Innovation is Key to Finding New Oil in an Old Sandbox - East Texas Stacked Play

Albrecht, Tony (Geoscience, Hawkwood Energy, Denver, CO, United States) | Kerchner, Stacy (Engineering, Hawkwood Energy, Denver, CO, United States) | Brooks, Scott (Petrophysics, Hawkwood Energy, Denver, CO, United States) | Kolstad, Eric (Drilling, Hawkwood Energy, Denver, CO, United States) | Willms, Trevor (Engineering, Hawkwood Energy, Denver, CO, United States) | Klein, John (Geoscience, Hawkwood Energy, Denver, CO, United States) | Stemler, David (Geoscience, Hawkwood Energy, Denver, CO, United States)

OnePetro 

Abstract

The Mesozoic-aged Brazos Basin, situated at the southwestern-most extent of the East Texas Basin and along trend with the Maverick Basin, is bracketed by the Edwards Reef, San Marcos Arch and the Angelina Caldwell Flexure (Davidoff, 1991). A significant wedge of siliciclastic and carbonate mudrocks accumulated outboard of the Harris Delta throughout the Cretaceous. This relatively restricted basin preserved good, clay-rich source rock which interfingers with a variety of conventional oil and gas bearing reservoirs deposited during the Upper Cretaceous. The Lower Eagle Ford (LEaF) source section sits beneath the Austin Chalk and above the carbonate platform of the Buda and Georgetown Formations. The silt and sand facies of the Woodbine Formation adds an internal target, where the LEaF thickens beyond 250'. Situated along the western flank of the basin, parts of Brazos, Burleson, Leon, Madison and Robertson counties pair good source rock facies with conventional reservoirs, creating a prolific stacked interval with multiple horizontal targets. Horizontal drilling and hydraulic fracturing technologies have opened up the LEaF formation and accelerated production in tight reservoir facies of the aforementioned intervals. Anadarko, Apache, Clayton Williams, EOG, Halcón and Hawkwood have led the charge to prove profitability of the LEaF unconventional play, which to date, has had compelling results. The LEaF has challenging rock characteristics, which made it easy to overlook when industry was exploring for TOC-rich unconventional plays in the mid 2000's. Along with low resistivity, high clay and questionable maturity, this area had relatively poor initial exploration success and little to no regional framework established. By combining petrophysical, detailed reservoir & production analyses, innovative mapping, targeted well placement, geophysical attributes, best in class drilling technology, and flexible completions Hawkwood is evaluating multiple plays in this area. The value to the play area has increased in several ways; gross interval of interest has increased from 200' to over 1200', oil in place calculations have doubled to 50-60 MMBO/sec, the number of prospective horizontal targets has increased from 2 to 6 and development is capable of delivering consistent & long term production. We present a series of maps depicting where plays stack, oil in place becomes greatest and economic viability flourishes.

  Country: North America > United States (1.00)
  Geologic Time: Phanerozoic > Mesozoic > Cretaceous (1.00)
  Industry: Energy > Oil & Gas > Upstream (1.00)