Examining Our Assumptions – Have Oversimplifications Jeopardized Our Ability To Design Optimal Fracture Treatments?

Tuesday, 09 March 2010 Read 4088 times
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Abstract

It is mathematically convenient to describe fractures as simple, vertical, planar features of predictable width and hydraulic continuity. Published conductivity data are used with the premise that laboratory tests provide a reasonable representation of expected flow capacity of actual fractures. Presuming homogenous reservoirs and predictable drainage boundaries dramatically simplifies reservoir modeling and development planning. All these assumptions, however, oversimplify a very complex problem. This presentation will contrast these assumptions against actual observations, and investigate the effect of these simplifications on fracture treatment design and well performance.

The speaker reviewed 150 published field studies documenting production changes when fracture designs were altered, and 40 reservoirs in which refracs were attempted. Frequently, the observed production results cannot be explained with simplistic assumptions of fracture geometry, reservoir homogeneity, and simplistic fluid flow.
This presentation will summarize evidence from a variety of sources demonstrating that:

  • Fracture geometry is frequently complex, with imperfect lateral continuity
  • Fluid flow regimes are complex – often causing pressure losses 100-times higher than predicted from published conductivity data
  • Reservoirs contain heterogeneities such as boundaries, laminations, lenticular sand bodies, faults, stresses, and anisotropic permeability that influence fracture performance.

Hydraulic fractures are key to the development of most low permeability reservoirs, yet they are frequently characterized incorrectly and poorly optimized. The primary message of this presentation is that unrecognized opportunities exist to improve well profitability. Challenging our misconceptions and examining actual field production has yielded techniques to improve fracture designs - despite the failure of our simplistic models to recognize those opportunities.

Mike Vincent is a consulting engineer with 19 years\' experience in economic optimization of hydraulic fractures. After completing his degree at the Colorado School of Mines, he worked with Amoco in Denver, and with ARCO in Anchorage, Kuparuk, and Denver. Mike started Insight Consulting in 1996, specializing in fracture design and reservoir analyses. Mike has been consulting with CARBO Ceramics since 1998, where his work is focused on helping clients improve fracture designs by accurately predicting production under realistic conditions. He has written more than 15 technical papers, has been awarded two patents, and has instructed more than 100 seminars on fluid flow, fracture design, and practical production optimization. He is very active in SPE, serving as a technical editor and on steering committees for several SPE meetings and workshops. Mike frequently lectures at universities and presents fracturing schools to numerous companies and organizations.

Congress Center of RF CCI. Start at 7 p.m.:

Meeting presentation

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