| Popis: |
Cased-hole fracpacks (CHFP) can deliver high-rate, low-skin completions by creating a highly conductive fracture that extends beyond the perforation tunnels, bypassing near wellbore damage and preventing formation sand production. While the industry has a long history of successful CHFP applications, well performance prediction for this type of completions has remained challenged by complex geometrical (fracture geometry and orientation with respect to arbitrarily deviated wellbores) and multi-physics factors (multiphase flow, turbulence). Most fracpack modeling tools are limited to analytical and simplified reservoir simulation models, which can lead to poor accuracy in quantifying near-wellbore effects, such as non-Darcy pressure drop, particularly important for high-rate gas wells. In this paper, we propose a new mechanistic approach to incorporate the cased-hole fracpack completion with non-Darcy flow through explicitly meshed perforation tunnels, fractures and rock formation in real dimensions. The fracture is modeled by Enriched Finite Element Method (EFEM), which flexibly accounts for arbitrary fracture geometry and orientation while enabling multi-physics effects, impact of perforation/gravel packing damage and perforation-fracture communication uncertainty on deviated well productivities. The proposed approach is validated using (1) analytical and numerical models, and (2) two Gulf of Mexico (GOM) CHFP wells, one vertical and one deviated; where skins measured from step-rate tests were history-matched to longitudinal and transverse fracture models. We also introduce the concept of fracture neighborhood width to account for perforation performance relative to its alignment with fracture opening and orientation. Finally, the new approach is used to predict the deliverability of a high-rate, high-pressure gas condensate well. Non-Darcy effects, condensate banking effects, perforation gravel packing, and geological model uncertainties are included in predicting the well production. |
