海上异常高压低渗透气藏应力敏感实验研究

STRESS SENSITIVITY EXPERIMENT OF OFFSHORE ABNORMAL HIGH PRESSURE LOW PERMEABILITY GAS RESERVOIR

南海某异常高压低渗透气藏储层非均质性强、产能低,为研究应力敏感对异常高压低渗透气藏开发效果的影响程度,利用真实岩心在地层真实条件下开展了应力敏感实验研究。结果表明,岩心渗透率及孔隙度伤害程度均不可逆,渗透率不可逆损失率在5%左右,孔隙度损失率在千分之几,应避免多次开关井。渗透率伤害程度强于孔隙度伤害程度,开发时应考虑应力敏感的影响,采用物质平衡方程计算储量必须考虑岩石弹性能量的影响。

The heterogeneity of abnormal high pressure low permeability gas reservoir is strong in South China Sea,and the off- take potential is low. In order to study the influence degree of the stress sensitivity on the abnormal high pressure low permeability gas reservoir development effect,the stress sensitivity experiment of real core was done under the condition of real formation. The results showed that the damage degree of core permeability and porosity was irreversible,and the irreversible loss rate of permeability was about 5%,porosity loss rate was a few in a thousand,and the multiple well startup and well shut- in should be avoided. Permeability damage degree was stronger than the porosity damage degree,the influence of stress sensitivity should be considered in development,and the reserves calculating by using material balance equation must consider the influence of the rock elastic energy.