Downhole Safety Valve and Hydraulic Control Line leak repairs
This article discusses leaks in Hydraulic Control Lines and Downhole Safety Valves at oil and gas wells. It proposes KCI’s Isolation-Gel - Fluid Piston (IG-FP) sealant as a viable solution, avoiding pressure loss while allowing production to continue.
Downhole Safety Valves (DHSV’s) are integral to oil and gas well safety. The DHSV must be kept open to allow the well to flow, however, in emergencies, a large spring within the DHSV closes the valve, securing and isolating the well.
Hydraulic leaks within a Control Line can also cause hydraulic pressure to build within a wellhead's Tubing Hanger Void or A-Annulus. This can create well integrity issues.
When the DHSV is closed, oil and gas wells cannot flow, causing production to cease. Wells are often shut-in or taken offline if the DHSV cannot be kept open effectively.
KCI's Isolation Gel - Fluid Piston (IG-FP) sealant reduces avoidable system pressure loss by isolating leaks while maintaining the functionality of the DHSV. This in turn allows production to continue safely and efficiently. Unlike other sealants used for this purpose, IG-FP is not pressure-activated.
Read on to find out more about IG-FP and how it works.
Hydraulic leak causes
Hydraulic leaks can be caused by several factors, some of which include:
Issues with compression fittings
Leaks from the DHSV piston itself
Wireline retrievable DHSV V-Packing leaks
General component wear and tear
All these originating factors can contribute to a loss of pressure, causing the DHSV to close.
Impact of DHSV closure
DHSV closure can cause many problems for oil and gas well teams.
Often, teams are unable to keep the well flowing for an extended period due to operational issues. Due to the leak, the well must often be shut-in. This leads to:
Expensive and extended downtime costs
Loss of production
Limited access for well intervention work
Limited reservoir modelling/pressure build-ups.
These issues could be avoided if it were possible to keep leaks isolated. It would reduce pressure loss, meaning the DHSV would be kept open. This would allow for maintenance whilst continuing production. Downtime would be reduced, as would the associated costs.
The solution: KCI IG-FP
KCI's IG-FP product is a solution to hydraulic control line leaks and subsequent pressure losses.
It is a non-curing, pre-activated sealant gel that quickly plugs leaks reestablishing pressure-retaining control systems. This in turn reinstates hydraulic control line integrity.
How IG-FP works
Deployed as a highly viscous fluid, the gel is pumped into the Control Line from the surface. The gel moves along the control line until it reaches the leak path. This is followed by the standard hydraulic operating fluid.
Once the gel reaches the leak area, it acts quickly, flowing into the leak path. This immediately creates an initial block that begins to raise the system pressure.
As the gel continues to be forced through the leak path, it fills the spaces in and around the leaking compression fitting or damaged DHSV piston seal. As the system pressure is slowly increased, more gel is squeezed into the leak path until it is fully isolated and blocked.
This restores full pressure to the system, which re-opens the DHSV. This allows production to continue with minimal downtime.
IG-FP works on systems using components that operate with a pressure between 1k - 10k.
Removing IG-FP
The sealant can be removed from the system only if the DHSV is removed or locked open. Once a communication path is established the IG-FP sealant can be flushed out. However, removal is not usually required or necessary.
Applications
KCI IG-FP has been designed specifically for use in downhole applications. It is used to plug leaks in Hydraulic Control Line Fittings, DHSV piston seals and Wireline Retrievable V-Packing Stacks.
Additional solutions
In addition to IG-FP, KCI has developed an extensive range of Isolation Gel products, which can be used in downhole and subsea applications.
Most of the IG-range of products are time-activated and convert into a resilient, self-bonding and flexible solid material when injected into a system. For most surface applications, it can be returned to a fluid using a breaker before being flushed out of a valve or pipeline or removed as a solid using conventional pigging systems.
KCI IG-L
IG-L has been specifically formulated to float on oil. This supports the isolation of large gate and ball valves within oil and gas pipelines.
IG-L naturally floats to the top of a closed ball or gate valve and displaces exiting fluids through leak paths.
Learn more about KCI IG-L here.
KCI IG-S
Designed for subsea applications, IG-S has been formulated as a solid barrier to separate seawater from oil.
It can be returned to fluid whenever required.
Learn more about KCI IG-S here.
KCI IG-H
IG-H is formulated to sink in heavy brines or well completion fluids found in the good annuli.
It can be used to isolate production packers and microporosity issues caused by gas or well fluids passing cracked cement creating sustained annulus pressure.
Learn more about KCI IG-H here.
Final thoughts
KCI IG-FP is an ideal, fast-working and non-pressure activated solution for pressure loss issues caused by Hydraulic Control Line and DHSV leaks in downhole applications.
Using IG-FP allows production to continue and maintenance work to take place with minimal downtime, avoiding production loss. This makes IG-FP a highly cost-effective solution.
While IG-FP is designed for downhole applications, alternative sealant products in the IG range can be used for subsea applications. All IG-range products have a similar function but have been designed for different applications.
Next steps
If you are interested in discussing cost-effective sealant solutions for Hydraulic Control Lines and DHSVs, get in touch with KCI.
We will discuss your oil or gas circumstances well and help you decide whether IG-FP is the right product for your needs.
Contact KCI here.