煤层气测与液测速敏实验分析对比

Comparative Analysis on Coal-formation Reservoir and Fluid Velocity Measurement Susceptibility Experiment

煤层的保护研究首先要进行储层速度敏感性研究,而许多煤层气藏的储层是低渗低孔储层,采用常规的方法无法测试,为了了解致密煤层的实际情况,尝试使用气体作为流动介质进行储层速敏性实验研究。以山西某致密煤层气藏岩心为研究对象,分别采用模拟地层水和高纯氮气为驱替介质进行了速度敏感性实验,并对2种测试方法及结果进行研究与分析。研究结果表明:渗透率越低的区块渗透率损害程度越不明显,采用二次气测速敏实验法得出的渗透率与液测渗透率基本是一致的。因此,对于致密气藏进行速度敏感性实验研究,可以考虑用气测替代液测实验评价。

The study on velocity sensitivity of reservoir is first conducted for the protection research of coal-formation reservoir, and many of the coal-formation reservoir is low permeability and low porosity reservoir,which can not be tested by the conventional method. To ob- tain the actual situation of coal seam,the authors tried to use gas as a flowing medium for reservoir velocity sensitivity experiments. Tak- ing a dense coal seam gas reservoir core in Shanxi Province as the research object,the simulated formation water and high purity nitro- gen were used as driving medium respectively for the displacement velocity sensitivity experiment and the two kinds of test methods were analysed and studied. Experimental results show that, the block with lower permeability has encountered less damage degree on permea- bility,and permeability obtained from the secondary air velocity sensitive experiment was consistent with permeability eaeulated from liquid measurement. Therefore, for dense gas reservoir velocity sensitivity experiments, it was feasible to use gas measurement instead of liquid measurement.