Reservoir prediction in diabase alteration zone,Huanghua depression
Yao Jun1, Liu Huaqing1, Zeng Jianhong2, Li Shuangwen1,2, Ni Changkuan1
1. Northwest Branch,Research Institute of Petroleum Exploration & Development,PetroChina,Lanzhou,Gansu 730020,China;
2. Exploration & Development Research Institute of Dagang Oilfield,Tianjin 300280,China
Abstract：In Huanghua depression reservoir fractures of diabase alteration zones are developed,but the thickness of alteration zones is thin,and consequently this makes reservoir prediction rather difficult.In order to overcome this difficulty,we take well logging data of drilling diabase alteration zone in district R of Huanghua depression as starting point,and analyze the characteristics of log response.We conclude that DEN value,CNL value and GR value are obvious in the interfaces between alteration zones and surrounding rock or diabase.Then we combine the impedance inversion and multi-attribute inversion to predict the distribution of diabase alteration zones and their thickness.According to the synthetic probability method,the well logs which are sensitive to fractures are calculated to obtain a fracture development exponential curve representing the degree of fracture development.Then utilizing multi-attribute inversion method again we predict the distribution of alteration zones and their fracture development.Actual drilling data proves reservoir predication accurateness of diabase alteration zone in the region by our approach.
