Waterflooding With Active Injection-Control Devices Improves Oil Recovery
Authors: Carpenter Chris 
Published: December 2018

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 189824, “Strategic Waterflood Optimization With Innovative Active Injection-Control Devices in Tight Oil Reservoirs,” by Kyle Barry, SPE, Ryan McDowell, SPE, and Kevin McArthur, Crescent Point Energy, and Anton Kozin, SPE, Trena Marie Stretch, Avo Keshishian, and Jawad Farid, Schlumberger, prepared for the 2018 SPE Canada Unconventional Resources Conference, Calgary, 13–14 March. The paper has not been peer reviewed.

This paper presents the implementation of an approach for improving oil recovery by water-injection optimization using injection-control devices (ICDs) in unconventional reservoirs. In late 2016, a trial campaign began in southeastern Saskatchewan that applied ICDs in relatively low-flow-rate environments to offset production decline and improve recovery. Early-term results show that an improvement in oil recovery greater than 25% over typical waterflood configurations is possible.

Introduction

To offset production decline caused by normal pressure decline and reservoir drainage, secondary recovery using water injection has been administered in three Saskatchewan tight oil plays. This study will be focused on the Bakken formation, the area with the most-complete historical data set available to the authors.

The original completion and well-spacing plan has resulted in occasional direct water channeling from injection to production wells. This is believed to be caused by hydraulic fracturing. In some cases, this communication has limited waterflood sweep efficiency and is referred to as short-circuiting of injection fluid. Chemical and mechanical diversion techniques have been implemented to address short-circuiting with varying degrees of success.

Field Development

The simplest means to waterflood a multi stage fractured well is to reverse the direction of flow and to bullhead water from the surface without diverting or compartmentalizing fluid flow. Because the water follows the path of least resistance, nonuniform fluid injection along the wellbore and into the formation may occur. In some instances, short-circuiting of producing wells through fracture paths may occur.

Using distributed temperature sensing (DTS), the operator was able to investigate wells that were suspected of short-circuiting or channeling. Many attempts were made to redirect flow from the paths of least resistance by use of various viscous fluids and solid diverters. The effectiveness of these treatments was inconsistent and, in some cases, required multiple applications. The operator began investigating the application of mechanical diversion and isolation of sections of the wellbore to enable physical control of flow rates into different areas along the lateral wellbore.

Compartmentalization With ICDs

The nozzle diameter of ICDs can be adjusted to compensate for variations in reservoir and fracture injectivity resulting from variable permeability effects and frictional pressure losses along the wellbore, known as the heel-to-toe effect. The installations can be run in openhole configurations and within cemented or noncemented tubulars.