Discrete wellbore and fracture modeling for unconventional wells and unconventional reservoirs

Randy D. Hazlett, D. Krishna Babu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)


Newly-developed, generalized analytic solutions to the heat equation for arbitrary 3D well trajectory in anisotropic media are demonstrated to solve benchmark horizontal and slanted well productivity problems with unprecedented speed and accuracy. Arbitrary well trajectory is constructed as an assemblage of spatially integrated, linear well segments, as opposed to a distribution of numerically integrated point sources,to provide advantages in both computational speed and accuracy in singularity handling. Production from each arbitrarily-oriented segment is reduced to a combination of purely analytic expressions and rapidly-convergent, exponentially-dampedinfinite sum approximations. With offered flexibility in cell boundary conditions,the expressions can yield stand-alone well productivity estimates for complex wells or serve as the basis for advanced well equations,if integrated within a numerical reservoir simulator. Transients are also computed with analytical integrations in time, thus requiring no time marching. The breakthrough speed and accuracy in productivity assessment opens possibilities for advanced well testing and reservoir characterization methods. We further demonstrate the usefulness of analytic methodology with several time-dependent,discrete fracture problems for shale gas production with typical Barnett conditions,allowing direct use of complex fracture patterns,such as those interpreted from microseismic. In addition to uniform flux and uniform pressure modeling options,a new analytic model is introduced that is capable of modeling both time-dependent material transport between matrix and a stimulated zone and the interplay between a well and fracture. We illustrate our solution method with fractured Barnett well examples from the literature. With optional effects such as gas desorption and stress-dependent fracture conductivity as easy add-ons, we can produce full operational life production forecasts for shale or tight gas reservoirs from discrete,complex fracture patterns along with reservoir pressure mappings in a matter of minutes on common PC platforms.

Original languageEnglish
Title of host publicationSociety of Petroleum Engineers - SPE Annual Technical Conference and Exhibition 2012, ATCE 2012
Subtitle of host publicationUnconventional Wisdom
PublisherSociety of Petroleum Engineers (SPE)
Number of pages21
ISBN (Print)9781622764150
Publication statusPublished - 2012
Externally publishedYes
EventSPE Annual Technical Conference and Exhibition 2012: Unconventional Wisdom, ATCE 2012 - San Antonio, TX, United States
Duration: Oct 8 2012Oct 10 2012

Publication series

NameProceedings - SPE Annual Technical Conference and Exhibition


ConferenceSPE Annual Technical Conference and Exhibition 2012: Unconventional Wisdom, ATCE 2012
Country/TerritoryUnited States
CitySan Antonio, TX

ASJC Scopus subject areas

  • Fuel Technology
  • Energy Engineering and Power Technology


Dive into the research topics of 'Discrete wellbore and fracture modeling for unconventional wells and unconventional reservoirs'. Together they form a unique fingerprint.

Cite this