Improving the performance of bentonite-free water-based mud with lignin-based biopolymer

Various drilling problems are associated with bentonite utilization in water-based muds, including formation damage, reduced production rate and overall cost. Various alternative solutions in terms of bio and synthethic based polymers have been tested to replace bentonite. However, due to their higher costs and availability, industry is looking for ecofriendly alternatives to overcome this issue. This work aims to utilize a lignin-based polymer (BioDrill FM400) for the formulation of bentonite-free mud blends with various dosages. The rheological and filtration properties were examined using the API standard procedures both at standard and high-temperature conditions. Seven mud blends with various dosages of the additive (0-12 ppb) were prepared, and mud's plastic viscosity, yield point and gel strength were measured using viscometer. Similarly, mud filtration characteristics were assessed both with API and HPHT filterpress. Three types of rock disks (0.25" thick x 2.5" in diameter) were utilized to mimic the actual pore plugging mechanism. The rheological findings showed that the PV, YP and GS were significantly improved. On the other hand, the filtrate volume and filtercake thickness were reduced by 63 and 42% for the Bandera Brown disk sample. The current formulation is useful in drilling the payzone section of the wellbore.