深层碎屑岩含油气储层发育特征

基于深层油气藏的最新数据,对世界范围内深层碎屑岩油气藏富集规律及储层发育特征进行了统计分析.中南美和北美(不包括美国本土48州)深层碎屑岩发现的油气探明和控制(2P)可采储量最多,其中北美发现的石油2P可采储量最多,而中南美发现的天然气和凝析油2P可采储量最多.全球深层碎屑岩油气最富集的六大盆地依次为墨西哥湾、东委内瑞拉、阿拉伯、南里海、塔里木和圣克鲁斯-塔里哈盆地.在深层条件下,尽管储层通常表现为物性整体差,但仍可发育优质储层.深层油气勘探应立足于对“甜点”的预测,重点考虑颗粒薄膜、孔隙流体超压和盐岩发育对深层砂岩储层原生孔隙的保存作用.

Geological features of siliciclastic reservoirs in deep petroleum accumulations

Based on the latest data of deep petroleum accumulations,this study aims at documenting distribution patterns and geological features of global siliciclastic reservoirs.Central & South America and North America (excluding the Lower 48 States) host the largest shares of the total proved and probable (2P) oil and gas reserves in deep siliciclastic rocks.North America contains the bulk of 2P oil reserves in deep siliciclastic rocks,whereas Central & South America has the lion's share of gas and condensate reserves.Of all deep petroliferous basins with siliciclastic reservoirs,the 6 most prolific basins are the Gulf of Mexico,East Venezuela,Arabian,South Caspian,Tarim and Santa Cruz-Tarija Basins.Deep siliciclastic reservoirs are generally characterized by poor petrophysics.It is fair to say,however,that high-quality sandstone reservoirs could be developed under favorable geological conditions at deep burials.The key of deep petroleum exploration is the better delineation of "Sweet Spots" in deep layers where grain coatings,fluid overpressure and/or well-developed salts might have preserved the considerable portion of original primary porosity.