RIASSUNTO
Abstract
Decommissioning of offshore oil and gas production facilities in California has always been and will continue to be a controversial and hotly debated topic.This Decommissioning has been occurring since the early part of the 20th Century and most recently involved four offshore platforms, a pier, and an island in State waters.It also involved the abandonment of over 23 sub sea wells and associated debris off the Santa Barbara, California Coast.Much was learned from these many decommissioning projects, and organizations were formed to coordinate future decommissioning projects and discuss alternatives. This presentation will summarize the lessons learned from past decommissioning projects, future projects and options available for future projects.There will be a discussion on the positions of the public, environmental communities and government on the approval process, facility removal process and final disposition of the facility.Focus of the presentation will be on the process that could be used to develop viable decommissioning options.
Introduction
The purpose of this presentation is to provide information about decommissioning of offshore California facilities from the early 20th century to today, and to explain actions now being taken to insure acceptable decommissioning practices in the future.It will not discuss the economics related to offshore decommissioning nor will it take a position regarding decommissioning.
Development of offshore oil and gas in California began early in the 20th century with the drilling of wells from piers set off the Central California coast.Many of these wells were drilled before the regulations concerning drilling and abandonment were as comprehensive as they are today.The first offshore field in the United States was at Summerland in 1894.Many piers, some of which are shown in figure 1, were set between 1894 and 1903 from which to drill wells. In the early 1900s, offshore facilities were usually decommissioned because of deterioration of the piers, fires, or storm damage. Early development of onshore oil and gas wells in Ventura and Santa Barbara Counties was not accompanied by adequate policies or techniques for abandonment or decommissioning of the onshore oil and gas structures (Muller 1997).The same was true for offshore.This is creating a problem even today because of the potential for oil to leak from improperly plugged wells and debris left on the ocean floor.
These practices are not acceptable today.The California State Lands Commission (CSLC), is responsible for leasing and management of mineral resources on State waters.The CSLC's jurisdiction includes sovereign tide and submerged lands adjacent to the coast and seaward to three nautical miles. This state agency did not exist until 1938 and did not lease offshore land for the installation of an offshore oil and gas development facility until 1954 with the construction of Belmont Island/platform, shown in figure 2, in waters off the Southern California Coast.Prior to that time many wells had been slant drilled from the coastline to offshore or from piers. Leases issued for the development of oil and gas from offshore facilities generally provide that, at the election of the state, the facilities must be removed and the surface of the ocean floor restored.
Participants in Decommissioning
There are many parties that have a stake or are interested in the practices used for decommissioning offshore structures:the State of California because the state owns the land up to three miles from the coastline, the Federal Government and the Minerals Management Service (MMS) because the Federal Government manages the land seaward of the three mile limit, environmentalists because of their concern about damage to the environment including marine life, local government agencies because of the impact to onshore residents, and the public because of conflicts with their use and enjoyment of the ocean. In California, many of the offshore facilities are close to land and highly visible.Thus decommissioning has become a very controversial issue because of past practices, the impact of facility decommissioning on the public, the impact upon the marine environment and other factors.