--> Abstract: Distinguishing Static and Dynamic Faults: Application for Gulf of Mexico Deep Gas Play; #90063 (2007)

Datapages, Inc.Print this page

Distinguishing Static and Dynamic Faults: Application for Gulf of Mexico Deep Gas Play

 

Connolly, David1, Bill Fraser2, Fred Aminzadeh3 (1) dGB Earth Sciences, Sugar Land, TX (2) Gulf Energy Exploration Corp, Austin, TX (3) dGB-USA, Sugar Land, TX

 

Distinguishing dynamic (leaking) faults from static (sealing) faults is critical for risking seal and charge. This is especially true in deep gas prospects such as Tertiary Gulf of Mexico and others places where DHI may be inconclusive. Many conventional methods aim at exploring for deep gas focus on finding effective reservoirs. However, often times, there is an ambiguity on whether those reservoirs are charged. For effective charging of deep gas reservoirs, it is necessary to detect dynamic faults which terminate vertically in the prospective interval.

 

Static faults are often narrow and well imaged on similarity or coherence data. They generally are dipping on vertical sections. Dynamic faults, in contrast, are characterized by vertically aligned chaotic zones in the seismic sections, often related to high shear stress. In map view they are characterized by a complex of splinter faults with circular pockmarks, often occurring at fault intersections. These vertically aligned chaotic zones, or gas chimneys, can be detected using a pattern recognition approach based on multi-dimensional multi-attributes and neural network modeling. The result is a data volume which represents the probability of chimney. When this chimney data is displayed along a fault trace, the dynamic and static portions of the fault can be shown.

 

An example data set from Offshore, Texas demonstrates dynamic faults charging a shallow gas field and a deep gas prospect. Integrating chimney results with AVO information where reliable data is availabe further validates interpretation.

 

AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California