Water-based drill cuttings, a shale gas extraction waste as supplementary cementitious material and optimization

The water-based drill cuttings, a kind of solid waste from shale gas extraction, are examined for their utility as supplementary cementitious material. After drying, calcining, and grinding, water-based drill cuttings are expected to partially replace ordinary Portland cement for their high calcium silicate and grinding-friendly nature. A central composite design investigated four variables (calcination time, calcination temperature, replacement ratio, and fineness) for their effects on the response (compressive strength). The optimization results suggest that the best product meeting the mechanical criteria and saving energy could be obtained by replacing 10 wt% ordinary Portland cement when controlling the calcination temperature of 830-870 degrees C, calcination time of 28-32 min, and fineness of sieving is 1600 mesh. The compressive strength was shown to be 39.00 MPa at 7 days, 47.00 MPa at 28 days, and 52.00 MPa at 90 days. Furthermore, the mechanisms of water-based drill cuttings were characterized to confirm the feasibility of supplementary cementitious material by various analytical techniques such as X-ray fluorescence, laser particle size analyzer, simultaneous thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy.

Automated summary

This study examines the potential use of water-based drill cuttings as supplementary cementitious material. After drying, calcining, and grinding, the drill cuttings can partially replace ordinary Portland cement, offering both high calcium silicate content and grindability. The research explores four variables (calcination time, calcination temperature, replacement ratio, and fineness) and their impact on compressive strength. Optimal results indicate that replacing 10 wt% of ordinary Portland cement, with controlled calcination temperature (830-870 degrees C), calcination time (28-32 min), and fineness of sieving (1600 mesh), can produce a product meeting mechanical criteria and saving energy. Compressive strengths of 39.00 MPa at 7 days, 47.00 MPa at 28 days, and 52.00 MPa at 90 days were achieved. Various analytical techniques were used to characterize the mechanisms of the water-based drill cuttings and confirm their feasibility as supplementary cementitious material.