Application of coiled tubing water shutoff on Well R-506 in Rumaila Oilfield

Main Pay is a primary oil pay zone within Rumaila Oilfield, where a lot of natural producers have stopped flowing recently due to high water cut. Coiled Tubing Water Shut Off（CTWSO） has a few advantages over the conventional WSO techniques in terms of flexibility, cost-effectiveness, and operation time. It can put the ceased wells back on production. Thus to carry out study of CTWSO is important for the purpose of developing Rumaila Oilfield more efficiently. In this paper the key points of CTWSO were discussed, the operational program was systematically optimized, and the suggestions were proposed based on the successful case of R-506 within Rumaila Oilfield. The results showed that the key technologies to ensure the success of CTWSO are basically as follows: the good properties of cement slurry is required, pre-flush and post-flush fluid is to be enough to protect slurry from pollution, the displacement of the fluids around WSO intervals is necessary prior to operation, the excess slurry needs to be displaced out of hole after spotting the plug, it is necessary to maintain back pressure at wellhead to prevent downhole influx.