致密砂岩储层“四性”关系及有效储层下限研究——以鄂尔多斯盆地东部王庄区长6油层组为例

Four Properties Relationship and the Effective Lower Limit of the Tight Sandstone Reservoir:A Case Study of the Chang 6 Oil Member in the Wangzhuang Area,Eastern of Ordos Basin

鄂尔多斯盆地东部王庄区长6油层组为致密砂岩储层,储层物性差,非均质性强,明确其储层“四性”关系及有效储层参数下限对甜点预测具有重要意义。通过岩心、测录井以及物性分析资料,明确了王庄区长6储层“四性”关系。其中细砂岩物性整体相对较好,声波时差与储层物性具有较好的对应关系,深感应电阻率则对含油性具有较好的指示性,油水层的深感应电阻率平均值为20~40Ω·m,水层为12~16Ω·m。在此基础上综合岩心、测录井、试油试采及多种分析化验资料,采用多种方法,最终确定王庄区长6油层组有效储层各项参数下限,分别为:孔隙度为8.0%,渗透率为0.2 mD,岩性下限为细砂岩,含油级别下限为油迹,含油饱和度为38.0%,深感应电阻率为20.0Ω·m,声波时差为215μs/m。

The Chang 6 oil member in the Wangzhuang area,eastern Ordos Basin is a tight sandstone reservoir with poor reservoir physical properties and strong heterogeneity.It is significant to clarify the relationship between the reservoir􀆳s four properties and the lower limit of effective reservoir parameters for dessert prediction.The core,logging,and physical property analysis data were used to clarify the“four properties”relationship of Chang 6 reservoir in the Wangzhuang area.The physical properties of fine sandstone are relatively good,and there is a good correspondence between acoustic time difference and reservoir physical properties.In addition,the deep induction resistivity has a good indication of reservoir oiliness.The average deep induction resistivity of the oil-water layer is 20~40Ω·m,while that of the water layer is 12~16Ω·m.On this basis,combined with core,logging,production test,and geochemical analysis data,and using a variety of methods,the lower limit of effective reservoir parameters of Chang 6 reservoir in the Wangzhuang area was determined.The results are as follows:the porosity is 8.0%,the permeability is 0.2 mD,the lower limit of lithology is fine sandstone,the lower limit of oil grade is oil trace,the oil saturation is 38.0%,the deep induction resistivity is 20.0Ω·m,and the acoustic time difference is 215μs/m.