelling, and so on.Through the indoor experiment and the successful application to 4 wells, it shows that the self-healing cement slurry system can satisfy the requirements of clastic rocks cementing, significantly improve the cementing quality.The high quality rate of reservoir section is over 70, and the rate of water content of two wells is 0, which provides a strong guarantee for the stability and efficiency exploitation of the old oil field.