超稠油Ⅲ类油藏夹层发育模式及SAGD提高采收率技术

风城超稠油油藏属陆相辫状河流相沉积,夹层广泛发育,特别是超稠油Ⅲ类油藏,非均质性强,导致SAGD开发过程中存在水平段动用程度低、蒸汽腔扩展不均等问题,严重影响SAGD开发效果。针对该问题,在风城超稠油油藏辫状河储层发育特征研究的基础上,将夹层发育状况归纳分类为4种典型模式,分析了4种模式下SAGD蒸汽腔的发育形态,并对应提出了直井辅助SAGD、多分支SAGD及储层改造等开发技术,形成了一套针对超稠油Ⅲ类油藏SAGD高效开发技术体系,在现场应用取得了较好效果。该成果对强非均质性储层超稠油油藏SAGD高效开发提供了技术支持,值得推广应用。

Interlayer Development Patterns and SAGD Enhanced Oil Recovery Technology in the Super Heavy Oil Category-III Reservoir

The Fengcheng super heavy oil reservoir is considered as a continental braided river facies deposit with well developed interlayers, especially the super heavy oil Grade-Ⅲ reservoir shows a strong heterogeneity, which results in low producing degree of lateral section, uneven steam chamber expansion and other serious problems during SAGD development and significantly influences the SAGD development performance. The interlayer development was summarized into 4 typical patterns based on the braided river reservoir development in the Fengcheng super heavy oil reservoir. The development morphology of SAGD steam chamber for the 4 typical patterns was analyzed and the corresponding technical countermeasures were proposed, including straight well assisted SAGD, multi-branch SAGD, reservoir stimulation and other technologies. A set of efficient SAGD development technology system for super heavy oil Grade-Ⅲ reservoir had been established and effectively applied in field development. This technology provides certain technical reference for the efficient development of low quality super heavy oil reservoir with SAGD and it worthy of promotion and application.