川东北地区碳酸盐岩气层识别方法研究

On Identifying Gas Zones in Carbonate Formation in Northeast Sichuan

川东北地区碳酸盐岩地层岩性复杂、储集空间多样、气层识别存在很大困难。根据电阻率、中子、密度、多极子阵列声波等测井曲线特征,探讨了双侧向电阻率分析、孔隙度比值、孔隙度-含水饱和度交会图、纵横波速度比值等多种气层识别方法,并针对不同识别方法分别研究了其适用性,由此对川东北地区碳酸盐岩地层不同孔隙结构的储层提出了相应的识别方法。对复杂岩性地层与孔隙结构类型多样的储层,最好综合多种判断方法进行分析判断。灵活运用这些方法,可在实际生产应用中见到良好效果。

Because of complex lithologies and various reservoir pore spaces, it is very difficult to identify the natural gas in the carbonate formation in Northeast Sichuan. Many identifying techniques（e, g. , dual lateral resistivity log, porosity ratio, porosity-water saturation cross plot, and the ratio of compressional wave velocity to shear wave velocity） and their suitability were proposed and discussed in this paper based on resistivity, neutron porosity, bulk density and MAC （Muhipole Array Acoustic） logs. Further, the gas identifying methods were proposed which suit for different reservoirs with different pore structures in carbonate formation in Northeast Sichuan. It was suggested that these methods should be comprehensively used for the complex lithology reservoirs with various pore structures. It can bring satisfactory results by using these methods flexibly in field practice.