It is reasonably well understood that hydraulic fracturing applications can be especially problematic when a fracture will be initiated from a wellbore that is passing through a reservoir at a trajectory that is highly deviated from the in-situ stress field. Numerous papers and texts are available that have addressed laboratory experimentation or example situations. It is generally recommended to avoid this wellbore condition when possible if fracture stimulation will be required. However, this may not always be possible.

Included herein is a summary review of basic problems that may be encountered when it becomes necessary to apply hydraulic fracturing to a zone with a highly deviated wellbore. Guidelines are offered for how to best adapt the well completion parameters to various specific reservoir conditions, including the following:

  • In regard to rock hardness and competency, the approach and result in soft rock will normally vary greatly from that of harder rock in more ways than simply permeability.

  • Measured depth and true vertical depth of the zone to be completed should be considered variables.

  • Formation thickness can be an important factor.

  • Single pay vs. multiple zone completions.

  • Thinly stratified pay intervals can be quite different

  • Perforating strategy can be the most important variable; it can often prevent effective stimulation, or conversely, can be used to enable fracturing success.

In some fields, the expanding application of horizontal completions may reduce the use of deviated wellbores. However, environmental concerns for reducing surface footprints during land drilling could increase the use of deviated wellbores. This paper will review the factors most critical to successful placement of hydraulic fracturing treatments in deviated wellbores.

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