Introduction to Cased-Hole Evaluations

This is a detailed course on Cased Hole Evaluations specially formatted for well intervention supervisors; there is a practical approach. However, the same course can be delivered to engineers with a more academic approach.

The first part of the course will focus on reviewing reservoir properties, well integrity - as related to well corrosion and perforations. A short presentation on tool conveyance and well completions will also be included. The main body of the course will concentrate on production logging and reservoir monitoring.

Reservoir properties will include reservoir rock types and properties, reservoir drive mechanisms, skin effects and reservoir fluids and their properties. These are all important parameters that control the inflow and outflow performance of a well.

Well integrity includes corrosion and perforations. These are critical parameters that also control well performance. The various corrosion mechanisms will be reviewed and corrosion monitoring will also be presented in details. Perforations will also be presented in details with emphasis on safety and on new technology in perforation, such as the PURE.

Production Evaluation and Reservoir monitoring cover the main body of the course.

Production evaluation will review the wide range of production logging tools and their range of applications. The presentation will focus mainly on the modern suite of cased hole imaging tools; namely GHOST, FloView and FloScan. Multi-phase flow will be presented in details with emphasis on applications in horizontal wells.  Single-phase, two-phase and 3-phase flows will be presented and discussed in details- this will include a workshop at the end of this module.

Leak detection is often ignored in most cased-hole analysis but this is an important area in production evaluation. Various aspects of leak detection are presented with field examples. The applications of geothermal temperature data base will also be outlined. The various techniques used in detecting leaks such as noise logs, temperature logs, water-flow logs, phase-velocity log and tracer injectors will also be discussed and presented in details with field examples.

Reservoir Saturation monitoring will be presented in details reviewing the various tools and techniques, including inelastic interaction (Carbon/Oxygen Ratio), pulse neutron capture and cased hole formation resistivity techniques. The theory of nuclear physics as applied to pulsed neutron logging is also presented as a background knowledge to these measurements. Cased-hole formation resistivity will also be presented outlining the theory and showing some field examples. Finally, the Cased-Hole Dynamics Tester (CHDT), with its applications for testing and sampling fluids behind the casing, will be presented.