Improve declining injectivity of water injector well

A water injector well in the Sabriya field in Kuwait exhibited falling injection rates over time. This was accompanied by an increase in injection wellhead pressure, which was negatively affecting the pressure support for other producer wells. Because blindly bullheading treatment fluid from the surface had only minimally improved injection rates in the past, Kuwait Oil Company (KOC) wanted to identify and target sections of the interval that needed stimulation or diversion. KOC had previously used traditional logging solutions, but it was interested in using newer technology that would save time and eliminate additional runs to obtain the needed information.

Identify and target intervals with real-time flow measurement services

Schlumberger suggested using the ACTive Q service and the ACTive DFLO tool to identify intake and tight zones, enabling the operator to adjust the pumping program to accurately target sections along the interval.

The ACTive Q service identified two primary thief zones, located at the heel and toe of the well. It also indicated that the middle section was not taking any fluid. Having this information allowed KOC to focus the treatment, using coiled tubing to spot acid along the middle section while leaving the toe and heel untouched. Because the ACTive DFLO tool is resistant to acid, engineers were able to monitor and adjust pumping of the treatment fluid while the stimulation was in progress.

Enhanced injectivity while reducing expenses and intervention time

Using accurate real-time flow data to target the stimulation treatment substantially improved the wellhead injection pressure from 1,000 psi to zero psi, with a constant injection rate of 8 bbl/min [1.27 m³/min]. In addition, the ability to combine real-time flow monitoring, injection profiling, and acid stimulation in a single run significantly reduced costs by eliminating three days of operations that would have been required to acquire information with spectral noise logging. Compared to traditional bullheading, the customized strategy saved fluid resources and also prevented the overstimulation of the major intake zones.