神木-米脂地区上古生界核磁共振录井三元图板建立及应用

Establishment and application of ternary chart for NMR physical property logging of upper Paleozoic in Shenmu-Mizhi area

神木-米脂地区致密砂岩气藏为烃类气体分子在分子膨胀力的作用下不断向周围拓展成藏,烃类气体未经大规模长距离运移,以垂向近距离运移为主。此类气藏不存在明显气、水分异的特点,常规录井评价在含水储层识别方面存在局限性,未能形成有效的含水储层识别解释图板和标准。中国石油长庆油田勘探开发研究院根据近几年该区34口井的核磁共振录井资料,基于核磁共振录井孔隙度、含水饱和度、可动水饱和度三个参数所占百分比,建立了识别含水储层的三元解释图板,并在该区推广应用,实现了储层流体性质的精确评价,提高了录井解释准确率。

Tight sandstone gas reservoirs in Shenmu-Mizhi area are reservoirs formed by hydrocarbon gas molecules constantly expanding around under the action of molecular bulging force,the hydrocarbon gas is mainly migrated vertically and in short distance without large-scale long-distance migration.There is no obvious difference between gas and water in this kind of gas reservoir.The conventional mud logging evaluation has limitations in the identification of water bearing reservoir and fails to form an effective interpretation chart and standard for the identification of water bearing reservoir.According to NMR physical property logging data of 34 wells in this area in recent years,based on the percentage of three parameters of NMR physical property logging porosity,water saturation and movable water saturation,Exploration and Development Research Institute of PetroChina Changqing Oilfield Company established a ternary interpretation chart for identifying water bearing reservoirs and popularized it in this area to realize the accurate evaluation of reservoir fluid properties and improve the accuracy of mud logging interpretation.