辽宁省北部秀水盆地下白垩统地质特征及含油气前景

秀水盆地下白垩统义县组的油气发现,使义县组成为辽宁省西北地区重要的油气勘探目的层系。通过开展钻孔岩芯编录、路线地质调查、有机地球化学测试分析,综合应用电法、二维地震和钻探等资料,分析了秀水盆地下白垩统发育特征、生烃条件及盆地形成发展史等。结果表明: 义县组三段泥岩分布范围广,沉积厚度大,有机质丰度、类型及成熟度适宜,具有良好的生烃条件,为中等—好的烃源岩; 秀水盆地早白垩世发育4期不同的构造演化阶段,使其具备了一定的生、储、盖油气地质条件,具有油气勘探潜力。该研究可为区内进一步油气资源勘探提供支撑。

Geological characteristics and oil-bearing prospect of Lower Cretaceous in Xiushui Basin of northern Liaoning Province

The discovery of hydrocarbon in Yixian Formation of Xiushui Basin has made Yixian the target formation for oil-gas survey in northwestern Liaoning Province. Based on the technical methods of drilling core cataloging, field geological survey and organic geochemical test analysis, using electrical exploration data, 2D seismic and drilling data, the authors analyzed the stratigraphic characteristics, hydrocarbon generation conditions, basin formation and evolution history of Lower Cretaceous in Xiushui Basin. The results show that the No.3 mudstone source rock of Yixian Formation has a wide distribution range, a large sedimentary thickness, and suitable organic matter abundance, type and maturity, which means the mudstone has good hydrocarbon bearing conditions and belongs to medium to good source rock. It is considered that Xiushui Basin has undergone four phases of tectonic evolution in Early Cretaceous, and has the source-reservoir-cap rock assemblages and the prospective area for petroleum exploration. The above research is expected to provide support for further exploration of oil and gas resources in this area.