Value of information for petrophysical data in unconventional plays can be extended far beyond perforation placement, but can also be used to develop strategic plans for the selection of costly proppants. Proppant is the single most expensive feature of Midland Basin Wolfcamp completions, especially in deeper (>10,000 ft. TVD) zones that are under high stress. Wire line petrophysical data has recently been adopted as a critical element in proppant capital stewardship.In particular, dipole sonic logs in the Wolfcamp play now provide critical closure stress information for the decision to attempt hydraulic fracturing of a zone and the selection of appropriate proppant for those zones. New proppant selection criteria relate zone stress to required hydraulic fracture conductivity given the expected formation permeability and production capacity. Before this study, frac stages and proppants were chosen on a paucity of available completion records. This resulted in a strategy to use ceramic proppants in all zones below 10,000 ft., or roughly > 6,500 psi closure stress. The incorporation of petrophysical log analysis has refined the process by which the prescription of expensive proppants and frac stages are made and ultimately reduces cost. Dipole sonic data is now collected every square mile of the active development area. The sonic data is converted into estimates of fracture gradient (psi*ft−1), minimum horizontal stress (psi), and closure pressure (psi). Average porosity of pay ranges from 6.3% (P10) to 9.5% (P90) in the mudstone prone Cline formation, while the ramp carbonates constituting the Strawn and Bend formations ranges from 3.2% (P10) to 12.8% (P90). Core analysis suggests the corresponding permeability are around 0.19 MD (P10) to 0.71 MD (P90) for the Cline while the Strawn and Bend range from 0.02 MD to 8.06 MD (P90). Log based, average P90 minimum horizontal stress in deep Pennsylvanian zones ranges from 7,743 psi (Cline Fm), 7,389 (Strawn Fm), to 9,783 (Atoka Fm). These relationships suggest that white sand provides adequate frac conductivity for 35% to 45% wells completing in the Upper Atoka and Atoka-Bend zones, or when average porosity is less than 7.5%. Likewise, the Strawn can be completed with white sand 80% of the time instead of ceramic because the zone has lower permeability and closure stress. The Cline formation should ceramic proppant only about 10% of the time. This method of prescribing the ideal proppant considering both sonic-based stress and formation permeability is projected to save around $96,000 per well. This translates to 6.4 million dollars for 67 wells to be drilled in Queen Anne's Field from the 2nd through 4th quarter 2014. This is a huge incremental value enabled by adding sonic logs and petrophysical analysis to the completion design paradigms.

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