Retrievable Rotor Thru-Tubing ESP Deployment System
Publication Date: 2016-Jun-30
The IP.com Prior Art Database
A system for deployment of ESP systems in a thru-tuning arrangement by splitting the motor stator and rotor whereby the stator is permanently deployed in the production tubing string (with traditional ESP cable to surface) and the motor rotor stack is deployed and stabbed into the stator whilst connected to the ESP seal and pumps sections and conveyed in the well using wireline or coiled tubing methods. Once landed the motor stator is energized as in a standard ESP and the rotor stack rotates (stabilized by a traditional bearing system) generating the power mechanical power to turn the shaft and provide torque to the ESP pump stages The invention involves splitting the two main parts of the traditional 3 phase, 2 pole induction motor used in current ESP systems to allow through tubing deployment of the ESP. The stator is deployed as part of the production tubing string with the ESP cable attached and penetrating the tubing hanger and any packers in between in a conventional manner and layout. An assembly including the ESP motor rotor stack, ESP seals and ESP intake and ESP pump is the conveyed into the production tubing bore from surface using wireline, coiled tubing or other lightweight deployment method. The rotor stock is deployed within a shroud which lands off on a on the stator assembly. The rotor stack in then free to be stabbed into the stator receptacle. This stabbing in could utilize existing wet connect electrical connector wiping technology is combination with the o-rings/t-rings on the bearings between each rotor section. When landed off, the rotor stack will be locked in place both radially and axially top and bottom to ensure stability during operation. A traditional ESP motor gauge units could be fitted to the stator during deployment. To enable through tubing deployment the pump intake and discharge must be isolated from each other using a flow diverter to isolate intake and discharge flows from one another. The flow path during operation is from production tubing or the full casing bore below. In the case of tubing below, a perforated joint is installed to direct the flow into the full casing bore. The production fluid then flows past the stator assembly to enable motor cooling. It then passes through a further conduit (such as a perforated joint) into the production tubing and in turn into the ESP intake. A flow isolator prevent recirculation of the discharge fluid to the pump intake and instead the discharge flow continues to surface within the full production tubing bore. Please see the attachment representation of the invented equipment and its use during deployment/intervention and ongoing fluid production.