The Marlim Field Development: Strategies and Challenges

Abstract

Abstract The Marlim field was discovered in February 19859 by the exploratory 1 RJS 219 A drilled in a water depth of 850 meters. This pushed the deepwater exploratory campaign culminating in several deep and ultra-deep water discoveries in Campos Basin. The necessity to overcome the environmental conditions, associated with a giant field located in high water depth and reservoir characteristics, were the main challenges in the search for new technologies in the way to operate the field. These developments were achieved by a research program created at Petrobras R&D Center. This program counted on Petrobras expertise acquired during Campos Basin development and with traditional oilfield equipment suppliers through technological agreements that led to the first oil in March 1991. The field extension and the reservoir characteristics required a large number of subsea wells and, consequently, several production platforms, so the development plan was based on the implementation of several phases in different periods. This model, also used in several other developments in Campos Basin, allowed that the required huge investments and resources to be distributed along the field development. Moreover, it allowed innovative solutions to be proposed and introduced by new oilfield equipment suppliers along the project in order to optimize CAPEX. Marlim is a remarkable achievement to the oil industry that culminated with a peak production of 650,000 bopd in 2002. It also served as a laboratory for other deepwater developments offshore Brazil. With the field maturation new challenges are being faced in order to increase the recovery factor and to reduce the OPEX. This paper will provide an overview of Marlim Field, the main achievements and problems faced up to this moment to manage its development. Introduction The Marlim field was discovered in February 1985 by the exploratory well 1 RJS 219 A drilled in a water depth of 850 meters. This discovery pushed the deepwater exploratory campaign culminating in several deep and ultra deepwater discoveries in Campos Basin. Located in the northeastern part of Campos Basin, about 110 km offshore the state of Rio de Janeiro, the Marlim field is part of the Oligocene Carapebus formation and covers an area of approximately 130 Km2, in water depths ranging from 650 meters to 1,050 meters. From rock quality point of view Marlim field Oligocene reservoirs are excellent with average porosity around 30%. The reservoirs have low silt, clay and calcite content. The core analyses of various wells indicate mean permeability of 2000 mD, mean porosity of 30% and highly friable sandstone. Marlim's reservoir exploitation strategy relies heavily on water injection as a source of reservoir energy replenishing. The field development plan was based on various phases by means of subsea wells, subsea manifolds and floating production units whose development had been scheduled in different periods in order to make feasible the huge investments and resources required. It also improved the overall performance of the field development once each phase guided the next ones through the experience obtained during its own development. To support the field development, a research program was created in the company in 1986 - the PROCAP - focusing on all the technologies required to install the first Floating Production Unit for the Marlim field.