For oil and gas well casing leak repair, perforation shutoff, tubing repair, and other remedial operations.
Published: 01/04/2017
Published: 01/04/2017
An operator needed to restore well integrity to begin fracturing a well in Cochrane, Alberta, Canada. A prematurely open fracture port at stage 30 of 36 stages required a patch, but heavier-weight pipe uphole and lighter-weight casing in the zone to be sealed made the operation challenging. The largest ball size required to pass through the set patch had an OD of 3.25 in [82.55 mm] and the fracture ports could only be milled out to a maximum ID of 4.56 in [115.82 mm] to gain access to port 30.
The well was killed using 7% KCl water before Saltel Industries placed a 5.5-in [139.7-mm] reinforced patch to seal the leaking fracture port. The top of the patch was set in 4.89-in [124.21-mm] nominal ID casing, pressed out over the restricted 4.56-in [115.82-mm] ID fracturing port, then pressed back into the nominal casing ID. A drift ring confirmed a final ID of 4.193 in [106.502 mm], enabling fracturing operations to restart with the largest fracturing ball passing through the patch easily.
All 29 stages of the well were fractured at 8,400 psi [58 MPa] pressure with a pump rate of 44 bbl/min [7.04 m3/min]. The patch withstood all 29 stages of fracturing with no leaks. The repair was a major success for the operator, because the well became one of its highest-volume producers in the Cochrane area.
Challenge: Repair a leaking fracture port to resume fracturing operations, leaving sufficient ID to use largest ball size
Solution: Use a Saltel expandable steel patch to accommodate the differing ID requirements of the fracture port and the nominal casing
Results: Successfully completed 29 stages of fracturing with no leaks