风城浅层油砂SAGD项目注汽压力优化  

Optimization of steam-injection pressures in Fengcheng shallow oil sand SAGD Project

作　　者：黄勇[1] 张磊[1] 何小东[1] 杨洪[1] 陈森[1] 游红娟[1] HUANG Yong;ZHANG Lei;HE Xiaodong;YANG Hong;CHEN Sen;YOU Hongjuan(Engineering Technology Research Institute of PetroChina Xinjiang Oilfield Company, Kelamay, Xinjiang 834000, China)

机构地区：[1]中国石油新疆油田公司工程技术研究院

出　　处：《石油钻采工艺》2016年第6期848-851,858,共5页Oil Drilling & Production Technology

基　　金："十三五"国家科技重大专项"油砂高效开发与提高SAGD效果新技术研究与应用"(编号:2016ZX05031002)

摘　　要：为加快风城浅层油砂SAGD循环预热启动速度,改善生产初期汽腔发育程度,优化不同阶段注汽压力,在岩石力学实验和地应力测试基础上,分析了储层弹性力学性质和地应力分布,根据Mohr-Coulomb准则,建立了注汽压力与抗剪强度的关系,同时通过CT扫描实验获得了风城油砂剪切裂缝特征。研究表明,风城浅层油砂的刚度和剪胀程度随温度升高而减弱;提高注汽压力能够降低有效应力,促进油砂产生垂直微裂缝;SAGD过程中,抗剪强度为应力圆半径1.5倍时可得出最小注汽压力,应力圆极限状态时可计算最大注汽压力;循环预热和生产初期阶段采用高注汽压力,稳定生产阶段采用低注汽压力,优化结果现场应用后效果良好。To accelerate pre-heating and initialization of SAGD circulation for development of Fengcheng shallow oil sand, enhance development of steam chambers during initial production and optimize steam injection pressure in different stages, elastic mechanics and distribution of stress in reservoir formation were analyzed based on geomechanic and formation stress tests, the correlation between steam injection pressure and shear strength was determined in accordance with the Mohr-Coulomb Theory, and features of shear fractures in Fengcheng oil sand were highlighted through CT scanning. Research results show that shallow Fengcheng oil sand hasrigidity and shear dilation decreasing with temperature. By enhancing steam injection pressure, it is possible to reduce effective stressand accelerate formation of vertical micro-fractures in oil sand. During SAGD, the minimum steam injection pressure can be determined with shear strength at 1.5 times of the stress circle, whereas the maximum steam injection pressure can be determined at upper limit of the stress circle. In conclusion, it is proposed to use high steam injection pressure during pre-heating and initial production stages, whereas lower steam injection pressure can be used during peak production stages. Field application results show satisfactory performances can be achieved through process optimization.

关 键 词：浅层油砂 SAGD 注汽压力 MOHR-COULOMB准则 岩石力学 抗剪强度 微裂缝 

分 类 号：TE357.4[石油与天然气工程—油气田开发工程]