基于核磁T2谱对数均值差异的碳酸盐岩气水识别

准确识别气水是气藏测井评价的一个关键问题，提出了利用不同观测模式下T₂谱中心位置差异来识别气水的方法。理论分析发现，改变核磁共振测量模式会使得到的T₂谱中心位置发生变化，而天然气对这种变化比地层水更为敏感，可以利用这一性质进行气水识别。编制了利用不同等待时间或不同回波间隔T₂谱进行气水识别的软件，并对四川盆地某地区碳酸盐岩储层气藏进行了测试，气水识别结果与试油结果一致，证明了所提方法的有效性。将该方法应用于多口井，结果显示具有较好的识别效果，同时发现利用不同回波间隔的2组T₂谱对数均值差异进行气水识别的准确性要高于不同等待时间的2组T₂谱。

Gas-water identification of carbonate reservoir based on log mean difference ofT2 spectrum

Identification of gas and water is a key problem in gas reservoir logging evaluation,and a method for identifying gas water by usingT₂ spectral center location difference under different observation modes is proposed.Theoretical analysis shows that the change of theT₂ spectrum center position can be changed by changing measurement mode,and the natural gas is more sensitive than the formation water.Based on the theory,gas-water recognition software is developed,and tested in Sichuan Basin.The result is confirmed by the oil testing conclusion,and the validation of the method is demonstrated.The method is applied in several wells,and results show that the method has good recognition effect.And we also found that recognition accuracy of different echo interval mode is higher than that of different waiting time mode.