文23气田储层结盐机理研究

RESEARCH ON SALT CRYSTALLIZATION MECHANISM IN WEN 23 GAS FIELD RESERVOIR

通过岩心模拟实验的方法研究文23气田储层结盐机理。应用天然岩心与人造岩心模拟不同驱替压力条件下的结盐过程,考察驱替压力与渗透率变化关系,从而确定结盐上限压力与观察结盐趋势。文23气田随着开发程度的提高储层将出现结盐现象,结盐与储层压力降低有着直接关系,当压力降低至20MPa以下时,开始出现结盐现象,当压力降到4MPa以下后,储层内结盐加剧。另外还研究了结盐后对渗透率的伤害程度,分析了孔隙喉道、孔隙度、比表面积等因素对结盐的影响。渗透率越低、孔隙度越低、比表面积越大结盐后对岩心的伤害程度越大,伤害程度可达90%以上。

The salt crystallization mechanism of Wen 23 gas field was studied by core simulation experiment.The crystallization course was stimulated in different displacement pressure with natural core and artificial core to investigate the relationship between displacement pressure and permeability to determine salt crystallization upper pressure limit and observe salt crystallization tendency.With the further development,salt crystallization would appear in the reservoir.The direct relationship between salt crystallization and decrease of pressure exists.Furthermore,this paper studied the harm degree of permeability caused by salt crystallization and analyzed the effect of pore throat,porosity and specific surface area on salt crystallization.