The broad variety of data types (the "building blocks") in the Significant Oil and Gas Fields of the United States Database support a correspondingly broad range of upstream analyses. These analyses include:
- Basin and Play Analysis
- Acquisition and Exploitation Analysis
- Play Conceptualization
- Risk Analysis
- Production Forecasting
- Petroleum Resource Assessment
- Systematic Analogs
In all cases, the database provides the means for grappling with major questions through focused, disaggregative analysis.
The database is explicitly designed to facilitate basin and play analysis. All of the building blocks contribute to providing a broad basis for understanding the distribution of known oil and gas accumulations within basins and plays. The organization of reservoir data by play and by readily correlatable formation codes is crucial to this task. The database provides spatial distributions of key reservoir properties (such as thickness, areal extent, temperature and pressure gradients, trap types, and hydrocarbon types) both within and across plays. How exploration concepts developed can be analyzed using spatial-temporal patterns of discovery. How development concepts evolved can be inferred from field and reservoir growth histories, the timing of post-primary recovery methods, and changes in well counts and well spacing. The distribution of plays by formation can be mapped and the genetic relationships among plays within the same formation can be inferred using the database.
Acquisition and Exploitation Analysis
The database offers a means for identifying reservoirs with recovery growth potential, thereby recognizing opportunities for acquisition and subsequent exploitation. The organization of reservoirs by play in the database is crucial for this task. It provides a means for readily grouping similar reservoirs, both within individual plays and between similar plays. Using these groupings, one can compare growth and development histories with rock and fluid properties and examine whether differences in recent growth histories and recovery efficiencies reflect differences in reservoir quality or differences in operator performance.
The database provides a systematic framework for play conceptualization, both for developing new ideas about known plays and envisioning new plays. Many of the same building blocks used in Basin and Play Analysis can be used for this task. Spatial-temporal patterns of discovery can be examined to determine how past exploration concepts evolved and whether play infill and extension opportunities still exist. Depositional axes and trends can be identified by mapping reservoir thickness and shape. The relationships by depositional style and trap type among plays in the same formation can be used to develop hypotheses about deeper downdip opportunities within that formation.
The database fosters an empirically grounded estimation of risk and uncertainty. For the estimation of prospect sizes, the database provides relevant distributions of field and reservoir sizes and their primary determinants - area, thickness, porosity, initial saturations, initial pressure and temperature, and recovery efficiencies. These distributions can not only be play-wide, formation-wide, or area-wide; they can also be created by period of discovery to determine how they may have changed over time. The play outlines can be combined with exploratory well data from other sources to determine historic success rates. Relationships among such factors as reservoir depth, temperature gradient, and hydrocarbon type or lithology, depositional style, and the distribution of reservoir sizes can be determined for analog basins and plays to help resolve major basin and play uncertainties.
The database provides the means for understanding historic production trends using a variety of disaggregated analyses. It thereby creates a more insightful foundation for predicting future production. The production histories of oil and gas fields and reservoirs by period of discovery and by play indicate how and why the composition of production has changed over time and thus helps identify the specific trends shaping production growth and decline. Production histories by play can be both readily correlated with recent recovery growth and discoveries and estimates of future growth and discovery potential. The Field Cross Reference Table can be used to correlate annual well completions with field, reservoir, and play production and recovery growth. This table provides a key link between drilling activity and production.
The database is designed to support many different resource assessment methods. For estimating growth in ultimate recovery, the database provides recent field and reservoir size histories and enables these histories to be correlated with both reservoir rock and fluid characteristics and various measurements of development intensity (such as reservoir well spacing and post-primary oil recovery methods). The field and reservoir original oil-in-place data can also be used to indicate both future potential and possible constraints on recovery growth. The database can be used with many methods for estimating future discoveries, providing the cumulative discovery histories used to create creaming curves, the discovery histories by size used in discovery process models, and field and reservoir numbers, size distributions, and field and reservoir spatial densities. For conceptual and emerging plays, the database provides a wealth of relevant analog distributions of sizes, areas, thicknesses, and the like.
The database provides systematic analogs for upstream evaluation. Traditionally, the use of analogs in exploration and development has emphasized single examples. The database provides distributions of relevant examples as analogs, thereby indicating the range of possibilities instead of only one (usually biased) sample. The various building blocks - particularly field and reservoir size and growth, reservoir rock properties, and reservoir fluid properties - offer a wealth of information for constructing illuminating analogs. The database not provides relevant distributions by play for prospect, reservoirs, and fields. It can also serve as a foundation for constructing play-level analogs. Using the play definitions in the database, play types can be developed using such characteristics as reservoir lithology and depositional environment, trap type, hydrocarbon type, and rate of reservoir deposition, thereby facilitating comparisons among plays of the same type.