致密砂岩气藏应力敏感的全模拟试验研究

AN EXPERIMENTAL STUDY OF SIMULATING HIGH-SPEED PRODUCTION IN TIGHT SANDSTONE GAS RESERVOIR

高温高压全模拟全直径致密砂岩气藏岩石降压开采试验数据揭示了致密砂岩气藏高速开采可对储层造成渗透率损害 ,损害的机理是孔隙介质中微粒迁移堵塞孔喉和高速开采所导致有效上覆压力增加使孔喉缩小所造成的综合效应。微粒迁移可通过提高生产压差解决 ,而防止大压差生产所引起的应力敏感则必须严格控制生产压差在 0 .2～ 8MPa范围内 ;,对渗透率低于 0 .2× 1 0 - 3μm2

In the whole simulating production experiment under formation conditions, the data of the whole tight sandstone cores indicate that high speed production can cause permeability damage. The mechanism is a comprehensive effect that particle transfer in porous media blocks up throat of pore which can be relieved by increasing the producing pressure drop and that the increase of effective overburden because of high speed production reduces necks of pore. As for sensitivity brought by stress, the producing pressure drop should be controlled strictly within 0.2 MPa to 8 MPa, or raised adequately if the reservoir permeability is under 0.2×10 -3 μm 2.