济阳坳陷油气勘探现状及主要研究进展

The present research status and progress of petroleum exploration in the Jiyang Depression

济阳坳陷勘探 40年共发现 70个油气田 ,资源探明程度达 5 6.97% ,已属中高勘探程度区。济阳坳陷剩余石油资源总量为 46.72× 10 8t ,占坳陷剩余资源总量的 5 5 % ,整个坳陷还有较大的油气勘探潜力。目前勘探存在 3方面问题 :①有待重新评价资源潜力和重新总结油气分布规律 ;②隐蔽油气藏 (尤其是岩性油气藏 )在新发现油气藏中所占比例逐年增大 ,但目前缺乏有效的预测理论和勘探技术 ;③岩性圈闭含油气性变化大 ,成藏机理还认识不清。用门限控烃理论研究的结果 ,济阳坳陷进入成藏门限的 19个成藏体系的剩余资源潜力为 1.42× 10 8～ 6.3 1× 10 8t,7个成藏体系尚未进入成藏门限 ;根据三元复合成藏理论 ,岩性油气藏的形成必须满足 3个条件 :一是砂体的成因类型要有利 ,二是包裹砂体的烃源岩生、排烃要达到一定数量 ,三是砂体的物性要达到一定的临界条件。图 8表 2参

Since commercial oil being gained in 1962, 70 fields, 40.1×10 8 t oil reserves and 361.41×10 8 m 3 natural gas reserves have been found in the Jiyang Depression. The resources proved degree has reached up to 56.97%, which shows the depression is at medium to high exploration degrees. The total residual resources are 46.72×10 8 t in the Jiyang Depression, suggesting there is still a good exploration potential. However, there are three problems to the exploration at present: ① there is magnitude discovery every year in some sags with high exploration degree whereas low exploration effect in some sags with low exploration degree, which indicates that resources potential should be reappraised or petroleum distribution pattern should be further summarized; ② efficient forecast theory and method are short of in the exploration of subtle traps (especially lithological reservoirs), and the ratio of the subtle oil gas pool in the newly found pools has been increased year after year, foreshowing a new exploration potential domain; ③ accumulation mechanism of lithological reservoirs is still unknown. The threshold controlling petroleum research shows that in Jiyang Depression, 7 of 26 accumulation systems have not reached accumulation threshold, and large scale exploration should not carried through, whereas 19 of 26 have reached accumulation threshold with residual resources potential from 1.42 ×10 8 t to 6.31×10 8 t. Based on the ternary accumulation theory, three conditions must be met in the formation of oil accumulation in lithological reservoir: favorable sedimentary environment and sand body type, favorable generation and expulsion conditions of source rock, and physical property of sand body reached certain critical condition.