Incorporating steel-industry waste in water based drilling fluids for hydrogen sulfide scavenging

Abstract

Drilling formations with hydrogen sulfide (H2S) pockets causes significant corrosion and operating issues for drilling equipment, as well as exposes working personnel to health and safety risks. Steelmaking, on the other hand, is an energy-intensive process that generates enormous amounts of waste, which is difficult to manage both economically and environmentally. Therefore, the objective of this study is to assess the possibility of using steel industry waste as an H2S scavenger in water-based muds. The H2S scavenging capacity was evaluated for the base mud and fluids containing commercialized SourScav® and steel-waste. The scavenging capacities were calculated using the H2S concentrations measured at the glass column's outlet after contact with the fluid sample. Also, the effects on drilling fluid rheological and filtration properties were investigated, and the corrosion rate was identified for the prepared fluids. According to the experimental results, utilizing steel-waste improved the base mud's H2S scavenging capability by 61%, compared to 50% with the SourScav at the required pH for drilling applications in sour environments. Incorporating steel-waste also raised the plastic viscosity and yield point by 16 and 9%, respectively, and improved the gelling structure with higher gel strengths. Furthermore, adding steel-waste reduced the filtrated volume by 25% with less potential formation damage and a slight reduction in composed filter cake thickness and weight, whereas the SourScav-composed filter cake characteristics were preferred, with weight and thickness reductions of 20 and 22%, respectively. Steel-waste and SourScav both had non-corrosive effects, with corrosion rates of less than 0.9E-5 lb/ft2. By exploiting and recycling steel industry waste, this study delivers an innovative and low-cost H2S scavenger that aids in waste management and, thus, the decrease of negative environmental and economic repercussions of these wastes.