Michael McCaskey2, Jason Byl3 (1) Scheevel
Geo Technologies LLC, Grand Junction, CO (2) Matrix Oil Corp,
The structural geometry is very difficult to interpret from logs alone because of vertical and overturned beds. Log signatures vary wildly with the wide range of penetration angles relative to bedding. Lateral variations in stratigraphy further complicate interpretation. Because of these difficulties, historical development has been based on a strategy of offsetting successful wells along strike.
Our study integrates log data, surface mapping, surface and subsurface dip data and hydrocarbon indicators into a 3D volume interpretation environment. Well correlation using bedding-parallel foreshortened views enables accurate true stratigraphic thickness correlations. Translation of surfaces conforming to dip control and perpendicular to layering (pseudo-concentric construction) aids construction of the faulted, near vertical and overturned footwall structures.
Horizons modeled in 3D were used to construct layered stratigraphic grids. Geostatistical and probabilistic modeling of rock-type consistent with paleodepositional trends were performed on these stratigraphic grids.
The resulting integrated 3D model reveals that the trapping of hydrocarbons in both the hanging wall and the footwall, is controlled by both stratigraphy and fault truncation. Further development drilling is planned to directly target stranded oil pay predicted from the integrated model.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California