Factors affecting methods for biodegradation testing of drilling fluids for marine discharge
- and others
Although general agreement was reached between the OSPARCOM (Oslo and Paris Commission) countries in 1994 regarding testing of drilling chemicals for approval for use aid discharge, there are still some practical variations concerning the implementation. In all standard environmental compliance areas, such as toxicity, bioaccumulation and biodegradability, there has been, or is, some concern about the reassessment of change. It is only recently that an agreement has been reached on test species for toxicity assessment of drilling fluids and chemicals for North Sea discharge. Regarding approval for the use of synthetic based muds (SBMs), biodegrability has probably been the most controversial issue with respect to the test methods, test results, acceptable degradation rates and overall environmental impact. Drilling fluids A in SBMs have low water solubilities and arc adsorbed onto drill cuttings. They are known to enter the marine sediments and will, in high concentrations, and when they are buried under a layer of cuttings or under sediments, accumulate in anoxic marine sediments. OSPAR has therefore required that both aerobic and anaerobic biodegradation test results be available for the base fluids of SBMs. Presently, a seawater biodegradation test protocol has been developed into an OECD Guideline for water soluble materials, but no standard test protocol has been agreed upon for poorly or non-water soluble materials. This is the case both for aerobic or anaerobic biodegradation tests. For the aerobic biodegradation test, several attempts have been made to come up with a standard seawater test, but presently different laboratories use different protocols. Small differences in existing test protocols for aerobic seawater tests have resulted in great variations in test results obtained between different test laboratories.
- OSTI ID:
- 414782
- Report Number(s):
- CONF-960623-; TRN: 96:004555-0084
- Resource Relation:
- Conference: International conference on health, safety and environment in oil and gas exploration products, New Orleans, LA (United States), 9 Jun - 12 Sep 1996; Other Information: PBD: 1996; Related Information: Is Part Of The third international conference on health, safety & environment in oil and gas exploration and production. Proceedings - Volume 2; PB: 934 p.
- Country of Publication:
- United States
- Language:
- English
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