A Flow Simulator for the Design of Extreme-Length Gravel Packs Utilizing Alternate-Path Technology

摘要

A transient flow simulator has been developed for the design of extreme length (5000 ft or longer), horizontal gravel pack operations. The flow simulator incorporates alternate path technology concepts which include shunt tube hydraulics to bypass bridges/barriers in the well/screen annulus. Alternate path technology has been successfully utilized for sand control in deep water wells and, over the past decade, this technology has been applied in gravel pack intervals up to about 3000 ft. Very recent works (Barry et al. 2007; Yeh et al. 2008) have reviewed the development of alternate path technology and presented the mechanics of slurry diversion in a revised design of the multiple-shunt manifold system for extending gravel pack operations to extreme lengths of 5000 ft or greater. In this paper, the revised design of the multiple-shunt manifold system (Barry et al. 2007; Yeh et al. 2008) is incorporated in the development of the transient gravel pack flow simulator. The shunt tube hydraulics for various slurry front locations in the well/screen annulus during gravel packing is depicted in example simulations. Results from the simulations are discussed from both steady-state and transient view points. Steady-state results include the variation of pressure and shunt tube flow rates with measured depth. Transient results are presented as variations of pump pressure, crossover tool pressure, and slurry front location with elapsed time. These simulations provide some insight into the shunt tube hydraulics and associated packing mechanism as well as key pressures during gravel packing. The flow simulator can be utilized to plan and design horizontal gravel pack operations in extremely long intervals in combination with emerging technologies such as openhole gravel packing with zonal isolation or selectively gravel packing targeted intervals using alternate path technology.