Coiled tubing (CT) fill cleanouts have been in existence for over four decades and today account for approximately 30% of the services performed. Both CT and conventional jointed pipe offer a forward or reverse circulation mode to remove solids; however, using conventional water-based fluids, a sand cleanout method may apply excess hydrostatic pressure to the formation, resulting in some lost circulation to a sub-hydrostatic reservoir. Nitrogen (N 2 ) can be used to reduce hydrostatics, but this requires a very precise job design and execution. Moreover, N 2 use can have adverse logistical and economic implications -large amounts of N 2 may be needed, especially in larger diameter wellbores and in horizontal wells.Several cleanout methods have been utilized in the past, employing a variety of different approaches. CT historically has incorporated limited circulation rates, exotic/costly fluids and reversing circulation to remove solids. The use of CT to remove sand from wellbores was one of its earliest applications and continues to be an important service today. This paper will discuss cost-effective solutions in Saudi Arabia, highlighting field cases and job optimization. The selection of the most appropriate sand cleanout method has to be based on both logistical and technical issues. This paper shows how to select the most cost-effective fills cleanout method for these wells. A few field cases are discussed to demonstrate the proper operational procedure, challenges and lessons learned. The combination of how to utilize the sophisticated solids transport software, downhole switchable nozzle, and proper operational procedure with the frequent evaluation of downhole conditions on site is essential to insure the fills cleanout is executed 100% successfully.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAlthough efforts are made to reduce or eliminate sand production in a producing well, sometimes sand fill is an unavoidable by-product of well conditions and the need for a cleanout intervention is necessary. Various cleanout methods have been utilized in the past, including the use of coiled tubing. Removing sand fill from a well using coiled tubing is one of the earliest applications for CT and continues to be an important service to the industry today.Historically, coiled tubing cleanouts have incorporated high circulation rates, exotic/costly fluids and reverse circulation to remove solids. Many of these conventional sand cleanout methods often apply excess hydrostatic pressure on the formation, resulting in lost circulation in low formation pressure reservoirs. Incorporating large liner geometries with smaller completion restrictions magnifies the task at hand as the annular velocities are drastically reduced even with higher coiled tubing circulation rates.Using a specially developed cleanout tool and a computer simulator for solids transport provides an opportunity to optimize the operation for the removal of solids to near 100% efficiency, with all fluidized solids being removed. Simplified operational procedures allow for making a more qualitative decision about the cleanout efficiency. This paper will show cost effective solutions utilized in Saudi Arabia from 2007 to present by providing an overview of all field cases and job optimization. The main focus of the paper will be to highlight and compare the coiled tubing cleanout job design process, operational procedures, results, and lessons learned from two case studies; the first case study being a successful cleanout, while in the second case study the cleanout objective was not achieved.