A novel approach to enhance rheological and filtration properties of water–based mud using polypropylene–silica nanocomposite

Abstract

Deeper drilling depths and high pressure high temperature (HPHT) wells require good well planning at minimum cost and unproductive time. Polymer nanocomposite has emerged as a promising additive to enhance the thermal stability of conventional water–based muds (WBMs). In this study, polypropylene–silica nanocomposite (PP–SiO2 NC) was synthesized using hot–emulsion sol–gel method. The performance of the PP–SiO2 NC in WBMs was critically examined and compared with that of partially hydrolyzed polyacrylamide (PHPA). Different characterization techniques were used to examine the morphology, structure information and thermal stability of the PP–SiO2 NC. The effect of 0.3 g, 0.6 g, 0.9 g, 1.2 g and 1.5 g each of PHPA and PP–SiO2 NC towards rheological properties, lubricity, filter cake thickness, and filtrate volume of WBM before and after thermal aging tests were studied. In addition, salt tolerance and cost analysis of the PP–SiO2 NC were evaluated. The results show that the PP–SiO2 NC has a spherical shape and a particle size distributed between 80 and 390 nm. The WBM with PP–SiO2 NC has better performance in controlling filtration and modifying rheological properties than the PHPA owing to the finely dispersed PP–SiO2 NC particles. With a concentration of 0.6 g after aging, the plastic viscosity of the PHPA mud decreased by 52.7% from 27.5 to 13 mPa s, while that of the PP–SiO2 NC mud reduced by 22.7% from 22 to 17 mPa s. Salt tolerance study showed that high concentration of potassium chloride affected the effectiveness of the PP–SiO2 NC in controlling HPHT filtrate volume. The cost analysis of the PP–SiO2 NC shows low cost of formulation. Hence, PP–SiO2 NC showed promising attributes for a good drilling mud.