Enhance the Run Life of Downhole ESP Equipment in Water Supply Wells

Abstract

Abstract More than 155 Electrical Submersible Pumps (ESP) are installed in water supply wells in one of United Arab Emirates – Abu Dhabi Onshore area fields (ADCO). The water supply wells producing wells are characterized by low reservoir pressures, high production rates, low levels of H2S and toxic gas. The produced reservoir formations mainly consist of soft limestone and with variable porosity. This paper will highlight the major techniques used to boost ESP system run life and enhance reliability in onshore application. These techniques are as follow: Equipment selection - Redesigning equipment to adapt to reservoir parameters and productionUpgrading of ESP equipment, accessories, seals and consumables to withstand reservoir pressure and fluid propertiesOperation Practice Developing guidelines to enhance operation practice and test equipment integrity in workshopWell condition –Monitor the well condition and advice field production and operation team to schedule the well for periodic clean out and stimulation to enhance the production The above technical enhancements made were to improve ESP performance in scale forming and corrosive environments. The focus will be on case histories to discuss what was implemented and the methodologies that were used to overcome specific challenges encountered with the use of ESPs. The analyses will overview ESP failures from the period 2011 to 2016. These proposed solutions helped the in improving overall ESP system run life and reliability from 459 days (year of 2013) to 878 run days (year of 2016). It also helped the in reducing the MTBF (Mean to before failure) from 581 days (year of 2013) to 1079 run days (year of 2016). Additionally it reduced the OPEX by 35%, ESP failures in ESP water supply wells from 35 failures (2013) to 18 failures (2016), well down time, and potential HSE risk related to well intervention and work overs.(fig 01) Figure 1No. of ESP failures in water supply wells