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Abstract
The Campos Basin in Brazil is one of the most challenging areas for completions in the world due to the lack of formation consolidation, the large percentage of fines present in the reservoir, the heavy oil, the low frac gradients, the low net-to-gross ratio, the low bottomhole temperatures and the requirement for pressure maintenance.

The development of the Albacora Leste Field in the ultra deep water Campos Basin was a key component of Brazil’s drive to achieve petroleum self sufficiency by 2006.

Because of the challenges presented by the heavy oil and the large geographical extension of the reservoir, the decision was made to develop the field with horizontal openhole gravel packs for both producers and injectors. Fifteen production wells and eleven injector wells were drilled and completed in the field.

As a result of the perceived technical complexity of the development, and requirement to maximize completion efficiency, the operator chose to maximize the integration of the services by bundling their acquisition from a single integrated services supplier, rather than contracting the required well construction services in a discrete manner, as had been traditionally done in the Campos Basin.

Horizontal openhole gravel packs, as planned for the development of Albacora Leste, were already an established and successful completion technique in the Campos Basin. However, the Albacora Leste wells were amongst the longest attempted in the basin, and due to the combination of the ultra deep water and limited sediment thickness, had significantly lower frac gradients than previously experienced.

The challenges of minimizing placement pressures, accurate modeling of gravel placement, rat hole mitigation, and injection well clean-up all had to be addressed. The solutions developed to meet these multiple challenges will be presented in this paper.

Introduction
With an area of 141 km² (34,842 acres) and OOIP of around 3,800 million barrels⁽¹⁾, the giant Albacora Leste field is the 4th biggest field in Campos Basin.

The field was discovered in 1986. However, at that time, the development of a field challenged by ultra deep water, heavy oil, and completely unconsolidated sands in a complex turbiditic reservoir, was beyond the technical capacity of our industry. Consequently, the development was delayed until 2002, to enable Petrobras to develop the necessary technology and expertise to meet these challenges.

In 1998, the appraisal well 4-RJS-477 was drilled and put on an extended well test (EWT). The well was completed with a cased hole gravel pack (CHGP), and the oil production pumped to a neighboring platform. This EWT required the deployment of the world's first Electric Submersible Pump (ESP) designed for use in ultra deep water.

Due to the geological complexity (resulting from a complex turbidity depositional system, mainly represented by channels, lobes and overbank facies and the action of later erosive channels) and complex distribution of fluids saturation in the reservoir, 7 pilot wells were drilled during the planning phase, prior to 2002. This pilot program led to a development plan with 16 horizontal producer wells, with lateral extensions around 650 m and 14 horizontal injector wells, with lateral extensions ranging from 650 m to 800 m. Further analysis added one producer and one injector into a new portion of the reservoir.