Mathers-Gordon

Geological Introduction

The Lands provide a multi-pay opportunity of the Pennsylvanian age Virgilian limestone, multiple Granite Wash sandstones, with Atoka detritus and Permian age Brown Dolomite. Regional strike is southeast to northwest with dip to the northeast.

The following describes the lithology of the Lands:

Brown Dolomite -- 4500': The generalized lithology is a tan to cream buff, very fine crystalline dolomite with intercrystaline and intracrystaline porosity in the upper section, grading downward to a vuggy porosity with scattered vitreous chert. Published core measurements show median porosities of 8 to 16% grading to as high as 24% in some areas. Permeability from core studies vary from a low .03 md. to a median of 10 -- 20 md.

Virgilian Limestone -- 5600': Regionally oolitic and skeletal grainstones are generally developed in a high energy environment with localized algal mounding. Within the prospect area the limestone is white to light grey, to light brown with pinpoint to secondary vuggy porosity ranging from 10 to 22 % with a median value of 12%.

Granite Wash -- 7800' to 8300': Granite Wash sandstones were sourced from the exposed Amarillo Uplift during Pennsylvanian time and deposited in sequential alluvial-fan, braided-stream, and fan-delta environment systems. Porosity consistently averages 11% between 7000' and 11,00' with variable permeability of 0.1 to 20 md. Specific gravity of produced gas ranges from .66 to .72. Generally the nature of the gas is 85% methane with a BTU of 1100. The trapping mechanism is stratigraphic or combination stratigraphic -- structural with reservoir drive mechanism being pressure depletion or combined pressure depletion water drive. The sands contain granite, quartz, chlorites, and feldspars. Characteristically the reservoirs calculate high water saturation due to chemically bound water in the chlorites, variances in the matrix velocity, and grain size.

Atoka - 11,500': Locally the pay sections of the Atoka are thin, dark colored argillaceous limestones generally interbedded and intermixed with siliclastic detritus. The amount of the siliclastic content causes marked lateral and vertical changes in porosity and permeability. Generally the reservoir drive is predominantly pressure depletion with some reservoirs being water drive. Porosities range from 8 to 12% with generally low permeability. Trapping mechanism is stratigraphic or combination stratigraphic-structural.