Researches On Simulation Experiment Of Natural Gas Forming Potential Of Humic Coal Under Different Environment Causes

Humic coal under different Environment causes exists in Upper Palaeozoic in Ordos basin. In this paper, with the combination of Organic geochemistry and Organic petrology、the combination of hydrocarbon generation potential evaluation and hydrocarbon generation simulation experiment methods to study hydrocarbon generation potential difference of humic coal under different Environment causes and the geochemical reason of the differences, basis on the study of source rocks in the Carboniferous-Permian coal measures, draw the following conclusions:1、Ordos coal geological environment in Upper Palaeozoic has the characteristics of diversification. Both has coal-forming environment affected by the action of water peat flat and continental coal swamp environment in the delta sedimentary system. Environmental differences led to the different source of organic matter.2、Studies have shown that the differences of coal-forming environments can be described with Pr/Ph chat and Pr/nO1n-Ph/nCig chat of Saturated hydrocarbon and three fluorine composition of aromatic hydrocarbon. This feature provides important reference basis for selection of simulation samples.3、Do hydrocarbon generation simulation experiment with humic coal in different formation, with different Pr/Ph. The experimental results show that humic coal with lower Pr/Ph usually has higher hydrocarbon generation evolution potential,in the same horizon and sedimentary environment has an important influence for the evolution of hydrocarbon generation potential of humic coal. Characteristics of gas rate chat shows that hydrocarbon gas production rate presents an obvious "bulge" in a simulated temperature 350 ℃- 525 ℃ (Ro from 1.00 to 2.30%) which embodies the process of soluble organic matter cracking as gaseous hydrocarbon under the condition of high maturity. Compared to gas rate curve in temperature 350 ℃- 525 ℃ and 525 ℃-650 ℃ for same sample known that compared with solid organic matter (kerogen), the contribution of soluble organic matter opposite hydrocarbon cannot be ignored.4、Comparative study shows that "exinite+ sapropel group" content characteristics are not obvious for different environment formation of humic coal, main differences embodied in hydrogen-rich vitrinite (especially matrix vitrinite) contribution of hydrocarbon generation. Research shows that the hydrocarbon generation of superfine lipid group contained by matrix vitrinite should be the main reason for the hydrocarbon generation potential difference of humic coal in different coal-forming environment.5、Soluble organic matter can detect a series of single methyl compounds in part of low Pr/Ph humic coal with higher HI and D, and the maceral test results show that,the contribution from Inferior students is extremely low, only a small amount of alginite B and mineral bituminous matrix can be found. It follows that there is a large number of different type of microorganisms (bacteria, fungi and protozoa) with higher plants as carbon source under the strong reducing sedimentary environment. In biological chemistry stage, microbial transformation effect of higher plants. On the one hand, microorganisms will consume part of higher plant organic matter as large amounts of oxygen at the same time, in order to improve the conditions of the preservation of organic matter; On the other hand these microbes with high degree of rich hydrogen organic matter will enter the formation after death, causes the coal organic matter rich hydrogen degree increase.