海相低勘探程度地区油气资源评价:以柴达木盆地德令哈坳陷石炭系为例

海相低勘探程度地区油气资源评价的难点是资料少、地质认识程度低、主要参数获取难度大,影响评价结果可信性.以柴达木盆地德令哈坳陷石炭系为例,系统评价德令哈坳陷石炭系生储盖条件,油气资源评价选用盆地模拟法与类比法相结合方法,关键参数的确定采用了地球物理、地球化学与石油地质学等多种方法,利用油气运移聚集模拟和不同运聚单元资源量...

Marine frontier basin petroleum resources assessment:A case study of the Carboniferous of the Delingha Depression,Qaidam Basin

Petroleum resources assessment for the marine frontier areas must face the challenges of few geologic data, low level of knowledge, and difficult parameter acquisition, which affect the credibility of petroleum resource assessment results. In this case study, we evaluated the Carboniferous of the Delingha Depression, Qaidam Basin using multiple methods, including resources assessment by basin modeling and analogous comparison and key parameter determination by geophysical, geochemical and petroleum geological analyses. Taking into account the source-reservoir-caprock association, we delineated the favorable exploration zones through simulation of hydrocarbon migration/accumulation and calculation of petroleum resources in different zones. There are four types of source rocks, mudstone, carbonaceous mudstone, coal and marl, in the upper Carboniferus, and two types of source rocks, mudstone and marl, in the Lower Carboniferous. In the Crook Formation, the upper Carboniferous source rocks have higher organic matter abundances, with the total organic (TOC) contents equaling >1.0%, 6.0%-10.0%, >60% and >0.3% in most mudstone, carbonaceous mudstone, coal and marl, respectively. The main types of organic matters are types II and III, with a small amount of type I. Most hydrocarbon rocks are mature and high mature. Clastic and carbonate reservoirs are developed in the Carboniferous strata into three sets of regional caprocks and five sets of local caprocks with varying forms of source-reservoir-caprock associations, including self source-self reservoir-self cap, lower source-upper reservoir and upper cap, and upper source-lower reservoir-upper cap. The hydrocarbon generation period of the Carboniferous was mainly from the Late Carboniferous to Middle Triassic, and the hydrocarbon generation peak moment was from the Middle Permian to Middle Triassic, when the basic geological conditions for petroleum formation were generally favorable. The Carboniferous of the eastern Qaidan Basin possesses 0.38 billion of petroleum, 0.16 billion tones of oil and 276 billion cubic meters of gas resources, with petroleum resources mainly distributing in the Ounan Sag and Oulongbuluke Uplift.