Schlumberger - Ngi Tool

: Designed to record data while moving both up and down the borehole. Downlogging helps reduce "stick-slip" effects that often blur images, saving rig time. Photorealistic Visualization

The 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.

The tool transmits electromagnetic waves from one antenna to a receiver. By comparing the and attenuation between receivers, the complex dielectric permittivity (( \varepsilon^* = \varepsilon' - j\varepsilon'' )) is derived. schlumberger ngi tool

In many workflows, the NGI is categorized alongside or as a successor to other high-tier imagers:

As the tool is pulled up the borehole, it records thousands of data points. These variations in electrical resistivity correspond to different rock and fluid properties, which software then renders into a continuous, high-fidelity visual image. Key Applications in Reservoir Characterization : Designed to record data while moving both

: Accurate imaging of the borehole helps in placing completion equipment more effectively, particularly in horizontal or highly deviated wells.

| Feature | Specification | |---------|---------------| | | Approx. 4.5 m (15 ft) | | Diameter | 2.5 in (63.5 mm) – slimhole compatible | | Detectors | 3 BGO scintillators (Near, Far, Long Spacing) | | Max Temp | 350°F (177°C) | | Max Pressure | 20,000 psi (138 MPa) | | Logging Speed | Up to 60 ft/min (18 m/min) – spectral mode | | Vertical Resolution | 6 in (15 cm) – standard; 2 in (5 cm) – high-res mode | | Depth of Investigation | 6–12 in (15–30 cm) into formation (dependent on density) | The tool transmits electromagnetic waves from one antenna

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Traditional electrical imaging tools work well in water-based muds (WBM), which conduct electricity easily. However, when drilling with oil-based muds (OBM)—which are highly non-conductive—traditional tools fail.