BSI was contracted to seal a leak in the 8-5/8” x 5-1/2” annulus on a well in Pennsylvania. An acoustic log identified an area of poor cement at 670’. The well was prepared by setting a bridge plug at 675’, cutting two narrow sand notches through the 5-1/2” casing just above the plug, installing 2-3/8” tubing to the depth of the bottom notch, and setting a packer just above the top notch.
Pressure was set at 500 psi in the 1st stage, with the flow rate holding steady just below 2 gpm. This held true across the 2nd stage as well, with no change in flow and around 160 gal of fluids injected. Flow was significantly lower at the start of the 3rd stage and fell abruptly throughout. The well was then shut in at pressure overnight, allowing calcium carbonate crystals to form.
Injection resumed the next morning at 550 psi. A much more gradual reduction in flow was seen in the 4th stage. Flow continued to fall across the next two stages. Pressure was then stepped up in the final two stages in an attempt to see if additional leakage pathways could be accessed and sealed, during which flow continued to fall.
The flow rate began at 1.919 gpm in the 1st stage and ended at 0.011 gpm at the conclusion of the 8th stage, with a total of 240 gal injected. This constituted a 99.4% decrease in injectivity, implying significant sealing.
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