COMPREHENSIVE RESEARCH OF TIGHT SANDSTONES GAS RESERVOIRS STRESS SENSITIVITY IN DANIUDI GAS FIELD
鄂尔多斯盆地大牛地气田致密砂岩气层应力敏感性综合研究

During exploiting the tight sandstone gas reservoirs, the descent of pore pressure will induce the virtual stress increase, which makes the permeability drop, and it is basic reason of the gas reservoirs production descent. The study of stress sensitivity damage mechanism can provide a reasonable foundation for protection the tight gas reservoir. Taking Daniudi gas field tight sandstone as example, the factors of rock compositions, fracture, temperature, water saturation and repeatedly pressuring were considered for the evaluation of tight gas sandstone stress sensitivity. It shows that the higher fluorescence content and higher temperature lead a higher stress sensitivity. The association behavior of temperature and effective stress made a more strong stress sensitivity. Water can give a stimulation action for tight sandstone stress sensitivity. Repeatedly pressuring will make the permeability continuously drop. The tight sandstone stress sensitivity of fracture sample is stronger than matix. Temporary shielding protection reservoirs method can reduce the stress sensitivity damage of tight sandstone gas reservoirs.