SS: Santos Basin's Pre-Salt Reservoirs Development: The Way Ahead

Abstract

This paper describes the current studies for the future development of the Pre-Salt reservoirs operated by Petrobras in the so called Santos Basin Pre-salt Cluster, offshore Brazil, in deepwater. The development of the whole area was divided in three phases:Dynamic Information Gathering Phase, composed of Extended Well Tests (EWTs) and Production Pilots. The EWTs will be implemented in parallel with the exploratory appraisal campaign and intends to evaluate the long term production behavior of the wells and the reservoir, as well as the fluid lift and flow assurance. The Pilot Projects, to be implemented after the EWTs in some areas, as in Tupi, will anticipate production and injection (water and/or gas+CO2) information, resulting in a better understanding of the secondary recovery mechanisms and reducing the risks of the future development systemsPhase 1, extending to 2017, will comprise conventional subsea completion systems and, wherever possible, standardization of the FPSO hulls and respective topside equipment, as usually done with the wells and subsea equipment applied in the development projects. In this phase many uncertainties will be still present, and the production systems will be planned to provide flexibility for different reservoir drainage solutions.Phase 2, which will consider non-conventional solutions, starting no later than 2017. Some of the concepts under evaluation by Petrobras are: the use of dry completion units; gas processing hubs; floating liquefied natural gas; digital field management; oil transportation through pipelines; gas storage in caves in the salt layer; EOR in selected areas considering the CO2 captured from the associated gas of neighboring areas, among others. One of the most important issues to support the development plans is logistics. In the remote Pre-Salt cluster, all areas related to the production will also have to be planned in advance, such as: hiring and training new employees, construction of onshore basis, transportation schemes (boats, helicopters), oil transportation and refining strategy, gas transference and commercialization strategies and other topics. Regarding the supply of the long lead items, it comprises the acquisition or leasing strategy of the critical production systems such as rigs, floating production units, pipeline laying vessels, flexible and rigid pipelines, X-mas trees, among others. INTRODUCTION The area known as the Pre-Salt Cluster, in the Santos Basin, is located in ultra deep waters, between 1,900 and 2,400 m, approximately 290 km offshore the Rio de Janeiro Coast, Southeast Brazil. Figure 1 shows the main blocks of the Pre-Salt cluster, currently in the Appraisal Plan Phase. The structure was created around 160 millions years ago, when the supercontinent Gondwana began to break apart, giving place for the South American and African continents. The rift phase created the conditions for the deposition of sediments on the trough between the two continents. The rift phase created the conditions for the deposition of sediments on the trough between the two continents. As the separation continued, the sea water began to fill the space, creating a low energy and high salinity environment, propitious to the growth of special bacterial colonia, such as the stromatolites. The secretion of these microorganisms, together with the precipitation of carbonate salts, created nucleus to form carbonate rocks, known as microbialites, where the oil in the Pre-Salt was discovered. Later on, due to the severe climate change on Earth, the salt dissolved in the sea water in this low energy environment precipitated, forming a thick salt layer that became a perfect seal for the hydrocarbon that migrated to the microbialites.

Interactions between Clays and Carbonates in the Aptian Pre-Salt Reservoirs of Santos Basin, Eastern Brazilian Margin

“…The giant oil and gas accumulations in Aptian lacustrine reservoirs in eastern Brazilian basins and their western African counterparts along the South Atlantic conjugate margins, known as the Pre-salt deposits [1][2][3][4][5][6], represent some of the most important discoveries of this century. These rocks represent a unique combination of calcite aggregates, magnesian phyllosilicates, dolomite, and silica.…”

Nanoparticle-based Magnetic Induced Heating for Oil Well Cement Slurries: Experimental Study and Modelling Development

“…The well's total depth can reach 7000 meters, with layers consisting of approximately 2000 meters of water, followed by rocks and salt. The upper pressure limit can reach around 90 MPa, while the maximum temperature of the formation can vary between 60 and 70°C (Filho and Almeida 2009;Pizarro and Branco 2012).…”

Experimental study of the effect of carbonated brine on wettability and oil displacement for EOR application in the Brazilian Pre-Salt reservoirs

“…The Brazilian carbonate Pre-Salt fields, which are among the greatest oil discoveries of the last decades, are natural offshore candidates for the application of EOR/CCS. Lula Field in Santos Basin contains 8.3 billion barrels of oil equivalent reserves (Formigli, Pinto, and Almeida 2009) with 28 °API oil, high salinity (23%) brine and gas to oil ratios (GOR) of up to 27 scf/stb with CO 2 concentration up to 12% (Pepin et al 2014;Pizarro, De Santanna, and Branco 2012). The main features for the application of CCS in Lula Pre-Salt field were presented elsewhere (de Almeida et al 2010).…”