低渗火山岩气藏可动流体T2截止值实验研究

使用核磁共振岩样分析技术与离心实验，确定出吉林、大庆和新疆3个地区低渗火山岩气藏储层标定可动流体T2截止值的合适离心力为2.76MPa，该离心力同时也是储层可动用流体对应的下限离心力。对3个地区102块不同岩性火山岩岩芯核磁实验研究表明：低渗火山岩气藏储层可动流体T2截止值分布范围很宽，不同地区和不同岩性火山岩储层T2截止值差别很大，102块岩芯T2截止值平均值为49.31ms，大于低渗砂岩但小于碳酸盐岩储层T2截止值；低渗火山岩T2截止值随岩芯渗透率的变化差异较大，与储层孔隙空间类型及孔喉连通性等因素密切相关。3个地区火山岩储层T2截止值从大到小依次为大庆、吉林和新疆火山岩，其中大庆流纹岩T2截止值平均值最大并且分布范围最宽，新疆玄武岩和安山岩最小。

EXPERIMENTAL STUDY ON THE MOVABLE FLUID T2 cutoff VALUE OF VOLCANIC GAS RESERVOIR

The most suitable centrifugal force to calibrate the T2 cutoff of volcanic gas reservoir rock in Jilin,Daqing and Xinjiang and the low limit of centrifugal force for the movable fluid is 2.76MPa,which is determined by nuclear magnetic resonance（NMR） technique and laboratory experiment on centrifugal force of fluid.The low limit of throat radius for movable fluid is 0.05 μm which is figured out according to the capillary law.There is no obvious functional relationship between T2 cutoff and porosity or permeability of volcanic rock.The research indicates that the range of the T2 cutoff value is very wide and there is a big difference between the T2 cutoff values of different regions or lithologies.But the relationship between T2 cutoff and porosity or permeability of Jilin tuff or Xinjiang graniteporphyry is a little obvious.The order of the T2 cutoff value for the movable fluid of different regions is as follows:Daqing，Jilin and Xinjiang.The average of the T2 cutoff value of rhyolite sampled from Daqing is the largest one and that of Xinjiang basalt and andesite is the smallest one.