Development characteristics and orientation of tight oil and gas in China

SUN Longde,ZOU Caineng,JIA Ailin,WEI Yunsheng,ZHU Rukai,WU Songtao,GUO Zhi

Table 4 Elements for tight gas accumulation in a foreland basin.

Reservoir type Typical field Source rock Reservoir Cap rock Types of structures Types of reservoirs formed Trap type Gas-water relationship Reservoir forming characteristics Distribution location Nappe belt-structure dominated Qigu, Junggar Basin Lake mudstone and coal in Middle and Lower Jurassic Braided river (fan) delta sandstone in Middle and Lower Jurassic Jurassic shale Thrust faults and folds Source below reservoir Anticline, fault block The reservoir is distributed in the high part of the structure, with boundary controlled by the contour, bottom and edge water, and obvious gas-water contact Overpressure filling, high-efficiency migration through faults, high quality combination of reservoir and cap rock Nappe belt Slope-lithology dominated Dibei, Tarim Basin Lake facies mudstone and coal in Triassic and Jurassic Ahe and Yangxia Formation river-delta sandstone Lower Jurassic Jurassic shale Slope at piedmont and faultblock Source below reservoir, and source-reservoir in one Lithology, structure- lithology trap The reservoir has boundary not controlled by the contour, no obvious gas-water contact, and water layer above gas layer Source and reservoir interbedded, near source accumulation, large scale reservoir forming Slope at piedmont