泌阳凹陷栗园地区基岩油藏石油地质特征

Petroleum Geological Characteristics of Base Rock Pools in Liyuan Area, Biyang Depression

泌阳凹陷栗园地区在基岩露头发现油气显示并钻遇基岩油藏,研究其地质条件和油气成藏过程对指导凹陷油气勘探具有重要意义。以露头、地震、钻井、测录井、岩心、地化资料为基础,深入分析栗园地区基岩油藏形成的油气成藏要素和成藏过程。研究认为:生烃洼陷内核桃园组地层形成的油气在鼻状构造背景下通过断裂-砂体复合输导体系向基岩内运移并聚集成藏。中元古界大河群蔡家凹组大理岩在构造作用下发育高角度剪切构造缝和溶蚀孔洞,孔渗性能良好,是主要基岩储层。上覆孤山头组片岩、边界断层泥、上盘泥页岩和稳定基岩内幕水动力条件为油气提供有效保存条件。栗园地区基岩油藏成藏模式分析可为同类型断陷盆地基岩油藏油气勘探提供借鉴。

Oil and gas shows are found in bedrock outcrop and bedrock reservoirs are discovered by drilling in Liyuan area of Biyang Depression.Studying its geological conditions and hydrocarbon accumulation process is of great significance for guiding oil and gas exploration in sags.Based on outcrop,seismic,drilling,logging,mud logging core,and geochemical data,the oil and gas accumulation factors and formation process of bedrock pools in Liyuan area are analyzed.It is considered that the oil and gas formed in the hydrocarbon–generating depression of the Hetaoyuan Formation migrated into bedrock and accumulated in the nose–like tectonic setting through the fault–sand complex transport system.The overlying Gushantou Formation schist,boundary fault gouge,upper wall shale and stable hydrodynamic conditions provide effective capping for oil and gas.The marble of Caijiawa Formation of Dahe Group in Mesoproterozoic developed high–angle shear fracture and dissolution hole under the action of structure.The pore permeability is good and it is the main bedrock reservoir.The analysis of hydrocarbon forming model of bedrock reservoirs in Liyuan area can provide reference for hydrocarbon exploration of bedrock reservoirs in the same type of fault basins.