伊宁凹陷侏罗系勘探思考与展望

伊犁盆地是在晚海西期褶皱基度上发育的中、新生代山间盆地,侏罗系是其盆地的主体。侏罗纪时盆地水体整体浅而不稳定,除早侏罗世八道湾组沉积期有局部的稳定水体外其余多为交织河和冲积扇与扇缘辫状河河沼相,煤第地层烃源岩品质普遍较差,暗色泥岩和碳质泥岩一般为中等烃源岩,局部为较好烃源岩;从中生代到新生代,由于地壳厚度不断增大,该盆地整体处于退热型区域大地热流背影场中,属于典型的“冷盆”,有机质热演化普遍处于不

Consideration and Prospect for Exploration of Jurassic in Yining Sag

Yili basin is a Mesozoic and Cenozoic intermontane basin developed in lute Hercynianfolded basement with Jurassic as its host. The whole waters in Jurassic basin is shallow and unstable except for local stable waters in Badaowan formation sedimentary Period of Early Jurassic, which is characterized by anastomosing stream, alluvial fan and fan-marginal braided river-swamp factes; commonly Poorquality of hydrocarbon source rocks in the coal measure strata with most medium hydrocarbon source rocksas dark mudstone and carbonic mudstone. From Mesozoic to Cenozoic, the basin lies in terrestrial heat flowsetting of de--heating area with constant increase in crust thickness, belonging to typical "cold basin", alongwith organic matter thermal evolution ranging from non-maturity to low maturity (R.=0'4%ro.7%). Becauseof limited oil generated from low maturity dark mudstone, component content during early hydrocarbon generation of coal bed in which generated hydrocarbons are only saturated with its micropores, early hydrocarbon now rate has little contribution to formation of reservoirs. It is pointed out that the future explorationshould focus in central subsiding area, select optimum traps in structural belt around the hydrocarbon generation center with caution. Also, we should make further study of the hydrocarbons generated conditionsand quantitative evaluations of the mudstone with low maturity.