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 Erosion by Proppant: A Comparison of the Erosivity of Sand and Ceramic Proppants During Slurry Injection and Flowback of Proppant
M.C. Vincent, SPE, CARBO Ceramics Inc; H.B. Miller, University of Arizona;
D. Milton-Taylor, SPE, FracTech Ltd; P.B. Kaufman, SPE, CARBO Ceramics Inc.
This paper examines the erosion mechanisms associated with particle-laden fluid flow. It demonstrates that theoretical and laboratory measurements are in agreement that lightweight ceramic proppants (LWC) are less erosive than sand products. This is due primarily to the superior roundness and sphericity associated with the ceramic proppants as compared to the more angular sand particles. Real-world results from many oilfields as well as oilfield supply manufacturers are reviewed to substantiate this conclusion. The findings of this study are applicable to both pumping as well as flowback conditions.
Tests simulating flowback conditions show that substituting a spherical LWC proppant for a more angular sand may reduce wellhead or other impingement erosion by up to 95%. Even the highest quality frac sand was 9 times more erosive than LWC. Erosion in chokes was found to be 3x higher with sand than with CARBOLITE®.
Finally, the paper also shows that, despite conventional wisdom to the contrary, studies have demonstrated that spherical proppants (like CARBOLITE®) are less likely to flow back from the fracture as compared to the more angular products like quartz sands. All data indicate that equipment erosion (frac as well as surface production) can be reduced substantially by using LWC proppant. |
