BARNETT SHALE MODEL- 1
Study develops decline analysis, geologic
parameters for reserves, production forecast
Scott W. Tinker
University of Texas
Ken Medlock III
A comprehensive study of the reserve and production potential of the Barnett shale integrates engineering, geology, and
economics into a numerical model that allows for scenario
testing based on several technical and economic parameters.
The study was conducted by the Bureau of Economic Geol-
SHALE-RESERVE ASSESSMENT, PRODUCTION FORECASTING
Log, microseismic data
Well spacing: well
Panel data analysis:
validate decline curve;
describe “typical well”
ogy (BEG) at the University of Texas at Austin and funded by
the Alfred P. Sloan Foundation.
In its base case, the study forecasts a cumulative 45 tcf
of economically recoverable reserves from the Barnett, with
production declining predictably to about 900 bcf/year by
2030 from the current peak of about 2 tcf/year.
The forecast falls in the mid to higher end of other known
predictions for the Barnett and suggests that it will continue to be a major contributor to US natural gas production
This study by geologists, engineers, and economists resulted in a cohesive model of the Barnett, linking geologic
mapping, production analysis, well economics, and development forecasting.
The study will be presented in two parts: Part 1 summarizes the geologic characterization, per-well production
decline analysis, and productivity tiering required to feed
into the detailed modeling of future reserve and production
forecasts. The conclusion (OGJ, Sept. 2, 2013) examines full
field economics and production and reserve forecasts.
Part 1 offers several unique contributions:
• Well-by-well analysis of production and calculation of
estimated ultimate recovery (EUR) for all wells.
• Development of a physics-based
decline curve that closely describes
Barnett well declines.
• Drainage explained by linear
transient flow, resulting in decline
rates inversely proportional to the
square root of time for the first 5-8
years and later exponential decline as
a result of interfracture interference
within the well drainage volume.
• Subdivision of the field into 10
productivity tiers, providing much-improved granularity for reserve forecasting and economics.
• Geologic mapping of porosity (PhiH) and net pay-zone thickness
across the entire play. PhiH was determined to be a key driver of well productivity.
profles (by tier)
pace of drilling,