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New Data Shows BP's Amodrill Olefin Drilling Fluid Is More Environmentally Sound Than Conventional Oil-Based Fluids
The data demonstrate that the Amodrill-based mud biodegrades faster, while providing a number of other environmental improvements, including lower toxicity, BP said. The results were unveiled at the SPE International Conference on Health, Safety and Environment in Oil & Gas Exploration & Production in Calgary.
Suzanne Visser, environmental microbiologist and faculty member at the University of Calgary, headed up the research team that measured the total extractable hydrocarbons and toxicity of soil samples containing each of the drilling fluids. Bioassays, conducted over a three-month period, showed better seed germination and total degradation for the Amodrill, compared to samples containing the oil-based fluids. At the same time, the Amodrill sample had zero levels of earthworm toxicity after 90 days.
Data also show that Amodrill muds convert to CO2 and water by-products -- and biomass that enriches the soil. Calculated to total biodegradation time, wells drilled with Amodrill-based muds biodegrade in two to three years, less than half the time it takes for wells drilled with conventional oil-based muds. In fact, four Canadian wells, which became Amodrill test sites just over two years ago, are nearing release point now.
Other environmental benefits of the synthetic fluid include reduced exposure to fugitive emissions of aromatic compounds, low volatility, high flash points (above 100 degrees Celsius) and less odour.
The environmental test data comes after an initial report (November 2003) demonstrating Amodrill's significantly improved rates of penetration (ROP) in hard rock. After two years of land-based drilling trials, testing showed that in rock with greater than 15,000 psi compressive strength, the Amodrill mud drilled more than 50% faster than conventional oil-based muds with similar properties. The trials showed that at greater depths, the rate disparity increased even more: below 2 000 metres (6,561 feet) ROP increased by an average of 84%, and below 2 500 metres (8,202 feet) that number jumped to 117%.
The Amodrill fluid is clear, colourless, water-white, mobile and more than 99% olefinic. Two grades of the fluid are available for land drilling: Amodrill 1400 and Amodrill 1410. The latter has a pour point as low as -34 Celsius (-29 Fahrenheit), and both grades have a high flash point at 116 Celsius (240 Fahrenheit). This high flash point and the fluid's lower volatility and odour make Amodrill safer for onsite workers.
