To obtain reliable vertical and horizontal resistivity estimates and increase confidence in well-placement decisions, a major operator tested the new AlphaSight™ 3D multi-depth reservoir mapping and horizontal look-ahead-while-drilling service, achieving a significantly higher signal-to-noise ratio and sensitivity to formation boundaries compared with conventional non-co-located, tilted-antenna LWD tools.
Accurate formation mapping and proactive geosteering rely on high-fidelity, multidimensional resistivity measurements taken close to the drill bit. Traditional deep and ultra-deep azimuthal resistivity (DAR/UDAR) tools use noncolocated, 45-degree-tilted antenna arrays. This design produces systematic errors, is hard to calibrate, and can blur boundaries. It also limits directional sensitivity, creates artifacts in resistivity inversions, and increases uncertainty in estimating layer thickness and the location of remote boundaries—especially in LWD geosteering and vertical look-ahead contexts. As a result, operators have struggled to obtain reliable vertical and horizontal resistivity estimates, lowering confidence and efficiency in well placement decisions.
The AlphaSIght service enables accurate, high-resolution resistivity boundary detection, improved layer vertical resolution, and enhanced look-ahead sensitivity, addressing calibration and sensitivity shortcomings of previous LWD architectures. Real-world field runs and synthetic modeling confirmed an improvement in mapping accuracy and the service’s ability to resolve both vertical and horizontal resistivity in complex, layered formations.
Deployed in the BHA close to the bit, the AlphaSight service features modular, triaxial, fully co-located transmitter and receiver arrays (MDAR-T and MDAR-R tools). In synthetic and field applications, the service delivered substantial improvements in distance-to-boundary determination, reduced mapping artifacts, and minimal signal loss under BHA flexure or challenging pressure/temperature regimes rated up to 150 degC and 30,000 psi. Additionally, the service’s inversion time to bit established as a new benchmark—quantifying operational speed gains for LWD resistivity mapping.
