Improved Interpretation of Deep Structures in Southern West Virginia through 2-D Variance and Blended Attribute Analysis

Carney, B. J.¹, Brian Toelle², and Richard Campbell^3
1 Columbia Natural Resources, LLC, Charleston, WV
² Schlumberger Data and Consulting Services, Pittsburgh, PA
³ Columbia Natural Resources, LLC, Charleston, WV

In recent years, the Ordovician Trenton-Black River thermobaric dolomite play has been the predominant exploration target in the Appalachian Basin. Prolific production has been centered in the Finger Lakes area of upstate New York, and many of the attempts to expand this play into other portions of the basin have encountered only fractured limestone reservoirs. However, given sufficient fracturing, these wells can also be productive.

To improve success rates in the fractured limestone reservoirs, a number of seismic attributes were extracted from a recently acquired 2-D seismic data set in southern West Virginia. The data reveals basement involved transpressional structures that are observable on standard amplitude seismic sections. However, greater structural details are exposed when 2-D variance and blended attribute sections are examined. The resulting displays unmask subtle structural and stratigraphic events not previously recognized, and are clearly associated with reactivation of basement faulting.

Two seismic lines associated with existing deep wells are chosen to display the effectiveness of the method. Line 18 has an associated productive well that clearly intersects the interpreted fault zone in the Trenton-Black River interval. The second line (line10) shows a dry well that does not intersect the interpreted fault zone in the desired interval. The variance and blended attribute sections from line 18 also depict newly interpreted faulting that was not previously recognized on the normal amplitude sections.

These imaging methods have traditionally been used in 3-D data analysis, but are now available for 2-D data, which benefits the Appalachian basin explorer. They provide new value to vintage data and an enhanced look at deeper exploration targets, such as the Trenton-Black River.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004