全球含油气盆地深层与中浅层油气藏压力分布特征

Pressure distribution features of deep and middle-shallow hydrocarbon reservoir in global oil and gas-bearing basins

基于全球52 928个油气藏压力特征统计,从盆地类型、储集岩性、储层物性、油气藏温度、油气相态等5个方面出发,对深层和中浅层油气藏压力特征进行对比分析。研究结果表明,在盆地中浅层,油气藏总体以常压为主,前陆盆地、碳酸盐岩储层、致密储层、高温环境、凝析气中更易形成超压油气藏;在盆地深层,油气藏总体以超压为主,被动陆缘盆地、碎屑岩储层、非致密储层、高温环境、油气混相中更易形成超压油气藏。不同压力特征油气藏随埋深呈现一定规律性:1负压和常压油气藏分别分布在深度2 500m和3 500 m以上地层中,超压油气藏主要分布在深度4 500 m以下地层中;2常压油气藏在冷盆、温盆、热盆开始大量出现的深度分别为2 400 m、1 600 m和1 200 m,呈变浅趋势;超压油气藏在冷盆、温盆、热盆开始大量出现的深度分别为4 400 m、3 600 m和2 800m,同样呈变浅趋势;3负压油气藏有利发育区主要位于盆地浅层,常压油气藏有利发育区主要位于盆地中层,超压油气藏有利发育区主要位于盆地深层;4冷盆超压油气藏发育范围较宽,热盆超压油气藏发育范围较窄,温盆介于两者之间。

Based on the pressure features of 52 928 hydrocarbon reservoirs around the world,a correlation analysis is conducted on the pressure characteristics of deep and middle-shallow reservoirs from five aspects,i.e.,basin type,reservoir lithology,reservoir physical property,hydrocarbon reservoir temperature,and oil-gas phase state.The results indicate that normal pressure commonly exists in middle-shallow hydrocarbon reservoirs of basins,while the overpressured hydrocarbon reservoirs are prone to form in foreland basin,carbonate reservoir,tight reservoir,high temperature environment and condensate gas.The overpressured hydrocarbon reservoirs are dominated in deep layers of basins,which are prone to form in passive continental margin basin,clastic reservoir,non-tight reservoir,high temperature environment,and oil-gas miscible phase.Reservoirs with different pressure characteristics present a certain regularity along with increasing burial depth:(1)abnormal low pressure and normal pressure reservoirs are mainly distributed in the strata with buried depth less than 2 500 m and 3 500 m,respectively;overpressure reservoirs are mainly distributed in the strata with depth more than4 500 m;(2)extensive normal pressure reservoirs are formed at the depth of 2 400 m,1 600 m and 1 200 m in cold,warm and hot basin;the overpressured reservoirs are largely formed at the depth of 4 400 m,3 600 m and 2 800 m in cold,warm and hot basin;(3)favorable development areas for abnormal low pressure,normal pressure and overpressure reservoirs are located in shallow layers,middle layers and deep layers of basins,respectively;(4)development scope of overpressure hydrocarbon reservoir is wider in cold basin,narrower in hot basin,and medium in warm basin.