College of Chemistry and Chemical Engineering, Southwest Petroleum University, No. 8 Xin Du Avenue, Xin Du District, Chengdu, 610500, China.
Appraisal Center for Environment and Engineering, Ministry of Ecology and Environment of the People's Republic of China, Beijing, 10012, China.
Environ Sci Pollut Res Int. 2021 Jun;28(23):29379-29393. doi: 10.1007/s11356-021-12847-4. Epub 2021 Feb 8.
Large amounts of water-based drilling cuttings (WDC) would be generated during the drilling of shale gas wells, which would occupy land resources and pose significant threat to soil and groundwater environment. The aim of this study was to assess the feasibility of using WDC as a replacement of natural clay to prepare sintered bricks. To determine the optimum preparation condition, the weight loss on ignition, bulk density, water absorption, and compressive strength of the samples were tested. Meanwhile, the environmental performance of the final products was evaluated and micro-analysis was conducted via X-ray diffraction and scanning electron microscopy. The results showed that using WDC to manufacture sintered bricks was technically feasible, but the physical mechanical performance would significantly decrease with the increase of the replacement ratio because of the presence of less silica and excessive calcium. The addition of waste glass and fly ash could promote the generation of molten glassy phase and form the crystal particle bonding structure, which would contribute to the physical-mechanical performance of WDC sintered bricks. Some mineral components in raw materials decomposed and formed minerals with better thermal stability during the sintering process. Under the optimum preparation conditions (mass ratio of WDC: waste glass: fly ash at 40:20:40, sintering temperature at 900 °C, and insulation time at 2 h), the physical-mechanical and environmental performance of WDC sintered bricks could meet the requirements of corresponding Chinese standards and ASTM standards. Thus, in this study, an effective solution to recycle WDC from shale gas development is provided.
大量水基钻井岩屑（WDC）将在页岩气井钻探过程中产生，这将占用土地资源，并对土壤和地下水环境构成重大威胁。本研究旨在评估将 WDC 用作替代天然粘土来制备烧结砖的可行性。为了确定最佳的制备条件，测试了样品的灼烧失重量、堆积密度、吸水率和抗压强度。同时，通过 X 射线衍射和扫描电子显微镜对最终产品的环境性能进行了评估和微观分析。结果表明，使用 WDC 制造烧结砖在技术上是可行的，但由于二氧化硅含量减少和钙含量过多，随着替代率的增加，物理力学性能会显著下降。添加废玻璃和粉煤灰可以促进熔融玻璃相的生成，并形成晶体颗粒结合结构，从而有助于提高 WDC 烧结砖的物理力学性能。在烧结过程中，原料中的一些矿物成分分解并形成具有更好热稳定性的矿物。在最佳的制备条件下（WDC:废玻璃:粉煤灰的质量比为 40:20:40，烧结温度为 900°C，保温时间为 2h），WDC 烧结砖的物理力学性能和环境性能可以满足中国相应标准和 ASTM 标准的要求。因此，在本研究中，为页岩气开发中回收 WDC 提供了一种有效的解决方案。
