Barzan Completions Success Through Innovative Stimulation and Testing Technologies

The North Field Barzan Development was executed with focus on identifying and implementing effective completion solutions that addressed new technical challenges and operational constraints presented by the wells of this project. The primary challenges were in areas of matrix stimulation, spent acid clean-up, and production testing. Stimulation issues included implementing designs for a wide range of permeability contrasts, addressing stimulation vessel pump rate and acid capacity limitations, managing live acid corrosion due to sour environment, and assessing effectiveness without production logs. Spent acid clean-up operations required protecting downhole safety valves and achieving fluids composition criteria required for production into carbon steel pipelines. Production testing challenges included fluids modelling and equipment solutions that decreased Safety, Health and Environment (SHE) risk and operational complexity, while allowing accurate measurement of gas and liquids flow rates and obtaining required fluid samples. The solutions included improvements to the acid stimulation system chemical diverter and corrosion inhibition package, custom design and manufacture of a subsurface safety valve protection sleeve, adoption of well clean-up criteria tailored to pipeline and facilities requirements, evaluation of multi-phase flow meter and real time fluids analysis technologies, and development of a simplified multi-phase flow rate calculation algorithm based on choke manifold and fluids composition data. Implementation of differentiating technologies enabled cost savings and SHE benefits due to reduced flaring, execution of single stage stimulations, smaller test equipment layout, and innovative flow rate calculation techniques. Stimulation designs were demonstrated as successful based on interpreted changes in zonal flow contributions derived from minimum surface fluid compositional data. Wells were completed and ready for handover, meeting all requirements for the surface production facilities.