鄂尔多斯盆地南部延长组有效烃源岩分布规律研究

Distribution Regulations of Effective Source Rock of Yanchang Formation in Southern Ordos Basin

充分利用大量的测井资料对研究区延长组烃源岩的有效性进行全井段整体研究,克服了可能会由地球化学资料不系统、单井地球化学数值不连续等方面的局限性而造成的对有效烃源岩空间分布特征难以把握的困难,提出了用优质烃源岩体积与有效烃源岩体积的比值作为有效烃源岩分布质量评价参数,运用该参数可以较好地评价研究区延长组不同油层组烃源岩的有效性及品质,比较客观地揭示了研究区有效烃源岩分布明显受沉积环境的控制,靠近湖盆中央的深湖—半深湖相带是优质烃源岩的主要发育区,同时预测了研究区常规与非常规油气勘探的重点区域。

Based on mass well-logging data, the effectiveness of source rock of Yanchang Formation in research area has been studied on the whole wells, which overcomes the diffcuhy to hold distribution of source rock restricted from unsystematically geochemical data and discontinuous single-well data. This paper proposes a ratio, source volume of high-quality to effective, as the evaluation criteria for distribution quality. With the ratio criteria, we can evaluate source effectiveness and quality in different oil-bearing bed of Yanchang Formation, and can more objectively reveal that the distribution of source rock in study area is obviously dominated by sedimentary environment. With this study we found that the main developed area for high-quality source developed in deep-lacustrine and semi-deep-lacustrine facies near basin center, and predicted the main exploration area for conventional and unconventional petroleum in study area.