Development of Downhole Magnetic Drive Systems for Rigless Artificial Lift Applications
Authors: Cochran Jamie , Maclean Iain Maciver , Denholm Allan 
Published: May 2013

This paper describes innovative small diameter electrical pump systems which can be installed through tubing or casing using cable deployment or coil tubing deployment, eliminating the need for a rig during pump installation and retrieval operations in the field. The capability is being developed for 10 bbl/day to 10,000 bbl/day pumping systems.

The underlying, new technology which enables small, high force dense pumping systems is permanent magnet technology, including novel permanent magnet motors and permanent magnet transmissions. This technology, which has been under development for the last 3 years, exists for pumps so small they can be retrofitted though 2 3/8?? production tubing (low volume pumping) and larger diameter for high volume pumping. Integrated downhole sensors provide valuable data for production management and condition monitoring of the downhole pumping system. Systems utilizing these technologies are currently undergoing qualification testing in preparation for field trials late 2012/ 2013.

Numerous rigless intervention opportunities can be realised in most oilfield environments as the technology enables a key industry transition from a workover activity to an intervention activity for installation and retrieval of pumping systems. Conveyance of pumping systems is decoupled from jointed pipe rigs, offering significant opportunities for operational cost savings and production uptime. For example, pumps can be installed and maintained from a riserless light well intervention vessel in a subsea well, or in a well on a normally unmanned offshore installation, or installed in a remote land location without a using rig.

Background

Artificial lift plays a major role in the production of hydrocarbon resources around the world. Today it is estimated that there are around 1 million producing oil wells worldwide approximately 85–90% of them on artificial lift. In addition, more and more natural gas wells are requiring artificial lift systems for deliquification in order to assist depletion of maturing gas reservoirs. For world-wide oil and gas well applications, the number of artificially lifted wells is approaching 1 million installations, however, this industry started from more humble beginnings.

Edwin L. Drake is, credited with discovering America's first commercial oil well. In 1859 he used a common water well hand pump in order to assist lifting the hydrocarbon from a depth of 69.5 feet and can thus be considered the first pioneer of pumped artificial lift.

Powered Oklahoma-type Pumping Jacks driving sucker rod pumps became was popular in many oilfields. They were operated by a central power source to which they were connected via rod lines. E.D. Yates obtained a patent in 1880 for a push-pull central power unit and via a series of inventions, his system evolved to the 1896 patented gear-driven model. Oilmen later adopted the 1913 " Simplex Pumping Jack" which allowed a single power source to drive multiple pump units as the preferred method of production.

Over time development of the Pumping Jack (which became affectionately known under many names such as nodding donkey, horse heads etc.) has continued through the use of electrical drive systems, localised power generation and efficiencies in pump and sealing technologies. However the basic principle extends back to before the turn of the 20th century.