Impact of hydroxypropyl guar polymer on rheology and filtration properties of water-based drilling fluids

Water-based drilling muds (WBM) are a very crucial component of the oil and gas industry; however, they often face challenges with inadequate rheological performance and excessive fluid loss. This paper introduces hydroxypropyl guar polymer (HPG) and fly ash (FA) as new additives to regulate the rheological properties and filtration loss of WBM. The primary objectives of this study are to reduce filtration loss, enhance rheological characteristics, reduce clay swelling, improve cutting dispersion, and control barite sag. The experimental procedure involves formulating optimized mud samples by incorporating HPG and FA up to 120 °C. The synergistic effect of HPG and FA enhances rheological properties and achieves a 56.52% reduction in filtration loss compared to WBM without additives. Additionally, HPG/FA incorporation resulted in controlling the clay swelling. The swelling dropped from 91.5% to 36.7% compared to the base mud. Shale cuttings recovery in the base fluid was 52.4% after hot rolling at 90 °C, 60 °C, and 40 °C for 16 h and treatment with 0.18% HPG inhibitors improved recovery to 82.1%, 54.1%, and 57.2%, respectively. The sag factor remained controlled compared to the base mud, staying within the acceptable range of 0.503–0.521 at both vertical and 45° inclined angles. The WBM with the addition of HPG and FA is more efficient and has enhanced the well integrity and reduced operational costs in the oil and gas industry. • HPG polymer act as a multipurpose additive in water-based drilling fluids. • The synergy of Hydroxypropyl Guar Polymer and Bentonite Clay improves rheology. • Bentonite, HPG polymer, and fly ash interact to form a strong filter cake that seals the permeable formation. • HPG effectively inhibited clay, significantly reducing swelling.