保山盆地新近系生物气资源及勘探前景

Biological Gas Resource and its Exploration Potential in Neogene,Baoshan Basin

保山盆地新近系羊邑组和南林组属于湖泊—扇三角洲沉积体系,暗灰色泥质烃源岩厚度为700～1000m,烃源岩有机质类型主要为混合型,含少量腐殖型,热演化程度处于未成熟阶段。根据生物气的形成条件和烃源岩的分布特征,在应用有机碳产烃率法分别计算了羊二段、羊三段和羊四段—南林组产气强度的基础上,采用排、聚系数法估算出生物气的总资源量为21×108m3。根据生物气对成藏特征的分析,指出有利探区为盆地西部摆宴屯次凹。

The Yangyi formation （N2y） and Nanlin formation （N1n） of Neogene in Baoshan Basin are lakefandeha deposition system, and the thickness of dark argillaceous hydrocarbon source rocks is about 700 to 1000 m. Microscope examination, rock pyrolysis and biomarker analysis reveal that hydrocarbon source rocks are mixed type. The source rocks are in the immature stageof thermal evolution. Based on the formation condition of biogas and the distribution of the source rocks, and the calculation of the gas production intensity of N2y2 section, N2y3 section, N2y1 and N1 n formation, this paper concludes using the method of hydrocarbon explusion and accumulation coefficient that the total biogas resources is about 21× 10^8m^3. The Baiyantun subsag in the west of the basin is favorable for exploration.