Northern Xinjiang, The Main Basin, Permian Source Rocks In Sedimentary Environment And Hydrocarbon Generation Characteristics,

The major basins in North Xinjiang include the Junggar basin,Turfan-hami basin and Yili basin , where located on North Xinjiang Tianshan mountain .The Permian system has the extensive distribution in these basins. The oil and gas are explored to confirm that the Permian system provide for the most of oil and gas in North Xinjiang.. This research not only can be inquire into the controlling of depositional environment in hydrocarbon source rocks to organic matters depositing and preserving on theory but can be made the objective evaluations to the Permian system oil and gas exploration foreground in the basins. Therefore it is possessed of great theory meaning and economic performance. According to depositional structure and characteristics such as construction,element geochemistry, palaeophyte distribution, rock geochemistry and oil and gas geochemistry etc in hydrocarbon source rocks for the first time, and from many angles, using many kinds of methods, the study on hydrocarbon source rocks stratum to be collated and stipulated has been syntheticaly discussed about geology environment with deposits and preserves of organic matters of Permian system hydrocarbon source rocks of major basins in North Xinjiang. The researches resulted about rock geochemistry element of hydrocarbon source rock in each basin are indicated that the most of elements abundance in mudstone source rock is closed with the clarke value of the earth's crust mudstone ( shale ), it is demonstrated that the depositional environment is weak relatively to his transformation effect . But most of element abundance of thin layer of carbonate rock source rock in the lake differ from greatly with the clarke value of earth's crust carbonate rock, it is explaned that depositional environment is relatively stronger to his transformation effect. Therefore it is advanced for the first time why organic matters abundance are lower partially in the carbonate source rock of thin layer in most of lakes to the mudstone., which the depositional environment is transformed to act on strong to be one of major cause . By means of hydrocarbon source rock stratum mineral combinations and organic carbon content to combine the methods of the instruction depositional environment in geochemistry wall the pH's value and Eh's value are infered during the deposit of hydrocarbon source rock in each basin.The study indicates that the water medium condition is overall for basicity and sulphide environment in effective hydrocarbon source rock deposited in the each basin． Using the element specific value law the Sr / Ba value and the B / Ga value of hydrocarbon source rock are analysed and contrasted .The palaesalinity distribution in this area is that the palaesalinity of the water body during depositing of carbonate source rock is more than the mudsource rock and the palaesalinity of the basin center is more than border and the palaesalinity of YiLi basin is more than the Junggar ,Turfan- hami basin overall. It is thinked that atmosphere precipitation has been controlled of palaeclimate and the change with relations of boil-off and pouring into and ancient water chemistry quality of the lake water indirectly, which lead to forming the deposit of different type hydrocarbon source rocks and the deposit and preserve condition of original matters finally. Juging by depositing structure and construction in the hydrocarbon source rock and syntheticaly researching on distribution characteristics of fossils demanstrate that depositing of the hydrocarbon source rock and the better layer of fossils preserved are the depositional environment that the deposit is mostly thin at the size and the water motive force condition is weak. Therefore the depositional environment of hydrocarbon source rock is favour of deposit and preserve of organic matters indirectly. Applying the newest research means such as fluorosccpic to observe and the biomarker distributes to test it is thinked that the organic matters abundance and organic matters macerral o...