Data Analysis of Barnett Shale Completions

Abstract

Abstract The north Texas Barnett shale illustrates successful commercialization of an unconventional reservoir. However, it took 17 years to evolve from pumping crosslinked gel (XLG) carrying more than 1 million pounds of proppant per job to slick water fracs (SWF) consisting of large volumes of water and small quantities of sand. This transition to SWF stimulation opened the door for widespread development that has advanced the Newark East (Barnett shale) to the largest producing gas field in the state of Texas. This paper investigates Barnett completion strategy during the time period from 1993–2002. The 393-well dataset includes completion, reservoir, and production data. Unique data visualization tools were used to investigate various completion parameters and their effect on production.1 This unbiased look at a large block of data challenges some of the preconceived opinions about Barnett shale, including: The Barnett shale is a continuous/homogeneous formation yielding commercial production in all instances. XLG fracture stimulation is damaging to the Barnett, and SWF always outperform XLG fracs. High rates and large volumes of fluid and proppant always give higher production. Reservoir quality is unimportant or has a negligible effect on production outcome. The effect of changes in stimulation variables on production is readily apparent. We found that production results show a broad scattering when crossplotted with various completion and reservoir inputs. This result is not uncommon when analyzing field data. The large number of variables and scatter within the data required the use of data clustering techniques to extract useful information. Advanced data mining techniques were used, including self-organizing maps (SOM) to reduce the statistical noise and highlight completion and reservoir parameters directly affecting production. The results show a production outcome based on reservoir quality and completion strategy.