The Comprehensive Evaluation Of Hydrocarbon Accumulation Conditions In Butumoji Sag Of Erlian Basin

This paper selects Butumoji Sag of Erlian Basin as the region of interest. Based onstudies of drilling, geology and seismic data, this paper analyzes and evaluates hydrocarbonaccumulation conditions in Butumoji Sag. The main knowledge and conclusions are asfollows:1. The Bayanhua group in Butumoji Sag exist four sets strata which included K1ba, K1bt1,K1bt2and K1bs. Remarkably, K₁ba and K₁bt₁are main oil-generating strata in this sag.2. The kerogen types of K₁ba and K₁bt₁source rock are both preferable, the types aremixed with Ⅱ₁+Ⅱ₂. The thickness and organic matter abundance of source rock are superior,so it has a certain amount of oil-generating potential. In K₁bt₁source rock, the TOC is0.9%,content of extracts“A” is0.17%, S_l+S₂is1.34mg/g. Meanwhile, in K₁ba source rock, the TOCis1.03%, content of extracts“A” is0.04%, S_l+S₂is2.22mg/g.3. Butumoji Sag is NNE-trending, it is single rifted sag faulted to the east and onlappedto the west. The sedimentary center is controlled by eastern boundary fault. It can be dividedinto three sub-sags. Butumoji Sag is not large, but burial of base rock is deep, main sourcebed and reservoir bed sediments are thick, therefore, it has oil-generating ability. Thesedimentary and tectonic background in this region provide good formation conditions to trap,the area of trap is relatively small. Hydrocarbon accumulation is mainly controlled by plane ofunconformity.4. According to calculate the prospective petroleum resources and contrast hydrocarbonaccumulation conditions in Butumoji Sag with other sags of Erlian Basin, this paper realizesthat the sag has a certain amount of exploration potential, its exploration prospects are moreoptimistic.