Abstract

Peregrino is an offshore oil field (block BM-C-7) located east of Rio de Janeiro, Brazil in the southwest part of the Campos Basin area. The oil field was discovered in 2004. Statoil Oil and Gas, Brazil has been operating the Peregrino Feld since 2008. The unconsolidated reservoir (Carapebus formation) shows a mid to high permeability and produces heavy oil.

The lower completion design requirements called for a screened completion with long openhole horizontal gravel packs for sand control and production optimization throughout the life of the field. Horizontal openhole lengths ranged from 800 m to 2,300 m for Peregrino producers. To date, 28 producer wells have been drilled and completed with horizontal gravelpacks. Since wells are not free flowing, artificial lift is required, and electric submersible pumps (ESPs) were chosen to perform the artificial lift; therefore, the upper completion architecture was designed with workover capabilities so that the pumps could be changed out as needed.

In order to maximize reservoir drainage, to save the platform's slot availability, and to optimize ESP efficiency, Statoil planned to drill and complete dual horizontal multilateral wells with horizontal gravel packs on each branch that would have the capability for selective production from each lateral section.For Well B05Y1/Y2, both branches were completed with two open holes of 1300 meters and 800 meters, respectively. These were fully gravel packed and had a Level 5 Junction installed.

This paper will describe:

  • The target zones

  • The gravel-packing challenges

  • The completion base of design

  • The installation sequences

  • The liner-conveyed gravel-pack technique used to gravel pack the lateral bore

  • The TAML level 5 MLT installation

  • The lessons learned.

The successful installation of a dual-bore horizontal gravel-pack completion with a Level 5 Multilateral System offshore was an industry first for Brazil that opened ambitious perspectives for the Peregrino field in terms of increased reservoir drainage that would improve the oil-recovery factor, and thus, the economic gains. This first multilateral well in offshore Brazil is part of the operator's increased oil recovery (IOR) efforts for the Peregrino field. This is also the first multilateral well in Brazil with gravel packs in both branches.

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