The remote field in Upper Zakum utilises 56 Plenty® TRIRO three screw pumps, which are being used for the transfer of crude oil from the wellhead to storage tanks, before being transferred onshore. Although the pumps have always worked well since they were installed in 1982, changes in the quality of the crude oil being pumped (it is no longer pure and contains sand, slurry and increased water cut), have impacted pump reliability. Therefore, due to this change, combined with a desire for increased pumping capacity, ZADCO’s OSMS-RM Job Officer, Slahadin Ali Ashair, conducted a thorough study which concluded with a recommendation to improve the metallurgy of the pumps’ screws to allow this ‘new’ quality of crude oil to be pumped either by hardening, replacement or carrying out replacement of the pumps in their entirety. Based on Life Cycle Cost Analysis (LCCA) and referral to SPX FLOW (the OEM), ZADCO decided to embark on the most technoeconomical reliable solution, being a pumps’ screws upgrade programme (using Plasma hardening/ coating) which would change the pump materials to make them more resistant to wear and failure and re-engineering the pumps for increased capacity. As part of a rolling program, SPX FLOW has been upgrading the pumps at its Abu Dhabi Service Centre with a two-week turnaround on each pump.
The pumps returned from the oilfield were in very poor condition due to the change in flow conditions, especially the salinity of the water contained within the crude. The upgrade involves a change to screw set and mechanical seal to increase life and reliability of the pumps, along with additional design modifications to improve pump life in current offshore conditions. As SPX FLOW was the original equipment manufacturer (OEM) of the pumps, it has been able to precisely manufacture the new screw sets in the enhanced materials. The Triple Screw pumping rotor set in the TRIRO pumps has a specialised thread form, which can only be replaced using advanced technology employed by SPX FLOW. In addition to being engineered from materials better suited to the changed flow conditions, the screw sets were also adjusted to achieve the increased flow requirements onsite.
SPX FLOW invested in advanced service capabilities at its Abu Dhabi Service Centre specifically to provide local service for projects such as this upgrade programme. Having local capability with cutting-edge technology and expert personnel, means a faster turnaround of the pumps and assurance of ongoing reliable operation.
To date, 12 of the Upper Zakum pumps have been upgraded and re-installed onsite. They are all operating normally and reliably. The SPX FLOW Abu Dhabi Service Centre has the technology and expertise to service and repair or replace all types of two and three screw pumps. It can replace all internal pump components and provide comprehensive, local, tailored OEM aftermarket engineering solutions to clients in the Middle East region.
Read the article online at: https://www.oilfieldtechnology.com/product-news/24092019/spx-flow-upgrades-upper-zakum-field-pumps/