稠油井火驱开发固井水泥浆性能评价与应用

Study and application of cement system for in-situ combustion in heavy oil reservoir

在运用火烧油层技术开发稠油油藏的过程中,高温及二氧化碳腐蚀易导致油井水泥石强度下降,渗透率增大,地层流体穿透水泥石腐蚀油层套管,严重影响油井的正常生产。根据新疆油区稠油井火驱开发固井水泥石面临的难题,优选了一套耐高温抗二氧化碳腐蚀的水泥浆体系。室内评价结果表明:水泥石试样经高温养护后,最小抗压强度为13.8 MPa,达到应力状态分析的安全标准,渗透率和孔隙度均变化不大;经二氧化碳腐蚀后水泥石形态致密,结构比较均匀,仍具有较高的强度,其性能能够满足火驱开发高温作业的要求。优选的水泥浆体系在新疆油区红浅1井区9口井进行了现场试验,测试合格率为100%,优质率达77.8%,取得了较好的应用效果,保证了火烧油层井的固井质量及生产安全。

The heavy oil wells are faced with problems such as high temperature and corrosion in the process of development of ISC in Xinjiang oilfield.This article optimally designed a set of cement system of resistant CO2 corrosion in the high temperature conditions. The indoor evaluation test results showed that the compressive strength of cement stone is 13.8 MPa after the high temperature and CO2 corrosion maintenance,the strength corresponded to the security of analysis of the stress state.The permeability and porosity of cement stone suffered little change,the morphology of cement stone was density and the structure was homogeneous after the stone cement corrosion.It also had good strength and toughness and properties,so it could meet the requirements of high temperature cementing project. This cement system used in 9 wells in Xinjiang oilfield,the results showed that the cementing quality achieved 100%,it ensured the cement quality and production safety and provide vast space to improve heavy oil recovery for Xinjiang old oilfield.