ABSTRACT: The Role of High Resolution Aeromagnetics and Other Non Seismic Methods in the Exploration of Oil and Gas

SEEWALD, K. and FAGAN, JOSEPH P., JR.

Most geologists are probably aware of and very current on the recent advances made in seismic acquisition and processing. 3-D seismic schools and seminars are as common now as horizontal drilling seminars were a few years ago.

What is not commonly known is the significant new developments in the acquisition, processing, and interpretation of aeromagnetic and gravity data and the impact it can make in funding new oil and gas reserves. Aeromagnetics and gravity have traditionally played an important role in reconnaissance exploration principally as a basin mapping tool. In today's world that role is still very important in mapping frontier basins outside the U.S. For those of us concemed with finding new hydrocarbon reserves within the U.S.A., it is important to recognize that the same advances that have enhanced our seismic techniques are also used in generating and processing magnetic and gravity data. By combining information on the stratigraphy and regional structural style of an area with properly interpreted high resolution aeromagnetic and gravity data, maps of structures within the sediments as well as maps showing the configuration, size, and elevation of basement uplifts can be generated.

Neural network systems have been applied to the structural interpretation of high resolution aeromagnetic data to automate the laborious process of profile interpretation. A neural network is trained to recognize the magnetic signature of a basement uplift, which is then located in the actual magnetic data. A similar process can be applied to the gravity data. By using the process on magnetic and gravity data together, an extra degree of confidence is added.

With the proper geologic input, these inexpensive non-seismic methods can provide significant input on the regional structural analysis o fan area that is extremely important in the planning and interpretation of 3-D seismic surveys.

AAPG Search and Discovery Article #90947©1997 AAPG Southwest Section Meeting, San Angelo, Texas