Increasing the value of 2-D seismic data through Application to development drilling
Carney, B.J.
Columbia Natural Resources, LLC.
There have been vast quantities of 2-D seismic shot in West Virginia to image various exploration targets in the Oriskany, Trenton/Black River, Newburg, and Tuscarora, just to name a few. However, once these targets are sufficiently tested in a prospect area, the seismic data is often shelved. That same old 2-D data can provide great value in maximizing your reserves in your Devonian shale drilling program.
Various seismic characteristics can be used to identify prospective areas for enhanced recovery from Mississippian and Devonian formations. Early Cambrian Rome Trough fault reactivation is shown to be an adequate predictor of improved fracturing, and thus, production in these shallow zones.
Estimated Ultimate Recovery (EUR) values for a group of wells were loaded into a database from which reserve “bubble” maps were constructed for a portion of southern West Virginia. A 2-D seismic database was then used to map various attributes relating to well production including basement fault trends, Onondaga fault trends, Onondaga structure, Berea structure, Big Lime structure, Berea to Onondaga Isochron and Isopach maps. Reserves were then compared to mapped seismic features.
A strong correlation between reserves and proximity to deep-seated faulting is evident. Two ideas for this correlation are proposed for this result, with the likelihood that a mixture of the two is occurring in the high-volume producers. Reactivation of deep faults could have created a buttress effect in the underlying Siluro-Devonian section, creating a mechanism for shallow thrusting in the Devonian shale. Secondly, the reactivation of deep faults could have propagated into the shales, where it dissipated into a series of smaller fractures.