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●“magic”

PERFORMANCE MAKES THE CASE get it is a hydrocarbon and you have to use the same care and handling.” FOR ENVIRONMENTALLY FRIENDLY The olefin muds have a higher flash point of 116 C compared to between 66 C and 76 C for DRILLING MUD BY ELSIE ROSS diesel-based muds, making it a safer choice. While BP manufactures two olefin products, the Amodrill 1400 fluid (isomerized tetracedene C-14) BP PETROCHEMICALS ALWAYS knew its metres compared to 280 hours using a diesel- is more suitable for Canadian winters because it patented Amodrill olefin drilling fluids had a based mud. At Noel, the average drilling time to has a lower pour point (the lowest temperature lot going for them from an environmental and 2 500 metres was cut to 245 hours for the olefin at which it will pour) of -35 C to -40 C. health and safety perspective. Originally mud compared to 425 hours for its competitor. However, the synthetic oil-based muds also designed to address concerns about “When you are working with diesel, at about come with a higher price tag — double that of degradation in offshore operations, the products 2 000 metres there is an inflection point and the cheaper diesel products. That premium, had low toxicity and rapid land reclamation all of a sudden it starts to a lot slower,” though, can be more than offset by shorter potential compared to diesel-based muds. says Palm. drilling times and lower remediation costs down But what has really been attracting attention Amodrill fluids — clear, odourless products the road, Palm suggests. is its performance for land-based drilling, espe- with an aromatic content of less than 0.001% The C-14 olefin “is a lot easier to deal with cially in deeper, harder rock formations, says — are made from ethylene compared to the than diesel cuttings, which are much more prob- Joe Palm, BP manager for linear alpha olefins diesel and mineral oil fluids that are refined lematical to deal with and have major effects (LAO). “Health and safety improvements do not from crude oil. As such it offers a “much nicer on ,” says Suzanne Visser, a research asso- mean as much unless people are drilling the environment” for rig workers as they are not ciate and adjunct professor in microbiology at ,” he says. exposed to volatile organic compounds such as the University of Calgary. Diesel-based muds and Two years of trials of the synthetic olefin diesel and benzene. “One of the drillers turned drilling cuttings typically are characterized by fluid in the Noel and Wapiti areas of northeast- to me and asked me ‘What is this magic stuff?’” extreme toxicity in the environment that can ern British Columbia and northwestern Alberta Palm recalls. But that quality can create its own persist following . “Diesel needs showed the synthetic oil-based mud drilled more problems. “It is so clean and so nice people for- to be incubated for a long time before it than 50% faster in shales (greater than 15,000 psi compressive strength) than conventional diesel muds with similar properties. The trials NEED FOR SPEED used the same mud properties, drilling parame- In hard rock ters and bits. drilling tests against two of “The benefits are seen most in deep wells its competitors, and when they go into hard rock,” says Palm. Amodrill fluid “The harder the rock, the better the rate consistently improves.” Below 2 000 metres (6,561 feet), led to faster the rate of penetration (ROP) increased by an drilling times. average of 84% and below 2 500 metres (8,202 feet) ROP surged 117%. The total drilling time for one was reduced to 17 days from 26 days, he says. “That amounts to real money when you’re paying $40,000 to $50,000 a day for equipment.” At Wapiti, of the seven wells drilled between 2000 and 2004, wells using an olefin mud took an average of 165 hours to drill to below 2 500

1 New Technology Magazine ◆ December 2004 www.ntm.nickles.com drilling&completions

completely detoxifies,” she says. there was 96% degradation after 28 months. In laboratory and field studies of the drilling results showed 99% degradation fluid Visser found LAOs degrade extremely rapidly over 36 months, meeting regulatory release lev- and any residue, usually very small, is non-toxic els. However, for the best results, cuttings must to organisms. Because there are little or no be properly incorporated in the and fertiliz- volatiles associated with the olefins, they offer a er added, she said. reduced health and safety risk compared to the Field data at the land farm site also support- diesel-based muds, she says. ed lab results that showed no impact on barley In her bioremediation research, Visser evalu- growth after degradation to one per cent LAO. ated the biodegradability of diesel and synthet- While survived at all concentrations ic-based fluids and their toxicities to flora and their growth and reproduction was affected at fauna. These included three types of plants that level. along with earthworms and springtails, small Studies of co- piles in northeastern soil-dwelling insects that are extremely suscep- B.C. by Newpark Environmental Services found tible to LAO. The application of linear alpha that the Amodrill olefin-based drill cuttings olefin along with isomerized olefin and isomer- reached regulatory release rates faster than ized tetradecene stimulated the most microbial conventional oil-based cuttings. Co-compost- activity, demonstrating they were the most ing involves mixing drill cuttings with wood degradable, she said in a paper presented to a fibre, and some soil to facilitate the Society of Engineers conference on natural of contaminants. health, safety and the environment in Kuala Researchers found olefin cuttings reached Lumpur, Malaysia. release levels of less than 0.1 extractable petro- In the laboratory, the very rapid rise in respi- leum hydrocarbon within 32 months, less than ration rates of olefin cuttings in soil is strong half the time it takes for wells drilled with con- evidence these fluids are available to be used by ventional oil-based muds. At that point, regula- GREEN SOLUTION Top: Bioremediation field studies the microbial biomass for growth and reproduc- tors would no longer consider the piles waste indicated rapid degradation of tion, according to the paper. The linear structure but simply wood chip piles. Amodrill drilling fluids when of the relatively short carbon chain length of The piles were ready to spread in the fall of fertilizer is added. the isomerized olefin made them readily avail- 2003 at hydrocarbon levels of around 0.5%, but Bottom: Barley growth was able for microbial degradation, Visser suggested. BP decided to continue the study. The piles unaffected after degradation to The study found that in the laboratory, there remained about 20 C above ambient temperature, one per cent linear alpha olefins. was almost complete degradation (96% to 97%) indicating continuing degradation to even lower of the C-14 LAO olefin cutting in the soil after levels, which was confirmed this past summer three months, says Visser. At 0.25% LAO, the when a reading below 0.1% was recorded in one reproduction was higher than the of the treatments. control sample due to the increased mass gener- Commercial interest in Amodrill products ated from the olefins degradation. has picked up over the past year and a half as Based on the barley, lettuce and root elonga- operators have begun to hear about its drilling tion assays, only the alpha olefin, isomerized performance, according to Palm. BP Canada has olefin and isomerized tetradecene would exhibit decided this drilling season that when it has to little or no toxicity following bioremediation, use an oil-based mud it will use the synthetic the study concluded. It noted that toxicity of olefins obtained through a service company. diesel to lettuce and root growth This year three different service companies are increased following bioremediation, suggesting using the Amodrill 1400, he says. the toxicity may be caused by metabolic prod- ucts produced as a result of the degradation. CONTACTS FOR MORE INFORMATION Further study is needed in that area, says Visser. Joe Palm, BP, Tel: (630) 961-7887 A field study showed a slower rate of degra- Suzanne Visser, University of Calgary, dation than in the lab. When C-14 LAO cuttings Tel: (403) 220-6375, were tilled into the soil and fertilizer added, E-mail: [email protected] www.ntm.nickles.com New Technology Magazine ◆ December 2004 2