Potential of Thermal Desorption Residue of Oil-Based Drilling Cuttings for Use in Subgrade Materials

Abstract

The high content of silicon and aluminum present in the thermal desorption residue of oil-based drilling cuttings (ODCR) makes it potentially suitable for use in subgrade materials. The main components of ODCR are akin to solid wastes such as slag, which can replace the fine aggregate of concrete. Cement, fly ash, additive (LG), and ODCR were used to prepare the subgrade in this investigation. LG is a newly formulated supplemental gel material. According to the Box–Behnken design of response surface method, the influence of raw materials formula on unconfined compressive strength (UCS) of the subgrade and the interaction among raw materials were explored. The hydration reaction mechanism was analyzed by X-ray diffraction and scanning electron microscope. In addition, the toxicity characteristic leaching procedure method (TCLP) was used for toxic leaching experiments on ODCR. The results showed that the UCS of the subgrade prepared with 10.64% cement, 14.97% fly ash, and 3.74% LG reached 4.61 MPa. This subgrade complied with the requirements of UCS to achieve 3–5 MPa in the standard, JTG E51-2009. The LG promoted the formation of hydration product calcium silicate hydrate and aluminum silicate hydrate gels, filled the pore of the specimen, and increased its UCS. Moreover, the leaching toxicity of ODCR met China standard, GB 5085.3-2007.