Shunted Gravel Pack Failures – And How to Prevent Them

Abstract

Abstract The success of any gravel pack treatment implies effective gravel coverage of the screens. Shunt tubes are used in both open and cased hole completions to overcome some of the challenges present for conventional gravel placement techniques by allowing slurry to bypass any premature bridges and continue packing downstream. Shunted gravel packs are therefore viewed as the most forgiving gravel placement technique, which has generated a myth that the use of a shunt tubes "guarantees" a successful gravel pack. However, failures of shunted pack placement are being experienced, resulting in wells that are incompletely packed. A better understanding of the limitations of shunt tube systems and an appropriate engineering design can effectively reduce the risk of shunted gravel pack failures. Case histories are used to present a variety of shunt tube gravel placement failures. Surface and bottom hole gauge data combined with an industry standard sand control simulation software has enabled more detailed evaluation and identification of the different failure mechanisms. These include incomplete packs due to shallow zone fracturing, the blockage of shunt entry due to fluid quality issues and shunts erosion failures, among others. This paper consolidates the various shunted gravel pack failure mechanisms that have been experienced in field operations and makes recommendations on how improved treatment designs can prevent them.