Novel Application of Distributed Temperature Sensing and Downhole Sensors Provides Unprecedented Confidence to Operate Conventional Sliding Sleeves in Horizontal Wells: Case Study from the United Arab Emirates

Abstract Sliding sleeve doors (SSDs) are widely used in well completions as flow management devices that allow selective communication between the production string and annulus. Although the industry has progressed with "smart" completions that allow SSD operations from surface, in many cases, SSDs continue to be operated mechanically using slickline (SL). For deviated wells or difficult environments (i.e.,reservoirs with heavy oil production) where SL operations are unsuitable, coiled tubing (CT) is required to help ensure safe access to the target depth. The use of conventional CT units to operate SSDs is widely adopted globally. However, service quality issuesare caused by several uncertainties, such as inaccurate depth correlation based on CT friction wheels, effective downhole force (calculated as a function of the surface weight), and the requirement to run a production logging test after CT operationsto verify the final SSD position. A case history is discussed wherein fiber-optic-equipped CT was deployed with a modular sensing bottomhole assembly (MSBHA) to operate SSDs with real-time downhole confirmation (tension and compression) followed by interval flow confirmation through distributed temperature sensing (DTS) in a single run. This approach reduced operational time and dramatically increased confidencein the results. The operationincorporated a combination of multiple technologies: Casing collar locator (CCL) for accurate depth correlationTension and compression data to confirm SSD activation and eliminate uncertainties related to string weight and friction lossesInternal and external pressure and temperature measurements to identify immediate reservoir responses Data from the bottomhole assembly (BHA) was then combined with the DTS analysis to provide a complete injection profile of the well before and after SSD manipulation. This verified fluid intake at each interval to confirm the operational status of each SSD. Downhole sensors provided superior accuracy in depth measurement and forces applied on the SSDs, while the DTS identifieda distinct pattern of high- and low-injectivity zones. Flow comparisonsbefore and after the SSD operation confirmed the device position, increased operational efficiency, and removed the requirement for additional confirmation runs. This case history represents a step-change in SSD operations in complex environments.The solution provided confidence and optimization in a single run, saved operational time, and ensured execution of the desired production arrangement as per the intervention objectives.