Coal-bearing Source Rocks Characteristics Research In Fansanjiang Area

Fansanjiang area is located during the Early Cretaceous in the sedimentary basin groups of eastern Heilongjiang Province from Sanjiang area to Mulenghe area. In our country, it includes Sanjiang basin, Shuangyashan basin, Boli Basin, Hulin Basin, Jixi basin, Ningan Basin, an area of about 8×10~4 km~2. The area distributes the Mesozoic - Cenozoic sedimentary strata, the thickness of sedimentary rocks more than 2000 meters above the ground with the features of thick strata, multi-layered coal, thick coal strata, large range of coal-formed environment, and with a certain condition to form an oil and gas reservoir. It is one of the key Mesozoic - Cenozoic oil and gas exploration areas in the Northeast China region in futurePaper guided by the theory of in petroleum geology and organic geochemistry, adopts the field geological survey and laboratory analysis, combining with the macro and micro methods of the study area in the previous research results and connecting with the samples testing data and new achievements, according to the source rocks evaluation criteria of the Daqing Oilfield Institute, the organic matter abundance, organic matter type and organic matter maturity of the coal-bearing source rocks in the Chengzihe formation and Muleng formation in the Fansanjiang area are evaluated systematically.Initially it is viewed that the Fansanjiang area source rocks with the better hydrocarbon conditions. Chengzihe formation and Muleng formation coal-bearing source rocks have the ranges of organic richness from general level to high level, the source rocks are typeⅢof kerogen, and the organic matter maturity is at the mature stage. The result of above analysis indicates that based on the parent materials hydrocarbon type analysis the lower-Cretaceous Chengzihe formation and Muleng formation coal-bearing source rocks are the good gas source rocks with a medium-good hydrocarbon generating potential. Overall, Chengzihe formation source rocks better than these of Muleng formation. from the analysis on coal-bearing source rocks characteristics in the Fansanjiang area, the coal-bearing source rocks which are in the Sanjiang basin, Boli basin and Jixi basin are good gas source rocks; from the analysis on the coal-bearing source rocks classification, the mudstone and coal in the Fansanjiang area make a great contribution on the oil and gas generation, especially in Sanjiang basin, Boli basin and Jixi basin, thus the scale of carbonaceous mudstone is limited, and has a little hydrocarbon generation potential.