Utilization of top-hole drilling cuttings as a raw material substitution in clay brick production

Abstract Onshore petroleum drilling operations produce a significant amount of drilling waste, particularly top-hole cuttings (THC) from the top-hole drilling phase. These cuttings are categorized as non-hazardous waste and are typically disposed of by landfilling in the drilling site without being utilized for other purposes. This study aims to explore the potential utilization of drilling waste as a raw material substitution in clay brick production. The physicochemical properties of THC were preliminarily examined, revealing that at depths shallower than 1,000 meters from the surface, THC primarily comprised sand and loamy sand with particles smaller than 0.06 mm (45-48% by weight). The pH was measured at 9.21 (at a soil/water ratio of 1:1), and electrical conductivity (EC) was recorded at 134.9 μS/cm (at a soil/water ratio of 1:5). X-Ray diffraction analysis (XRD) identified quartz as the primary component in THC, consistent with its predominance in the sand composition. The analysis showed that levels of heavy metals such as cadmium, manganese, lead, chromium, and zinc were within permissible limits according to Thai Soil Quality Standards for residential and agricultural purposes, with manganese content peaking at 85.3016±7.7491 mg/kg in the cutting samples. In clay brick production trials, varying proportions of THC were added as a substitute for sand at weights ranging from 0%, 10%, 20%, and 30%. Bricks containing 30% by weight THC demonstrated water adsorption capacities meeting TIS standards - specifically TIS 77-2545-Class A and TIS 153-2545-Class B standards. Leaching tests indicated that these bricks met waste management standards relevant to petroleum activities. This study concludes that top-hole drilling cuttings could effectively serve as a suitable raw material substitute in clay brick production processes. The study offers an environmentally sustainable solution to repurpose drilling waste that would otherwise be disposed of in landfills. In terms of economic viability, implementing this approach could lead to cost savings through reduced disposal expenses for drilling waste and potentially lower demand for traditional raw materials used in brick production.