Overview

Careful well-test design applied intelligently to exploration and development situations is the reality check for information that many times can only be inferred from other reservoir-evaluation tools. With drilling rigs in short supply and day rates at historic high levels, smart application of well-test technology may reduce costs considerably by use of short-duration openhole wireline-test equipment. Commerciality can be determined quickly and rigs moved on to the next objective or well. In contrast, extended well tests, conceived to prove a commercial hydrocarbon accumulation, may provide enough data to validate a reservoir description and clear economic hurdles without drilling an additional well—important for time-critical decisions on adjacent leases.

Many times in the operating environment, a petroleum engineer may use well-test results to provide a reality check and economical data acquisition for geophysicists, production geologists, and simulation engineers on one end of the organization and production operations personnel pushed to maximize well rates on the other end. Careful well-test planning and analysis can satisfy both extremes. Reservoir-characterization professionals can validate reservoir boundaries, pressures, and the accuracy of production history. Production operations can maximize production confidently in a miscible-gas flood without going below minimum miscibility pressure and compromising recovery. A delicate balance can be maintained with little or no production loss, allowing responsible reservoir management while maximizing rates and ultimate recovery.

With oil prices hovering around U.S. $60/bbl, there has never been a larger incentive to optimize well testing in exploration, development, and production environments. This month’s selections show how relatively conventional testing procedures, applied intelligently, can accelerate development decisions. Deconvolution of real-time reservoir performance is always going to be an attractive goal in well-test analysis to eliminate production loss from conventional pressure-transient analysis. Use of multiple analysis techniques can be complementary to other reservoir-characterization methods. Advances in intelligent completions, permanent data-acquisition systems, and flow-measurement technology continue to entice petroleum professionals into devising innovative techniques for advanced well-test analysis.

Use of DST for Effective Dynamic Appraisal: Case Studies
Deconvolution of Variable-Rate Reservoir-Performance Data Using B-Splines
Extended Well Test for Identifying Connectivity Between Adjacent Compartments

Jay Stratton, SPE, is Petroleum Engineering Team Lead for Anadarko’s Groupement Berkine partnership with Sonatrach in Hassi Messaoud, Algeria. He is actively working in the area of new-well testing and completions, stimulations, flow-measurement technology, and production optimization. Previously, Stratton was with Occidental Petroleum of Qatar as Operations Engineering Adviser, working in the areas of reservoir development with horizontal multilateral re-entry completions, single-bore production/injection electrical-submersible-pump completions, polymer water-control treatments, and offshore well interventions. While at Arco Alaska as a senior operations engineer, he was involved in drillsite development, hydraulic-fracturing technology, artificial-lift optimization, and well services. In his 20-year career, Stratton has worked in the Arctic, North Africa, Middle East, former Soviet Union, Pakistan, and west Texas. He has authored technical papers on the application of multilateral completions and polymer water-control technology. Stratton serves on the JPT Editorial Committee and holds a BS degree in petroleum engineering from Texas A&M U.

Overview

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