Prevents Gas Migration in 70-Year-Old Well, Protects Water Table, Avoids Surface Leakage
Objectives
Isolate permeable and hydrocarbon-bearing formation to protect underground resources.
Set bridge plug inside 5-1/2 in. casing to support the cement in the main bore and prevent the flipping of fluids.
Our Approach
Weatherford was approached by the customer to determine how to best plug and abandon (P&A) an injection well while protecting the underground environment and avoid surface leakage.
After a review of the well data and logs, Weatherford engineering experts observed that sustained casing pressure (SCP) was still occurring in the well and recommended the Reclaim thru-tubing plug and abandonment system to seal off the A annulus and main bore.
Performed as a three-stage operation using both coil and wireline conveyance, the well was perforated and a bridge plug was set 5 ft to 10 ft (1.5 m to 3.0 m) below the lowermost perforation. Wireline was then rigged down and the Weatherford acid wash tool (AWT) was deployed on the coil to perform the washing cycle.
With the AWT positioned at the top of the upper-most perf, the washing cycle was performed by moving the AWT down in 2-ft intervals. Upon completion of the washing cycle, the AWT was run to TD and the bridge plug tagged.
Once the depths were confirmed, the interval was cemented dynamically. Cement then exited the AWT slots before entering the perforations where it circulated up the A annulus to re-enter via the perforations above the AWT. The cement re-entering above the AWT was pulled through the bypass via a vacuum effect created by the dynamic pump-and-pull nature of the cementing operation.
The annulus and main bore were successfully cemented.
Value to Customer
The Weatherford Reclaim thru-tubing plug and abandonment solutions created a permanent hydraulic seal in one trip, establishing the barrier without impacting current or future production zones.
Single-trip efficiency reduced rigtime and risk associated with milling in conventional abandonment operations.
Gas migration to the surface was effectively shut off in the 70-year-old well, protecting the underground environment and potable-water resources.