Research On Gas Genesis Of Dehui Depression

The paper by the abundance of organic matter, organic matter type and source rock maturity three aspects research source rock geochemical characteristics of the Yingcheng formation 、 Shahezi formation and Huoshiling formation in Dehui fault depression. this dissertation researches the Geochemical characteristics and gas source of gas pools of Lower Cretaceous Quantou formation and Upper Jurassic Huoshiling formation the Characteristics of gas composition, carbon isotope characteristic, gently characteristics, and rare gas characteristics and mades the main research results as follows:Hydrocarbon source rocks in Dehui fault depression is mainly composed of dark mudstone. Huoshiling thick dark mudstones and Shahezi dark mudstone thickness greater than the thickness of the Yingcheng shale. Hydrocarbon source rocks all reached above average levels, Comparison of three layers, Shahezi than Yingcheng, relatively poor Huoshiling. Dehui faulted hydrocarbon source rock types are mainly intermediate,A bit humic substances type. Wherein Yingcheng shale mostly Ⅱ1 type and Ⅱ2 type,Shahezi and Huoshiling mudstone with Ⅱ1, Ⅲ type-based. Dehui faulted maturity of organic matter is ripe- high ripe stage, description Dehui faulted hydrocarbon source rocks have good potential to produce gas.Natural gas in Dehui fault depression is mainly composed of hydrocarbon gas.,moisture is the main kind of Dehui fault depression. Quantou formation to Yingcheng formation natural gas as a mature stage, Shahezi formation and Huoshiling formation natural gas in the mature to high mature stage. According to gas composition and normal carbon isotope analysis showed Dehui faulted natural gas as organic causes of gas. Dehui faulted gas composition showed Quantou, Denglouku gas belong sapropelic natural gas,;Yingcheng belong humic substances type gas; Shahezi and Huoshiling gas belong sapropelic natural gas. Through single well isotope analysis,Quantou to oil-gas main, the presence of coal gas and oil-gas mixed gas, Yingcheng He3 well and He 4 well are greater contribution of coal gas, Shahezi Nong 103 wells,Nong 101 wells Huoshiling possible contribution to the larger oil-gas. Use light hydrocarbon indicators show Shahezi and Huoshiling natural gas to oil-gas main. The above three methods of analysis showed that Quantou and Denglouku natural gas to oilgas main, Yingcheng natural gas to coal- gas main, Shahezi and Huoshiling natural gas to oil-gas main.After gas resource tracing by the Characteristics of gas composition, carbon isotope characteristic, Light hydrocarbon parameters cluster analysis and rank sum test, I concluded that Quantou, Denglouku and Yingcheng natural gas mainly from Yingcheng and Shahezi source rocks, Shahezi natural gas mainly from the source rock itself,partly from the Huoshiling source rock, Huoshiling natural gas mainly from Huoshiling and Shahezi source rocks.