Design and Execution of Horizontal Wells in Gas Shales Using Borehole Images and Geochemically- Enhanced Formation Evaluation
Miller, Camron1, Rick Lewis2, and Keith Bartenhagen2
1Schlumberger, Oklahoma City, OK
2Schlumberger Data and Consulting Services
Horizontal drilling is a key technology used worldwide in
conventional and unconventional reservoirs to maximize and speed
the recovery of hydrocarbons. Most conventional reservoirs within
the United States have been exploited, and the focus is now on the
development of unconventional plays. Organic shales, the
hydrocarbon source for conventional reservoirs, have become a viable
target resource for gas. The poor reservoir characteristics of shales
make them ideal candidates for horizontal drilling development. This
paper will focus on new technologies and strategies for horizontal
well placement within gas shales.
These projects require interaction between geologists, engineers, and petrophysicists to develop an integrated approach to the design and execution of horizontal wells. Key reservoir parameters and evaluation packages have been established for gas shale deposits.
Borehole images and geochemical data have become the standard evaluation technique for gas shales. Geochemical logs provide a gamma-ray-independent clay content and a matrix density that corrects for the complex lithology of shales. These data are used along with borehole images to identify shale layers with the optimal mineralogy for reservoir performance and drillability. Borehole images allow one to identify and define the orientation of bedding, drilling-induced and natural fractures, and faults. These data are used to determine the drilling azimuth and inclination angle for the horizontal well.
These techniques have been successfully applied to many horizontal wells within the continental United States. Several examples will be presented. Sharing new technologies and strategies for horizontal well employment should allow operators to become more successful in these ventures.
AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah