苏里格气田东区致密砂岩储层物性下限值的确定

Determination of the lower limits of the physical properties of consolidated sandstone reservoirs in eastern Sulige gas field

长庆油田苏里格气田东区盒8、山1、山2段致密砂岩储层具有典型的低孔、低渗及多层系含气特征。储层下限标准的研究是划分有效储层的基础,也是气层识别和容积法储量计算的前提。采用经验统计法、测井计算-Sg法、孔隙结构参数分布等几种方法对研究区储层物性下限进行研究。结果表明,地面条件下有效储层的孔隙度下限为5.0%,渗透率为0.10×10-3～0.15×10-3μm2,含气饱和度下限为50%～60%;原始地层温度压力条件下,孔隙度下限为4.5%,渗透率仅为0.001 0×10-3～0.001 5×10-3μm2。研究结果得到了试气试采资料的证实,为储量计算提供了依据,对储层的开发生产具有指导作用。

The consolidated sandstone reservoirs in the He8,Shan1 and Shan2 members in eastern Sulige gas field of Changqing Oilfield are characterized by low porosity,low permeability and multiple gas-bearing layers.The lower limits of the reservoirs are not only the benchmark for dividing the effective reservoir,but also the prerequisite for identifying the gas formations and calculating the reserves by volumetric method.This paper studied the lower limits of the physical properties of the reservoirs in the study area with several methods,such as empirical statistics,log calculation of Ф-Sg,and pore structure parameter distribution.The results indicate that under surface conditions,the lower limit of porosity of the effective reservoir is 5.0%,permeability 0.10×10-3～0.15×10-3μm2 and gas saturation 50%～60%.Under the initial formation temperature and pressure conditions,the lower limit of porosity is 4.5%,permeability merely 0.001 0×10-3～0.001 5×10-3μm2.The study results were confirmed by the data from well tests and production tests,providing a basis for the calculation of reserves and guidance for the production of the reservoirs.