CompletionTools Proven Successful in Deepwater Frac Packs and Horizontal Gravel-Packing
Authors: Hill Leo E. , Coutinho Neto Arthur Barreto , Ratterman Gene , Baycroft Perry , da Silva Amaral S. Anderson 
Published: December 2007

This paper describes the crucial need for teamwork linking the operating company and the service providers to properly unite technologies and ensure successful deployment. The authors outline some of the obstacles encountered and describe how the tools and procedures were designed for successful execution.

Case histories illustrated the tools and techniques developed while completing 81% of the horizontal open hole gravel packs in deepwater Brazil and frac pack completions in deepwater Gulf of Mexico. To concentrate on the risks in deepwater, operator's developments, deploy, and optimize the most up-to-date technologies to reduce risk and increase their production. Open hole horizontal and frac pack completion technologies have been optimized and proven to achieve these objectives.

The operators’ quest to progress in net present value and accelerate reserve depletion means they will complete a well with a horizontal gravel pack or a frac pack based on reservoir conditions and well objectives. Horizontal wells are typically applied to reservoirs with good vertical permeability where the horizontal well reaches out to drain the reservoir in a desired azimuth. The long reach of horizontal wells provides the operator the ability to selectively drain a reservoir and historically provides the operator with the lowest cost per barrel oil equivalent (BOE).

Typically, frac packs are applied to formations where vertical permeability limits the application of horizontal wells, or well bore construction places multiple targets behind casing. Frac packs provide vertical connection and bypass near-wellbore damage, enhancing the connection to the reservoir to accelerate reserve depletion.

When reservoir characteristics are homogeneous with high vertical permeability, open hole horizontal wells are becoming a preferred completion method in the deepwater market because the approach allows a larger wellbore at the reservoir and provides extensive reservoir exposure. Combining open hole horizontal and multilateral technology can further enhance economic return by reducing the number of wells to drain the reserves. More than forty open hole horizontal gravel pack completions have been successfully performed in Brazil's deepwater Campos Basin.

These include completions both in horizontal producers and injectors. The dramatic increase of frac packing in deepwater Gulf of Mexico has intensified engineering efforts to meet the demands specified by the operating companies for fracturing high permeability formations. Frac pack applications in deepwater can require pump rates of 30 bpm (4.8 m3/min), with proppant concentrations of 12 ppa (1.44 kg/l). Specialized tools and performance software address the increasing demands and risk management required in today's deepwater market. Applications of these tools to evaluate and control risks are reviewed in this paper.

Operators chose best in class sand control techniques and technology for well life optimization and operational risk minimization on deepwater projects. The latest technical advancements, design software, gravel pack packer design and premium screens, have enabled the application of well life sand control in low fracture gradient reservoirs with laterals successfully gravel packed at lengths exceeding 7,000 feet (2,133 m) in water depths of 6,163 feet (1,878 m). These technical advancements make it possible to achieve well lifelongevity and optimum field economics for deepwater field development.