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 Tip Screenout Fracturing Applied to the Ravenspurn South Gas Field Development
J.P. Martins, SPE, BP Exploration (Alaska); K.H. Leung, SPE, M.R. Jackson, SPE, D.R. Stewart, * SPE, and A.H. Carr, SPE, BP Exploration, Europe
*Now at Hamilton Bros. Oil & Gas
This case study describes the theory and a field-proven procedure for designing Tip Screen Out (TSO) treatments. The authors considered fracture conductivity to be the key to cost-effective fracturing in higher permeability formations.
Application of TSO fracturing in the Ravenspurn South gas field was shown to result in seven-fold productivity increases (relative to a prefracture skin of zero), compared with three-fold increases for aggressive conventional treatments. Extensive baseline and post-frac data gathering and analyses were performed and are documented in the paper.
Post-fracture analyses on wells that received standard, aggressive fracture treatments showed fracture conductivities of only a few hundred millidarcy-feet, despite the use of up to 500,000 lbm of 16/20 mesh intermediate strength ceramic proppant at up to 12 lbm/gal, pump rates of 50 bpm, and rigorous quality control procedures. These conventional treatments were believed to achieve average proppant concentrations between 1.25 and 1.8 lbm/ft2.
Wells stimulated with TSO technology were shown to yield fracture conductivities between 1,000 and 10,000 md-ft, even in the presence of severe non-Darcy effects. This 10-fold increase in conductivity was shown to provide at least twice the productivity increase of alternative fracturing strategies.
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