Chemical Solution to ESP Packer Penetrator Corrosion Problem

Abstract

Electric Submersible Pumps (ESP) are common artificial lift equipment for boosting well productions. One of the challenges faced with ESP applications is the ESP system reliability. High percentage of ESP failures resulted from problems of packer penetrators that locate beneath the ESP packers. These failures could be attributed to the corrosion of the power delivery systems by highly corrosive chemicals and harsh downhole conditions. A method is developed to generate a low density gel system that isolates the electric connector from downhole chemicals in order to provide prolonged protections of electric connectors against corrosive environments. Mixture of low-density polymeric materials can be pumped through the bypass tubing. The mixture has lower density than downhole fluids so that it travels upwards in the wellbore. Under high temperature in the well, a rigid gel system forms and isolates the electric connector from the hostile chemicals thus providing a better protection. The rigid low density gel system was tested in the lab scale. The tested fluid system comprises of colloidal particles and thermal plastic microspheres. The colloidal particles forms a rigid gel under elevated temperature while the thermal plastic microspheres act as light weight fillers. Gelation tests are conducted under different temperature and pressure conditions. The system has a lower density than crude oil and the gelation process can be controlled by chemical concentration. Sealing effects with the presence of crude oil are tested in rusty metal pipe to imitate casing material. A wellbore injection physical simulator was also setup to observe the flow dynamics and chemical reaction that could take place in the wellbore. The field trial test was performed after a through engineering design. Coiled tubing (CT) was selected as the optimum solution for intervention and placing the fluid system. Mixture of low-density materials and gelling agent were prepared on the surface and then pumped into the targeted section utilizing 2.0" coiled-tubing (CT) nozzles. Conventional bottomhole assembly was utilized to seal the tubing section and divert the fluid system to annulus.