Development of a Filter Loss Reducer for Palm Oil Base Drilling Fluid

Palm oil has the advantages of good biodegradability, low cost and being environmentally friendly. It can be used as the base fluid of oil base drilling fluid. Palm oil has different components and molecular structures than those of diesel oil and white oil, and filter loss reducers presently available for use in conventional oil base drilling fluids cannot be used in palm oil base drilling fluid, and it is thus necessary to develop filter loss reducers special for use in palm oil base drilling fluid. Dry method, wet method and chloroformylation reaction were used to prepare and optimize filter loss reducers for palm oil base drilling fluid. Evaluation of the performance of the optimized filter loss reducer indicated that a filter loss reducer FLA made from SAA-6 (an organic modifying agent) and sodium humate through ionic adsorption reaction (wet method) had the best performance. FLA had colloidal coefficient of 92% in palm oil drilling fluid, and the optimum reaction conditions for the production of FLA was 95℃, 2 h of reaction time, and ratio of sodium humate to SAA-6 of 5.5. A palm oil drilling fluid treated with 5% FLA had API filtration rate of less than 4 mL and yield point of about 8 Pa, demonstrating good filtration behavior. The FLA treated palm oil drilling fluid had good thermal stability; it functioned properly at 150℃, and had HTHP filter loss of less than 9 mL. Laboratory experiments showed that this drilling fluid had inhibitive capacity, lubricity, contamination resistance, reservoir protective capacity and bio-toxicity that all satisfied the needs of drilling operations. This study provides an experimental base for the application of palm oil in drilling fluids.