Successful Utilization of Fiber Optic Telemetry Enabled Coiled Tubing for Water Shut-off on a Horizontal Oil Well in Ghawar Field

Abstract

Abstract Water control is the key to prolong well life for economical and efficient oil recovery. When water reaches certain levels, oil production profitability decreases dramatically and even goes to negative. One feasible option in this case is a rigless water shut-off treatment, which involves an intensive process, starting from candidate selection and finishing with post-treatment well performance analysis. This kind of operation becomes more challenging for horizontal wells with open hole completion. Well A, a horizontal open hole producer with 2,440 ft of reservoir contact, was drilled and completed in November 2000. The last well production profile was determined by a Flow Scan Image (FSI) log, which showed 51% of water cut and the entry of most of the water was from the toe of the horizontal section. Based on economical and technical feasibility, fiber optic telemetry enabled coiled tubing (CT) was selected for an accurate and effective way to isolate the water producing interval, reduce water cut and enhance oil production. The advanced and intelligent CT enables real time downhole measurements via fiber optic telemetry system. The system consists of surface readouts including dynamic interpretation software, fiber optic cable, and bottom-hole sensors, which provides Casing Collar Locator (CCL) readings, Distributed Temperature Survey (DTS), temperature, internal and external CT pressure measurements. Permanent zonal isolation, utilizing an inflatable packer with a cement plug above the packer, was successfully performed using CT conveyed fiber optic system. The availability of CCL, temperature and differential pressure readings enabled precise depth control, proper packer inflation and optimization of the cement design. This paper highlights the application of a CT equipped with fiber optic advanced technology on a rigless water shut-off job. The paper also discusses the water shut-off (WSO) job design and execution challenges. Introduction Drilling horizontal wells become the norm in many Saudi Aramco fields. As horizontal wells mature, oil rate is reduced due to increasing water production, which dictates the need to perform water shut-off jobs to sustain oil production.