Study of Almond Reservoir Connectivity in Wamsutter Field

Soto, Luis E.
BP, Houston, TX

     Wamsutter is a giant tight gas field in Wyoming that covers over 2,500 square miles, and has produced over 4Tscf from 2,000+ wells. Around 85% of total production is coming from the prolific Almond Formation.
     The Almond formation consists of shales, coals and sandstones bodies deposited in fluvial, coastal plain, lagoonal, tidal channel, and marine bars environments during the transgressive cycle of the late Cretaceous Interior Seaway in several.
     As in many fields, Wamsutter has gone through several down spacing processes from the initially developed at 640 acres, to it's current development at 80 acres. BP is evaluation a new down spacing scenario to maximize the recovery in the gas field.
     Down spacing decisions have been mainly driven by drainage area evaluations. There fore reservoir connectivity has been incorporated as one of the most relevant parameters to focus on in a multidisciplinary effort attempting to develop a more comprehensive reservoir understanding. Ultimately, this evaluation will allow BP to determine to optimum well spacing for the most efficient field development.
     The reservoir connectivity study corroborates unexpected pressure depletion recorded in the field at 40 to 80 acre spacing.
     This reservoir connectivity presentation covers the most significant aspect of the study. It will include results, methodology and the parameters affecting reservoir connectivity. Those parameters take account of depositional environment, reservoir architecture, sand body dimensions, sand to gross ratio and porosity permeability distributions. They were independently studied, integrated and evaluated using 3D stochastic and dynamic modeling techniques.

AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah