Design, Development and Testing of a Voltage Ride-Thru Solution for Variable Speed Drives in Oil Field Applications

ChevronTexaco initiated a plan in 1996 to develop the Boscan Oil Field just West of Maracaibo, Venezuela, that included the expansion and reconditioning of the existing 24 kV distribution system in order to assure a reliable service for the new and existing wells. About 75% of the southern field production uses electrical submersible pumps (ESP) while the remainder uses Beam Pumps and Progressive Cavity Pumps (PCP). All of the ESPs and PCPs, and some of the Beam Pumps are driven by variable speed drives (VSDs). About 255 km of overhead lines results in high exposure to lightning events resulting in subsequent sags and interruptions that cause well-site VSDs to trip, severely impacting production goals. A strategy was developed to combine VSD ride-thru with a recloser system so that most disturbances would have no effect on production. This paper describes the successful development, building and testing of a VSD ride-thru prototype for the PCP drives. The strategy of providing ride-thru for the PCP drives in conjunction with a recloser system is explained. Results of a technical literature survey and evaluation of possible solutions for Boscan Field are evaluated. Target specifications for a prototype ride-thru unit are given along with development plans and testing requirements. Based on this analysis, a prototype ride-thru module for the PCP drives was built using power electronic components and ultra-capacitors. This paper describes the design, development and testing of the ride-thru modules for the VSD's and describes the applicability of this solution to the overall industry.