Chiew, Kah Heng, , creator author. text my 2025 2025 monographic eng xvi, 100 pages : illustrations ; The oil and gas industry face significant challenges related to wellbore instability and the environmental impact of synthetic drilling fluid additives. Water-based muds (WBM) are widely used in drilling operations, but their performance depends on effective additives that enhance rheological and filtration properties. This research explores the extraction and optimization of saponins from coconut husks as a sustainable alternative to conventional additives, leveraging their natural surfactant properties to improve WBM performance. Phytochemical screening was conducted to identify the coconut husk variety with the highest saponin content. The Soxhlet extraction method, combined with a Design of Experiments (DOE) approach, optimized extraction conditions by varying parameters such as extraction time, sample mass, and ethanol concentration. The extracted saponins were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) to confirm their chemical composition and structural properties. Results showed that the Gading coconut husk contained the highest saponin content, with a foam height of 0.4 cm. The optimal extraction conditions yielded 2.03 g of saponins using a 2-hour extraction time, 30 g of coconut husk powder, and 90% ethanol concentration. FTIR and GC-MS analysis confirmed the presence of key functional groups, including O-H, C-H, and C-O glycosides, validating the successful extraction of saponins. The application of extracted saponins in WBM demonstrated significant improvements in drilling fluid properties. Rheological tests showed an increase in the yield point (YP) to plastic viscosity (PV) ratio from 0.4 (control WBM) to 0.83–0.87 with extracted saponins, enhancing mud stability. Fluid loss was reduced from 29.9 mL (control) to 20 mL at a 0.35 g saponin concentration, outperforming commercial saponins, which reduced fluid loss to 26.6 mL. Additionally, mud cake thickness decreased from 6/32 inch (control) to 4/32–5/32 inch, while pH remained stable, with only a slight decrease from 8.93 to 8.64. Interfacial tension (IFT) decreased from 35.52 N/m to 30.76 N/m, demonstrating improved emulsification and surface activity. Lubricity tests confirmed reduced friction, though commercial saponins performed slightly better. The findings confirm that coconut husk-derived saponins enhance WBM performance, offering a sustainable alternative to synthetic additives. specialized Chiew Kah Heng Faculty of Chemical and Process Engineering Technology Final Year Report (Bachelor of Technology Mechanical Engineering (Petroleum) with Hons ) -- Universiti Malaysia Pahang Al-Sultan Abdullah - 2025 Include bibliographical reference Faculty of Chemical and Process Engineering Technology Dissertations Universities and colleges Dissertations Theses Dissertations THE0010785 (Local) https://umpir.ump.edu.my/id/eprint/47856 https://umpir.ump.edu.my/id/eprint/47856 UMPSA 260729 20260729114300.0 eng