双河油田Ⅳ5-11层系密闭取心井饱和度校正方法研究

Study on saturation correction for sealed coring well in the Ⅳ5-11 series of strata in the Shuanghe Oilfield

双河油田Ⅳ5-11层系密闭取心过程中,由于岩心受降压脱气油水溢出的影响,室内分析油、水饱和度值普遍偏低,两相之和远低于100%。针对该问题,分析影响室内岩心含水饱和度测量值的相关因素。采用物理模拟校正方法,模拟密闭取心降压脱气全过程,建立地下饱和度真实值与地面分析饱和度之间的关系,并利用岩石变形公式对饱和度进行修正,从而确定适合本区块的密闭取心校正饱和度公式,使其更接近实际地层中的真实含水饱和度。对校正后油水饱和度结果进行分析,发现该方法有助于准确判断油层水淹状况,提高油气采收率。

Laboratory analysis shows that the values of oil and water saturations are generally low,with the sum of the two phases far below 100% as affected by pressure release,degassing,deoiling and dewatering in the course of sealed coring from the Ⅳ5-11 series of strata in the Shuanghe Oilfield. This paper analyzes the relevant factors affecting measurements of laboratory water saturation. A correction formula of saturation is determined for sealed coring in this block by establishing the relationship between true saturation in formation and analyzed saturation on surface through physical simulation of the whole process of sealed coring and by correcting with rock deformation formula,thus obtained water saturation more approximate to the actual value in formation. Analysis of the corrected oil and water saturations shows that this method may help accurately determine water out behavior and improve oil and gas recovery factor.