Marlim Complex Development: A Reservoir Engineering Overview

Abstract

Since the discovery of the Garoupa Field in the Campos Basin, Rio de Janeiro, Brazil, in 1973, Petrobras has been moving to deeper waters. Subsea engineering and well technologies have been developed and applied to overcome the environmental restrictions. Today more than 50% of Brazil's oil production comes from fields located offshore in water depths over 1,000 m. In this scenario, the Marlim Complex - which comprises the Marlim, Marlim Sul and Marlim Leste fields - plays an important role. Discovered in 1985, the Marlim Field started production in 1991, with a pilot system comprising 7 wells connected to a semi-submersible unit moored in a water depth of 600 m. Currently, the field production is about 85,000 m3/d (535,000 bpd), with 60 producers and 32 water injectors connected to 7 floating production units. As with other Campos Basin turbidites, the Oligocene/Miocene reservoir of Marlim Field presents 3 outstanding characteristics: predictability, from seismic data and geological modeling, excellent petrophysical properties and good hydraulic connectivity. The extensive use of 3D seismics as a reservoir characterization tool allows the reduction of risks and the optimization of well locations. Additionally, 3D visualization techniques provide a new environment for teamwork, where seismic data is interpreted and input into detailed reservoir simulation models. Among the deep water well technologies employed to develop the Marlim Complex it is worth mention: slender wells, high rate well design, horizontal and high angle wells in unconsolidated sands, efficient low cost sand control mechanisms, selective frac-pack with isolation between zones, pressure downhole gauges (PDG's), new techniques for the connection of flowlines and X-mas trees, subsea multiphase pumping and special techniques to remove paraffin in the flowlines. However, new developments are required, such as extended reach wells, selective completion in gravel-packed wells, isolation inside horizontal gravel-packed wells with External Casing Packers (ECP's), smart completion and improved recovery techniques for viscous oil. Much has been learned during the planning and development of the Marlim Field and this knowledge is currently being applied in the development of Marlim Sul and Marlim Leste fields. Some important points must always be observed:the development plans must be defined by using optimization techniques considering the geological risks;the number of wells of the initial development plan must be defined through a detailed optimization study, considering economic indicators, oil recovery and risks;the wells must be designed to allow high production rates, with "rest of life" completions, as simple as possible;the sand control mechanisms must be simple, efficient and low cost,the seismic resolution or the production data analysis must be of sufficient quality to guarantee that there will be good hydraulic connectivity between the producers and the corresponding injectors;the pipelines and risers must be designed to avoid bottle-necks or conditions for deposition of wax or hydrates andthe reservoir management and particularly the water injection system management must be made with an integrated teamwork approach. In this paper we present some aspects of the reservoir engineering and of the development plan of the Marlim Field and briefly discuss how this experience is being used in the development of the neighboring Marlim Sul and Marlim Leste fields. Introduction The Marlim Complex comprises 3 giant deepwater oil fields - Marlim, Marlim Sul and Marlim Leste - located in the Campos Basin, 110 km offshore Rio de Janeiro, Brazil (Fig. 1). Besides the geographic location, these fields have other similarities: the main reservoirs are turbidites of Oligocene/Miocene age; 3D seismic data allows accurate prediction of the reservoir occurrence; rock characteristics are excellent; relative permeabilities are favorable to water injection and well productivities are very high.

Integration of geophysical and geomechanical data to understand the depletion of the Marlim field, Campos Basin

“…The property was subject to the facies and distributed by sequential Gaussian simulation. For the interval 6 (reservoir), the parameters used for property distribution followed an N57°W rotation, which is an approximation of the turbidite system deposition direction (Figure 1), indicated by Pinto et al (2001), and anisotropy of 2. Anisotropy was not defined for the remaining intervals.…”

“…The Marlim field is located in the Campos Basin, about 150 km from the coast of the city of Macaé, Rio de Janeiro, Brazil. The reservoir has its deposition associated with eustatic sea-level variations during the Oligocene/Miocene, responsible for forming the two main systems of turbidity flows (Figure 1) found in the field (Souza et al, 1989;Pinto et al, 2001;Oliveira et al, 2007;Pelisman and Vincentelli, 2017). It consists of a succession of amalgamated lobes and presents medium-to-fine sandstone facies, with low silt (< 10%) and clay (< 2%) content, poorly consolidated, Figure 1.…”

“…Orange and red colors represent thicker sandstones. Modified from Pinto et al (2001) and Oliveira et al (2007). and with excellent porosity (Lorenzatto et al, 2004;Johann et al, 2006;Oliveira, 2008).…”

Methods in Oil Recovery Processes and Reservoir Simulation

“…After primary and secondary recovery, oil companies have begun with more complex Enhanced Oil Recovery (EOR) processes involving fluids or chemical reactions that require a greater detail of the phenomena taking place in the porous medium. In addition to these complications there exist non-technical related factors that might increase the risk of an investment [6]. An example of this may be the development of off-shore platforms, plants located in remote areas of the world or the exploitation of unconventional deposits (heavy oil, shale oil, tar sands).…”

High-Mobility-Ratio Waterflood Performance Prediction: Challenges and New Insights

“…Waterflood has been conducted in many high-viscosity reservoirs in the past, and several water-injection projects in high-viscosity reservoirs are ongoing and planned around the world (Oefelein and Walker 1964;Jennings 1966;Roark 1960;Nelson 1976;Woodling et al 1993;Jenkins et al 2004;Adams 1982;Edgson and Czyzewski 1985;Kasraie et al 1993;Smith 1992;Lim et al 1993;Ko et al 1995;Etebar 1995;Pallant et al 1995;Foerster et al 1997;Yang et al 1998;Forth et al 1996;Yao 1999;Hanafy 1999;Cook et al 2000;Jayasekera and Goodyear 2000;Capeleiro Pinto et al 2001). However, published data on HMRWF performance are limited, and results are sometimes conflicting.…”