Case Study : Patch prevents sustained casing pressure before shale fracturing

Patch prevents sustained casing pressure (SCP) before shale fracturing

In conjunction with squeeze, Saltel Xpandable patch cures SCP before multistage stimulation (MSS)

Context

The client had bad cement sections in his 5.5in 20 lbs/ft casing. These sections were impeding high-pressure multistage stimulation operations; This was due to the high risk of Sustained Casing Pressure in the annulus. The client perforated and squeezed the cement sections with resin. Once the resin squeeze processed, they still needed an additional innerlining barrier to:

• Protect the squeeze both from numerous cycles of frac pressure and from the large volumes of proppant to be pumped during the stimulation.
• Reinforce, and help the squeeze act as a solid barrier, against fluids or gas migration behind the casing leading to micro-annulus.

Solution

Saltel proposed three Patches 5.5in reinforced, to cover three sets of resin squeeze perforations, as a complementary barrier. Saltel Xpandable steel patch did not only isolate perforation shots but also drastically mitigated the risks of gas migration in the annulus. The internal pressure rating of the casing was wholly restored and allowed sustaining high fracturing pressures applied.