Sourceless neutron porosity, sigma, and spectroscopy measurements

EcoScope multifunction logging-while-drilling service integrates a full suite of formation evaluation, well placement, and drilling optimization measurements into a single collar that can be deployed faster than conventional LWD tools. Multiple near-bit sensors offer a compact design that eliminates the need for an americium beryllium (AmBe) chemical source in LWD nuclear porosity logging, substantially reducing transportation and wellsite risks.

Formation evaluation measurements include azimuthal natural gamma ray, a resistivity array, and a nuclear section with neutron porosity, sigma, spectroscopy, and an azimuthal density and photoelectric factor from a side-loaded cesium source.

Minimizing rathole and improving well placement

Because multiple LWD sensors are integrated into a single collar and located closer to the bit, flat time associated with making up and breaking down the BHA is reduced. Having fewer connections also reduces the number of tools needed in the BHA assembly, minimizing the amount of rathole that must be drilled to provide comprehensive formation evaluation measurements and improving well placement and production and reserves calculations.

Real-time formation evaluation

The PNG used in the EcoScope service enables generating neutrons on demand and eliminates the need for an AmBe chemical source. In addition to resistivity, neutron porosity, and azimuthal gamma ray and density measurements, the multifunction LWD service evaluates elemental spectroscopy and sigma. Measurements include those from the APWD annular pressure-while-drilling service, which enables monitoring hole cleaning as well as leakoff test and connection pressures.

Delivering high-speed information

EcoScope service’s large memory capacity enables recording of 2 data points/ft at ROPs up to 450 ft/h. A high effective data transmission rate, provided by the TeleScope high-speed telemetry-while-drilling service and its Orion II data compression platform, ensures that the full suite of EcoScope service measurements is available in real time to improve decisions and mitigate risk.

Dedicated internal diagnostic electronics also record information used for preventative maintenance, which can significantly extend drilling footage between failures and reduce drilling risks and NPT.

When combined with EcoScope service multiple borehole images, the EcoView integrated petrophysical interpretation system assists in the analysis of the LWD service’s comprehensive data suite. The software enables the multifunction LWD service to compute an advanced petrophysical interpretation using 2D and 3D visualization tools, requiring only water salinity as input from the user.