Aggressive drawdown on unconventional wells commonly leads to the return of proppant pumped during the stimulation treatment, reducing propped fracture aperture, with potential impact on hydrocarbon production. Despite being identified by the available literature as a source of concern to operators, how much proppant flowback affects unconventional well production is a question that remains unanswered.

This study quantifies the impact of proppant flowback on gas production under different drawdown scenarios through numerical simulations history-matched with proppant production measurements in the field.

The numerical simulations were performed with a fully coupled reservoir, fracturing and geomechanics commercial simulator (ResFrac) using its module to simulate proppant flowback. The physical model employed to quantify proppant production was tested, validated, and improved with this study. Two different operators shared proppant flowback and production data from two gas wells in the Vaca Muerta Formation (Argentina) to carry out this analysis. Such field data was utilized to history-match proppant flowback data from unconventional wells for the first time. The calibrated models were used to understand the effect of drawdown management on proppant flowback and its impact on early-time gas production and its estimated ultimate recovery. A series of sensitivity analyses on critical variables in the model were also conducted to further study the potential influence of proppant flowback on gas production under different conditions. Results show that proppant flowback may not always be detrimental to gas production, and that its influence varies depending on each case.

This presentation was given by Agustin Garbino, from the University of Texas at Austin. Agustin holds a Bachelor of Science in Petroleum Engineering from Instituto Tecnologico de Buenos Aires (ITBA). He has six years of experience as a reservoir engineer in the oil and gas industry, contributing to the development of conventional and unconventional assets in Argentina. He holds a Master of Science degree in Petroleum Engineering from the University of Texas at Austin focused on geomechanics and hydraulic fracturing modeling. He is currently working as an Engineering Data Analyst specializing in offset pressure analysis at Reveal Energy Services (a Kappa Engineering company).

Click here to view slides presented.

Click here to view a copy of Augustin’s thesis that includes documentation of the workflow followed in the presentation.