Case study – Frac port isolation with saltel PreFRAC patch
The client had a frac port prematurely open at stage 30 (total 36 stages). The upper ports were milled to 116 mm / 4.56 in. to allow access to port 30. The client then completed a clean-up trip to set the casing patch to fully restore well integrity to continue on fracturing the remainder of the well.
The purpose of the patch was to restore well integrity and resume fracturing operations. Once the patch set, the largest ball size required was 3.250 in [82.55 mm] OD. Having heavier pipe weight uphole 75.44 lbs/ft [34.22 kg/m] and lighter casing weight in the zone to seal was a critical challenge for the job.
The well was killed using 7% KCl water. Saltel Industries ran a 5-1/2in Reinforced casing patch to seal stage 30 (Leaking frac Port). When set, the patch had a Drift ID of 4.19 in [106.49 mm] allowing the largest frac ball (3.250 in OD) to easily pass through it. The top of the patch was set in 4.89 in [124.26 mm] casing nominal ID then had to be pressed out over the restricted 4.56 in frac port ID, then pressed back into 4.89 in casing nominal ID. Once fully set, the patch was pressure tested to 20 MPa and held solid, allowing the frac to commence.