The Eastern Basin Group Of Cretaceous Hydrocarbon Source Rock Evaluation In Northeast China

The eastern basin group is located in China’s heilongjiang and jilin province in northeast China, a total of 38middle- small basin. The hydrocarbon potential evaluation of hydrocarbon source rock is usually use 3 + 2 model, that is,from hydrocarbon source rocks of the abundance, type, maturity, and lithologic facies and thickness. Through the eastern basin group of sample analysis, the results show that the best period for development of the hydrocarbon source rocks are lower cretaceous, organic matter abundance of hydrocarbon source rocks in the study area has the characteristics of low meteorological north, the change characteristics of the organic matter abundance is closely related to sedimentary environment at that time. In the southern region, the development of lower cretaceous is mainly freshwater lakes, and a small amount of swamp facies, formed the dark lacustrine mudstone and shale, has reached the medium preference degree of hydrocarbon source YanFeng standards; And in the northern region, sedimentary environment and varied, but the sedimentary water body is shallow, the main development in the land and sea, fan delta and offshore shallow lacustrine facies and hydrocarbon source rock organic carbon content is higher, but not hydrocarbon generation potential, belong to the poor- medium abundance of hydrocarbon source rocks. The organic matter maturity has the characteristics of low from north to south distribution, controlled by the depth of moho depth. Through the determination of hydrocarbon expulsion threshold and hydrocarbon-discharging time, analyzed the influence factors of hydrocarbon expulsion threshold, the hydrocarbon expulsion threshold of the organic matter abundance, type, the influence of geothermal gradient and burial history. The organic matter type, the better, the less the hydrocarbon expulsion threshold RO, hydrocarbon expulsion the earlier; Organic matter abundance is high, the higher unit volume hydrocarbon of hydrocarbon source rock, the more critical oil saturation, So easy to achieve hydrocarbon expulsion hydrocarbon expulsion threshold RO is smaller, the earlier time of hydrocarbon expulsion; Moho the shallow buried, the higher the terrestrial heat flow and geothermal gradient is higher, the earlier time of hydrocarbon expulsion; The larger the buried rate of source rock of the oil and gas into the hydrocarbon expulsion threshold.