The advantage of cable deployed electric submersible pump (CDESP) systems are beginning to be understood and realized as experience has been gained with the deployment and retrieval of these systems. Cable deployed ESP systems have at times been touted as a temporary system for failed conventional ESP systems. Long-term successes have demonstrated the value of permanently installed CDESP systems, which provide the benefit of reduced production deferral, less costly change-out, and reduced HSE risk. The decision to change from conventional ESP to a rigless CDESP system is not necessarily a simple conclusion. The decision must consider technical, economic, and operational considerations to gain the full benefit from the technology. The learnings developed over multiple deployments and retrievals will benefit decision makers in the evaluation of the technology use. The technology application presented in the paper sheds the light on a journey to develop and bring alternative ESP deployment from concept to reality, overcoming technical and operational challenges. The current CDESP requires a rig to initially construct the permanent completion to accept the rigless CDESP system. Production rates requirements determine the ESP size, and in turn the tubing and wellhead size. Pressure control equipment is installed on top of the Christmas tree. Rigless installation and retrieval of the CDESP is performed on an elevated tower with the wellhead in place. The tower design has been improved to allow the production flowline to remain in place. A minimum of two well barriers, with one barrier well kill fluid, are in place at all times. A key learning of the killed well CDESP system is the need to understand the potential changes to the reservoir after sustained production in planning the replacement of a failed ESP. Kill fluid losses can be higher than expected with restorative well cleanup and production. Actual deployment or retrieval time can be improved with successive change-outs. Long-term operational robustness of the CDESP is proven with a system continuing to operate after 5 years of cumulative operations. This paper shares the lessons learned from an early technology adopter with multiple deployment and retrievals in various well environments including highly fractured reservoirs and high hydrogen sulfide wells.

As a result of the continuous development of drilling technology, more complex wells can be drilled to overcome reservoir challenges and reach target intervals. Over the last decade, innovative drilling techniques have enabled a significant increase in the number of multilaterals and extended-reach wells; this imposes new challenges regarding well accessibility for rigless intervention techniques, which has driven operators, manufacturing, and service companies to develop innovative strategies for servicing these fields. In Saudi Arabia, one extended-reach power water injector (PWI) well was sidetracked to enhance injectivity. During the sidetrack, it was necessary to drill more than 1,000-psi overbalance due to the presence of high-pressure zones across the horizontal section, which resulted in formation damage on the low-pressure intervals. Based on this situation, a well intervention plan was considered which would use Coiled Tubing (CT) acid stimulation to remove the formation damage especially toward the end of the open-hole horizontal section. This operation involved two particular challenges; the first of which was the CT reach across the open-hole section, especially when CT forces simulation predicted a maximum coverage of 50% of the target zone. The second challenge was implementing the proper jetting tool to be able to function with the combination of the downhole tractor and high rate acid stimulation to ensure penetration across the filter cake and remove formation damage in the entire target zone. In order to make this solution feasible a specially designed downhole tractor was engineered, manufactured and incorporated with a newly designed high pressure jetting tool to be able to have full functionality of the downhole tractor while still performing full high rate stimulation to penetrate the damaged zones. This paper describes the combination of slim tractor and high-pressure jetting tool to conduct an effective acid stimulation job in an extended-reach PWI and have a CT reach of 98% instead of the predicted 50% reach in one of the major carbonate reservoirs in the Saudi Arabia. In addition, this paper provides design methodologies, best practices and industry lessons learnt from the experiences gained in the implementation of multi-purpose tool solution in Saudi Arabia.