Project Description Ferron Sandstone

Geological and Petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir

Utah Geological Survey (UGS), Salt Lake City, Utah 84114
Principal Investigator: M. Lee Allison, UGS
Phone: (801) 537-3300; fax: (801) 537-3400
Contract No. DE-AC22-93BC14896

Objectives and Project Description

The primary objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be constructed for improved oil-field development in similar U.S. reservoirs. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project.

The project is divided into four tasks: (1) regional stratigraphic analysis, (2) case studies, (3) development of reservoir models, and (4) field-scale evaluation of exploration strategies. Regional stratigraphic analysis will provide a more detailed interpretation of the stratigraphy and gross reservoir characteristics of the Ferron Sandstone as exposed in outcrop. Case-studies will develop a detailed geological and petrophysical characterization, at well-sweep scale or smaller, of the primary reservoir lithofacies typically found in a fluvial-dominated deltaic reservoir. Tasks 3 and 4 will develop reservoir models and field-scale evaluations of exploration strategies. These tasks will incorporate data and results of the regional stratigraphic analysis and case-studies.

Project Performance Facts

The Ferron Sandstone project consists of $909,353 of non-federal cost sharing, which is over 54 percent of the total project cost. The project is currently within budget with approximately $500,000 remaining. Most project tasks are on schedule for final completion in the Fall of 1996; some deliverables have been submitted ahead of schedule while a few are slightly behind. The project is meeting original performance expectations with several additional spin-off products and results.

Participating Organizations

The following organizations are conducting work on the project: Utah Geological Survey* (prime contractor), AMOCO Production Company(* 93 percent cost share), Mobil Oil Corporation(* 100 percent cost share), University of Utah (Dept. of Geology and Geophysics)*, Brigham Young University (Dept. of Geology), Utah State University (Dept. of Mathematics and Statistics), P.B. Anderson (geological consultant)*, and The Aries Group (*indicates that the organization is contributing to cost sharing).

The Federal Government’s Engagement in this R&D

Industry R&D capacities are rapidly disappearing and small companies have little or no capabilities of their own. Drilling budgets and operation costs are dependent on the price of oil. Small fluctuations (decreases) in oil prices can cause these fields to become uneconomic and abandoned. For many operators, the cost of conducting detailed analysis of reservoir heterogeneity and developing reservoir models may be equal to a significant part of their net worth or their total investment in the fields. However, many of the operators tell us they would be eager to employ our Ferron Sandstone models in their fluvial-deltaic fields.

Federal and State governments have an economic interest in seeing increased production in these fields. Both receive direct revenues from mineral interests, royalties, and taxes. Both receive indirect benefit from increased economic activity. We envision this project as a prudent investment by government in maximizing return on the resources that government manages and regulates on behalf of the citizens of Utah and the U.S. Both the Federal and State governments have had an implicit partnership with oil producers since the time leases were issued or taxes levied. The DOE Geoscience/Engineering Reservoir Characterization Program and this project specifically, recognize that long term partnership, and seek to enhance production to mutual benefit.

Specific R&D Products/Accomplishments

The public technical and business benefits from this project will: (1) increase recoverable reserves by identifying untapped compartments created by reservoir heterogeneity, (2) increase deliverability by exploiting the reservoir along optimal fluid-flow paths, (3) enhance the application of new technologies, such as horizontal drilling, by identifying optimal drilling directions and locations to maximize fluid-flow, (4) identify reservoir trends for field extension drilling, (5) prevent premature abandonment of fluvial-dominated deltaic fields, (6) reduce development costs by more efficiently siting infill drilling locations, (7) allow limited energy investment dollars to be used more productively, and (8) increase royalty income to Federal, State, and local governments, fee owners, and the Ute Nation in Utah’s Uinta Basin (where most reservoirs on tribal lands are fluvial-dominated deltaic).

This type of work has not been performed on a large scale and with such broad applications. Much of the R&D work that has been done, is not available to the public because that research was performed by major oil companies for their internal use and is held confidential. However, because the Ferron project is Federally funded, the target includes all operators of fluvial-deltaic reservoirs especially those in the Gulf Coast, Rocky Mountain region, and Alaskan North Slope.

There has been one additional and significant benefit of the Ferron Sandstone project. The project was originally submitted to the DOE as study of a surface analogue to fluvial-dominated deltaic oil reservoirs. Since that time, the Ferron Sandstone itself has become a major coalbed methane play in Utah. Databases, strip logs, and maps produced from the project have become very useful to the numerous operators exploring and developing this new resource. Based on data generated in this project we estimate the play will support 3,400 wells, nearly doubling the total number of producing wells in Utah.

Expected R&P Products and Timetables

In addition to the products already released to the public (databases, strip logs, and maps), we expect to produce a useful final product by the Fall of 1996 (the end of the 3-year project contract. This final product from project milestones will include: (1) characterization of flow units influencing single well production, (2) reservoir simulation results, (3) exploration, development, and reserve estimation strategies, and (4) assessment of number and type of data needed to develop geologically-derived enhancements to fluvial-dominated deltaic reservoir models. Each completed or partially completed project milestone leads to progress on the next milestone. The completion of these milestones and the deliverables produced from them is a measurement of project success.

The market penetration rate for the industry will gaged by careful monitoring of those who use the project to increase production and reserves. The UGS has identified more than 60 operators (60+) that are following the project and waiting to use the results. The UGS will also sponsor field trips to the project area the review our work and conclusions. Follow-up contacts with these operators will be conducted to gage the success and implications of the project.