Early evaluation of Tazhong 4 oilfield by using formation test data

An early evaluation is made in combination with other static data, such as logging, coring and well logging by using the analysis results of pressure buildup, vertical interference and productivity testings in Tazhong 4 oilfield. The result of evaluation shows that in the oilfield the physical properties of reservoirs within the same group are similar, but there exists bigger difference between groups. An obvious boundary response exists in group C1, in which lateral continuity is poor and distribution range is limited; there is a big variation of reservoir physical property in group C1; in group C1 there exist boundary responses from some of the reservoirs, the main responses include that within the detection range the characteristics of homogeneous formation are infinite, reservoir physical property is good, its thickness is big, distribution range is wide, productivity is high enough and in the reservoir vertical percolation character is obvious. It is proposed that horizontal well would be chosen to improve the efficiency of oilfield development.