Cement slurry set retarding potential of oil palm kernel shell wastes for oil well operations

Abstract

One major problem of the agro –industries in Nigeria is the management of its wastes generated from its processes. These wastes can be converted to useful products and are attractive for being an alternative to solving the disposal issues in the industry. This study assessed the synthesis of lignosulfonates from Oil Palm Kernel Shells (OPKS) and evaluated its performance as a retarder additive for oil well cementing operations. OPKS was synthesized using the pulping process and filtered to isolate the lignin from cellulose and hemicellulose. Sulfonating process was carried out using Sodium Bisulfite (NaHSO3) to produce sodium lignosulfonate. Thereafter, Fourier Transform Infrared spectroscopy (FTIR) was applied to determine the functional groups present in the synthesized product. The product was evaluated for its performance as a retarder through the thickening time test using an automated HTHP Cement Consistometer at different temperatures, concentrations and consistency (Bc). A linear increment of cement slurry thickening time up to 40% with increase in concentrations was observed in relation to a reference (commercial retarder). The results also showed that lignosulfonates from OPKS has the potential to retard the set of cement slurry, however to maximize its retardation function, more investigations needs to be carried out to purify and modify the synthesized lignin. Its utilization as a cement retarder will promote the preservation of the environment and also reduce the overdependence on expensive cement additives.