Equalization of the water injection profile of a subsea horizontal well

Combination of inflow control device and premium sand-control screen increases oil rate while decreasing watercut.

Anderson da S. Amaral, Jody Augustine and Knut Henriksen, Baker Oil Tools; Valdo Ferreira Rodrigues, Daniel Escobar Steagal, Luiz Carlos Alves da Paixão and Valdir Pereira Barbosa, Petrobras

This article focuses on the world’s first installation of a water injector well with a lower completion system that incorporates both premium sand control screens and water injection profile equalization. The equalization of the water injection profile of horizontal wells has been a key issue in many development projects worldwide and has the potential to increase the reservoir’s ultimate recovery by increasing the water sweep efficiency.

Inflow Control Devices (ICDs) integrated with premium sand control screens have a long history of application in production wells. In these cases, the main objective is to create a uniform inflow profile along the horizontal section, delaying unwanted water and gas production and increasing oil recovery. The method through which ICDs equalize the inflow of oil can also be used to equalize the outflow of water. Historically, sand control completions for water injection wells included stand-alone conventional screens and openhole gravel packs. Stand-alone conventional screen completions do not provide equalization of the water injection profile. Openhole gravel packs provide for an effective acid treatment of the water injector well but create operational risks, high costs, as well as expensive rig time.

The installation was carried out in a subsea horizontal sea-water injector well in the Campos Basin, offshore Brazil. The article presents the overall completion plan, the lower completion installation, the acid treatment through the ICD, and the initial water injection results based on production logs and water injectivity tests. The main concerns during the planning phase are discussed, highlighting the procedures adopted to overcome them..