Abstract

The Fee ’AL’ #910 well cored 506 ft. of Upper Leonard Shale, Lower Spraberry Shale, Upper Wolfcamp, and ’Cline’ formations from 8,035’ to 10,853 ft. These cores are core contributions in the Tight Oil Reservoirs of the Midland Basin Consortium conducted by Core Laboratories.

The Upper Leonard interval (8,035’-8,095’) is dominated by silty shale with associated siltstone, packstone, and wackestone deposited in a basinal setting. This interval is often referred to in industry as “Lower Clear Fork”, but recent palynological analyses establish an age of Late Leonardian to Early Guadalupian. The Lower Spraberry Shale core interval (9,033’-9,384’) consists of interbedded silt-stone, silty shale, and detrital limestone. The detrital limestone units comprise packstone, wackestone, floatstone, and rudstone textures, deposited as mass transport complexes within a slope environment.

The Upper Wolfcamp (’Wolfcamp B’ 9,859’-10,031’) consists of detrital limestone, siltstone, silty shale, and shale. Detrital limestone beds represent mass transport deposits in a slope setting and the silty shale interval represents basinal deposition. The ’Cline’ (10,586’-10,852’) is a shale- and limestone-dominated interval, with associated silty shale and siltstone deposited in a proximal basin plain to lower slope environment. These intervals are organized into stacked, log-scale coarsening upward parasequences, characterized by skeletal packstones and burrowed silty shales. The ’Cline’ interval is of Late Pennsylvanian (Missourian) age, established by palynological analyses.

Mineralogy of the studied intervals measure quartz+feldspar (25 to 75%, avg. 50%), calcite+dolomite (0 to 45%, avg. 12%) and clay (10 to 50%, avg. 25%). Hydrocarbon filled porosity ranges from 1% to 7%, and total porosity from 3% to 10%. TOC ranges from 1 -5 wt.%, TMax is from 440-455, and Ro values range from 0.77-1.06% which is middle to upper oil window.

The well was completed with 9 frac stages from the Atoka Lime to the 1^st Spraberry. The well tested 122 BOPD & 154 MCFD (max. 30-day ave.) and has produced 13 MBO and 26 MMCFG in 8 months.