Strawn porosity object of proprietary tests

A proprietary geophysical technology rooted in astrophysics is being tested in the prediction of economic levels of porosity in Pennsylvanian Strawn carbonates in West Texas.

Alan Petzet
OGJ Chief Editor-Exploration

HOUSTON, Jan. 21 -- A proprietary geophysical technology rooted in astrophysics is being tested in the prediction of economic levels of porosity in Pennsylvanian Strawn carbonates in West Texas.

The patented QuantumRD software advanced by ViaLogy PLC, London, analyzes 3D and multicomponent seismic data, well logs, and geologic records to predict porosity.

The technique, new to the oil patch, was applied to a 10 sq mile acreage block in Andrews County. ViaLogy said the software predicted a continuous zone of 6%+ porosity, and a well has been drilled to total depth of 11,241 ft.

“Initial well log analysis shows potential for multiple zones that could be highgraded, highlighted by a net interval of over 50 ft of significant porosity in the Strawn formation alone,” ViaLogy said. Well tests are needed to confirm productivity.

Private Midland, Tex., independent Fasken Oil & Ranch Ltd. drilled the well on its sprawling ranch based on ViaLogy’s recommendation. The firm has opened part of its property to researchers for tests of geophysical innovations in the Midland basin, where much undeveloped acreage remains.

Strawn targets are typically found below 9,000 ft and are uneconomic at 3% porosity or less, ViaLogy said. Of 18 Strawn wells drilled in the prospect area the past 50 years, three produced. Of the other 15, seven found no Strawn porosity and were completed in the shallower Wolfcamp, and eight were dry.

Porosity variations in Strawn stratigraphy generate a weak signal on seismic and are difficult to amplify using conventional geophysical processing, said Dr. Bob Hardage of the University of Texas Bureau of Economic Geology.

Geophysicists like to remove noise from seismic data, but the QuantumRD routine is to introduce noise to enhance the signal-to-noise ratio in processed seismic data. ViaLogy said that allows the technique to extract more information and “identify subsurface characteristics more effectively than other techniques.”

The technique is untested on formations such as Wolfberry, Devonian, and Ellenburger.

Contact Alan Petzet at alanp@ogjonline.com.

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