低孔低渗油藏分级溶蚀增注技术矿场实践

Field Practice of Graded Dissolution and Injection Technology in Low Porosity and Low Permeability Reservoir

现河低渗油藏孔喉半径小、渗透率低,低孔低渗区域水驱动用差,常规增注手段无法满足开发需要。针对该类问题,文章在充分调研国内外微观孔隙渗流、增注机理及矿场应用基础上,基于典型砂岩油藏为研究对象,开展储层微观孔隙认识、黏土矿物构成分析,通过酸岩溶蚀试验、电镜扫描、数字岩心建模等技术方法,形成了低孔低渗油藏分级溶蚀增注模式,优选评价了酸液体系及用量配比,实现扩大渗流通道、增进孔隙连通的目的。矿场实践证明,该技术取得了低孔低渗砂岩油藏增注技术的突破,有效提高了水驱动用程度,对同类油藏水驱开发具有借鉴意义。

The conventional injection methods can not satisfy the development needs for Xianhe low permeability reservoir which is with small pore throat radius and low permeability, especially with poor water driving development effect in low porosity and low permeability area. Aiming at these problems, based on the full investigation of home and abroad for micro pore seepage, injection mechanism and field application, with the study of typical sandstone reservoirs, this paper carries out reservoir micro pore understanding and clay mineral composition analysis, and forms a graded dissolution injection model for low porosity and low permeability reservoirs through acid rock dissolution test, electron microscope scanning, digital core modeling and other technical methods. The acid system and its dosage ratio are optimized, realizing the purpose of expanding seepage channel and improving pore connectivity. Field practice shows that this technology has made a breakthrough in increasing injection technology of low porosity and low permeability sandstone reservoir, effectively improved the degree of water driving production, and has reference significance for water driving development of similar reservoirs.