颗粒碳酸盐岩测井相及其对滩相储层的指示意义

碳酸盐岩滩相储层具有极强的非均质性，储层的优劣严格受沉积微相和微古地貌起伏所控制，而测井相的变化能很好地反映由台地内次一级古地形起伏控制的沉积分异作用。以四川盆地中部磨溪气田为例，分析了下三叠统嘉陵江组嘉二2亚段A层的测井相类型、特征及测井相分布，指出自然伽玛曲线形态呈箱型、钟型+漏斗型的地区是强水动力条件下滩核微相的测井响应，反映古地形相对高处，储层发育好；而曲线形态呈指型和尖峰型的地区则为滩间洼地或滩缘微相的响应特征，反映古地貌相对较低，储层发育差，认为颗粒碳酸盐岩测井相研究是准确解释标志层岩性的重要手段，而解释成果则是沉积微相精细描述和沉积期微地貌 恢复研究的必要依据，也是碳酸盐岩隐蔽滩相薄储层预测和储层非均质性研究的基础。

LOGGING FACIES OF GRANULAR CARBONATE ROCKS AND ITS IMPLICATION ON RESERVOIR EVALUATION

Reservoirs of carbonate rocks in beach facies are strongly heterogeneous. The reservoir properties are controlled by sedimentary microfacies and palaeogeomorphology. As variations of logging facies of rock can reflect the sedimentary differentiation controlled by palaeogeomorphology in the carbonate platform, this paper analyzes the basic types, characteristics and distribution of the logging facies of T1j2^2 using the Moxi gas field in the middle of Sichuan basin as a case study. The GR curves have several types. The trunk type and bell-funnel compounding type represent the beach ridge microfacies which is located in high palaeogeomorphology and has stong hydrodynamic force and high quality reservoirs. The finger or hill finger type reflects the beach margin and depression area among beaches, which is located in low palaeogeomorphology and has weakly hydrodynamic force and low quality reservoirs. These results indicate that the logging facies research of granular carbonate rocks is important in standard stratigraphic bed marking, sedimentary facies interpretation, palaeogeomorphology reconstruction, and the researching of reservoir aeolotropism as well as the thin reservoir prediction of beach facies.