The Study Gas Generation Regularities Of Dissipated Soluble Organic Matter In Sichuan Basin

The marine strata has high degree of thermal evolution of organic matter in Sichuan basin, ability of gas generation in kerogen is very limited, it mainly relies on the soluble organic matter as parent material, and provides gas source for gas reservoir. According to different position, parent material of gas generation can be divided into three classes, dissipated soluble organic matter in source rocks, dissipated soluble organic matter out of source rocks, and organic matter in paleo-reservoir. Traditional evaluation method of gas resource ignored the contribution of the dissipated soluble organic matter out of source rocks, and thus affected the evaluation of the time and the center of gas generation. In this paper, use the improved ΔlogR model to predict the distribution of organic carbon content in hydrocarbon source rocks and reservoirs. In the study of conversion rate and gas production rate of soluble organic matter generating gas, use gold-tube pyrolysis experiments of octadecane mixed with different amounts of water to simulate the influence of conversion rate and gas production rate with different water in soluble organic matter generating gas. In the result, find that water can improve 6% to 28% of gas production rate of soluble organic matter in the high stage of evolution, average activation energy of the soluble organic matter under conditions of water cracking into gas reaction is higher than the one without of water, which makes the time of soluble organic matter under conditions of water cracking into gas later than the one without of water and this is good for late gas generation. Use the hydrocarbon potential method to calculate the expulsion efficiency of source rocks in Qiongzhusi Formation and thrird sections of Dengying Formation. Use chemical kinetics application methods to calculate mount of gas generated by dissipated soluble organic matter out of source rocks in fourth sections of Dengying Formation of Schuan basin. is 52.82 × 1012m3 and 24.65 × 1012m3 in paleo-reservoir. The mount of gas generated by dissipated soluble organic matter out of source rocks in second sections of Dengying Formation of Schuan basin. is 22.65 × 1012m3 and 6.07 × 1012m3 in paleo-reservoir. Wherein the mount of gas generated by dissipated soluble organic matter out of source rocks from Permian to Cretaceous in fourth sections of Dengying Formation accounts for 99% in the entire. the mount of gas generated by dissipated soluble organic matter out of source rocks from Permian to Cretaceous in secong sections of Dengying Formation accounts for 92% in the entire. from a point of Instantaneous gas yield kerogen, dissipated soluble organic matter in source rocks, dissipated soluble organic matter out of source rocks and organic matter in paleo-reservoir generated gas one by one. Dissipated soluble organic matter out of source rocks and organic matter in paleo-reservoir belong to later period gas generation. From the distribution of each period gas generation intensity gas generation move from the center of depression to uplift area...