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Innovative Logging Techniques for Taranaki. Innovative Logging Techniques for Taranaki. Industry has Evolved since 1970’s Strong Focus on Efficiency & Cost Rig time Equipment reliability data quality? Difficult to quantify. 2 examples Dramatic improvements Minimal cost.
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Innovative Logging Techniques for Taranaki • Industry has Evolved since 1970’s • Strong Focus on Efficiency & Cost • Rig time • Equipment reliability • data quality? • Difficult to quantify
2 examples • Dramatic improvements • Minimal cost
Mangahewa Formation • Characteristics • Low porosity (10pu) • Residual hydrocarbons • Quantitative Petrophysics • requires Precision • Data Acqusition • Data Analysis • Compromised • Poor hole conditions
Primary F measurement >Density log Pad device with caliper
Summary • Simple & cheap solution – available to all operators • Significant advance in Data quality • Density, Rxo, NMR etc • Quantitative log analysis a Reality. • Detailed reservoir characterisation - permeability • But • Preparation important • On site monitoring essential
Wellbore seismic • Severe signal attenuation -only onshore -related to coupling
Options • Pohokura South-01A VSP • Shoot from offshore • Vibroseis • Enlarged source pit • 5m deep, 30o slope sides, 3mx3m base • Modified “small bore” source pit
Lowering the liner into the gun pit.Steel pipe 9m x 0.91m x 1cm , 2 ton.
3D vs. VSP Processed 3D Seismic Line Processed VSP
Summary • Relatively cheap solution • Minimal Environmental impact • Improved high frequency & resolution • Improved signal strength • But • Work intensive • Onsite monitoring critical • Hole collapse
Acknowledgements • Shell, Todd and OMV • Permission to publish • STOS and the Pohokura Team • Support • Schlumberger • Technical and financial help