The Staged Field Experiment (SFE) Well No. 2 is the second of four wells funded by the Gas Research Institute (GRI) for the advancement of research in fracturing and completion technology. This tight gas well is located in a lease owned by Amoco, in the North Appleby Field, Nacogdoches County of East Texas. The well is completed in the Travis Peak Formation which is a sequence of sand shale layers found from 8,000 to 10,000 ft. The permeability and porosity average approximately 0.05 to 0.08 md and 5 to 9 %, respectively.

Extensive pre- and post-fracturing tests were conducted by a consortium of academic and industry participants under the direction of a main GRI contractor. These include the stress testing of 25 zones and two mini-fracturing treatments ranging in volumes up to 6550 bbls. This paper derives a closure stress profile and possible variations using these data and related field experience, and simulates the main fracture treatment using a three dimensional fracture simulator. The simulations suggest fracture width reduction (pinching) at the perforations because of the presence of a low stress zone below and unsymmetric fracture height growth.1  Significant fracture height is indicated by both field data analysis and simulations. Fracture treatment design strategy is significantly affected by this occurrence, which suggests changes to common fracture design practices of many operators in the area. The simulations are compared with post-fracturing field data analysis to assess the resulting fracture geometry and the predictive capabilities of the simulations. Fracture design strategies are suggested for the area resulting from the experience gained from the SFE No. 2 well.

You can access this article if you purchase or spend a download.