Print this pageAnalyzing Hydraulically Fractured Gas 
Well
Performance in the
Greater Green River Basin of Wyoming
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.