A common problem in oil and gas wells is excess free gas or water production from only certain portions of the completed interval. Other portions of the lower completion may still have viable oil or gas production potential if a method can be devised to successfully shut off the unwanted fluids.

A coiled tubing deployed profile modification technique was developed primarily to shut off excess free gas production from the heel of cased and perforated horizontal oil wells. The technique has also been used for water and gas shut-off in both vertical and horizontal wells in a variety of lower completion types. The technique involves installing a temporary plug back to protect the toe or bottom most perforations to be preserved, then pumping a polymer gel followed immediately by a microfine cement to shut off the shallower or heel perforations. The objective of the gel and cement is to intentionally damage the rock matrix for a radius of ~2 ft around the perforated intervals to be shut off, creating a zone of little or no permeability adjacent to the wellbore. If successfully executed, there is no cement to be milled out of the liner post squeeze and no restrictions or liner diameter reduction after the job.

Approximately 30 horizontal wells have had a cumulative total of almost 13,000 ft of perforated intervals squeezed with this method. The technique has also been used to shut off liner corrosion leaks in horizontal wells and for perforation shut off in deviated wells. Post-job production logs in several of the wells indicated little or no flow from the squeezed intervals even 1 to 2 years after the job.