Quantifying Non-Darcy Effects on the Productivity of a Cased-Hole Frac Pack (CHFP) Well

Abstract

Abstract Well completion plays a critical role in the performance of a well in its entire life. More and more advanced well completion options are available for potential deployment in new wells, especially those in deep water and offshore; however, the cost could vary significantly from one completion type to the other. So could the well performance under a specific type of well completion. There are many different completion options available in the industry, including open hole, slotted liner, inflow control devices, intelligent well completions (DIACS), perforated cemented liner, wire wrapped screen, ECPs, gravel pack, and frac pack, etc. Under most circumstances, the completion for a new well is selected based on its cost, performance, sand control potential, water shut-off possibility, reliability, and so on. An appropriate well completion design requires an accurate prediction of well performance. Unfortunately, well performance prediction models available in current commercial packages need to be improved for certain well completion types to account for the details of fluid flow in the completion. One of the completions falling under this category is cased-hole fracpack completion where fluid flow would suffer because of the bottleneck effects associated with fluid flow in fractures and fluid flow along perforation tunnels. In particular, for high rate gas wells, non-Darcy flow would play a significant role for fluid flow along perforation tunnels, in fractures and formation, and thus would have substantial negative impacts on well productivity. Appropriate quantification of the non-Darcy flow effects is critical for accurate well performance modeling for the cased-hole fracpack completion. In the present paper, the non-Darcy flow impacts will first be discussed for fluid flow in fractures, in formation, and along perforation tunnels. Methodologies to quantifying the impacts will then be discussed and the procedure to account for the effects in well performance modeling will be proposed. A series of sensitivity studies will then be conducted to illustrate the relative importance of key parameters on the non-Darcy flow. Finally, the new approach will be applied to a fictitious field to demonstrate what the difference in well productivity prediction would make with and without reasonable account for the non-Darcy flow effects.