热处理对岩石波速及孔渗的影响

EFFECTS OF THERMAL TREATMENT ON WAVE VELOCITY AS WELL AS POROSITY AND PERMEABILITY OF ROCK

在常压条件下 ,对干燥粉砂岩、灰岩和砾岩 3种储层岩石进行了高温处理 ,测量并分析了岩石波速、渗透率和孔隙度与温度的变化关系。结果表明 ,热处理过程中岩石波速、渗透率和孔隙度等物理性质的变化存在一个突变温度域。经过高温处理后的岩石 ,其波速随温度升高而下降 ,渗透率和孔隙度随温度升高而增加。在阈值温度附近岩石波速、渗透率和孔隙度变化幅度最大 ;高于阈值温度后 ,影响岩石渗透率和孔隙度变化的主要机理是早期产生的微裂纹宽度增加。该实验结果为现场储层热处理效果评价及技术应用提供了依据。

The experiments on high-temperature treatment of siltstone, limestone and conglomerate obtained from reservoir formation were carried out under the normal pressure. The change of wave velocity, permeability and porosity of rocks with temperature was determined. The experimental results indicate that there exists a jump threshold temperature for wave velocity, permeability, porosity and other properties. The wave velocity decreased with temperature rising, while the permeability and porosity of rock increased. The wave velocity, permeability and porosity of rocks changed obvious around the threshold temperature. When temperature is higher than the threshold, the main change of permeability and porosity was resulted from the increment of micro-fissure width. The experimental results provide a basis for field evaluation and application of high-temperature treatment.