Loop Metering And Proving Systems
Authors: Raine W. , Jakubenas P.P. , Menefee W.F. 
Published: October 2008

The Louisiana Offshore Oil Port (LOOP) project will be the first deep water port constructed in the United States for the importation of foreign crude oil. The port facility will be located in the Gulf .of Mexico southwest of Grand Isle, Louisiana. The LOOP Deep water port will be able to unload ships up to 700,000 DWT via single anchor leg mooring (SALM) systems, a pumping platform complex (PPC), and submarine pipelines directly into underground storage cavities located onshore at Clovelly. From the onshore terminal, pipelines will distribute the crude oil to various parts of Louisiana and the Midwest. High accuracy flow measurement by turbine meters will be a key feature of the operation of the deepwater port because of stringent line surveillance and custody transfer requirements. The paper describes the design and operation of the skid-mounted metering and proving systems that will measure flow rates up to 100,000 BPH with a very high degree of accuracy, resolution and reliability. The metering systems will be installed at the inlet and outlet of each pipeline with online provers to allow meter factor calculations at any time during unloading operations. The paper also describes the portable calibration equipment that will be provided for offline checking of the main system provers and the state-of-the-art methods that will be employed for accurate sampling of the crude oil and automatic computer control of the metering and proving facilities.

INTRODUCTION

The LOOP facilities are being developed by a consortium of major oil companies and it is the first facility in the United States designed specifically for unloading very large crude carriers (VLCC's).

It is licensed and is being constructed under design criteria approved by the Louisiana Offshore Terminal Authority and the Department of Transportation. Full operation of the facility is planned for 1981.

The facilities comprise a Marine Terminal, a booster pump station at Fourchon, a salt dome storage terminal at Clovelly, an operations control center at Galliano and headquarters at New Orleans, Louisiana. Figure 1 shows the relative locations of the facilities. The Marine Terminal is located approximately 18 miles offshore in 115 feet of water. It consists of an offshore unloading complex of SALMs, 56 inch submarine pipelines, pumping platform and control platform. The metering system is located on the upper deck of the pumping platform as shown in Figure 2. The crude oil is transported through a 48.inch diameter submarine pipeline to the booster station at Fourchon which is located approximately 3 miles inland from the Gulf of Mexico. The crude oil is then transported through a 23 mile long 48 inch diameter buried pipeline to the salt dome cavity storage terminal at Clovelly where it is metered again before injection into the domes. Initially eight domes, each with a capacity of approximately 4 million barrels (Bbls) will be used. The operations center at Galliano is located approximately 3 miles from the Clovelly storage terminal. Additional LOOP metering systems measure the delivery from the storage terminal into connecting carriers.