Monitoring the Effect of Nearshore Development and Production in the Beaufort Sea

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 98500, "Monitoring the Impact of Nearshore Development and Production in the Arctic Beaufort Sea, Alaska," by G. Durell and J. Neff, Battelle; J. Brown, Exponent; and J. Trefry, Florida Inst. of Technology, prepared for the 2006 SPE International Conference on Health, Safety, and Environment in Oil and Gas Exploration and Production, Abu Dhabi, UAE, 2–4 April. The Arctic Nearshore Impact Monitoring in Development Area (ANIMIDA) project was initiated to monitor effects of nearshore development and production in the Beaufort Sea, Alaska. This program was expanded in 2004 with the 5-year Continuation of ANIMIDA (CANIMIDA). Contaminant levels are assessed in sediment, water, and biota, and geophysical measurements are being made to determine the sources and fate of natural and anthropogenic hydrocarbons and metals. Introduction Development and production of oil and gas on the North Slope of Alaska has until recently occurred only on land. However, there is an increasing interest in developing the unique offshore environment of northern Alaska. The ANIMIDA project was a 5-year study started in 1999 to assess potential spatial and temporal changes related to oil development and production in the Beaufort Sea. ANIMIDA provided baseline data and monitoring results for potential chemical contaminants from development and natural sources, ecology, and subsistence whaling in the vicinity of the Northstar and Liberty development sites. Monitoring for Northstar included preconstruction, construction, and early production periods; development of Liberty is on hold, and monitoring there has generated baseline preconstruction data. The 5-year CANIMIDA began in 2004 to continue and expand the nearshore monitoring in this area. The CANIMIDA technical-task objectives include the following.Characterize hydrocarbon and metal distributions in sediments in the study area.Determine sources, concentrations, and dispersion pathways for suspended sediment and associated chemicals.Characterize potential anthropogenic chemicals in amphipods, bivalves, and fish, and determine bioaccumulation and biological effects of anthropogenic chemicals.Monitor the unique ecosystem and local subsistence whaling. Methods Field surveys are conducted in the spring and summer. Bottom and suspended sediment, water, and biota samples are analyzed for more than 40 polycyclic aromatic hydrocarbons (PAHs), a suite of individual saturated and total petroleum hydrocarbons, chemical biomarkers and tracers, 13 trace and major metals, and supporting geophysical parameters. Deployed blue mussels and semi-permeable-membrane devices (SPMDs) also are used as sampling devices to concentrate contaminants and assess potential for contaminant bioaccumulation. In addition, suspended-sediment transport and loading to the Beaufort Sea (primarily from rivers) are being determined, along with natural sources of contaminants that may also have anthropogenic sources (e.g., from oil and gas activities). Field work is being conducted during the relatively brief open-water season (July and August) and also during the spring high-flow and ice-breakup periods when there is a large influx of fresh water and suspended solids; the spring sampling is conducted both under ice offshore and in the major source rivers.