Development and Optimization of Epoxy-Resin Based Cement Reinforced with Low-Cost Fly Ash for High Durability Environmentally Friendly Cement

Abstract

ABSTRACT Cementing is an integral operation in any oil and gas well. Although conventional cement has been used for many years, it suffers from two significant problems. These include significant numbers of failures especially at extreme conditions, and environmental damage due to high emissions generated during cement production. This research overcomes these two problems by developing a novel environmentally friendly and high durability epoxy based cement reinforced with low cost fly ash. More than 100 different samples were prepared for the novel cement for evaluation. Different formulations were designed for testing by varying the fly ash concentration. The formulations had a fly ash concentration of 0, 10, and 30%. The samples were tested under temperatures of 25, 80, 120, and 160 °C, and hydrochloric acid (HCl) concentrations of 1, 10, and 20%. The samples were also tested for sedimentation, and density increase with the increase in fly ash concentration. Compared to the conventional class G cement, the developed cement showed higher acid and alkali resistance, higher thermal stability, and much higher overall compressive strength. INTRODUCTION After an oil well is drilled, metal piping called casing is placed in the hole to support the drilled hole from collapsing. In order to fix the casing to the hole wall, cement is used. The cement must have unique properties to avoid problems (Fakher, et al., 2020; 2021; 2022). These properties include high compressive and tensile strength, high bond strength with the casing and the formation, low porosity and permeability to avoid fluid migration through the cement, and high resistance to temperature, acidity, and alkalinity to avoid cement interaction with different underground fluids (Wagle, et al., 2021; Fakher, and Khlaifat, 2022). Although conventional cement has been used for many years in oil and gas wells, it suffers from two main drawbacks. Firstly, conventional cement relies on limestone as its raw material; this results in an ever-increasing cost of cement and the large volume of greenhouse gas emissions associated with the burning of the limestone to produce cement (Alanqari, et al., 2022; Lummer, et al., 2017; Fakher, 2020). Secondly, with the increase in technology, deeper wells are being drilled with more extreme conditions which results in cement failure. It is therefore necessary to produce enhancements to the cement in order to be able to withstand these severe conditions.