Research On The Oil-source Correlation In Chaluhe Fault Depression

Hydrocarbon source rocks, which is the core of the oil and gas geochemical research,has a very important role in oil and gas exploration, its application is mainly manifested in two aspects, one is the hydrocarbon source rock evaluation, the second is oil source correlation. Chaluhe fault depression basin for a second-order tectonic units, located in northern Yi Tong graben, respectively, from south to north, Liangjia structural belt, Xinanpu sag, Wanchang structural, botai sag, Soudengzhan structural belt and Gudian slope, fault depression contains Xinanpu and Botai two major hydrocarbon-generating sag。Chaluhe fault depression of crude oil and oil source correlation work exploration of this area has very important significance. Through the basic principle of oil and gas geochemistry, this paper applied organic geochemical analysis, system analysis the Chaluhe fault depression hydrocarbon source rocks and geochemical characteristics of crude oil, and for the system of hydrocarbon source rock evaluation, according to the geological characteristics of the Chaluhe fault depression, made a more refined oil source correlation.Aiming at the problem of unknown sources of oil trapped in chaluhe, Collected data of hydrocarbon source rock of Chaluhe fault depression, recount the dark mud thickness, total organic carbon(TOC), chloroform bitumen a, hydrocarbon potential Ro, etc. Evaluation of Chaluhe fault depression of the hydrocarbon source rocks of the abundance, type and maturity of the organic matter etc. Determine the effective hydrocarbon source rocks in the horizontal and vertical distribution. The results showed that Chaluhe fault depression of effective hydrocarbon source rocks are mainly distributed in the Xinanpu and Botai two sag.The dark mudstone developed in different layers of Yongji,Sheling and Shuangyang formation. Xinanpu sag and Botai sag, except for E2y3, E2y4 reach to a good level, the organic matter abundance of the Botai is a little low compared with the Xinanpu sag. The type of organic matter analysis showed that the Botai type is slightly better than Xinanpu, the number of type Ⅱ 2 and type III cheese is quite in Botai sag. Xinanpu sag predominant typeⅢ kerogen. Chaluhe fault depression of Xinanpu depression organic matter in depth reaches2000 m began to mature, Botai sag is up to 1500 m reach maturity.Chaluhe area in crude oil physical property scattered,shows that crude oil source is complex, there can be multiple sources,Through the saturated hydrocarbon, aromatic hydrocarbon and light hydrocarbon chromatography mass spectrometry, light hydrocarbon,and monomer hydrocarbon isotope method to the fork in the Chaluhe fault depression thegeochemical characteristics of crude oil and mudstone is analyzed. The results show that the condensate oil has obvious gas washing characteristics in C51 well,The single hydrocarbon isotope ratios of E2 s and E2 sh in the Xinanpu sag and the Botai sag are not comparable to the oil, which may be derived from the E2y; Data of C2 well and C5 well proved the crude oil of E2 y is mainly derived from the source rocks of E2y;The C12 well upper part of the oil in E2 sh should a good relationship with E2 sh source rocks, the lower part of the crude oil is mainly derived from the E2 S mudstone, C30 well area of crude oil iin E2 sh probably a mixed source,both the supply of E2 sh source rocks and E2 s source rock supply. Analysis of maturity,temperature and pressure of Chaluhe fault depression in the northwestern margin of the condensate oil distribution is predicted based on. The results showed that the E2 s is conducive to the formation of a native of condensate oil and gas reservoir and E2 sh, E2 y are conducive to the formation of secondary of condensate oil and gas reservoir.