Innovative Concentric 4×1 Design for Multi-Path Gravel Pack System Extends Effective Packable Length and Eliminates Additional Make-up Time

Abstract

A common problem for modern horizontal gravel pack operations is the development of an annular bridge that blocks the flow of gravel slurry and prevents formation of a complete pack. Causes of annular bridging include high-rate leakoff zones or swelling shale layers within the reservoir. Secondary flow path technologies enable slurry flow to bypass any annular bridge and complete the packing of an openhole annulus. Current secondary flow path technologies on the market either lack the flow configuration to extend farther than several hundred feet, or they add complicated makeup and running procedures to align and secure a secondary slurry flow path. A tube configuration has recently been developed to add redundancy to the flow path geometry as well as greatly increase the overall flow area, extending the effective packable length of the system. The 4×1 concentric tube design has been combined with an integral internal cross-coupling communication system, connecting tubes at each joint and adding no additional makeup time to the running procedure of conventional sand screens. This paper presents the results of full-scale gravel pack simulations with leakoff and an annular barrier. The prototype multi-path system was run horizontally inside a simulated 8½-in. open hole. Slurry flow, prepared using conventional proppant in a viscous carrier gel or with ultra-low density proppant, successfully bypassed the sand dune created by the leakoff zone and the solid annular barrier, reaching all void areas and creating a complete pack. By enabling slurry flow to bypass any annular bridge and reliably complete the packing of longer and longer horizontal intervals, secondary flow path technology promises to provide a reliable, low-cost solution for delivering failure-free gravel pack completions. Emerging technology in this field strives to simplify running procedure, extend functional length of secondary flow paths and reduce relative packing time.