The use of palm oil fatty acid methyl ester as a base fluid for a flat rheology high-performance drilling fluid

Exploration for oil and gas in increasingly difficult environments is constantly fueled by rising world energy demand. Exploration is now extending into environmentally-sensitive regions, particularly in offshore fields. Oil and synthetic-based muds have always performed better with hostile drilling cases. However, they are also a cause for environmental concern and potential long-term liabilities for damage caused by mud spills, and are associated with problems in disposing of oil-contaminated drill cuttings. In response to these concerns, the oil industry has been replacing high-aromatic oils (e.g., diesel) with low-aromatic mineral oils as well as synthetic oils. One of the possibilities in avoiding these problems, while keeping the advantages of oil-based muds, is to substitute mineral oils with biodegradable vegetable oils. In this paper, it is shown that palm oil fatty acid methyl ester is successfully used as a base fluid for a high-performance, oil-based flat rheology drilling fluid. The performance of this newly formulated vegetable oil-based drilling fluid is compared to that of commercially available oil-based drilling fluids to evaluate the potential of their use. Fluid samples were formulated up to 18 ppg density and passed contamination tests. The formulated fluid was also statically aged and hot rolled for performance tests. The resulting drilling fluid is an environmentally-friendly fluid suitable for environmentally sensitive areas. The fluid testing results are then used to perform hydraulic simulations to estimate the fluid performance in the field.