Integrated geomechanical, geophysical, and geochemical analysis of the Bakken Formation, Elm Coulee field, Williston Basin, Montana
dc.contributor.advisor | Sonnenberg, Stephen A. | |
dc.contributor.author | Rolfs, Spencer A. | |
dc.date.accessioned | 2015-08-27T03:55:29Z | |
dc.date.accessioned | 2022-02-03T12:52:37Z | |
dc.date.available | 2016-06-08T04:18:44Z | |
dc.date.available | 2022-02-03T12:52:37Z | |
dc.date.issued | 2015 | |
dc.identifier | T 7819 | |
dc.identifier.uri | https://hdl.handle.net/11124/20130 | |
dc.description | 2015 Fall. | |
dc.description | Includes illustrations (some color), maps (some color). | |
dc.description | Includes bibliographical references. | |
dc.description.abstract | Hydraulic fracturing is widely implemented in unconventional reservoirs. It requires comprehensive characterization of rock properties in order to determine accurate hydraulic fracture design and well placement. Core analysis has become a critical part of unconventional exploration and development. However, due to the exorbitant costs of core extraction, wireline acoustic logging tools have become the primary source of downhole measurements of geomechanical properties. This study is an integrated approach at defining the core derived geomechanical properties of the Bakken Formation and its relationship with wireline logs, facies characterization, and field scale structural features. The Bakken Petroleum System at Elm Coulee Field is comprised of three formations of upper Devonian to lower Mississippian age: the upper Three Forks, Bakken, and lower Lodgepole (the Scallion Member and the False Bakken) formations. Elm Coulee Field is located in Richland County, Montana and covers 530 square miles on the southwestern margin of the Williston Basin. The Bakken Formation within this field contains three members: the Upper Shale, Middle Bakken silty dolostone, and Lower Shale, with total thicknesses ranging from 8 to 50 feet. Bulk mineralogy provided for this study describes a dolomite-rich interval in the Middle Bakken Member, which is where primary Bakken production occurs within Elm Coulee Field. In order to assist in the upscaling of geomechanical properties to wireline logs, a lithofacies, bulk mineralogy (XRD), and elemental (XRF) analysis were performed using two supplied cores. This information provides insights onto the depositional environment and helps define why specific mechanical components occur in determined zones. Core mechanical analysis was conducted using a micro-rebound hammer, Proceq Bambino, to acquire the Leeb hardness value of the rock. Hardness refers to the measure of resistance to a permanent deformation and can lead to the evaluation of fine-scaled heterogeneity and anisotropy of the rock. To confirm this data, TerraTek supplied core analysis work from TSI scratch testing and confirmed the converted Leeb hardness values with the Unconfined Compressive Strength (UCS) values. The UCS values show a direct correlation to the mechanical properties of the formation. The ductile nature of the Upper Bakken Shales represent lower UCS values and the dolomite rich upper Middle Bakken Member display brittle mechanical properties. Log analysis was performed on 25 wells within the study area to create synthetic shear sonic logs by using an Artificial Neural Network (ANN) to train off one well that was supplied with a shear sonic log. Using this new log suite, dynamic geomechanical logs were calculated as well as cluster analysis tagging for all wells. Cross-sections transecting the study area were created to identify the geomechanical properties derived from the cluster analysis in relation to the dynamic logs. Geomechanically ideal reservoir conditions and the ductile nature of the UBS were identified with the cluster analysis and highlighted throughout the well-log cross-sections. The Flying Squirrel seismic survey was then used to interpret small scale structural features and compared the results to the cluster analysis cross-sections to highlight fracture prone zones within the Bakken Formation at Elm Coulee Field. | |
dc.format.medium | born digital | |
dc.format.medium | masters theses | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Colorado School of Mines. Arthur Lakes Library | |
dc.relation.ispartof | 2015 - Mines Theses & Dissertations | |
dc.rights | Copyright of the original work is retained by the author. | |
dc.subject | geochemical | |
dc.subject | geophysics | |
dc.subject | Williston Basin | |
dc.subject | geomechanics | |
dc.subject | Bakken formation | |
dc.subject | seismic | |
dc.title | Integrated geomechanical, geophysical, and geochemical analysis of the Bakken Formation, Elm Coulee field, Williston Basin, Montana | |
dc.type | Text | |
dc.contributor.committeemember | Humphrey, John D. | |
dc.contributor.committeemember | Davis, Thomas L. (Thomas Leonard), 1947- | |
dc.contributor.committeemember | Hart, Bruce | |
dcterms.embargo.terms | 2016-06-08 | |
dcterms.embargo.expires | 2016-06-08 | |
thesis.degree.name | Master of Science (M.S.) | |
thesis.degree.level | Masters | |
thesis.degree.discipline | Geology and Geological Engineering | |
thesis.degree.grantor | Colorado School of Mines | |
dc.rights.access | Embargo Expires: 06/08/2016 |