Memorial University DAI: Minimum-structure borehole gravity inversion

advanced search

Digital Archives Initiative
Memorial University - Electronic Theses and Dissertations 4

menu off

add document to favorites : add page to favorites : reference url

back to results : previous : next

Search this object:

0 hit(s) :: previous hit : next hit

View:

previous page : next page

Document Description

Title	Minimum-structure borehole gravity inversion
Author	Mosher, Craig R. W. (Craig Robert Wilson), 1983-
Description	Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Earth Sciences
Date	2009
Pagination	xvi, 153 leaves : col. ill., maps
Subject	Borehole gravimetry; Mines and mineral resources; Prospecting--Geophysical methods;
Degree	M.Sc.
Degree Grantor	Memorial University of Newfoundland. Dept. of Earth Sciences
Discipline	Earth Sciences
Language	Eng
Notes	Includes bibliographical references (leaves 112-117).
Abstract	The borehole gravity technique has been well established in hydrocarbon exploration geophysics since the 1970's. The concept behind borehole gravity is simply to measure the variation in the Earth's gravitational field while traveling along a borehole. Densities both close to and far from the borehole can be derived from such measurements. However, the borehole gravity technique has not yet been routinely used for mineral exploration because gravimeters that fit in the narrower diameter holes used in mineral exploration have not existed. Such gravimeters are now being developed. Complementary investigation and development of interpretation procedures for borehole gravity data in a mineral exploration context are required. Here, results are presented of a study inverting synthetic borehole gravity data for three-dimensional, mineral exploration relevant Earth models. The forward-modelling on which the inversion is based is a finite-difference solution of Poisson's equation. The inversion is performed using a standard minimum-structure algorithm for multiple scenarios of varying borehole locations, amount of borehole data and varying model parameters. The intention is to demonstrate what we can expect to determine about the density variation around and between boreholes given varying amounts and locations of down-hole and surface data. It is observed that the benefits of borehole gravity data depend on the locations of the boreholes relative to the anomalous mass. Inversions which produce images of complex subsurface density distributions are attainable with the most successful models resulting from combined surface and borehole data. Minimum-structure borehole gravity inversion is shown to be a beneficial interpretation option which can provide accurate information of an anomaly's shape with proper depth resolution and density distribution.
Type	Text
Resource Type	Electronic thesis or dissertation
Format	Image/jpeg; Application/pdf
Source	Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
Local Identifier	a3243700
Rights	The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
Collection	Electronic Theses and Dissertations
Scanning Status	Completed
PDF File	(18.33 MB) -- http://collections.mun.ca/PDFs/theses/Mosher_Craig.pdf
CONTENTdm file name	65183.cpd