Based on case history and laboratory research, this paper documents the efforts made to date to solve the problem of excess water production in the large gas condensate fields located in the southwestern part of Pannonian Basin Croatia.
According to laboratory studies, a polymer-gel system could be an applicable method to shut off water production in reservoirs characterized as extremely hostile (ultra-high downhole temperature, geologically complex payzone and sour gas, rich with CO2). Phenol-formaldehyde crosslinked gels appear to be the most promising for use under such harsh conditions. Long-term stability during in vitro tests, and selective rock permeability reduction during core flooding tests have been achieved at 180°C. The problem of retarding the gelation time at reservoir conditions has to be further investigated prior to performing the water shutoff treatment on a candidate gas condensate production well.