Establishing an Environmental Performance Standard and Waste Management Toolbox for Offshore Drilling Discharges

摘要

Chevron Global Upstream has developed a global environmental performance standard and a computer-based waste management toolbox with the overall objective of reducing the potential for impacts from drilling fluids and associated cuttings in the offshore environment. The drilling discharge standard establishes minimum environmental performance requirements for offshore drilling projects. Requirements include no discharge of whole non-aqueous drilling fluid and drilled cuttings containing mineral or diesel oil. In addition, the standard requires the use of cuttings dryers and centrifuges when cuttings containing synthetic drilling fluids are discharged. A unique feature of the standard is the requirement that all ffshore drilling projects undergo an environmental screening evaluation prior to discharge of muds and drilled cuttings. The screening evaluation considers a set of drilling, toxicity, biodegradation, and oceanographic data to assess whether a given drilling project has the potential to have an ecolog ical impact. If this evaluation indicates a potential for impacts, steps must be taken to further understand the potential for impacts and, if necessary, mitigate them. Mitigation options might include selecting alternative drilling fluids, instituting additional treatment of the cuttings, reducing the total discharge cuttings volume, or seeking alternatives to discharge. To support implementation of the standard and help drilling engineers make the best drilling waste management decisions, a toolbox has been developed to evaluate and optimize waste management technology alternatives for offshore projects. The toolbox possesses a user-friendly computer-based interface that allows the drilling engineer to evaluate and select the most appropriate waste management technologies for their project based on drilling technical requirements, environmental performance, regulatory requirements, and cost. The overall integration of the drilling waste management toolbox and the environmental performance standard provide drilling operations with an enhanced combination of reduced risk to the offshore environment and cost-effective waste management technology.