Geophysical response characteristics and exploration trend for buried-hill reservoir in Beier Depression
Wang Jian-gong1, Duan Shu-fu2, Wang Tian-qi1, Jin Zhen-long3, Lei Ming1, Guo Bo4, Fang Jie2
1. Northwest Branch, Exploration&Development Research Institute, CNPC, Langzhou City, Gansu Province, 730020, china;
2. Exploration&Development Research Institute, Beijing City, 100083, china;
3. Haita Branch, Daqing Oilfield Co.Ltd., Daqing City, Helongjiang Provinc, 163453, china;
4. BGP, CNPC, Zhuozhou City, Hebei Province, 072751, China
Abstract：By integration of geological,seismic and well logging data,the tectonic evolution for Beier Depression,the reservoir characteristics and geophysical response of basement buried-hill were analyzed in this paper.The analysis results brought the following conclusions:The formation of the basement buried hill accompanies the 3 evolution processes of the extensional rift basin,that is,the initial rifting stage (Tongbomiao Formation) stage,the fast faulting (Nantun Formation) stage,fault-depression conversion (Damoguaihe Formation) stage,so the 4 buried hill types,high and steep fault block type,wide-gentle anticline type,fault terrace type and isolated hammock type,were formed. The reservoir types of buried hill include the two types,the weathering erosion and structural fracture.The seismic wave group of weathering crust look like a lens outside,and there exists the weak reflection inside. The main fractures of the basement buried-hill are high angle,low angle,grids and so on. The high angle parallel fractures cause positive scope difference in the dual-lateral data,and the low angle fractures causes negative scope difference. The well logging response characteristics were affected by the dip and the included angle of the two sets of parallel fractures. The high and steep fault block buried-hill in the south of Sudeerte,the wide-gentle anticline buried-hils in Huodemoer and Bayantala will be the favorite exploration targets for the next step.
