StackFRAC slimhole system significantly increases stage count and speeds up refrac well operations

MIKE KENYON, Packers Plus  

Packers Plus deployed the StackFRAC^® Slimhole completion system to support an operator that required a high stage count, ball-activated refrac system to increase production from a well targeting the Lodgepole formation in western Manitoba, Canada. 

In just a few months, Packers Plus completed design, simulation, prototyping and testing for several tools in the StackFRAC Slimhole system (Fig. 1) that created a large inner diameter (ID) throughout the wellbore and enabled the successful completion of the 24-stage system in just 10 hrs. 

Fig. 1. The StackFRAC® Slimhole system enables operators to maximize production from mature assets with targeted stimulation.

CHALLENGE 

The targeted oil well was previously completed, using a different multi-stage cemented completion technique on a 4.500-in. liner. In an effort to restimulate the reservoir and increase production from the well, the operator’s refrac program required installation of a refrac system on a 2.875-in. liner, with the capability to stimulate all 24 stages of the original completion. 

While multi-stage, ball-activated completion systems have proven to be very effective and operationally efficient, they have historically faced some limitations when it comes to stage counts, specifically in refrac systems. 

SOLUTION 

The StackFRAC Slimhole system is specially designed with a smaller liner outside diameter (OD), enabling operators to re-enter vertical or horizontal wells, Fig. 2. This system provides a cost-effective solution for restimulation and well recovery applications by enabling exact placement of stimulation treatments in one continuous pumping operation, saving operators time and money.  

Fig. 2. The Slimhole system is specially designed with a smaller liner outside diameter, which allows operators to re-enter vertical or horizontal wells.

Further modifications and optimizations of the tools have been made to meet current stimulation challenges that operators face, such as stage counts, pressure rates, and increased sand tonnages. These changes were applied to the full product line for sweet and sour applications and 3.5-in. or 2.785-in. liner options are available, as required, to meet desired stimulation rates. 

Key tools that make up the StackFRAC Slimhole system include the Hydraulic Set RockSEAL^® IIS Liner Hanger Packer, Tandem Hydraulic Packer, and the FracPORT™ HD-X Sleeve. Working closely with the operator, Packers Plus made modifications and optimizations of the tools, ensuring all changes were compatible with L80 steel and completing rigorous testing. 

RESULT 

The 24-stage StackFRAC Slimhole system was run on 2.875-in. liner in the previously completed well, which had a measured depth (MD) of 2,305 m. The stage lengths of the well ranged from 40 m to 68 m. The 1/32-in. ball seat increments in the FracPORT HD-X sleeves enabled the largest ID possible while selectively targeting every stage in the well.   

After successful installation of the system, the completion was pumped in one continuous operation. Every sleeve opened, and full treatment was delivered for a total of 906 m³ of fluid pumped in just over 10 hrs. SF901 dissolvable balls were used to activate the FracPORT HD-X sleeves in each stage during the completion to eliminate drill-out and bring the well on production quicker. 

ABOUT THE AUTHOR 

MIKE KENYON has over 25 years of oil and gas experience and has been involved in the running and designing of open-hole multi-stage systems since their inception. Over his career, he has worked in various operational and sales roles. Mr. Kenyon is currently the Regional Sales manager of Canadian operations for Packers Plus Energy Services Inc.