Analyzing
Hydraulically Fractured Gas Well
Performance in the Greater Green River Basin of
Wyoming*
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Abstract
Hydraulic fracture stimulation often
dictates the economic outcome of wells completed in low permeability gas
reservoirs. Evaluating well
performance - the rate and pressure behavior of a
well
over its productive life - provides the opportunity to discover the key
elements driving stimulation and completion effectiveness in any particular
environment. This presentation demonstrates the integrated use of reservoir
engineering, petrophysical and geologic
analysis
to evaluate
well
performance,
identify flow regimes and distinguish between reservoir and completion induced
behavior. Tools used include
well
log
analysis
(for pay identification and
petrophysical calculations), the reciprocal productivity semi-
log
method (to
normalize the inevitable variations in flow rate when evaluating the
post-linear, infinite acting radial flow period), fractured
well
type-curve
analysis
, pressure buildup
analysis
and numerical simulation. The main emphasis
is an expanded discussion outlining the fundamentals of production data
analysis
. Case studies from the Greater Green River Basin of Wyoming of single
wells and entire fields draining low permeability gas reservoirs are used to
demonstrate this methodology, and significant reservoir, completion, and
production factors affecting
well
performance are identified as an outcome. The
impact of critical completion and production factors will be revealed and
discussed. These problems and factors include wellbore liquid loading (in
reducing or eliminating the effective hydraulic fracture length), treatment
sizing, treatment isolation strategies and sequencing of multi-pay completions,
treatment flowback strategy, use of velocity/ tubing strings and selection of
landing depths, and shutting in a producing
well
. Remedies are suggested for
stimulation and completion induced problems.
Almond Formation, Lookout Wash Field, Washakie Basin
Lodgepole 20-29, underperforming welll, Moxa Arch / La Barge Platform