Stepping Back: Exploration Synthesis & Business Opportunities that Opened up the Delaware Basin WolfBone Resource for Economic Development
Eagle Oil and Gas
Application of detailed-oriented advanced technology is critical in achieving best production and economic returns as Permian Basin plays become more mature, manufacturing-oriented. The Permian Basin advantage over other resource plays and resource basins is the greater number and scope of source rocks, resource plays and transitional conventional reservoirs in resource settings that are under exploited, undefined or undiscovered. Making these economic is often not application of advanced technologies but practical application, synthesis and integration of known geologic skills, techniques and principles that create the greatest economic return for our companies and their investors. There are multiple opportunities yet undiscovered or discovered but not yet economically defined in the Permian Basin and other resource plays throughout the U.S., North America and world-wide.
Today we will review the early exploration, de-risking and early development of the WolfBone Play in the Southern Delaware Basin. These include the geologic observations and techniques used to identify and encourage our company to make assertive business decisions and investments to capitalize on the geologic observations and work.
The WolfBone is an unconvential oil resource in the southern Delaware Basin. Exploration and development has been a systematic evolution from geologic concept to drilling, production, evaluation and revision of targets. Originally exploration focused on Wolfcamp sandstone reservoirs below and Third Bone Spring sandstone reservoirs above to current focus on the 1,000' thick, oil-rich, unconvential Wolfcamp shale.
The Wolfcamp is a heterogeneous resource consisting of quartz, carbonate and kerogen. The geologic and economic sweet spot is limited to the basin floor on the gently-dipping western flank. In this setting quartz and kerogen accumulated in the quiet deep-basin interrupted by episodic deposition of shelf to basin floor carbonate and slope to basin floor quartz-rich debris flows that settled basin-ward of the slope to basin floor de-acceleration boundary. These depositional processes resulted in compositional and grain-size heterogeneities and accumulation of the thick organic-rich, technically and economically exploitable targets.
During maturation large volumes of oil were sealed in place. Expansion from kerogen to oil in a sealed system resulted in overpressure, development of organic porosity, and geo-pressure fracturing of the source/reservoir rock. The "Super Sweet Spot" of this play is where these are best developed and enhanced by structural development of the Delaware Basin. This is defined by residual trend structural surface and second derivative mapping. Individual wells have flowed over 80 MBO from 11,000' prior to initiating artificial lift; atypical of Permian Basin reservoirs. Farther into the basin and upslope these conditions do not exist and are outside the economic sweet spot. Upslope the unit thins is gas-prone and the mixture of coarser-grained shelf carbonates and sandstones provided migration pathways breaching the closed system, limiting available hydrocarbon, fracturing, productivity and ultimate economic recovery. Geologic/Reservoir models are being developed to more accurately predict those parameters and economic outcomes of current and future drilling targets.
Since 2009, this play has been developed with vertical wells co-mingling the oil-resource with conventional reservoirs. Interpretation of imaging logs has identified the primary fracture orientation and zones with conjugate fractures systems. Integration with production logs has optimized horizontal target identification. During 2013 continuing presently, horizontal development drilling targeting the highest potential zones has increased dramatically. In some areas and for some companies, vertical drilling will continue to be the better choice. We will examine those choices.
AAPG Search and Discovery Article #90205 © AAPG Geoscience Technology Workshop, Permian and Midland Basin New Technologies, September 4-5, 2014, Houston, Texas