In the last 5 years, GE Oil&Gas and Panamerican Energy worked on alternatives to produce Wells below perforations. All wells are produced by 3.75″ motor having refrigerating shrouds with very good performance. Today's failure index with this technology is 0.20. Besides the fact this is the simplest way to produce below perforations on vertical wells, having mentioned performance for high temperature and deep wells, it is required to overcome some limitations with this technology: In particular one of the problems that shrouded systems have in small series motors is the length of the equipment. This requires up to 30 meters achieving 100hp for a given rating. In general 4 to 5 motors are needed increasing installation time. Also, shrouds have the limitation on well's having doglegs: sometimes shrouds are lost during installation. Long shrouded equipment installed in small casing could also lead to some pressure drops due to scale deposition, reducing production capabilities.
This paper shows the experience in Pan-American Energy on alternative deployments below perforations having production recirculation tubes named Motor Cooling and Snorkel systems, and some comparative results with shrouded system.