Lessons Learned from the First Openhole Horizontal Well Water Shutoff Job Using Two New Polymer Systems - A Case History from Wafra Ratawi Field, Kuwait

Abstract

Abstract With the introduction of water injection in the Wafra Ratawi Oolite reservoir, in the Partitioned Neutral Zone of Saudi Arabia and Kuwait, came the water production problems, especially after drilling horizontal wells. An economical method to reduce this unwanted water influx was needed. The process was complicated in the horizontal openhole producing wells. Not only the water producing section of the part of the horizontal section has to be treated to reduce unwanted water production. A good, cost-effective method of temporarily protecting the producing horizontal section during this treatment was also needed to protect the potential oil-producing zone for future post-treatment production. This requirement necessitated a good placement technique and the use of two gel systems, one to temporarily protect the oil zone and the other to permanently damage the water producing zone. This paper describes the application and techniques of placing a nondamaging temporary gel system to isolate the oil-producing heel side of a horizontal section in an openhole horizontal well and the use of another organically crosslinked polymer system to shut off water from the toe side of this horizontal openhole wellbore. A candidate openhole lateral horizontal well was selected for this application and the suspected high water cut from the toe side was caused by interference between a nearby injection well and this producing well.