Case Study: Successful Application of Coiled Tubing Conveyed Inflatable Straddle Packer for Selective Reservoir Treatments in Deviated and Horizontal Wells of Rajasthan Field, India

Abstract

Abstract Field X in Rajasthan, India has been developed with 22 Injectors wells &40 Producers wells. Most of the producers are completed with standalone screens of different types like conventional, ICD's and SSD types. Almost 60% of the producers are completed with ICD type screens. The open hole for screens section has been drilled with 10.2 ppg SBDIF (Synthetic based drilling fluid)which includes dolomite and barite as weighting agents. After running the screens, the screen section is displaced with 8.4 ppg low weight SBDIF(Synthetic based Drill-In Fluid) which has organophilic clay (Viscosifier) and emulsifier as the key components. Due to some operational delay in bringing the wells online, mud was left inside the screens for a few months. The deposition of mud filter cake and heavier hydrocarbon probably choked the ICD screen sensuing a number of ICD's non-contributing. Conventional stimulation techniquesdidn't help in achieving good results. To effectively remove the suspected damage a coiled tubing based solution was implemented which involved the application of Inflatable Straddle Packer tool. It provides pinpoint accuracy for conventional, horizontal and multilateral stimulation treatments. Coiled Tubing Conveyed Re-Settables elective straddle packer elements allow multiple settings in one trip. Treatment Valve allows precise injection of treatment fluid & adjustable element spacing helps in straddling the long interval. A case history of successful application of CT conveyed inflatable straddleapcker tool in field X in India is presented in this paper which enabled the correct placement of a series of stimulating chemicals targeting different damage mechanisms i.e. wax deposition, mud filter cake, inorganic scaling etc. Post stimulation production logs showed excellent improvement of conformance in zonal contributions. The learning from this stimulation technique was also applied to the horizontal wells in field Y with very encouraging results.