Today and in the future many of the deepwater projects in the Gulf of Mexico and elsewhere around the world will be producing under waterflooding conditions to increase hydrocarbon recovery and support reservoir pressure. The success of the water injection program is critical to the overall project economics. As such a clear methodology, workflow and attention to detail are needed in the planning, design and implementation of these projects.

This paper presents an integrated and practical approach for implementation at the Front End Engineering Design (FEED) stage of a project to optimize the future field development strategy, injectors design, facilities planning, and to maximize the total value of the asset. The proposed method efficiently interconnect elements related to surface facilities, topsides process, subsea architecture, subsurface equipment, water quality, well completion, down-hole flow controls and target injection rates in a common context.

The workflow consists of coordinating the diverse elements of design in the project: facilities design (pump requirements and water treatment options), topsides-subsea network flow design, injector, drilling and well planning, and critical data gathering. Results of the studies to be conducted will provide reliable estimates of well injectivity, fracture lengths under different injection scenarios, the impact of thermal stresses on injectivity and fracture growth, injector completion design, surface injection pressure requirement, and subsea-subsurface flow parameters. The development of a comprehensive model incorporating these elements subsequently allows the evaluation of the major factors that can impact the fracture length, bottom-hole and surface injection pressures based on: injection rate and temperature, water quality, reservoir pressure, Young's modulus, absolute and relative permeability to water, and rock thermal coefficient for diverse completions types.  Ultimately, a robust design of the waterflooding project with long-term water injection is obtained.

This methodology plays a crucial role guiding the planning, design, evaluation and development of the details and specifications for the water injection system. The output generated helps to improve overall field understanding, utilizing and linking valuable information and technologies that are available to the subsurface and topsides design teams. Likewise, this approach represents a tool to solve technical and business challenges associated with waterflood project design.