北乌斯丘尔特盆地成藏组合分析与油气资源潜力评价

Analysis of petroleum play and resources evaluation in the North Ustyurt Basin

北乌斯丘尔特盆地是中亚地区油气资源丰富的盆地之一。根据北乌斯丘尔特盆地最新的数据资料,应用含油气系统综合分析方法,将盆地划分为8个成藏组合;以成藏组合为评价单元,利用统计法和类比法求取评价参数,采取蒙特卡洛法模拟计算盆地未来30年油气待发现可采资源量潜力。结果表明:北乌斯丘尔特盆地待发现石油、天然气和凝析油的可采资源量(均值)分别为13.1474×10^7 t、1.5472×10^11 m^3、239.1×10^4 t,合计2.5812×10^8 t油当量。最具潜力的含油气系统是滨里海—侏罗系含油气系统和中侏罗统—渐新统含油气系统;区域上,油气主要分布于北布扎奇隆起、库尔图克凹陷、切尔卡尔凹陷和苏多奇凹陷,表现为“西油东气”;层系上,油气主要富集于中侏罗统和下白垩统。最有潜力的成藏组合为西部布扎奇侏罗系、西部布扎奇下白垩统和北乌斯丘尔特中侏罗统成藏组合。

The North Ustyurt Basin is one of the petroliferous basins in Central Asia.On the basis of up to date data,eight plays were identified in this basin with an integrated approach of petroleum system analysis.Each play was regarded as an assessment unit for resources evaluation.Monte Carlo simulation was used to calculate recoverable oil and gas resources which could be discovered in next 30 years and parameters were determined with statistical and analog methods.Results show that the mean undiscovered recoverable resources in the North Ustyurt Basin are 13.1474×10^7 t of oil,1.5472×10^11 m^3 of gas,and 239.1×10^4 t of condensate,i.e about 2.5812×10^8 t of oil equivalent.The Caspian-Jurassic and the Middle Jurassic-Oligocene petroleum systems account for the largest share of undiscovered petroleum resources.Oil and gas are areally distributed in the Beibudsaki Uplift,Kurtuk Trough,Cherkal Trough,and Sudoci Sag,which is characterized by oil in the west and gas in the east.Stratigraphically,oil and gas are mainly accumulated in the Middle Jurassic and Lower Cretaceous.The most potential plays are developed in the Jurassic and Lower Cretaceous in Beibuzachi,and Middle Jurassic in Ustyurt.