resistivity logging

Resistivity logging is perhaps the most important tools available to a petrophysicist. Today there are a number of different types of electrical logs. There are tools that can cope with extremely highly resistive borehole fluids (i.e. oil-based mud systems), which rely upon electromagnetic coupling and an induced alternating current (Induction logs). The Induction log actually measures conductivity, and hence is sometimes called the Conductivity log.

The modern tool for measuring resistivity in high salinity (low resistivity) borehole fluids is the Laterolog, which focuses its current into a thin sheet to improve vertical resolution and penetration depth. Both the Induction logs and the Laterologs come in different types, which are sensitive to different depths of investigation. Hence resistivity determinations for the invaded, partly invaded and undisturbed rock zones can be measured. In addition, there are also resistivity devices (i.e. Micro-resistivity tools) that are designed to measure the resistivity of invaded zones.

The main use of the electrical tools is to calculate the water saturation of a reservoir formation, and hence the STOOIP.

Applications:

• Determination of Rt
• Indications of lithology
• Sand – Shale Laminations
• Determination of well-to-well correlation
• Invasion profiling for permeability determination
• Identification of fluid contacts
• Determination of Rxo

Features and benefits:

• Combinable with Nuclear, Acoustic, and Auxiliary Logging for a complete Formation Evaluation Solution
• Probe’s portfolio of Resistivity tools can facilitate over 90% of all well types.
• Compatible with Warrior™ Acquisition System
• Customizable to client Surface Acquisition System
• Works on proprietary PTX Telemetry System