Downhole Packer & Casing Shoe Isolations using IG-H
Designed to isolate and seal leaks in deep-set Production Packers and Casing Shoes, IG-H is an easily deployed solution with a very low risk of affecting well operations.
Leaks in deep-set Production Packers can cause extensive delays, expensive repairs and require a long time to fix. KCI’s new Isolation Gel - Heavy (IG-H) removes these pressures through being simple and quick to deploy. IG-H is deployed as a liquid into a fully filled annulus and creates a seal around the Packer element, isolating the annulus space, which also allows easy retrieval upon decommissioning.
Beginning as a weighted gel which drops through the liquid-filled annulus, hydrostatic pressure from above forces the IG-H to gather and squeeze around the Packer and between the Tubing and Casing. This creates a solid yet flexible seal, blocking off any gas or liquid movement up or down.
IG-H is a specially engineered, time-activated product; formulated to work within the specific parameters of each well, curing to a solid yet flexible gel that compresses and energises under hydraulic pressure from above.
Needing only two team members to prepare and deploy, IG-H is simple to use and can be mixed using hand-portable, air-operated equipment. This means IG-H requires less Well downtime than most alternative solutions, minimising overruns and costs.
Every batch of IG-H is formulated against the specific Well parameters’ optimal efficiency.
IG-H can be deployed against Annulus pressure.
More important than the pressure against which we deploy the IG-H, is the ability to establish and maintain a hydrostatic overbalance that allows the gel to be energised and kept in place.
How does IG-H work?
Upon identifying a leak or an anomaly in the Well, IG-H can be deployed into a fluid-filled annulus. The fluid allows the gel to sink quickly to the target depth, where it will gather and amalgamate between the Tubing or Casing of the Well. The gel will settle on top of the Packer Element, sealing it off and blocking off Well fluids from passing either up or down.
The A-Annulus fluid through which the IG-H passes must have a maximum density of 13ppg, to allow the gel, which has a maximum weight of 15ppg, to drop to the required depth.
IG-H has a very high compression value but a low torsion/tear threshold, meaning that it will break up when the Packer is retrieved.
Certain parameters and overbalance pressures must be met for IG-H to be deployed:
Minimum difference of 2ppg between the two fluids to allow for the IG-H to drop through the annular liquid
Minimum overbalance of 200psi i.e. Lower pressure from below than is achievable from the Hydrostatic Head above
An angle less than 50° Well deviation
Maximum downhole temperature of 185℃
When might Casing shoe isolations be needed?
Pressure and temperature changes within the tubulars & cement can create cracks and micro-porosities within the casing shoe. This can cause sustained annulus pressure, which may eventually lead to casing or Wellhead seal damage.
Deployment of IG-H will allow for the isolation and repair of leaks both as a temporary solution and as part of an abandonment option for both deep and shallow Well isolations.
To create an isolation further downhole in both the Packer and the Casing Shoe, we create a 3-5ft column of IG-H gel, the volume of which depends on the annular volume between the Packer and Casing. In some cases, using a shorter column allows for greater energisation from pressure applied from above; pushing the IG-H all the way into the toe of the Casing Shoe, creating the best seal possible.
The combination of compression and energisation of the sealant gel mean the IG-H does not need to be squeezed through the leak path. Instead, it sits above the Packer, sealing against liquid and gas leaks in both directions.
IG-H Deployment success stories
Since carrying out the first Packer isolation with IG-H in 2015, we have successfully deployed the gel to operations around the world, with no failures reported.
Our successes include this case study from a Well in Malaysia:
An influx of gas in the Well’s A-Annulus was identified as a leak that went up past the upper production Packer. We established the local conditions as: an initial surface pressure of 1200psi, a treatment depth temperature of 96°C, a Packer depth of 5708ft, and a Well deviation angle of 28°. This allowed deployment of IG-H to seal the target annulus.
We prepared the required volume of 3 batches of 10 litres of IG-H at a density of 12.0ppg. This allowed for it to drop through the existing 9.2ppg Sodium Chloride Completion Fluid.
The A-annulus was topped up to full liquid capacity with 20bbls of seawater, which then enabled the deployment of 30 litres of the specially prepared IG-H to be dropped to the leak site to cure. Following pressure testing, the IG-H seal was declared successful.
Is IG-H the right solution for you?
Unlike other solutions on the market, IG-H provides flexibility which allows for the removal and recovery of Packers. IG-H can be deployed to both shallow and deeper downhole leaks.
Upon deployment, IG-H minimises disruption and Well downtime. This allows for maximisation of operational time, mitigating potential losses. Some companies offer solutions that require a high-pressure differential to activate their products which limits the efficiency and polymerisation of this type of sealant.
Resin-based solutions are hard and brittle which may not seal the leak and could lock the Packer in place, creating issues during workovers and abandonment. The time-activated nature of IG-H means that the gel remains fluid until it has reached the area where it will have the most effect without damaging the rest of the Packer, Tubing or Casing.
Deployment of IG-H not only requires fewer crew members than many alternative solutions, but the amount of equipment and intervention necessary at surface-level is minimised. This means repairs require less invasive intervention and no downhole tooling.
The seal created downhole by IG-H is not brittle or prone to cracking, unlike other solutions. Many of these require high differential pressures, placing solid products above the Packer, or rigging up equipment to force a hose down the annulus. All these solutions come with their own drawbacks, from jeopardising recovery, increasing difficulties upon decommissioning, and creating a situation which leads to the Well being unable to build up enough pressure to create the required levels of polymerisation. As a hydrostatically energised gel, IG-H is kept in place by the pressure created by the Well itself, limiting the risk of causing damage. Upon Packer retrieval, the IG-H simply breaks apart when unsupported and sinks to the bottom of the Well.
Making use of KCI’s IG-H solution to isolate Downhole Packer and Casing Shoe leaks not only avoids costly workovers but also supports Well integrity, simplifying the process of installing the sealant while creating an effective isolation.
IG-H is ideal for use in situations where a simple, easy to use solution, requiring minimal personnel for deployment is necessary.
Engineered onshore, the IG-H is formulated specifically to customer requirements, ensuring maximum efficiency in each case. The only personnel needed to deploy IG-H are a KCI Technical Services Specialist, and general assistant to provide aid when necessary.
For further information on KCI’s Packer and Casing Shoe isolation solutions, including IG-H, as well as technical videos, further case studies and to schedule a review, head over to the KCI website today.
Next Steps
To discuss Downhole Packer and Casing Shoe Isolation solutions, using Isolation Gels, including IG-H, contact KCI here.