碎屑岩注气井固井技术初探

随着老区油藏压力衰竭,注水注气复合驱替提高油气采收率成为必要的增产稳产手段。然而,塔里木盆地碎屑岩储层成岩机理复杂,水层发育,油气水层间隔层薄,固井质量本就一直难以保证。随着天然气复合驱提高采收率技术新方法的提出,碎屑岩固井更增添了新挑战:①井口注气压力高;②注替过程存在交变载荷,这更容易引起层间封隔失效。针对这些技术难题,提出了通过固井设计软件模拟优化工艺参数,采用弹性及自愈合水泥浆体系复配优化水泥石力学性能满足长期井筒完整性要求,调整优化泥浆及水泥浆流标参数提高顶替效率等措施,并在TZ-XX井实践,确保了固井质量取得了非常良好的效果。

Discussion on Cementing Technology of Clastic Rock Gas Injection Well

With the pressure exhaustion of old reservoirs,water injection and gas injection compound displacement has become a necessary means of increasing production and stabilizing production to improve oil and gas recovery.However,the diagenetic mechanism of clastic reservoir in Tarim Basin is complex,the water layer is developed,and the interval between oil and gas water layers is thin,so cementing quality has been difficult to guarantee.With the development of new technologies for EOR of natural gas compound displacement,new challenges have been added to the cementing of clastic rocks:1)The wellhead gas injection pressure is high;2)There is alternating load in the injection displacement process,which is more likely to cause interlayer sealing failure.Aiming at these technical problems,the paper puts forward some measures,such as optimizing the process parameters by cementing design software,optimizing the mechanical properties of cement stone with elastic and self-healing cement slurry system to meet the requirements of long-term wellbore integrity,adjusting and optimizing the flow standard parameters of mud and cement slurry,and improving the displacement efficiency.The cementing quality has been ensured by the practice in Tz-xx well.