Fracture evolution in a fold-and-thrust belt and the adjacent foreland basin: an example from the Northeastern Brooks Range, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2010 "Fracture networks can enhance permeability in a reservoir, creating pathways for fluid migration. This study uses detailed surface and subsurface mapping, new and existing thermal and geochronologic data as well as observations of fractures in...

Full description

Bibliographic Details
Main Author: Loveland, Andrea M.
Format: Thesis
Language:English
Published: 2010
Subjects:
Online Access:http://hdl.handle.net/11122/12741
Description
Summary:Thesis (M.S.) University of Alaska Fairbanks, 2010 "Fracture networks can enhance permeability in a reservoir, creating pathways for fluid migration. This study uses detailed surface and subsurface mapping, new and existing thermal and geochronologic data as well as observations of fractures in outcrop provide a framework for fracture development in the range front region along a surface to subsurface transect in the western part of the northeastern Brooks Range. Set 1 fractures formed prior to 45 Ma at>6 km depth, ahead of the Brooks Range mountain front in response to elevated pore fluid pressure and low differential stress. Set 2 fractures developed during the early stages of folding at a depth of ~7 km. Both Sets 1 and 2 developed synchronously with hydrocarbon generation and may have been early migration pathways, but were likely destroyed during advancement of the thrust belt. Late fracture Sets 3 and 4 formed at shallow depths in the absence of fluids and are probably related to the onset of uplift at ~25 Ma. These late sets postdate regional generation and migration, but may enhance reservoir permeability"--Leaf iii American Association of Petroleum Geologists, Arctic Energy Technology Development Laboratory, Air Logistics, Anadarko, EnCana, ConocoPhillips, Alaska Division of Geological & Geophysical Surveys, Alaska Division of Oil & Gas, U.S. Geological Survey, Andrea Krumhardt of the University of Alaska Fairbanks, Apatite to Zircon Inc., and Petro-Fluids, Inc. 1. Introduction -- 2. Geologic setting -- 2.1. Regional structural geology -- 2.2. Brooks Range cooling events -- 2.3. Regional stratigraphy and structural style of the northeastern Brooks Range -- 2.4. Hydrocarbon systems in the northeastern Brooks Range -- 2.5. Previous fracture studies in the northeastern Brooks Range -- 3. Fault-related folds and fractures -- 3.1. Types of fractures -- 3.2. Fracture initiation -- 3.3. Fractures in flat-lying rocks -- 3.4. Fold-related fractures -- 3.5. Neotectonic joints -- 3.6. ...