Overview: Completions Today (September 2006)
Authors: Horvat Damir 
Published: February 2015

The clear objective for any well is that it should perform to the full potential of the formation it penetrates and remain stable throughout its lifetime. This goal is best achieved by avoiding formation damage in the first place, but in most cases this is not possible. In reality, all reservoirs are damaged to some extent by drilling/completion fluids. The important issue is whether this damage affects well productivity significantly.

Optimum completion design is essential in maximizing the value available from the reservoir. Poorly planned or executed completion strategies can easily reduce production (and revenue) streams by up to 50%. While there appears to be a consensus on the mechanism of formation damage, there is growing divergence over how it may be combated or avoided.

Recent research indicates that fluctuations in wellbore pressure during the first milliseconds after perforation-gun firing govern the perforating-tunnel cleanup, rather than the initial static underbalance as originally thought. A completion design in which perforating bypasses invasion combined with a new design that ensures dynamic underbalance at all times has yielded very good results.

Intelligent-completion technologies provide downhole sensing and communication and remote control of completion tools. This technology allows operators on the surface and in remote locations to optimize reservoir performance by interpreting downhole data in real time, then operating flow-control devices accordingly.

To get a broader uptake of intelligent-completion technologies, there is a need for compelling success stories documenting the value of new and existing technology. Sharing these experiences could increase opportunities for broader implementation among operators of both conventional and unconventional reservoirs.

With the current oil and gas revenues, many opportunities exist for major operators to spend more capital on intelligent-completion technologies; a 10 to 20% increase in hydrocarbon recovery can balance the risks and opportunities of investing in challenging projects and the capabilities to bring them to fruition.

The willingness to share success stories as well as failures when documenting new technology is an important factor in achieving faster deployment of advanced completion technologies. As this concept becomes a reality in more fields, the upstream petroleum industry will enjoy increased efficiency and ultimate hydrocarbon recovery at lower cost.

Considering that completion takes a substantial stake in the total capital expenditure for a new well, the cost and effect of the well completion is too significant to be ignored.

Completions Today additional reading available at the SPE eLibrary: www.spe.org

SPE 97175 "External Casing Perforating Provides Optimal Treatment Coverage in Horizontal Pay" by J.L. Rodgerson, BJ Services Co., et al.

SPE 99691 "First Through-Tubing Gravel-Pack Recompletion Performed in Japan" by M. Numasawa, Japan Petroleum Exploration Co. Ltd., et al.

SPE 100413 "Efficient Cost Saving Through an Appropriate Completion Design" by L.-B. Ouyang, Chevron Energy Technology Co., et al.

SPE 96395 "Numerical Investigation of Horizontal-Well Performance With Selective Completion" by R. Kalita, Schlumberger, et al.