Hydraulic fracturing is often used in unconventional shale reservoirs, and 50%–95% of the injected hydraulic fracturing fluid remains in the formation due to the capillary effect. This phenomenon has been observed in the Montney shale formation, Canada, where the flowback water recovery is generally less than 25%. Surfactant is one of the hydraulic fracturing fluid additives for reducing surface tension and capillary forces to facilitate water flowback recovery. Surfactant loss due to adsorption by the reservoir rocks reduces the chemical’s efficiency, and this causes water retention in the formation and reduces water flowback recovery. The compatibility of surfactant with reservoir rock is critical to minimize surfactant adsorption on the rock surface because this diminishes the primary function of the surfactant hydraulic fracturing fluid additive and to ensure cost-effectiveness. This study evaluates surfactant efficiency to improve flowback recovery for the Montney shale formation based on IFT, surface tension, and adsorption. This study evaluates surfactant performance and performs a fluid–fluid interaction experiment and fluid-rock compatibility investigation. Several commercial surfactants are screened for low interfacial tension and surface tension. Further analysis is carried out by evaluating the fluid-rock compatibility using the static soaking test at reservoir pressure and temperature. The pre-soaking and post-soaking test fluids were analyzed for water composition, liquid–liquid interfacial tension, surface tension, and pH. Results showed that the selected surfactant is a critical determiner of the hydraulic fracturing fluid performance. SOLOTERRA 938 is an anionic surfactant that has good compatibility with Montney shale formation. Unlike other non-ionic surfactants, SOLOTERRA 938 retains the interfacial tension and surface tension after seven days of interaction with reservoir rock. The interfacial tension remained unchanged at 0.1 mN/m. The surface tension decreased from 28.4 to 27.5 mN/m with air and from 21.7 to 20.8 mN/m with hydrocarbon because surfactant behavior changes with pH change. The surfactant concentration was measured using high-pressure liquid chromatography, and the loss was 12% after seven days of interaction with the reservoir rock (from 0.1 to 0.088wt%). The adsorption calculated based on the concentration volume showed a low value of between 0.43 and 0.97 mg/g rock.

水力压裂通常用在非常规的页岩储层中，由于毛细作用，注入的水力压裂液中有50％–95％保留在地层中。在加拿大的蒙尼页岩地层中已经观察到这种现象，那里的回流水回收率通常低于25％。表面活性剂是用于降低表面张力和毛细作用力以促进水回流的水力压裂液添加剂之一。由于储层岩石的吸附而导致的表面活性剂损失降低了化学物质的效率，这导致水滞留在地层中并降低了水的回流回收率。表面活性剂与储层岩石的相容性对于最小化表面活性剂在岩石表面的吸附至关重要，因为这会削弱表面活性剂水力压裂液添加剂的主要功能，并确保成本效益。这项研究评估了表面活性剂的效率，以基于IFT，表面张力和吸附来改善Montney页岩地层的返排采收率。这项研究评估了表面活性剂的性能，并进行了流体-流体相互作用实验和流体-岩石相容性研究。筛选了几种市售的表面活性剂以降低界面张力和表面张力。使用储层压力和温度下的静态浸泡试验评估流体-岩石相容性，可以进行进一步的分析。分析了浸泡前和浸泡后的测试液的水成分，液-液界面张力，表面张力和pH值。结果表明，所选择的表面活性剂是决定水力压裂液性能的关键因素。SOLOTERRA 938是一种阴离子表面活性剂，与Montney页岩的形成具有良好的相容性。与其他非离子表面活性剂不同，SOLOTERRA 938在与储层岩石相互作用7天后仍保持界面张力和表面张力。界面张力保持在0.1mN / m不变。空气的表面张力从28.4降至27.5 mN / m，碳氢化合物的表面张力从21.7降至20.8 mN / m，这是因为表面活性剂的行为随pH的变化而变化。使用高压液相色谱法测量表面活性剂浓度，与储层岩石相互作用7天后，其损失为12％（0.1至0.088wt％）。