LWD Resistivity

LWD Resistivity is a core logging technology in oil and gas exploration and development, used to evaluate hydrocarbon-bearing formations. By measuring formation resistivity in real-time during drilling, it provides critical data support for geosteering and reservoir evaluation. The technology is based on electromagnetic wave propagation or induction logging principles, utilizing downhole tools to emit high-frequency electromagnetic fields to detect conductivity differences between fluids (oil, gas, water) and rock matrices, thereby inverting formation resistivity parameters.

LWD resistivity tools are equipped with multi-frequency, multi-spacing transmitter-receiver coil arrays, enabling measurements at different radial depths of investigation (deep—up to 6 meters, medium, and shallow) to effectively distinguish between virgin formation, invaded zone, and flushed zone characteristics. For complex borehole environments (high temperature/pressure, high-salinity mud), anti-interference shielding designs and adaptive signal processing algorithms are employed to ensure measurement accuracy within ±2% (for resistivity range of 1–100 Ω·m). Combined with anisotropy correction and thin-bed resolution enhancement techniques, the system can accurately identify resistivity anomalies in thin interbeds (resolution up to 0.15 meters) and low-permeability reservoirs such as shale gas formations.

The measured data is transmitted to the surface control system in real-time via mud pulse or electromagnetic telemetry. Integrated with geological models and interpretation software, it enables rapid calculation of formation porosity, water saturation, and hydrocarbon reserves, guiding directional drilling trajectory adjustments and completion design. Widely applied in both terrestrial and marine sedimentary formations, LWD resistivity provides reliable support for improving drilling efficiency and reducing exploration risks.