RECONFIGURING A CALIFORNIA PLATFORM FOR OFFSHORE CRUDE DEHYDRATION AND WATER DISPOSAL VIA INJECTION

Venoco Inc. operates Platform Holly off the California coast near Goleta. Produced fluids from Holly were historically transported to the Ellwood Onshore Facility for separation and processing. To reduce operating costs and GHG emissions, Venoco undertook a program to reconfigure the platform so that oil could be dehydrated offshore and produced water injected into wells directly from the platform. The Holly platform is compact in design, so the challenge was to economically reconfigure the process and identify equipment for removal so an electrostatic treater could be installed. In this paper, the reconfiguration of the platform is described, starting with the production header. The service of several vessels was changed. The production separators were upgraded to provide initial 3‑phase separation and allow wet oil to be dehydrated in the new treater. Three test separators were removed, an acid surge drum was converted first to a water skimmer and then converted to a test separator, and a surge vessel was converted to a water skimmer. State‑of‑the‑art internals were utilized in all vessels to improve both performance and capacity. Three PD water injection pumps were installed and three wells were converted to water injection service. A laser‑scan was performed in order to generate a 3‑D model of the existing platform and develop the design for the new piping. The 3‑D model provided guidance for the actual installation of the new treater and identified spatial conflicts. The model facilitated both demolition of old piping and the efficient installation of new piping with a minimum amount of rework and shut‑down time.