for specific borehole diameters (e.g., 8-in vs 5.8-in). Case studies on fracture analysis using OBM imaging. Comparison tables between NGI and Quanta Geo features. Quanta Geo Photorealistic Reservoir Geology Service | SLB
Modern iterations of Schlumberger's spectroscopy services, such as the Litho Scanner or the Pulsar service, build upon the foundational physics of the NGI tool. These newer systems often use to provide even higher definition mineralogy and fluid saturation data in both open and cased hole environments. Comparison: Wireline vs. Logging While Drilling (LWD)
As the tool is conveyed via wireline (or slickline with a memory module), the Cs-137 source emits gamma rays. These rays interact with the surrounding matter via . High-energy gamma rays collide with electrons in the material (gravel, sand, fluid, or gas), losing energy and changing direction. schlumberger ngi tool
The data provided by the NGI tool enables reservoir engineers to make high-value decisions throughout the life of the well.
As a flagship component of the Schlumberger Pulsar multifunction spectroscopy platform, the NGI (Neutron Gamma Inelastic) tool represents a paradigm shift in cased-hole formation evaluation. By leveraging advanced pulsed-neutron technology and high-resolution gamma-ray spectroscopy, the NGI tool allows engineers to obtain critical reservoir data—such as oil saturation and gas detection—without the need for costly intervention or removing the casing. for specific borehole diameters (e
Standard NGI log presentations overlay three curves:
Outcome: The operator performed a "choke and kill" operation to wash out the top void, repacked the interval using a circulating wash tool, and re-ran the NGI log. The density increased to 2.0 g/cc across the entire interval. Production increased by 45% immediately. Quanta Geo Photorealistic Reservoir Geology Service | SLB
The Schlumberger is a specialized borehole imaging tool designed specifically for use in oil-based mud (OBM) environments. Standard electrical imaging tools often struggle in OBM due to the fluid's insulating properties, but the NGI uses capacitive coupling to bypass this hurdle. 🛠️ Key Technical Specifications
This is perhaps the most vital application of the NGI tool. Traditional Sigma (capture) logging relies on the difference in salinity between formation water and hydrocarbons. However, in many mature fields, operators inject fresh water or low-salinity water to maintain pressure. Because fresh water and oil have similar capture cross-sections, Sigma logs cannot easily distinguish them.
Identifies structural dip, folds, and fault orientations within the reservoir.