BSI was contracted to reduce bradenhead pressure on a producing well in Colorado. Bond logs indicated there was a micro annulus behind the 5-1/2” production casing. The well was prepared by setting a bridge plug around 3,000’ , perforating through the 5-1/2” casing at two locations just above the plug, and setting 2-7/8” tubing at the depth of the bottom perforation.
Four injection stages were run over a 36-hour period. Pressure was stepped up incrementally in the 1st stage to 2,000 psi and a significant volume of fluids were injected. Over the next two stages, pressure remained similar and the volume injected remained significant, but decreased with each stage.
The well was then shut in at pressure overnight to allow calcium carbonate to continue to form in leakage pathways. The next morning a 4th stage was run. Pressure was quickly brought up to 3,000 psi to test previous plugging efforts and see if any new leakage pathways could be opened and subsequently closed. However, very little fluid was injected, indicating plugging was complete.
The flow rate began at 0.322 gpm in the 1st stage and ended at 0.028 gpm at the conclusion of the final stage, with a total of 206 gal injected. This constituted a 91.3% decrease in injectivity, implying significant sealing.
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