API TR 1152-2013 pdf download.Industry Recommended Subsea Dispersant Monitoring Plan Version 1.0.
This document describes a proposed method for monitoring the efficacy and character of subsea dispersant injection to inform operational oil spill response decision-making and Unified Command (UC) strategies for protecting worker health and safety. It is intended to be used as a model which can be modified to meet the needs of a specific facility or incident. This plan is intended to complement the Subsea Dispersant Operations Plan, and it is imperative that effective communications be maintained between the organizational units that implement both. This plan does not address surface dispersant operations, but effective communications with units engaged in surface dispersants application and monitoring is also essential. Incident Command System (ICS) elements (i.e., Health & Safety, Simultaneous Operations, Logistics, Communications, Data Management, etc.) that may be involved in implementing various aspects of this plan include the Environmental Unit, Source Control Branch, Subsea Well Containment Group Leader, Safety Officer, and potential subordinate organizations of each. If these organizations are not physically co-located, consideration should be given to establishing liaison positions within each to ensure two way communications between operational and monitoring activities. The subsea monitoring plan proposed here is intended to be consistent with Subpart J of the National Contingency Plan (NCP) (40 CFR 300.910), and applicable National Response Team (NRT) and Regional Response Team (RRT) guidance, plans, or requirements. This document is intended to supplement, not replace, existing RRT pre-authorizations and the Special Monitoring of Applied Response Technologies (SMART) protocols. The purpose of sampling and monitoring as described in this document are to: • Determine dispersant efficacy; • Characterize the nature and extent of subsea, or near surface, dispersed oil plumes; and
Introduction Subsea dispersant injection has not been integrated into standard industry references on dispersant operations as it is a relatively new concept. The basic operations are as follows: • A surface vessel carries and supplies dispersants to the spill site. • Dispersant is injected from the surface vessel through a line that is connected to a nozzle held at the spill source by a Remotely Operated Vehicle (ROV). • The ROV positions the nozzle to directly inject dispersant into the flow of oil as close to the release point as possible. If possible, the nozzle should be inserted into the release point to inject dispersant into the oil before it discharges to the environment. • Dispersant is pumped at a controlled rate from the deck of the surface vessel through the nozzle and into the oil. • Increasingly, well-capping structures are being equipped with dispersant injection ports built into them facilitating dispersant application in some instances. This monitoring plan is adaptable and applicable to this type of subsea injection as well. The subsea dispersants monitoring program is designed to complement the dispersant application program and is divided into three sections, organized chronologically, and in increasing level of complexity. Under optimal circumstances, all sections would be implemented simultaneously, but logistical considerations may require implementation in the order presented. The phased approach was developed to allow implementation of subsea dispersant injection with only Phase 1 monitoring in the event that delays in implementing more complex stages would delay injection. If this were to occur, additional monitoring would be implemented as soon as practical. The three sections that follow address dispersant efficacy, delineation of resultant dispersed oil plumes, and chemical characterization of dispersed oil in the water column.
Water column monitoring seeks to determine the location, extent, and characterization of the dispersed oil plume at depth. The extent of such monitoring increases with the length and volume of the release. Local oceanographic data together with hydrodynamic models, if available, will determine the likely direction of movement of the sub-surface oil.