Applied Production Logging and Reservoir Monitoring

• Nomenclature used in cased hole data acquisition.
• Depth Control in Cased Hole.
• Well head pressure control.
• Why Run Production Logs? Overview:
  • Outline of the various processes used.
  • Determine Productivity Index (PI) of oil wells and the injectivity of water wells, zone by zone.
  • 2 Phase flow rates: Water/Oil, Oil/Gas, Water/Gas.
  • Three Phase Flow
  • Interzone crossflow

• Inflow Production Performance of oil and gas wells:

  • Productivity Index (PI) of oil wells.
  • Absolute Open Flow (AOF) Potential in gas wells.
  • The effects of skin.
  • Slippage velocities: theory and empirical charts applications.
  • Various techniques to measure fluid velocities- A wide range of applications:
    • Spinners: inline spinner, full bore spinner and micro-spinner.
    • Oxygen activation to measure water velocity.
    • Radioactive tracer to measure oil and water velocities.
    • Phase velocity log to measure using gadolinium to measure oil and water velocities.
    • Gas bubble velocity from the optical sensor (GHOST).

• Spinner calibrations in multi-phase flow regimes:

• The principle of spinner calibrations
• Applications for quality control.
• Importance of zone-by-zone calibrations.
• Effects of fluid densities on the spinner calibrations.

1-hour workshop on spinner calibrations and Productivity Index (PI).

• Holdup measurements in 3 phase flows:

  • Various tools and their applications.
  • Borehole differential pressure.
  • Capacitance: measuring of fluid dielectric.
  • Electric sensors (Flowview).
  • Optical sensors (Ghost).
• Equations applied in multi-phase flow regimes:
  • Conservation of momentum equation to define the spinner velocity.
  • Reynolds Number.
  • Unit integrations to compute production.
• Single phase flow:
  • Production Logging using two chokes under flowing conditions
  • Spinner calibrations to convert rotations per second of spinner to flow rates.
  • Determine the productivity Index (PI) for any selected zone. Zone selection is not needed before data acquisition.
• Uneven Depletion and resulting Crossflow:
  • Causes of uneven depletion.
  • Modelling of uneven depletion.
  • Basic Production Logging
  • Spinner Calibrations.
• Using 2 chokes to estimate Productivity Index.
• Estimating Productivity index (PI) and reservoir pressure (Pr) for each zone
• Estimating the inter-zone crossflow caused by uneven depletion

1-hour workshop on single phase flow and uneven depletion and crossflow.

• 2-phase and 3-phase Flow.
• Production interpretations in 2-phase flow (oi/water, oil/gas, water/gas).
• Running Production logs using two flowing chokes.
• Data used: Spinner, 1 hold-up measurement, Oxygen activation, phase velocity log, gas bubble speed.
• Production log interpretations in horizontal wells.
  • Data acquisitions in horizontal wells.
  • Zonation.
  • Spinner calibrations.
• Why Run Reservoir Monitoring Logs
• Covers the wide applications of reservoir monitoring logs to estimate changes
• in water/oil/gas saturations with time behind casing.
• Defines water salinity behind the casing.

• Nuclear physics of Neutron interaction with the formation. This cover:

  • Pulse Neutron Generator.
  • High Energy Neutron interaction (inelastic).
  • Gamma-Ray spectroscopy.
  • Low energy neutron interaction (capture mode

1-hour workshop Production Log Interpretations in horizontal wells

• Reservoir Monitoring Tools:

• Pulsed Neutron Logging (PNL) Tools- theory and applications of neutron interaction with the formation. This is used to obtain Neutron Capture cross-section and the Carbon/Oxygen (C/O) ratio in the formation.
• Formation Resistivity (Rt) measurement behind conductive casing.
• Slim induction log applications in non-conductive (plastic, fibreglass) casings.
• Scintillation Detectors: Various types and their characteristics.

• Neutron capture mode (Σ) interpretation:

• Interpretation process.
• Graphical solution.
• Estimating Water salinity in 100% water zone.
• Estimating water salinity in zones swept by water flood.
• Quick look graphical interpretations of water saturation (Sw).

• Neutron inelastic for Carbon/Oxygen (C/O) logging applications

• C/O data acquisition.
• The various graphical solution to borehole compensations
• C/O applications to obtain Sw independent of water salinity. 

 1-hour workshop on C/O and Σ log evaluations.

• Cased Hole Formation Resistivity behind steel casing:

  • Tool design, theory, configuration and Limitations.
  • Examples of field applications.
• Formation Resistivity behind non-conductive (plastic, fibre glass) casing:
  • Principle of the induction log- slim hole induction (2”).
  • Examples of field applications.

• Modern High Technology PNL logging tool: PULSAR

• New Generation of PNL tools- Pulsar.
• New and more powerful Pulsed Neutron Generator.
  • Much improved scintillation detectors by few orders of magnitude.
  • Evaluation of Total Carbon (TC) and Total Organic Carbon (TOC).

1-hour workshop on Cased hole resistivity evaluations.