The Barnett Shale (Ft. Worth Basin) as an Exploration Model

Bowker, Kent A.
Star of Texas Energy Services, The Woodlands, TX

In terms of monthly production, the Newark East (Barnett Shale) field recently became the largest gas field in Texas. Production has grown from 80 MMCF/D in January 2000 to over 700 MMCF/D at present because of accelerated new-well drilling and old-well reworks/refracs. There are over 2.5 TCF of booked proven gas reserves in the field at present. Newark East field is located in the northern portion of the Fort Worth Basin, just north of Fort Worth. The Mississippian Barnett rests on an extensive angular unconformity. Recent horizontal drilling has shown great promise to expand the play outside the current economic limits of the play. The thermal history of the basin is an important reason for the success of the Barnett. The thermal history of the Fort Worth basin is directly related to the emplacement of the Ouachita system. In the late 1990s, Mitchell determined that the previous gas-in-place values for the Barnett were low by over a factor of three. There is approximately 150 BCF/mi2 of in-place gas in Newark East field. The realization that the primary completion was only recovering 7% of the gas in place per well spurred the current (and very successful) rework/refrac program underway in the field.

The success of the Barnett play may provide a model for prospecting for other shale-reservoirs. Lessons learned from the Barnett can be used to shorten the learning curve while evaluating other shale projects. E.g., relying on a poorly-determined estimate for gas-in-place (gas content) hindered the development of the Barnett.