SPE Drilling & Completion
Volume 27, Number 3, September 2012, pp. 348-354

SPE-143304-PA

The Effect of Fracture-Face Matrix Damage on Productivity of Fractures With Infinite and Finite Conductivities in Shale-Gas Reservoirs

  • Jun Li, China University of Petroleum (Beijing)
  • Boyun Guo, University of Louisiana at Lafayette
  • Deli Gao, China University of Petroleum (Beijing)
  • Chi Ai, Eastnorth Petroleum University

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DOI  More information 10.2118/143304-PA http://dx.doi.org/10.2118/143304-PA

Citation

  • Li, J., Buo, B., Gao, D. et al. 2012. The Effect of Fracture-Face Matrix Damage on Productivity of Fractures With Infinite and Finite Conductivities in Shale-Gas Reservoirs. SPE Drill & Compl 27 (3): 348-354. SPE-143304-PA. http://dx.doi.org/10.2118/143304-PA.

Summary

Producing natural gas from shale-gas reservoirs presents a great challenge to petroleum engineers owing to the low-permeability nature of this type of gas reservoir. Large-scale and expensive hydraulic-fracturing operations are often required for enhancing gas well productivity. Because of the shaly characteristics of the reservoir rock, the hydraulically fractured gas wells are vulnerable to damage by fracturing fluids. However, the true significance of the formation damage in shale-gas reservoirs is still not clear. It is highly desirable to have a simple method for predicting the degree of fracture-face matrix damage and for optimizing fracturing treatments. This paper is meant to fill this gap.

A new mathematical model was developed in this study to predict the effect of fracture-face matrix damage on the productivity of fractured gas wells in shale-gas reservoirs. A unique feature of the new model is that it considers reservoir/fracture crossflow in finite-conductivity fractures. Results of the model analyses were sensitized to reservoir properties and facture-face matrix-skin properties determined by the fracturing-fluid properties and treatment conditions. Large ranges of possible leakoff and spurt-loss coefficients were investigated. We concluded that, in the ranges of reservoir and fluid properties used in this study, well productivity should drop by less than 15% even if the residual matrix permeability is reduced to only 5% of the virgin reservoir permeability in the damage zone. Neglecting the resistance to flow in the fracture will overestimate the effect of matrix damage on well productivity. The well-productivity drop caused by matrix damage is most sensitive to the invasion depth and damaged permeability.

© 2012. Society of Petroleum Engineers

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History

  • Original manuscript received: 7 September 2011
  • Meeting paper published: 8 June 2011
  • Revised manuscript received: 4 February 2012
  • Manuscript approved: 28 March 2012
  • Published online: 2 August 2012
  • Version of record: 18 September 2012