克75井区油气地化特征及成因分析

OIL-GAS GEO-CHEMICAL FEATURES AND GENETIC ANALYSIS IN KE-75 WELL AREA

克７５井区位于克拉玛依市东南方向约二十多公里处，构造位置处于准噶尔盆地西北缘中拐隆起东北翼、克乌断裂下盘斜坡区。钻井揭示该区具良好含油气远景。通过研究组分、碳同位素、轻烃色谱、饱和烃色谱、生物标志化合物等各项指标，论述了克７５井区天然气、凝析油和原油的地球化学特征。根据原油孢粉、天然气δ１３Ｃ等指标综合判断该井区的油气源，认为原油来自上二叠统风城组低成熟生油岩；天然气为煤型气，来自下伏下二叠统佳木河组高成熟油气源岩。最后，结合地质情况分析了油气聚集史，结果反映出油气聚集具多源性、多期性和复杂性。

Ke-75 Well area is located in southeast part of Kelamayi City about 20 km. Its structure is in the northwest part of Zhongguai Uplift, slope region of Kewu fracture lower wall, on the northwest fringe of Zhungeer Basin.Drilling indicates the oil-gas potential in the area is good. Through researching the indexes of component, carbon isolope, lighter hydrocarbon chromalogram, saturated hydrocarbon chromalogram, biomarker etc, the geochemical features of the gas,condensate and crude in the area are expounded. The oil-gas source is comprehensively judged in the light of the sporapollen of the crude, δ13C of the gas in the area. It is considered that the crude is from the low mature oil bearing rock of Fengcheng formation of Upper Permian, the gas(as coal-type one) is from high mature oil-gas source rock of Jiamuhe formation of underlying Lower Permian. Finally the oil-gas accumulation history is analysed by combining the geological conditions, which shows the accumulation has the features of multiple sources,multiple periods and complexity.