中国东北地区古生界油气前景展望

中国古生界油气勘探取得了重大进展,在塔里木、四川、鄂尔多斯等盆地发现多个大中型油气田,但对中国东北地区古生界油气资源量仍存有分歧。在前人工作基础上,总结探讨了中国东北地区古生界地层沉积、油气资源潜力、成油组合及成藏条件,并指明了油气勘探方向。研究表明:中国东北地区晚古生代由额尔古纳、松嫩-张广才岭、佳木斯及兴凯等微陆块组成;该地区古生界地层发育于前震旦系结晶变质基底之上,发育较为齐全,下古生界为海相沉积,上古生界为海陆交互相沉积;东北地区岩浆活动十分强烈,岩性齐全,海西期岩浆活动最为突出,以中酸性火山岩为主;东北地区古生界地层发育齐全,具多套烃源岩及储盖组合,油气成藏条件良好,以致密气为主,是今后天然气勘探的重要接替领域。

Prospect of Paleozoic Oil and Gas in Northeast China

Great progress has been made in Paleozoic oil and gas exploration in China. Several large and medium-sized oil and gas fields have been found in the Tarim, Sichuan and Ordos Basins. However, there are still divergences on the amounts of the Paleozoic oil and gas resources in northeast China. On the basis of predecessors’ studies, this paper summarizes and discusses the Paleozoic stratigraphic sedimentation, hydrocarbon resource potential, oil-forming assemblage and hydrocarbon accumulation conditions in northeast China, and points out the directions of oil and gas exploration. The study shows that:The northeast China during Late Paleozoic consisted of Ergun, Songnen-Zhangguangcai Mt., Jiamusi and Xingkai micro landmasses. The Paleozoic strata in this area are relatively developed completely on the pre-Sinian crystalline metamorphic basement. The Lower Paleozoic is marine sediments, and the Upper Paleozoic is paralic sediments.The magmatic activity in northeast China was very strong with complete lithologies. The Hercynian magmatic activity was the most prominent, mainly intermediate acid volcanic rocks.The Paleozoic strata in northeast China are completely developed with multiple sets of source rock-reservoir-cap rock assemblages. The oil and gas accumulation conditions are favorable, dominated by tight gas. It is the main domain for natural gas exploration in the future.