Abstract:

Shuanghe oilfield in Biyang depression is one of the large structural-lithologic composite oil reservoirs in eastern China. Cumulative proved oil reserves in place have reached 101.76 million tons by the end of 2001 since overall exploration and development began in 1977. This oilfield has rich source rocks, well-developed sandbodies, good migration pathways, favorable matching of trap formation and sandbodies, and superior preservation conditions, all of which are favorable for hydrocarbon accumulation. Along with the formation and evolution of Shuanghe nose structure, sandbodies in the 3^rd member of Hetaoyuan Formation in southern Biyang depression change gradually from downdipping pinch-out to upwarping pinch-out, leading to the formation of the small but prolific Shuanghe oilfield with large reservoir space and enough time for charging hydrocarbon.

Key words: structural-lithologic composite reservoir, reservoiring factors, reserves in place, Biyang depression