Sand Clean Out With Coiled Tubing and the Use of a Special Sand Clean Out Tool: A Case Study in Depleted Wells in Colombia

Abstract

Abstract Cleaning sand effectively from horizontal wells with slotted liner, low formation pressure, and lost circulation can be very challenging. This paper begins by examining all the relevant factors to develop a suitable job design and applying it to the given conditions for successfully removing sand from depleted wells in Colombia using Coiled Tubing (CT) and a Special Sand Clean Out tool (SSCOT). The main considerations for the cleanout of depleted wells will be examined, and the steps required to carry out the correct execution of the well cleaning will be shown, considering the main risks that can occur while carrying out the operation. Post-job evaluation is performed to ensure a successful sand cleanout was achieved. During cleanout of these types of wells, it is necessary to use tools that create turbulence in conjunction with gelled and foamed fluids to keep the particles suspended without affecting the well's productivity and allowing full access to the target depth. Once the cleanout is complete, placement of screen liners in the producing zones can be carried out successfully, reducing future sand production and recovering the production of these wells that have been shut down for many months, even years, due to sand plugging, affecting productivity of the entire field. Foamed fluids were used for efficient and effective sand cleanout due to the resulting low hydrostatic pressure that reduces the possibility of lost circulation, its high solids transport capability, and compatibility with the formation fluids. This was combined with carrying out the operation using a Special Sand Clean Out Tool (SSCOT), effectively reducing the probability of sticking the CT and achieving efficient sweep results.