Experimental Analysis of Persea americana as Filtration Loss Control Additive for Non-Aqueous Drilling Fluid

Abstract

Persea Americana is well known for its short shelf life while the seed is widely considered a waste material by domestic consumers and industry processors. This paper presents the results of the study carried out to evaluate the possibility of using three parts of the Persea Americana namely: its seed, a combination of the Persea Americana seed and its pulp and the Persea Americana pulp as filtration loss control additives in a non-aqueous drilling fluid while using Sodium Asphalt Sulfonate as a control. The evaluation was conducted under high pressure, high temperature (HPHT) static filtration test conditions (at 250°F and 500 psi) based on American Petroleum Institute Standard. From the study, the result showed that all three samples from the Persea Americana fruit showed good potential to control filtration loss when used to formulate a synthetic oil based mud. The filtration control capacity increased as their concentration in the mud was increased. However, in comparison, the pulp was 2.5 times and 1.5 times more efficient in controlling filtration loss when compared to the seed only and the seed and pulp combination respectively. Also, in terms of filtrate volume and filtered cake thickness, an equal concentration of Sodium Asphalt Sulfonate and the proposed additive gave good results; but the existing filtration loss control additive is slightly better than the proposed one. The low fluid loss volumes recorded with Persea Americana as fluid loss additives at HPHT conditions is an indication of its stability at elevated temperature conditions. The cake thickness was thin, impermeable and 1mm in size for all the samples of the Persea Americana. This meets the API requirement of mud cake thickness of less than 2mm.