Leakblock-HD Polymer
Producing Well Case Study
An Arbuckle producing well in Rooks County, Kansas exhibited a sharp increase in water production, with a complete loss in oil production. A produced water analysis indicated foreign water encroachment from the salt section had flooded the well. Two casing leaks were pinpointed in the salt section between 2158' and 2853' overall. Injection rates were taken on each interval to determine the polymer formulation and volume requirements for each leak.
The bottom interval was given 100 bbl Leakblock-HD polymers with a one hour setting time. Tools were then moved to isolate the top interval, which was given 50 bbl Leakblock-HD polymers. Pressures increased from 0-800# during the injection. After letting the polymer set for 2 hours, tools were lowered below both leak intervals, excess polymer was circulated from the wellbore, and the hole was swabbed down. Swab tests determined that no fluid was entering the wellbore from the previous leak intervals. The well was placed back on production and has produced normally for 7 years.
The operator reported significant cost savings because multiple cement squeeze and drillout operations were not required, as had been the case on the other wells in the area.
Leakblock-HD as a Protective Annular Gel
A disposal well in Ellis County, Kansas had failed to pass an MIT, with only slight pressure leak off. The operator felt it would not be possible to locate such a small leak. A protective annular gel system was designed using Leakblock-HD polymer. The packer was unset and left swinging at its injection seat 1120' from surface. 12 bbl of polymer was spotted, filling the entire annulus from 1120' to surface, and the packer was set. A small amount of polymer was then squeezed into the leak. The well successfully passed the MIT test.
A Lost Circulation Application
An operator had been unsuccessful in previous attempts to fish an anchor and 300' of tubing from a depth of 7500', in an old well in Garvin County, Oklahoma, because of several deep casing leaks that had been acting as thief zones, preventing the circulation of fillup out of the hole. A review of the casing inspection log led to the decision to spot two 25 bbl slugs of Leakblock-HD polymer over severe leaks noted at 5800' and 4200', respectively. The polymer gels were spotted and bullhead squeezed into the leaks, and then allowed setting for 2 hours. Although the operator previously had no returns to surface while attempting to wash over the tubing, after the polymer squeeze, the well was reverse circulated with nearly full returns at the surface. The operator went to fish the tubing and anchor out of the hole with no further problems. The well was recompleted and has been returned to production.