The Application of One VSD Driving Multi-ESPs Technology (OVDMT) in Offshore Heavy Oil Field

摘要

SZ36-1 oil field is the largest developed offshore heavy oil fieldrnin China, located in Liaodong bay of Bohai, where the winterrntemperature is very low and the water depth is about 30 m. Sincern1993, 4 blocks of this field have been directly put intornproduction with electric submersible pump (ESP), watercutrnvaries from 0% to 40%, ESP has played an important role inrnkeeping an annual output of 1.3~2.1x10 6 tons. However, therncombined actions of such factors as heavy oil, power supplyrnsystem failure, low air temperature and cold sea water poserndifficulties in restarting of ESP after shutdown. What's worse,rn1~2 sets of the ESP motors were damaged each time whenrnrestarting. Aiming at the problem of difficult-to-start and limitedrnplatform space, we have developed the OVDMT. Now, with thernaid of OVDMT, ESP can be softly started with VSD( variablernspeed driver). The device is capable of controlling multi-ESPs,rnthus reducing the areas of space-taking ESP surface equipment.rnSo far, 3 sets of this system have been installed in SZ36-1 oilrnfield, controlling 40 ESP wells, the average runlife of ESP inrnthis field has been increased from about 360 days to 460 days.