IHS Energy's New Gulf of Mexico Deepwater Production Performance Study Reveals Accelerated Rates of Extraction, Increase in Channel Gas Completions
HOUSTON — (Sept. 27, 2004) – A new report from IHS Energy indicates channel sands have emerged as a key focal point for operators in the Gulf of Mexico (GOM) Deepwater while production/reserve ratios (a measure of extraction rate) have increased from historic lows of 10 percent to recent highs of 30 percent.
These conclusions, along with those showing recent finds have slanted toward gas, are among the many drawn from IHS Energy's 2004 GOM Deepwater Production Performance Study, an in-depth analysis of 72 existing GOM fields (67 active) in depths greater than 1,000 feet and reservoirs comprised of deepwater facies.
With production data studied through November 2003, the report is designed to assist E&P companies in making informed decisions about production optimization and acquisition/exploration targets in the deepwater operating environment.
“We were surprised at the increased emphasis on channel gas reservoirs when all of the production performance measures clearly point to sheet sands as the target of choice,” said Tom Harris, president of PetroSolutions Ltd., which teamed with IHS Energy to create the study. The report is the only comprehensive deepwater GOM study combining seismic analysis with production performance methodologies.
Harris speculates that the emphasis on channel gas reservoirs may be a function of seismic visibility along with robust gas prices and technology (completion and flow assurance).
Research Methodology
The objectives of the study are to first categorize each completion by fluid type and depositional environment, then evaluate the production performance for each zone to ascertain differences between good versus poor performance. The study evaluates only producing fields where reservoir facies are limited to deepwater environments. And 3-D seismic data is also included with log-based models to identify seismic AVO signatures for a wide variety of fluid, facies and production types. Research methods relied on traditional reservoir analytical techniques such as decline-curve analysis, Nodal and material balance as well as newer methods that apply well-test theory on monthly production data.
These methods were used to determine, where possible, the original volumes of hydrocarbons-in-place, an expected ultimate recoverable volume, the schedule of recovery, drainage areas, decline rates, plateau periods, elapsed time for water breakthrough, abandonment conditions and reservoir-drive mechanisms to evaluate efficiencies. The result is a unique, interactive database that GOM teams can use to benchmark drilling, to prepare for lease-block bidding and to make M&A decisions.
“The study provides the level of regional, detailed benchmark information necessary for effective exploration strategies,” said Steve Trammel, senior product manager, New Product Development at IHS Energy. “The ability to access this baseline data at a reasonable cost gives an operator more time to focus on the high-level work required for specific company prospects and projects.”
Key Study Findings
According to Harris, the study underscores that the deepwater GOM continues to present more active fields than any deepwater arena worldwide with a growing resource and production base. Moreover, the industry has witnessed an eight-fold increase in maximum flow rates and monthly production volumes during the last 20 and 10 years, respectively.
In all, 550 completions for 467 wells were evaluated to derive the study's conclusions, including:
- Of the 72 fields studied, 67 are active. The number of active producing wells in these fields ranges from 41 to one. The median field size has three active wells.
- Flow rates per completion for sheet sands average 11,000 bopd; channel sands average 6,000 bopd and channel levee sands average 4,000 bopd.
- One oil well has produced almost 50 million barrels of oil. Five gas wells have each produced in excess of 100 BCF each with rates exceeding 200 MMCFD.
- Deepwater oil reservoirs are initially under-saturated. Three primary drive mechanisms have been recognized: fluid expansion, aquifer influx and formation compressibility.
- Based on geocellular modeling and petrophysical simulation for three fields, there appears to be areas of unswept oil in channel complexes and down-dip oil column potential in several channel sands.
The comprehensive study is available immediately in both a digital format and in two, hardcopy binders. It includes an HTML interface for company Intranet capability and a detailed bibliography of technical articles. The digital file is deployed in an Access™ database and produced on CD-ROM.