Satellite fields: expanding North Slope production.

• Author: Ehm, Arlen

Oil companies once thought some oil accumulations too minor to deal with. But with new technology, companies can tap into smaller fields from larger operations without leaving footprints.

North Slope operators are devoting considerable amounts of scientific analyses toward locating, drilling and producing small to moderate amounts of oil from smaller isolated oil accumulations. Production from these fields is expected to augment present North Slope production from the large fields presently in operation today. Although the contribution from each of these smaller fields is minor compared to the larger fields, the collective contribution from all of them is substantial.

A satellite field is one that would not be economically viable except for its fortuitous location adjacent to an existing field and its already completed infrastructure. The satellite field is able to share the production facilities and pipelines of the existing field at nominal costs, but would not be profitable as a stand-alone facility.

The presence of some of these hydrocarbon accumulations has been known for some time as a result of information derived from the drilling of wells in the larger fields. However, it was not always economically feasible to delay the drilling and production of the larger fields just to explore for and possibly produce these smaller accumulations. An additional factor that delayed the satellite exploration and development was the lack of any facility sharing agreements among the various owners. The implementation of these agreements has now allowed for the sharing of facilities for additional uses beyond those originally intended.

Other factors also play a role in the decision to now explore for and develop the satellite fields. The use of three-dimensional (3-D) seismic to further evaluate and delineate the larger fields has provided high quality data, and is now available for use in the satellite fields. While 2-D seismic is of some value in this regard, the use of 3-D clearly provides an advantage. Companies are now able to identify reserves that they couldn't detect with seismic technology several years ago.

Tarn is an example of a field in which the operator, Arco Alaska, Inc., states that the key to understanding the reservoir is through 3-D seismic data. It will be drilled from two new drill sites in the Greater Kuparuk area, and the production will be processed at the Kuparuk central processing facility. This field is estimated to...