委内瑞拉奥里诺科重油带地质与油气资源储量

Geology and reserve of the Orinoco heavy oil belt,Venezuela

奥里诺科重油带是目前世界上最大的重油富集带，位于东委内瑞拉盆地南缘的北倾单斜上，总面积为54000km^2，重油地质储量约2000×10^8t，可采储量约500×10×8t。该重油带主要储集层是一套第三系河流-三角洲相砂岩，油层埋藏浅，厚度大，孔隙度、渗透率、含油饱和度高，岩石固结程度差，非均质性强。重油带油藏以岩性圈闭为主，局部受断层控制。重油带被划分为4大区32个可开发区块，目前探明储量主要分布在JUNIN和CARABOBO两个地区，区内油藏具有三高一低可流动的特点，即：高比重，高含硫，高含重金属钒和镍，低黏度，可形成泡沫油。冷采条件下可流动并能获得很高的单井产能，水平井冷采产量一般可达200t／d，冷采采收率较低，为5％～10％。

Orinoco heavy oil belt is the largest heavy oil enriched area in the world, with the total area of 54 000 km^2 , heavy oil reserves of about 200 billion tons, and recoverable reserves of about 50 billion tons. It is located in the marginal uplift belt of East Venezuela Basin, and is a monocline dipping to the north. The main reservoir is Tertiary fluvial deltaic facies sandstone characterized by shallow depth of oil layer, large thickness, high porosity, high permeability, high oil saturation, poor consolidation, and strong heterogeneity. The main trap is lithologic trap, and locally controlled by faults. The belt is subdivided into 4 large areas with 32 blocks, and the proved reserves are mainly in the JUNIN and CARABOBO regions. Oil pools are characterized by ＂three highs and one low＂ in the fluidity of the heavy oil, that is, high gravity, high sulfur, high content of heavy metals vanadium and nickel, and low viscosity, and foamy oil can be formed. Under the conditions of cold production, the oil can flow and single well production is high, the production with horizontal well is up to 200 tons per day, and the oil recovery is relatively low （5%-10%）.