关键词: 低渗透气田, 应力敏感, 六升六降, 试井分析, 数值模拟

Abstract: Low permeability gas reservoirs take up a quite large percentage in the developed gas reservoirs in China, the influence of stress sensitivity on gas field development is drawing great attention. Aiming at such problems as in most low permeability gas reservoirs, the stress sensitivity test is done by the way of fixing inner pressure and changing confining pressure, and in practical production, inner pressure changes but the overburden pressure is constant, a test way changing inner pressure and fixing confining pressure is put forward. The way is used to test the stress sensitivity of low permeable cores in the process of net overburden pressure rising and lowering six times respectively. The stress sensitivity curves are used to study the characteristics of low permeable gas well test and single well production performance. Result shows that the way of changing inner pressure and fixing confining pressure is more similar to reservoir practice, in the stage Ⅱ on well test curve, there is big difference while considering and not considering stress sensitivity well test, the well test analysis of closing and opening well five times respectively indicates the existence of permeability stress sensitivity effect is unfavorable for gas reservoir production, stress sensitivity impacts single well simulation bottom hole flowing pressure greatly, considering stress sensitivity, the pressure difference of gas well production increases apparently. So, in the process of low permeability gas field production, the influence of stress sensitivity on gas field production must be taken into consideration.

Key words: low permeability gas field, stress sensitivity, rising and lowering six times, well test analysis, numerical simulation