No abstract

No abstract

ZADCO owns more than 500 wells operating in UZ, UA & ST fields to contribute in achieving the production targets as set by the Shareholders. To ensure that wells operate as designed for their assigned life (or greater) with all risks kept as low as reasonably practicable or as mentioned, it is important to insure individual well's integrity. Hence, ZADCO developed an in-house "Well Integrity Management System (WIMS)", which defines & provides the operating standards & guidelines for maintaining the well integrity parameters, ensuring safe well operations and securing well potential availability during its life cycle so that return on investment is maximized without the sacrifice of safety and environment. The implementation of ZADCO's well integrity process follows the cycle assurance testing, preventive measures, monitoring, evaluation / assessment, control & remedy, audit / verification. This paper reviews WIMS in ZADCO. WIMS is structured to include wellhead (surface) equipment, downhole equipment and operational (process control). WIMS places much emphasis on the requirement of barriers for safety and environmental protection. Introduction The objective of developing Well Integrity Management System (WIMS) is to provide standard guidelines to ensure that technical integrity of all the wells is maintained throughout their life cycle, they operate under safe condition and are capable to function continuously to achieve the targeted production/injection requirements. Well integrity is based on the establishment and maintenance of confinement barriers in the particular well. As per WIMS standards, a well is considered integral if at least two separate and sound confinement barriers across each flow path between the potential reservoir and surface are available all the time. WIMS very much emphasis on the problem prevention based approach (endeavour to predict & solve the problem before it happens) that can accommodate several direct advantages and benefits like reduction in operating down time, enhancement in well control and safety aspects, minimized unplanned repair intervention & cost impact etc. Major well issues that would have impact on the technical integrity and operability of a well viz; Surface Completion Components (Wellhead & X-mass tree), Sub-surface Completion Components (downhole safety valve (DHSV), Gas lift valves, electric submersible pump (ESP), Well Construction (Casing & Annulus), Communication Problems, Corrosion, Scaling, Non-hydrocarbon Effluents / Products, Well Operation Suspension, Well Intervention Services (Electric/Slick Line, Stimulation, coiled tubing unit (CTU), Risk Management Process & Auditing System, etc. have been thoroughly discussed in the WIMS manual.

No abstract

Legislative pressures emanating from the recent Clean Air Act, Clean Water Act and “Carbon tax” have introduced complications to the management of refineries. This situation is exacerbated by the instability in oil prices which makes long term corporate forecasting and planning an arduous responsibility. Added to these explicit concerns are the costs associated with compliance of these environmental regulations which is causing US oil companies to look to other countries for their refining needs and/or open up subsidiaries abroad. In fact, many an African country has reported a surge in US oil activities. Recent indications are the erosion of profit margins of US oil business in contrast to foreign activities.