AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
Gravity Gradiometry Resolution Study and Its Application from Synthetic Data from the Middle East
(1) Saudi Aramco, Dhahran, Saudi Arabia.
(2) ARKeX, Cambridge, United Kingdom.
Gravity Gradiometry has long been known as a fundamentally useful geophysical quantity. Early applications of Gradiometry surveying required cumbersome instruments that required time consuming and delicate operation, making effective coverage of large areas difficult and expensive. Modern instrumentation has enabled Gravity Gradiometry to be performed from an airborne or marine platform, enabling accurate measurement of gravity gradient over explorationally significant areas in a reasonable time scale.
The ability of a modern moving platform gradiometer to isolate its measurement from the acceleration of the aircraft over a bandwidth between ~300m and 100km enables the complete field to be measured, without spatial aliasing, at low observation height. This allows the survey to capture signal from subsurface anomalies through the depth range of interest to both mineral and hydrocarbon explorationists, while facilitating accurate definition of the overburden through integrated interpretation. A demonstration of the application of this approach, in a typical Middle Eastern salt structure in areas of seismic uncertainty, is made through the construction of a “realistic synthetic” gravity gradient dataset, using an Earth Model and imposing realistic survey noise and uncertainty. The Earth Model parameters are perturbed to demonstrate sensitivity to typical time and depth domain velocity (structural) uncertainty and density uncertainty to derive the sensitivity of the integrated technique to variations in the subsurface.