不同浓度、pH值SDBS压裂液对页岩储层特性影响研究

在页岩储层压裂过程中，不同浓度、不同pH值的SDBS压裂液体系会直接影响页岩储层稳定性，进而影响造缝性能。通过实验分析了页岩储层在不同浓度、pH值的SDBS压裂液作用下的膨胀抑制性、润湿反转性能。实验结果表明：0.02%SDBS压裂液下页岩储层的膨胀变形最小、膨胀变形速率最慢，即膨胀抑制效果最好；0.03%SDBS压裂液下页岩的润湿性改造最好，接触角为30 °。pH值为8的SDBS压裂液对炭质页岩的膨胀变形和膨胀速率起到了最佳的抑制作用；pH值为9的SDBS压裂液对炭质页岩的润湿反转起到了最好的效果，接触角为31.6°。综合分析认为不同浓度、不同pH值的SDBS压裂液对页岩储层特性影响差异较大，说明在对页岩储层的开发利用中，调整SDBS浓度和pH值对提高页岩气开采效果是可行的。

Study on the Effect of Concentrations and pH Values of SDBS Fracturing Fluid on Shale Reservoir Characteristics

SDBS fracturing fluid system of different concentrations and pH values will directly affect the stability of shale reservoirs, and then affect created fracture properties in Shale reservoir fracturing processing. Expansion deformation and wetting reverse of shale reservoir under the action of different concentrations and pH values of SDBS fracturing fluid were analyzed. The results showed that: Shale reservoir expansion deformation was minimized and swelling deformation rate was slowest in 0.02% SDBS fracturing fluid. The maximum contact angle of 30° was obtained in 0.03% SDBS fracturing fluid. Shale reservoir expansion deformation was minimized and swelling deformation rate was slowest in SDBS fracturing fluid with pH value of 8. The SDBS fracturing fluid with pH value of 9 and contact angle of 31.6° showed the best wetting reverse effect on carbonaceous shale. Comprehensive analysis showed that the influence of concentrations and pH values of SDBS fracturing fluid on shale reservoir characteristics has been quite different. That means that it is feasible to increase the rate of exploitation of shale gas by adjusting concentration and pH value of SDBS fracturing fluid.