Integrated Application of ESP & Sand Control in Sandy and Gassy Wells

Abstract

Production optimization by Gas Lift to ESP Conversion in SK field present challenges for pumps to handle low production, gassy and sandy wells (proppant, hydraulically fractured) in TLS zone. Low ESP run-life were experienced due to these wells conditions. An integrated ESP with special gas & sand handling equipment are required to improve the performance and run-life of the ESP systems to succeed the conversion program.
The ESP conversion for TLS zone initiated by trial on 3-wells, which considers low liquid rate, high gas production, potential sand (proppant) intrusion into ESP string. These considerations affecting the selection of the suitable pumps, and additional equipment by providing sand control and gas separation systems to handle gas and sand. Based on the trial results some notes are taken prior continuing the extensive application to other TLS wells. More extensive application is currently in progress, with 13-wells currently installed and another 12-wells to be installed within this year.
The trials were completed in 2014-2015 with promising result. ESP's were able to operate more than 200 days without downhole failures. The ESP string were installed below perforation and completed with gas separation. Casing shroud and sand screen were installed in 2-wells only, while 1-well was not equipped with screen due to casing size limitation. No sand problem & pump stuck reported until end of the rental time. 13-additional wells were then installed in 2016-2017. Current average run-life are 400-days, with the longest run life 663-days. The shortest run life occurred to 1-well without sand screen, with only 30-days operation prior pump stuck because of sand problem. In total, 3-wells suffered from sand problem since there were no sand screen installed (5.5" casing size).
As lesson learn from the previous conversion, a study has been done to provide completion string for sand screen installation in 5.5" casing. It is expected there will be no downhole failures caused by sand problem in the next installation. The integrated ESP with Gas & Sand handling application in SK field has successfully reduced the needs of ~3 MMSCFD of GL recycle, and expected to reduce another ~3 MMSCFD within this year.