Dual completed wells producing from the mature carbonate formation in northern Kuwait are encroached by injected water from adjacent wells presenting a challenge for the operating company. Greater oil demand coupled with limited surface water handling facilities increased the importance of stimulating this type of challenging wells due to the drastic permeability contrast across the pay zones. Typically the treating fluid in a matrix treatment flows into high permeability sections and/ or high water saturation "thief zones" resulting in higher water cut due to the over stimulation of the water zones instead of the oil bearing zones. The objective of the present field case study was to place the stimulation fluid equally throughout all intervals of the oil bearing layers while temporary protect the zones suspected to be mainly contributing with water from the stimulation fluid, using two different types of viscoelastic surfactant (VES) polymer free diversion systems placed with coiled tubing (CT) providing effective plugging of the layers producing water and providing a uniform stimulation fluid coverage across the entire pay zone. Subsequent production rates showed substantial oil production increase and water production decrease, 360% and 40% respectively. Background In the Sabriyah field of northern Kuwait, the wells are usually completed with a dual completion string which provides the mean to access both Mauddud carbonate formation and underlaying Burgan sandstone formation (see Fig. 1). Mauddud formation is a thin low permeability carbonate layer with an average permeability of 20 md and porosity of 22%. The formation contains large amount of natural fractures and produces 23–25º API gravity oil. Due to the lack of nature water influx, the formation has been under water flooding since 1997 in order to sustain the reservoir pressure and field production. However, water breakthrough becomes an issue as soon as the water flooding was started. This is confirmed by the production logging results. Once the water is broken through those high permeability streaks or natural fractures, the oil production rate is dropped dramastically. The formation damage like organic deposits and scales has also contributed to the decline of oil production. The ideal solution would be shut off the water breakthough intervals and then stimulate the oil bearing intervals only. However, conventional isolation tools and stimulation techniques will not work in this case because the Mauddud formation is usually completed in the short string. It is quite challenging to isolate the water intervals and place the stimulation fluids precisely into the oil bearing intervals unless the entire completion is pulled out and each particular interval can be accessed seperately by using a straddle packer. This approach will not only involve the workover rig but also impact the production from the lower Burgan sandstone formation, as well as formation damage associated with the workover operation. Several wells were treated with this approach in the past, but the results showed not to be very cost effective considering the complexity of the operation as well as the production loss from the lower Burgan formation during the workover. Thus an engineering solution of stimulating oil bearing intervals but avoiding suspected water breakthough intervals with the current completion in place is highly required.