--> --> Abstract: Mapping and Delineating Prospective Geology with FTG Gravity Data, by Colm A. Murphy; #90082 (2008)

Datapages, Inc.Print this page

Mapping and Delineating Prospective Geology with FTG Gravity Data

Colm A. Murphy
Bell Geospace Limited, Aberdeen, United Kingdom

FTG Gravity data are routinely acquired on airborne and marine platforms worldwide on exploration related projects from geological mapping of prospective regions to detailed target delineation of specific geological targets.

The technology measures 5 independent Tensor components that collectively describe the gravity field. The components capture unique signature patterns related to specific attributes of target geology that when collectively interpreted enable detailed imagery of the target itself in terms of geometry, composition and depth.

The horizontal tensor components Txx, Tyy, Txy, Txz & Tyz are commonly used to identify and map lineaments associated with structural and/or stratigraphic changes or target geometry in a survey area. The vertical tensor component, Tzz, is used to estimate depth and predict compositional information related to target geology.

Combining all Tensors as singular representations prove best for extracting geological signature patterns from lineament mapping to target identification. This is possible through the usage of Invariant analysis. Horizontal components are combined independently of the vertical axis (Tzz) to facilitate fault framework mapping. Combining all of the components simultaneously enables target identification and analysis across a survey area. Target depth and geometric relationships are quickly assessed prior to detailed quantitative modeling exercises.

The resultant interpretation enables the end-user to fast-track the exploration initiative by quickly evaluating target geology for detailed follow-up, e.g. within a seismic analysis workflow or fine tuning additional data acquisition programmes.

Examples of this approach will be presented from a series of surveys that include regional evaluation surveys offshore NW Europe and onshore Africa to prospect generation in the Barents Sea offshore Norway.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery