Experimental and factorial design analysis of viscosity and fluid loss control of water-based mud treated with pineapple leaves

Abstract

The cost of oil and gas drilling fluids with their chemical additives is fairly high above the total well cost. It is imperative that mud engineers find cellulose-rich agro wastes local alternatives to cut down costs. In this work, we analyzed the effect of pineapple leaves as a cheaper and more environmentally friendly alternative additive on certain drilling fluid properties. Laboratory analysis and Factorial Design of Experiment (FDE) were carried out to study the effect of Pineapple leaves (PL) on water-based drilling mud’s viscosity and fluid loss at an ambient temperature of 29 °C, and pressure of 100 psi. Full 2³ and 2⁴ FDE which consider aging; the concentrations of Carboxymethyl cellulose (CMC) and PL; fluid loss time are independent variables while viscosity and fluid loss are the response variables that were managed. The main and interaction effects were investigated. Results showed that pineapple leaves are slightly acidic and cannot completely replace CMC. Combining it with CMC yields a better viscosity and fluid loss property. 1 g of CMC combined with 10 g of PL in a barrel of drilling mud gave a filtrate volume slightly higher (9%) than the control mud with 2 g CMC only, whereas, combining 5 g/10 g of PL with 2 g CMC reduced the filtrate volume by 5 and 24 %, respectively, making PL a good complementary fluid loss agent. Analysis of the main and interaction effects from factorial design also revealed that the PL and its interaction with CMC contribute about 30% to viscosity and prevented fluid loss by 5%. A plot of the plastic viscosity and fluid loss volume of samples containing 10 g of PL and varying CMC concentrations showed that combining the two additives in a CMC to PL ratio of 1.5:10 yielded mud properties comparable with the control mud. The volume of PL agro-wastes was also reduced.