Considerations in Reducing Risks in FPSO and Shuttle Vessel Lightering Operations
Authors: Daughdrill William H. , Clark Tricia A. 
Published: October 2008

Abstract
Some observers estimate that more than 70 Floating Production, Storage and Offloading Systems (FPSOs) are in operation worldwide. Currently, there are no FPSOs in use in the United States (U.S.) sector of the Gulf of Mexico. Recent U.S. regulatory developments have improved the chances that a FPSO will be proposed for use on the U.S. Outer Continental Shelf (OCS). Recent quantitative and qualitative risk assessments commissioned by the U.S. government have concluded that offshore lightering between FPSOs and shuttle vessels has a low overall risk of accidents and oil spills that is comparable with other offshore oil production and transportation options.
Current Coast Guard rules that apply to offshore lightering are published at 33 Code of Federal Regulations (CFR), Part 156, Subparts B and C (33 CFR 156.200 - 156.330). These requirements are general in nature and not focused on FPSO operations. In addition, the operational requirements in 33 CFR 156, Subpart C only apply to lightering operations conducted within specific areas in the Gulf of Mexico designated by the U.S. Coast Guard (USCG). Thus, a regulatory gap currently exists with respect to operational requirements for offshore lightering involving FPSOs and shuttle vessels not operating within these designated lightering areas.
The offshore marine industry now has an opportunity to help define an appropriate scheme of operational procedures for FPSO/shuttle vessel lightering. Several guidance documents produced by the Oil Companies International Marine Forum (OCIMF) and the International Association of Independent Tanker Owners (INTERTANKO) may provide flexible guidance on offshore lightering involving FPSOs and shuttle vessels. These documents summarize the experience of FPSO operators in the North Sea and worldwide and provide guidance in developing operational procedures to minimize risk. A summary of key operational procedures is provided to assist potential operators of FPSOs and shuttle vessels. The reader is referred to the actual source documents for detailed guidance in developing appropriate procedures for FPSO/shuttle vessel operations.

Introduction
For several years, the U.S. Minerals Management Service (MMS) and the USCG have been considering the regulatory and environmental issues associated with the potential use of FPSOs on the U.S. OCS. On February 2, 2001, the MMS released the final Environmental Impact Statement (EIS) on the proposed use of FPSOs on the Gulf of Mexico OCS (Central and Western Planning Areas)1. The FPSO EIS is a programmatic document developed in accordance with the National Environmental Policy Act to evaluate the potential impacts from the proposed use of an FPSO in the Western and Central Planning areas. On December 13, 2001, the MMS Associate Director for Offshore Minerals Management signed the Record of Decision for the FPSO EIS2. In it's Record of Decision, the MMS approved the conceptual use of FPSOs in the Western and Central Planning Areas of the deepwater (greater than 650 feet) Gulf of Mexico, with the exception of USCG designated lightering prohibited areas. This MMS decision increases the likelihood that an offshore operator will propose the use of an FPSO to develop a deepwater oil discovery.