中东T油田灰岩储层自然伽马能谱测井的应用

中东地区T油田主力含油储层受高放射性物质影响,导致利用常规自然伽马测井资料无法合理求取泥质含量。同时,由于岩芯分析资料较少,确定各主力含油储层的黏土类型就显得比较困难。针对这些问题,笔者基于自然伽马能谱测井中铀、钍、钾与地层中黏土矿物的密切关系,利用无铀伽马测井资料对泥质含量进行了合理计算,参考斯仑贝谢理论交会图版,利用钍与钾交会图法确定了黏土类型,通过制作钍与铀比值的直方图对沉积环境进行了研究,取得了较好的应用效果,为油田后期的开发提供了更加可靠的资料支持。

The application of natural gamma spectrometry log to limestone reservoir in T oilfield of Middle East

The main reservoir can be affected by high radioactivity minerals in the T oil field of Middle East ; as a result, shale content cannot be calculated exactly by natural gamma log data. In addition, it is difficult to confirm clay types of each main oil-bearing reser- voir because of insufficient core analysis data. To tackle these problems, the authors used the close relationships between clay minerals and uranium, thorium, potassium from natural gamma ray spectrometry log to reasonably calculate argillaceous matter content by thorium and potassium content . According to the interpretation charts of Schlumberger, the clay types were defined by using Th-K crossplots, and depositional environment was studied by making Th/U histogram, with satisfactory results achieved. The results obtained by the authors provide dependable reservoir evaluation data for late development of oil field.