塔河油田碳酸盐岩油藏缝洞分隔性研究

Separation of fractures and cavities in carbonate reservoirs in the Tahe Oil Field

针对塔河油田碳酸盐岩缝洞型油藏主体区剩余缝洞水淹程度高、油水关系复杂、加密部署风险大的问题,结合油藏生产实际,提出了碳酸盐岩缝洞型油藏分隔缝洞体的概念,形成了基于油藏地质背景的缝洞分隔性研究的技术思路和方法,总结出"三大类七亚类"的缝洞分隔模式:河道(管道)分隔型(支流河道分隔型、充填分隔型、U型管分隔型)、断裂分隔型(内幕断裂分隔型、交错断裂分隔型、平行断裂分隔型)和岩溶沟谷分隔型。以基于油藏地质背景的缝洞分隔性研究为基础的老区加密部署效果良好,投产新井产能明显提高,突破了井位部署大于500 m井距的限制,较大程度上增加了可开发缝洞体潜力,降低了加密调整水淹风险。

Most of the fractures and cavities that remain in carbonate reservoirs are water flooded in the Tahe Oil Field. This complex distribution of oil and water makes successful exploration and production more difficult. A new concept and some methods for separating fractures and cavities in carbonate reservoirs are proposed based on petroleum geology cocepts. Separation models were classified into three types and seven sub-types as follows：separation by river channels or pipes（ separation by branch channels,fillings,or U pipes）,separation by faults（ separation by internal faults,intersecting faults or parallel faults）,and separation by karst channels. This method was applied to some old oil fields,and was proved effective in deploying a denser coverage of new wells.The traditional well spacing limit of at least 500 m was broken. The potential of fracture and cavity reservoirs is proposed,and the risk of water flooding in the dense deployment of new wells was reduced.