Design and Development of a Novel Fluid Loss Additive for Invert Emulsion Drilling Fluids from a Renewable Raw Material

Abstract

Commonly used fluid loss additives (FLAs) in today's invert emulsion drilling fluids include materials with various attributes. The unmet needs of existing materials may include: Environmental restrictions due to ecotoxicity or biodegradability concernsPerformance issues at high temperaturesOverdosing at high temperaturesHigh costsFormation damage To address these challenges, a FLA was developed for invert emulsion drilling fluids that is made from a renewable raw material and performs at high temperature and high pressure. The renewable raw material used to make this novel FLA is a biopolymer byproduct of the paper pulping process, and was chemically modified under controlled conditions to create a high-performing FLA. Detailed testing was done to determine the additive's performance in different base oils (mineral and diesel), at various mud weights (12 to 16 ppg), at elevated temperatures and in different fluid systems characterized by rheology and high-pressure, high-temperature (HPHT) fluid loss. The novel FLA was compared to other commercially available FLAs for fluid loss performance. The novel FLA outperformed or was on par with the industry available FLAs tested in this study. The novel FLA realized comparable fluid loss performance of less than 10 ml at 375 F at lower concentrations as compared to the industry FLAs. In some cases, the novel FLA performed at higher temperatures, whereas some of the industry available FLAs did not. The novel FLA also boosted the electrical stability (ES) of the emulsion in certain fluid systems. The novel FLA showed minimum change in the rheology of the oil-based fluids as compared to the industry available FLAs. The novel FLA demonstrated reasonable performance in different mud weights, base oils and fluid systems. Since this novel FLA is derived from a renewable raw material, it may have less of an environmental impact compared to other FLAs utilized today. The novel FLA: Was developed from a renewable raw material for invert emulsion drilling fluids;Performed on par or outperformed industry available FLAs; andBoosted the ES of the emulsion for certain fluid systems.