Case Study: Slimhole MWD Enables Logging While Drilling at Average ROP of 27 ft/h in the Middle East

DigiScope service simultaneously powers multiple LWD tools above and below in BHA configuration, transmits high-quality measurements in real time

Challenge: Evaluate a slimhole horizontal section while drilling ERD well, acquiring complete suite of LWD data.

Solution: Use DigiScope slimhole MWD service to simultaneously power all components in complex suite of LWD services and transmit multiple measurements back to surface while drilling at high ROP.

Result: Powered the complex suite of LWD services, enabling acquisition of all required data, and delivered high-quality data to surface without compromising drilling performance.

Acquire formation evaluation data in slim ERD section

An operator in the Middle East planned to drill a slimhole section in an extended-reach drilling (ERD) project and needed to acquire the full breadth of data to evaluate reservoir accessibility, completion design options, fluids contacts, formation pressure, and rock fluid properties. To build such a BHA, the company needed an MWD option that could simultaneously power multiple LWD tools both above and below in the BHA configuration as well as transmit the measurements of the entire suite of LWD services for real-time evaluation while drilling at high ROP.

Power complex BHA and transmit data at high bit rate

Recognizing the immense demands of this operation, Schlumberger recommended the DigiScope slimhole MWD service. This service sends 110 W uphole and 110 W downhole to power complex suites of LWD services and delivers a high-quality signal with an unparalleled range of frequencies from 0.25–24 Hz at up to 36 bps physical transmission rate.

Knowing the MWD needs were covered by DigiScope service, the team designed a complex BHA with PowerDrive X5 rotary steerable system (RSS) and PeriScope bed boundary mapper, as well as MicroScope resistivity- and imaging-while-drilling, StethoScope formation pressurewhile-drilling, SonicScope multipole sonic-while-drilling, and adnVISION azimuthal density neutron services. The BHA was designed to meet objectives for drilling the 61/8-in evaluation well section to greater than 20,000 ft MD (nearly 5,000 ft TVD).

Achieved objectives for MWD while maintaining good ROP at 27 ft/h

During operations, the DigiScope service enabled drilling to continue at average on-bottom ROP of 27 ft/h while acquiring as many real-time measurements as possible for formation evaluation. The power generated by the two-stage turbine of the DigiScope service enabled almost every LWD service in the suite to run without batteries. And the high data transmission rates provided high-quality data from multiple LWD services simultaneously—without compromising drilling performance.

Download: Slimhole MWD Enables Logging While Drilling at Average ROP of 27 ft/h in the Middle East (0.88 MB PDF)

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DigiScope service simultaneously powers multiple LWD tools above and below, transmitting data at up to 36 bps. Visit DigiScope Slimhole MWD page