Schlumberger Ngi — Tool !free!

Guide to the Schlumberger NGI (Near-Gas Imager) Tool

1. Introduction

The Near-Gas Imager (NGI) is a wireline logging tool developed by Schlumberger (now part of SLB) designed to address a critical challenge in petrophysics: evaluating low-resistivity, low-contrast (LRLC) pay zones, particularly those associated with gas-bearing reservoirs.

1. Natural Gamma Ray Detector: Measures the natural radioactivity of the formation. This is crucial for identifying shale beds and correlating with offset wells.
2. Inclination Sensors (Accelerometers): Provide high-resolution deviation and azimuth data, allowing drillers to know exactly where the bit is pointing in three-dimensional space.

The NGI tool's primary mission is to provide an accurate "True Resistivity" ( Rtcap R sub t schlumberger ngi tool

7. Integration with Other Tools

For a complete evaluation, combine NGI with: Guide to the Schlumberger NGI (Near-Gas Imager) Tool 1

What distinguishes the NGI tool is its sophisticated detector array. Unlike older generations of sigma tools that used a single near and far detector, the NGI employs a multi-detector system (typically three detectors). This configuration allows for the measurement of both borehole and formation signals simultaneously. The NGI tool's primary mission is to provide