鄂尔多斯盆地子北油田长6储层有效油水层测井解释

Log Interpretation of Effective Oil-Water Layers in Chang 6 Reservoirs in the Ordos Basin

鄂尔多斯盆地子北油田长6储层为特低渗透致密砂岩,孔隙结构复杂,非均质性强,需压裂才能出油,无纯油层,产油层都为油水同出,产油量低、含水率普遍较高。以往有效厚度解释主要研究区分油水层、水层,但按探明储量计算要求,油水层产油量如达不到储量起算标准就不能确定为有效厚度。开展了有效油水层解释综合研究,将油水层解释类别细分为有效油水层、低效油水层,确定合试层测井资料选用办法,规范储层测井资料读值方法,研制并确定有效油水层解释标准。实际应用表明,它们提高了特低渗透致油水层的有效厚度解释精度,对类似复杂地质条件的油藏研究具有借鉴意义。

Chang 6 reservoir in the Zibei oilfield in the Ordos basin is tight sandstone with ultra-low permeability and complex pore structures and strong heterogeneity.It can produce oil only after fracturing stimulation.In the reservoir,there is no pure oil layer,all oil reservoirs produce oil and water at the same time,the oil production is low and the water cut is generally high.Previous interpretation of the thickness of pay zones was to distinguish oil-water layers from water layers.However,according to the calculation standard of proven reserves,an oil-water layer cannot be defined as a pay zone if its oil production cannot meet the starting reserve.In this study,the interpretation of effective oil-water layers focuses on how to divide effective and less effective oil-water layers,determines how to select logging data in commingling test layers,standardizes the reading method of logging data,develops and determines the interpretation standard of effective oil-water layers.Applications show these methods can improve the interpretation accuracy of pay zones with extra-low permeability,and are references to the study of reservoirs with similar complex geological conditions.