Baselining and Reducing Air Emissions from an Offshore Drilling Contractor’s Perspective

In recent years, global climate change and local air quality have become some of the most pressing environmental concerns. These concerns have led to collaborative international efforts to reduce the concentration of greenhouse gases and criteria pollutants. Greenhouse gases include carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) that occur naturally and as the result of human activity. Criteria pollutants include emissions of nitrogen oxide, sulfur dioxide, carbon monoxide, and total unburned hydrocarbons. Drilling contractors can play an important role in environmental stewardship by reporting carbon emissions from drilling operations, eliminating redundant emission measurements, and leading the industry in efforts to reduce these emissions.

Noble Corporation is proactively pursuing methods to manage and reduce greenhouse gases and criteria pollutant emissions, improve diesel engine efficiency, and reduce diesel consumption as a means of lowering emissions. This paper presents Noble’s current environmental initiatives and successes to date, including:

• The completion of a three-year base line inventory of greenhouse gas emissions from its drilling units worldwide—a first in the drilling industry

• Voluntary participation in the EPA Climate Leaders program, a greenhouse gas emissions monitoring and reduction program

• Noble’s strategy for setting targets for reducing the amount of greenhouse gases produced by its offshore drilling operations and improving diesel engine efficiency through new diesel-injection technology

• Implementation of a new rig-engine efficiency program, which has led to the reduction of nitrogen oxide (NO_x) emissions by 30% and fuel consumption of 2%, a cost reduction that will amount to an average of $5,000/year for each engine.

To establish a base line of greenhouse gas emissions, Noble used ChevronTexaco’s SANGEA™ Emissions Monitoring Software and equipment specifications to calculate greenhouse gas emissions retroactively and establish methods to measure greenhouse gas emissions going forward. In addition, Noble is measuring the output of criteria pollutants using Continuous Emissions Monitoring System (CEMS) technology and is evaluating the performance and durability of the technology in harsh offshore conditions, with the ultimate goal of installing gas analyzers on all of its offshore assets.

Reducing its fuel consumption not only reduces emissions of greenhouse gases and other pollutants, it promotes a cleaner workplace and allows Noble to pass along fuel cost savings to its customers.