Campos Basin: 20 Years of Subsea and Marine Hardware Evolution

Abstract

Abstract Since 1977, when the first oil was produced to a floating rig through a test tree inside the BOP Stack (Enchova-01 well), around 30 Floating Production Systems were installed in Campos Basin, offshore Brazil. Due to the prolific geological conditions of this province, production ranges from shallow (100m) up to deep waters (1027m), demanding significant breakthroughs in the applied subsea and marine production equipment which were used for the exploitation of these fields. This paper presents the technical evolution of the associated hardware, as manifolds, umbilicals, flowlines, monobuoys and mooring systems, highlighting some milestones which made viable the achievement of the present water depth limits of oil and gas production. Their field performance is also shown and gives a real solid background for the extension of the water depth limits up to 2000m for future production systems under design/construction, not only in Campos Basin but also for other offshore sites around the world. Introduction Campos Basin is located offshore Rio de Janeiro State, on the Southeast Region of Brazil. Its area covers approximately 100sq. Km ranging from 20m up to 3400m Water Depth (WD). Environmental conditions can be considered as relative "benign"; 100 year return period conditions are:wind: 37mls;waves: 14m height/l2s period;surface current: 2.0m/s;bottom (1 000m WD): 0.8m/s. The continental shelf may be described as a flat surface with a very slight inclination (constant gradient around l°) up to water depths around 200m. Beyond this border, the gradient increases gradually up to values around 10° or more in some locations, featuring the so called continental slope. Ocean floor is generally smooth all over Campos Basin but some local canyons in water depths ranging from 400m till 1500m are outstanding. Clay sediments are predominant at the mud line with dispersed occurrences of live and dead deep water corals. The first field discovered at Campos Basin was Garoupa in 1974 through the wildcat 1-RJS-9A; in a short period of time, Namorado and Enchova fields were also discovered: these were the former evidences this area could be a prolific oil province. Based on this assumption, it was necessary to improve the exploratory efforts. At the same time, Brazilian political and economical situation demanded a significant increase in the domestic oil production using the fastest pace as possible. The traditional conception to produce fields with similar characteristics - a stationary jacket platform (eventually installed over a template with pre-drilled wells) - would demand more than half a decade for producing the first oil.