志丹-甘泉地区古生界天然气烃源岩特征及其综合评价

Characteristics of the Hydrocarbon Source Rocks of Paleozoic In Zhidan Ganquan Area and Its Comprehensive Evaluation

为了明确志丹—甘泉地区烃源岩发育特征,本文通过对20多口探井的烃源岩测井识别及4口单井评价资料,绘制出烃源岩厚度平面图,分析了潜在烃源岩的展布特征,同时参考国内外烃源岩评价标准并结合烃源岩地球化学特征,最终对古生界天然气烃源岩进行综合评价。研究结果表明:鄂尔多斯盆地主要发育下古奥陶系碳酸盐岩和上古生界石炭—二叠系煤系两套烃源岩。有机质类型大都以富镜质组、富腐泥组,贫壳质组(二富一贫)特点。北部以高等植物来源的镜质组为主,南部则以藻类及其它低等生物来源的腐泥组为主;上古富镜质组,下古则富腐泥组。综合分析认为:两套烃源岩有机质含量偏低,但是有机质类型、成熟度较高,具备一定的生气潜能。单井与区域、烃源岩评价与试气结果存在一定的差异性,其原因可能与目前评价标准、取样代表性、测试技术有关。

In order to research the development characteristics of hydrocarbon source rocks in Zhidan Ganquan area,this article draws out of the hydrocarbon source rocks thickness planar graph by logging identification of the 20 exploratory wells and the evaluation of the four single well logging data,and analyzes the distribution characteristics of potential source rocks. Of course,it also reference the evaluation standard of source rock at home and abroad and combine with the geochemical characteristics of hydrocarbon source rocks. finally,the paper came to the comprehensive assessment about source rocks of natural gas of Paleozoic.,The results show that： Erdos basin mainly developed the Ordovician carbonate rocks under the ancient and the upper Paleozoic Carboniferous Permian coal measures and two sets of hydrocarbon source rocks. The organic matter has a rich vitrinite,rich sapropel group,poor exinite（ referred to as ＂two rich lean＂）. It is mainly vitrinite of higher plant sources in the north and sapropel group of Algae and other lower organisms sources in the South. Comprehensive analysis showed that： two sets of hydrocarbon source rock organic matter content was low,yet the organic matter has higher maturity with some angry potential. There were also some difference between the single well and regional,source rocks＇ evaluation and testing results,the reason may be related to the evaluation criteria,representative sampling,testing technology.