含油气盆地深层碳酸盐岩近源-优相-低势复合富油气模式与有利目标预测评价——以塔里木盆地塔中地区鹰山组碳酸盐岩为例

以塔里木盆地塔中地区鹰山组为研究目标,利用地质剖析与数理统计相结合的方法,对塔中地区碳酸盐岩油气成藏特征进行研究,探讨油气富集主控因素与模式.研究表明:塔中地区碳酸盐岩油气藏为岩溶、裂缝改造而成的礁滩体岩性油气藏,油气分布主要受优质岩石物理相储层、目的层内外毛细管力势差、烃源岩控制;优相储层控藏作用表现为储层物性越好油气越易富集,毛细管力势差控藏作用表现为围岩与储层间毛细管力势差越大油气越易富集,烃源岩控藏作用表现为储层距油气充注点越近油气越易成藏.优相储层、目的层内外势差及烃源岩联合控制了塔中地区深层碳酸盐岩近源-优相-低势富油气地质模式,近源-优相-低势综合控藏指数小于0.5的区域不利于油气富集,控藏指数越大,油气富集概率越大,目前已发现的12个油气藏都分布在预测出的油气富集有利区带内,中古17井区-塔中72井区的北东地区、中古17井-中古22井区之间地区及中古44井-中古52井区的西南地区为潜在油气富集目标区.

A near source-excellent facies-low potential hydrocarbon enrichment mode and favorable target prediction and evaluation of deep carbonate reservoir in hydrocarbon bearing basin:a case study from Yingshan carbonate in Tazhong area of Tarim Basin

Taking Yingshan Formation in Tazhong area of Tarim Basin as the research object, features of carbonate reservoir accumulation in Tazhong area were studied based on geological analysis and mathematical statistics. Further, main controlling factors and mode of oil and gas enrichment were discussed. Researches show that carbonate reservoir in Tazhong area is reef-flat lithologic hydrocarbon reservoir transformed by karst and fissures. Oil and gas distribution is mainly controlled by high-quality petrophysical facies reservoir, potential difference of capillary force inside and outside target strata as well as source rock. For control of high-quality facies reservoir on the hydrocarbon accumulation, the better the physical properties are, the more easily the oil and gas enrichment can form. For control of potential difference of capillary force, the greater the potential difference of capillary force between surrounding rock and reservoir is, the easier the oil and gas enrichment will become. For control of source rock, the shorter the distance from reservoir to oil and gas charging point is, the easier the oil and gas accumulation will be. The near source-excellent facies-low potential hydrocarbon enrichment mode in Tazhong area is jointly controlled by excellent facies reservoir, potential difference inside and outside target strata as well as source rock. The area with FPSI(Facies-Potential-Source Index) less than 0.5 was not favorable for hydrocarbon enrichment; FPSI increased with probability of hydrocarbon enrichment. All of discovered 12 hydrocarbon reservoirs are distributed in the predicted favorable hydrocarbon enrichment zone. The northeastern ZG17-TZ72 wellblock, the zone between Well ZG17 to ZG22 and the southwestern ZG44-ZG52 wellblok are potential target areas of hydrocarbon enrichment.