LWD Petrophysics


LWD Petrophysics Log Interpretation

Real-time and recorded formation-evaluation data can deliver a more complete quantitative picture of your reservoir’s structure for informed petrophysical decision-making.

Analysis of petrophysical data while drilling can reduce reservoir uncertainty, improve overall analysis, and help optimize production through exact wellbore placement.

LWD Petrophysics Spectralwave

Weatherford logging-while-drilling (LWD) services provide an industry-leading suite of petrophysical measurements for a clear picture of your reservoir’s physical properties.

The Weatherford Wave series of advanced formation-evaluation tools and services complement our existing multisensory portfolio to provide accurate petrophysical measurements, even in extreme logging environments. Combining spectral gamma ray, azimuthal acoustic slowness, and formation pressure with traditional resistivity, density, porosity, and other measurements provide options for an array of interpretations that facilitate real-time and completion decisions.

The Weatherford LWD service is among the industry's fastest and capable of delivering wireline-quality data at drilling speeds up to 400 ft (122 m) per hour.

Engineered to withstand extreme temperatures, pressures, and well depths, the system also offers enhanced signal detection and outstanding resistance to drilling shock and vibration. This versatility improves the accuracy and reliability of real-time, formation-evaluation data.

LWD Petrophysics HAGR ExpandedView

Weatherford has a complete suite of advanced LWD and well-planning services, designed and built for today’s extreme drilling environments.

We can help reduce drilling time and costs in challenging environments by providing highly accurate formation-evaluation and well-placement data. Highly skilled and experienced log analysts and engineers help successfully plan and execute your evaluation job with maximum efficiency and minimal nonproductive time (NPT).

Weatherford acquires and analyzes petrophysical data to help you better understand and react to the composition of the environment at every step of drilling operations. This allows you to make on-the-fly changes that can improve well integrity.

LWD Petrophysics SineWave 2

Available LWD Petrophysics Imaging Technologies:


Real-time, high-temperature gamma ray measurements while rotating and sliding

The high-temperature azimuthal gamma ray (HAGR) tool is an insert-based gamma ray sensor composed of multiple banks of Geiger Muller tubes. Five banks are used in the 4 3/4-in. tool and eight banks are used in the 6 3/4-in. and 8-in. tools. The tubes are arranged symmetrically to provide azimuthal total gamma ray measurements while rotating and sliding for petrophysical evaluation. The HAGR tool operates at up to 30,000 psi and 180C (200C survival.) The HAGR tool features a total gamma measurement that is corrected for mud weight, borehole size, and K concentration.


Noise-free, formation-resistivity measurements in any mud system

The MFR (multi-frequency resistivity) sensor has a fully compensated antenna-array design and digital electronics to provide highly accurate and noise-free, formation-resistivity measurements in virtually any mud system. The MFR operates at 2 MHz and 400 KHz with antenna-receiver spacings of 20 in., 30 in., and 46 inches. All antenna arrays are fully compensated and integrated into the drill collar to increase reliability and to simplify maintenance. With a 6-in. vertical resolution at logging speeds up to 300 ft/hr, the MFR provides highly accurate resistivity measurements at high rates of penetration (ROPs). Digital signal processors (DSPs) are used to measure phase and attenuation at each transmitter-receiver pair, resulting in 48 measurements. These measurements are combined to produce 12 fully compensated resistivity measurements at unique radial distances from the borehole. The fully compensated antenna design and DSP electronics result in both phase and attenuation accuracy specifications of +/-.25 mmhos and +/-.5 mmhos respectively.

Petrophysical Applications

  • Real-time and recorded Rt, Di, and Rxo

  • Anisotropy inversion, Rv/Rh


Detailed petrophysical evaluation in real time

The Weatherford AZD (azimuthal density) sensor provides highly accurate bulk density, bulk-density correction, standoff, caliper, and Pe in real time and recorded operations for detailed petrophysical evaluation. The AZD sensor can provide all measurements azimuthally – 16 sectors for both realtime and recorded  modes. The AZD sensor uses a two-axis magnetometer, which synchronizes and orients itself to the directional sensor at each connection to azimuthally bin the density data, thereby generating bulk density and standoff images. For the real time azimuthal data, the AZD groups the 16 sectors into four quadrants and can provide a quadrant-density image in real time as well as up, down, left, and right bulk-density measurements.

Petrophysical Applications

  • Real-time and recorded Rhob, Pe, hole-size indication and standoff


Enhanced statistical accuracy with minimal environmental effects

The Weatherford TNP (thermal-neutron porosity) sensor uses multiple He3 detectors at two spacings to provide a highly accurate, compensated neutron-porosity measurement. The TNP combines a strong Am241Be source with large He3 detectors to obtain higher count rates for better statistical accuracy with minimal environmental effects. The TNP measurement is corrected for borehole size, borehole salinity, mud weight, and lithology. Temperature, pressure, formation salinity, and additional formation captures can also be corrected by request.

Petrophysical Applications

  • Real-time and recorded neutron porosity, N/F overlay

The AZD and TNP service delivers wireline-equivalent accuracy and statistical repeatability at logging speeds up to 400 ft/hr. The AZD and TNP sensors are designed to minimize standoff effects and maximize count rates. The AZD sensor features robust spine and rib correction combined with stronger nuclear sources and larger sensors that allow for corrections of up to 1 in. of standoff. The AZD sensor patented self-binning technique and rapid sampling of 50ms allow the AZD sensor to group data in bins of equal standoff while disregarding areas with high standoff. The increased shielding also reduces borehole effects on the measurement accuracy. The AZD and TNP sensors will operate at up to 30,000 psi and 150°C (180°C survival).


Precision total gamma ray data while drilling in real time

The Weatherford SpectralWave spectral azimuthal gamma ray sensor provides real-time, spectral gamma ray data (K, U, Th), azimuthal gamma ray borehole images, and precise total gamma ray information while drilling. The spectral gamma ray data can provide interpretation of the organic richness and clay content of an unconventional shale reservoir. This single LWD tool delivers outstanding value for unconventional reservoir evaluation and well placement.

Petrophysical Applications

  • Evaluation of shale organic content from relationships between uranium and total organic carbon (TOC).

  • Evaluation of shale reservoir clay content from potassium and thorium, even in the presence of kerogen-associated uranium, which invalidates clay evaluation from total gamma ray.

  • Accurate well-to-well correlation from high-precision total gamma ray measurement.

  • Clay typing from K, U, and Th data.


360° high-resolution imaging of natural and induced fractures

The Weatherford LWD SineWave microimager provides high-resolution borehole images (comparable to wireline microresistivity sensors) while drilling in a wide range of water-based mud conditions. High-resolution SineWave images can reveal natural and induced fractures, faults, vugs, and fine-scale bedding features to provide detailed structural and stratigraphic geological information. Advantages of the SineWave microimager include full 360° borehole coverage and real-time images for proactive geosteering and early formation evaluation.

Petrophysical Applications

  • Evaluation of secondary porosity

  • Identification of natural and drilling-induced fractures

  • Tectonic stress interpretation from fracture orientation

  • Determination of the location and orientation of faults

  • Evaluation of thinly-bedded formations


Reliable and versatile logging-while-drilling data

The Weatherford ShockWave sonic tool provides robust, reliable, LWD sonic data for key, real-time applications such as seismic time-depth correlation, pore pressure determination, and porosity evaluation. The high-output transmitter and unique attenuator design combine with advanced acquisition modes and real-time-processing techniques to provide accurate, reliable data in the widest variety of downhole conditions—pressures to 30,000 psi (207 MPa) and temperatures to 329°F (165°C).

Petrophysical Applications

  • LWD porosity logging including large boreholes and/or behind bi-center bits

  • Gas detection from Vp/Vs ratio

  • Formation mechanical properties


Mission-critical formation pore-pressure and fluid-mobility data

The Weatherford PressureWave formation tester provides direct measurement of the formation pore pressure. When used with the hostile-environment-logging (HEL) LWD suite, the PressureWave formation tester also delivers mission-critical formation pressure and fluid-mobility information, allowing safer drilling and a more comprehensive evaluation program. The tool takes fast, reliable formation-pressure measurements with pumps either on or off. While testing with pumps on, data can be transmitted as fast as one pressure measurement every four seconds with 1/2-psi resolution. High-resolution, 32‑bit pressures are recorded at five samples per second into memory. This data enables informed decisions about the reservoir and formation potential early in the life of the well and reduces drilling risk with direct measurement of pore pressure.

Petrophysical Applications

  • Real-time and recorded formation pressures and permeability indication

  • Developing and updating reservoir models while drilling

Visean information service

Web-based, real-time LWD data

Weatherford Visean information service delivers critical logging-while-drilling (LWD) wellsite data over the Internet in real time, which enables you to more effectively leverage your skilled personnel by simplifying and streamlining the flow of information to their workstations. The service integrates a suite of powerful tools to support visualization, printing, export, and real-time reporting of all critical mud-logging and electronic-drilling-recorder data.


  • Remote real-time monitoring of LWD data

  • Support for mud-logging and drilling-recorder data

  • Management of drilling-project-related documents and reports