The Evaluation Of Source Rock In Bayanhushu Sag

Effective source rock has a very important significance to identificate and evaluate oil and gas resource potential, and to reveal the generation, migration, accumulation and enrichment regularity of oil and gas scientifically. Based on the modern oil and gas theory as the guide, based on the existing drilling, mud logging, wire logging data and core analysis data, this paper evaluates hydrocarbon indicator of main source rock comprehensively, has a comparative evaluation of hydrocarbon potential between Bayanhushu sag and other sag of Haita basin, analysis longitudinal growth characteristics of the source rock in Bayanhushu sag, predicts the distribution of effective source rock, and estimate the amount of resources of Bazhong subsag. The conclusion of evaluation is that:source rock in Bayanhushu sag has high abundance of organic matter, good type, to reach the standard of the good source rock on the whole, the three sets of major source rock in lower section of second member in Nantun formation, the upper section of first member in Nantun formation and Tongbomiao formation belong to the mature source rock, only source rock in first member in Nantun formation belong to the mature source rock in western slope belt. Source rock in Nantun formation contains a lot of p-carotane (m/z=125) and γ-wax alkane (m/z=191), which means the source rock formed in the salty-brackish water lake environment, with good potential of hydrocarbon generation, crude oil GC-MS map and biomarker compounds indicate that the crude oil in Nantun Formation mainly comes from itself. Compared with other sag, Bayanhushu sag has the characteristics of high abundance of organic matter, good type, and the shallow depth in mature threshold. Dark mudstone are the most developed mudstone in Nantun Formation, the distribution of effective source rock range is huge, should be the main source rock. Mature source rock is mainly distributed in Bazhong subsag on plane, its potential resource is large, and prediction of oil resource is x.xxx*108t.