Geology and Geometry, A Geological Perspective on Maximizing Performance of Hydraulic Fractures

Willis, Roger ¹, Moyer, Charles ², and Fontaine, Jim ¹

¹Universal Well Services, Inc., Meadville , PA

²Great Lakes Energy Partners, LLC, Hartville, Ohio

Thousands of wells are hydraulically fractured in the Appalachian Basin each year.  The stimulation treatment design is generally seen as  an engineering discipline.  Recent advances in understanding the dependence on both geology and the geometry of the created hydraulic fracture suggest that major improvements can be made in well performance.  In order to optimize spacing and efficiently drain a field  in mature or immature areas, the geologist must understand fracture orientation and geometry.  It is equally important that an infill well is not placed in an existing wells drainage pattern. 

This paper will illustrate how a geologist might analyze a particular geological  target and understand how the fracture design should be modified to maximize the effectiveness of the stimulation treatment.  Many geological features of the particular target such as permeability, faults, natural fractures, etc. and the orientation of these features in relation to the regional in-situ stresses can significantly affect the results of a stimulation treatment.

Case specific examples will be outlined and utilized to illustrate the result the geological characteristics can have on the geometry and dimensions of the created hydraulic fracture. 

Results of the first Micro-Seismic fracture imaging of an Appalachian Basin stimulation will be discussed and reviewed to demonstrate what the state-of-the-art is regarding the understanding of creating hydraulic fractures.