利用分形理论预测潜山储层裂缝的分布

Using fractal theory to predict distribution of fracture in buried-hill reservoir.

裂缝型潜山油藏的裂缝发育程度控制了油气的富集。潜山裂缝主要为断裂伴生裂缝,断层与裂缝多为同一应力场下破裂程度和相对位移量不同的裂隙,具有自相似性,满足分形理论。实际资料表明断层和裂缝也存在自相似性。以岩心裂缝密度为桥梁,将区域断裂信息维与取心段裂缝信息维定量联系起来,断裂分维值大的区域,裂缝分维值也高,说明裂缝越发育;反之亦然。根据研究区井的油气情况统计,确定出裂缝分维值门槛,便可有效预测出裂缝有利区及含油气范围。

The development of fracture in fractured buried-hill reservoir controls the accumulation of oil/gas. The buried-hill fracture mainly is fault-associated fracture, and the fault and fracture mostly are fracture with different damage level and relative displacement in a same stress field, which has self-similarity and meets the fractal theory. The practical data showed that fault and fracture also have self-similarity. Taking the density of core fracture as bridge, the regional fault information dimension is quantitatively associated with fracture information dimensions in cored interval, the region with the larger fractal value of fault has larger fractal value of fracture, demonstrating the development of fracture; and vice versa. According to statistics of oil/gas in the wells of studied area, the threshold of fractal value of fracture was determined, which can effectively predict the zone favorable to develop fracture and oil/gas-bearing range.