Geoscience Revelations from Analytic Production Modeling

Stuebinger, Lon¹, Don Shaw^2
1 Fires for Him, Inc, Evergreen, CO
² Patina Oil & Gas, Denver, CO

A new source of geologic information has arisen from an old source: basic production data. Especially valuable in tight or unconventional gas reservoirs (including CBM), analytic production modeling (APM) has revealed some surprising - and some disturbing - new perspectives. APM can assist engineers and geoscientists alike in differentiating between reservoir influences and completion and production practices on well performance. Using basic production data, valuable insights can be quickly revealed, providing explanations for anomalous production and further refinements of geologic interpretations.

Productivity is oftentimes used as a proxy for changing reservoir characteristics without quantitative recognition of completions or production efficiencies that may lead to missed opportunities. Poor wells are frequently attributed to poor reservoir potential while good wells are just anomalous for unknown reasons. APM signatures can distinguish wells in radial vs. non-radial flow, moderate fracturing from sparse or intense fracturing, dual-porosity/permeability systems, operating problems, interference, completion effectiveness, etc. Completion effectiveness can be further qualified beyond traditional Xfe (effective half fracture length) values to differentiate between completed or producing net pay vs. net pay thickness. Such signatures can help define or redefine geologic interpretations of net pay, depositional environments (channel or bar sands), reservoir boundaries, natural fracturing and reservoir continuity through depletion.