NOW READ OUR ARTICLES IN 40 DIFFERENT LANGUAGES.
HOME PAGE SUBSCRIPTIONS, Print Editions, Newsletter PRODUCTS READ THE PETROLEUM NEWS ARCHIVE! ADVERTISING INFORMATION EVENTS

SEARCH our ARCHIVE of over 14,000 articles
Vol. 22, No. 22 Week of May 28, 2017
Providing coverage of Alaska and northern Canada's oil and gas industry

Intriguing possibility

Hilcorp has been investigating the oil potential of the Iniskin Peninsula

Alan Bailey

Petroleum News

With a huge geologic anticline, clearly visible from the air, and associated surface oil seeps, the Iniskin Peninsula on the west side of Alaska’s Cook Inlet, opposite Kachemak Bay, seems an obvious target for oil exploration. But, since wells drilled in the early 1900s, in the 1930s and in the 1950s failed to make a commercial oil discovery, the area has remained dormant since then from the perspective of petroleum exploration.

Until, that is, 2013 when Hilcorp Alaska signaled its interest by shooting a 2-D seismic survey on the peninsula, a survey that for the first time revealed some information about the peninsula’s subsurface structure and stratigraphy.

Positive findings

On May 23, during the Association of American Petroleum Geologists Pacific Region annual conference, Hilcorp geologist David Buthman talked about some of his company’s findings on the peninsula. Hilcorp is encouraged by what it has found and would be interested in drilling an exploration well on the peninsula at some time in the future, Buthman said.

The drilling conducted in the ’30s and ’50s had reached depths of 8,775 to 11,231 feet in the “up-plunge” or higher section of the anticline on the peninsula. Although oil was encountered, the flow rates were deemed to be too low for viable development, Buthman said. But modern development techniques involving the use of hydraulic fracturing open the possibility of either conventional or unconventional development on the peninsula, he said. Moreover, the large thicknesses of the rock units with oil potential compensate for the poor rock permeability, he commented.

55,000-acre prospect

The Iniskin prospect consists of a 55,000-acre structural closure, with two potential oil and gas reservoirs, 1,292 feet and 300 feet thick, in the Middle Red Glacier formation, part of the Jurassic Tuxedni group that sourced most of the oil in the Cook Inlet oil fields. These are mud-rocks within the thermal window in which oil may be generated — they could provide unconventional tight oil targets.

The rocks have fractures that follow characteristic orientations and could transport fluids. And the nature of the rocks seems similar to the Wolfcamp shale, a tight oil source in the Permian basin of Texas, Buthman said. In addition, there are known to be numerous oil-saturated, low permeability, low porosity sandstones in the region of the Iniskin Peninsula that could make other unconventional targets.

Volcanic breccia and sandstones within the Lower Red Glacier formation also appear to provide highly prospective conventional targets.

Although attempts at fracturing the wells years ago did not boost the oil flow rates to acceptable levels, advanced fracking techniques available nowadays can potentially work effectively in the Iniskin Peninsula rocks, Buthman said.

Offset crest

Moreover, Hilcorp’s 2-D seismic data on the Iniskin Peninsula indicate that the anticline on the peninsula has a surface crest offset to the west relative to the crest of the deeper structure. As a consequence the wells that were drilled into the structure many years ago missed that deeper crest, Buthman said. He also commented that live oil was observed in eight of the seismic shot holes that were drilled on the crest of the surface structure in conjunction with Hilcorp’s seismic survey.

Asked about the prospects of further investigation, Buthman commented that drilling on the peninsula should be straightforward but that moving the equipment and personnel to the remote location, negotiating the Cook Inlet tides at the landing point with a barge, would be difficult.



Did you find this article interesting?
Tweet it
TwitThis
Digg it
Digg
Print this story | Email it to an associate.

Click here to subscribe to Petroleum News for as low as $89 per year.


Petroleum News - Phone: 1-907 522-9469 - Fax: 1-907 522-9583
[email protected] --- http://www.petroleumnews.com ---
S U B S C R I B E

Copyright Petroleum Newspapers of Alaska, LLC (Petroleum News)(PNA)©2013 All rights reserved. The content of this article and web site may not be copied, replaced, distributed, published, displayed or transferred in any form or by any means except with the prior written permission of Petroleum Newspapers of Alaska, LLC (Petroleum News)(PNA). Copyright infringement is a violation of federal law subject to criminal and civil penalties.