储层临界物性对岩性圈闭油气成藏的意义——以准噶尔盆地东部白家海凸起侏罗系储层为例

准噶尔盆地东部白家海凸起侏罗系岩性油气藏发育,同一个区带上不同岩性圈闭的成藏机理存在差异性.针对岩性圈闭多元控油、主元成藏的特征,从岩性圈闭成藏主控因素中的储层临界物性出发,采用孔渗交会法和含油产状法,结合试验分析,对白家海凸起彩43井区侏罗系西山窑组的地层条件含油临界孔隙度进行研究.同时尝试从地层条件下的含油临界孔隙度、含油临界渗透率及含油孔喉特征等方面,对西山窑组现今及白垩纪末期的储集层含油性进行分析,发现常规实验室条件下侏罗系储集层的含油临界渗透率为0.1×10-3μm2,临界孔隙度值约为11.5%.垂向上储集层的含油临界孔、渗物性随埋深变化.采用有效含油孔隙度、有效含油渗透率和优势流动系数3个储集层临界物性参数进行分析,发现储层临界物性对白家海凸起侏罗系油气藏形成具有明显的控制作用.

Control of critical physical properties of reservoir to the hydrocarbon accumulation in lithological traps:taking Jurassic of Baijiahai uplift in the eastern Junggar Basin as an example

There developed lithological hydrocarbon reservoirs in Jurassic of Baijiahai uplift in the eastern Junggar Basin.There is difference in the forming mechanism of different lithological traps in the same zone of the basin.According to the characteristics of multiple-factor controlling oil and main-factor controlling reservoir formation of lithologic traps,the critical oil-bearing porosity and permeability of Xishanyao Formation reservoir of Jurassic in Cai-43 wellblock were studied by porosity-permeability intersection and oil-bearing occurrence analysis.It is found that the critical oil-bearing porosity and permeability of the reservoir under conventional laboratory conditions are about 11.5% and 0.1×10-3 μm2.But the critical oil-bearing porosity and permeability under surface conditions are different from those under formation conditions.They vary with the buried depth of reservoir.The critical oil-bearing porosity and permeability of the reservoir under formation conditions are presented by pressure correction.According to the analyses of effective oil-bearing porosity,effective oil-bearing permeability and advantage flow coefficient,it is found that the critical physical parameters have control effects on the hydrocarbon accumulation of Jurassic in Baijiahai uplift.