About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 98, No. 3 (March 2014), P. 563585.

Copyright copy2014. The American Association of Petroleum Geologists. All rights reserved.

DOI:10.1306/08201313011

Integrated reservoir characterization and simulation of a shallow, light-oil, low-temperature reservoir: Umiat field, National Petroleum Reserve, Alaska

Catherine L. Hanks,1 Grant Shimer,2 Iman Oraki Kohshour,3 Mohabbat Ahmadi,4 Paul J. McCarthy,5 Abhijit Dandekar,6 Joanna Mongrain,7 Raelene Wentz8

1Geophysical Institute and Department of Geology and Geophysics, University of Alaska, Fairbanks, Alaska 99775-5780; chanks@gi.alaska.edu
2Department of Geology and Geophysics, University of Alaska, Fairbanks, Alaska 99775-5780; gtshimer@alaska.edu
3Department of Petroleum Engineering, University of Alaska, Fairbanks, Alaska 99775; imanoraki@gmail.com
4Department of Petroleum Engineering, University of Alaska, Fairbanks, Alaska 99775; mahmadi@alaska.edu
5Department of Geology and Geophysics, and Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775; pjmccarthy@alaska.edu
6Department of Petroleum Engineering, University of Alaska, Fairbanks, Alaska 99775; adandekar@alaska.edu
7Shell International Exploration and Production Inc., 200 North Dairy Ashford, Houston, Texas 77079-1197; Joanna.Mongrain@shell.com
8Department of Geology and Geophysics, University of Alaska, Fairbanks, Alaska 99775; present address: Exploration Department, Sumitomo Metal Mining Pogo LLC, Delta Junction, Alaska 99737; Raelene.Wentz@smmpogo.com

ABSTRACT

Umiat field in northern Alaska is a shallow, light-oil accumulation with an estimated original oil in place of more than 1.5 billion bbl and 99 bcf associated gas. The field, discovered in 1946, was never considered viable because it is shallow, in permafrost, and far from any infrastructure. Modern drilling and production techniques now make Umiat a more attractive target if the behavior of a rock, ice, and light oil system at low pressure can be understood and simulated.

The Umiat reservoir consists of shoreface and deltaic sandstones of the Cretaceous Nanushuk Formation deformed by a thrust-related anticline. Depositional environment imparts a strong vertical and horizontal permeability anisotropy to the reservoir that may be further complicated by diagenesis and open natural fractures.

Experimental and theoretical studies indicate that there is a significant reduction in the relative permeability of oil in the presence of ice, with a maximum reduction when connate water is fresh and less reduction when water is saline. A representative Umiat oil sample was reconstituted by comparing the composition of a severely weathered Umiat fluid to a theoretical Umiat fluid composition derived using the Pedersen method. This sample was then used to determine fluid properties at reservoir conditions such as bubble point pressure, viscosity, and density.

These geologic and engineering data were integrated into a simulation model that indicate recoveries of 12%–15% can be achieved over a 50-yr production period using cold gas injection from five well pads with a wagon-wheel configuration of multilateral wells.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Protected Document: $10
Internal PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Members Only username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership through the AAPG Members Only program. For more information, contact the AAPG Membership Department at members@aapg.org.

establishment