Natural Fracture Quantification for Optimized Completion Decisions
Olsen, Thomas, Tom Bratton, Randy Koepsell, and Adam Donald
Schlumberger, Greenwood Village, CO
Natural fracture enhanced formations are one of the key
parameters for commercial production from many of the
unconventional gas reservoirs in North America. Natural fractures
can enhance system permeabilities one to two orders of magnitude
over matrix permeabilities, and enable economic production from
unconventional sources. However these natural fracture systems can
be very prone to damage from cementing and fracturing fluids, which
can cause completion difficulties and greatly temper the productive
potential from these wellbores.
This paper presents a process for quantifying the natural fracture
azimuth and porosity through fracture characterization logs, and uses
this information to optimize the cementing and fracturing systems in
order to minimize invasion damage and maximize the productive
potential of these natural fracture systems. A customized natural
fracture leakoff control package based on specific characterization of
the natural fracture systems and properties can greatly reduce both the
frac fluid invasion damage as well as decrease near wellbore frac
gradient increases due to poroelastic leakoff effects. The result is
naturally fractured reservoirs that can come much closer to their full
productive potential with less secondary damage and near wellbore
flow constrictions. In this paper we present example applications
from the Piceance basin and the Greater Green River basin,
presenting production data, fracture analysis as well as micro seismic
evaluation.
AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah