应用核磁共振测井T2谱划分裂缝型储层

Classification of fractured reservoirs by T2 spectrum of nuclear magnetic resonance log

1. 石油大学,东营257061;2. 胜利油田地科院,东营257015

Petroleum University, Dongying 257061

应用核磁共振测井T2谱划分储层类型的关键是T2截止值的确定。提出了先通过压汞等实验手段或测井间接计算确定束缚水饱和度,然后在核磁共振测井图上直接确定T2截止值的方法。胜利埕北302井的灰岩压汞和核磁共振实验资料一方面为提出的方法验证了可行性,另一方面表明束缚水饱和度和T2截止值随样品不同而变,多数情况下不能简单地用一个T2截止值进行解释。在此基础上,总结了应用核磁测井解释孔隙类型的解释模式,并通过应用实例证明在核磁测井孔隙类型解释的基础上可应用核磁测井进行裂缝性储层的储层类型划分。

The key to reservoir classification by T2 spectrum of nuclear magnetic resonance log is the determination of T2 cutoff values. This paper proposes a new method to determine the T2 cutoff values directly from nuclear magnetic resonance log if the irreducible water saturation is obtained from experiments such as mercury penetration, or calculated from log data. The experiment data from mercury penetration into limestone and nuclear magnetic resonance in Well 302 in Chengbei area of Shengli Oilfield confirmed the feasibility of the new method. The data, on the other hand, also shows that the irreducible water saturation and T2 cutoff values vary with depth. Therefore, the log interpretation can not be made from a single T2 cutoff value. Based on the above results, the author summarized the interpretation patterns of different types of pores in interpretation of nuclear magnetic resonance log, and illustrated with real examples that nuclear magnetic resonance log is applicable in the reservoir classification of fractured reservoirs.