<![CDATA[Cementing operations in oil and gas wells require precise control of cement slurry properties to ensure successful zonal isolation. Two critical parameters—fluid loss control and setting time—significantly influence cement performance. Carboxymethyl cellulose (CMC) has been widely employed to regulate these properties; however, commercial CMC presents cost challenges for large-scale operations. This investigation evaluates the effectiveness of CMC which is synthesized from the waste of pineapple leaf fiber as an alternative additive for Class G drilling cement. The high cellulose content (69.5-71.5%) in pineapple leaf fibers indicates its potential as a cost-effective source of CMC that is compared to conventional agricultural wastes. CMC was extracted from pineapple leaves through alkaline delignification and chemical modification. The slurry of class G cement was formulated with varying CMC concentrations ranging from 0% to 0.4% by weight of cement (BWOC). Fluid loss was measured by using LPLT filter press following API standards, while setting characteristics were evaluated at 40°C and 60°C by using an atmospheric consistometer. Filtrate volumes decreased from 214.69 ml to 153.94 ml as CMC concentration increased from 0.1% to 0.3% BWOC, with all values conforming to API specifications (150-250 ml) for primary cementing. Commercial CMC from literature demonstrates comparable filtrate volumes of 160-180 ml at similar concentrations. Setting time was extended from 329 to 362 minutes at 40°C and from 188 to 266 minutes at 60°C with 0% to 0.4% CMC addition. Temperature significantly influenced hydration kinetics, with elevated temperatures accelerating cement setting regardless of CMC concentration. Pineapple leaf-derived CMC demonstrates comparable performance to commercial additives in controlling fluid loss and extending setting time in the systems of Class G cement. The optimal concentration of 0.3% BWOC provides adequate fluid loss control while maintaining acceptable setting characteristics. Further validation under high-pressure, high-temperature (HPHT) conditions and field-scale implementations are recommended.]]>
