SERVICES
Geothermal Suite
Geothermal wells present high-temperature challenges;
COLOG remains cool under pressure.
COLOG is pleased to offer a suite of high-temperature borehole geophysical logging services, tailored specifically to geothermal wells, where extreme temperatures and pressures require specialized instrumentation and expertise. COLOG’s current “hi-temp” suite includes the Pressure-Temperature-Spinner (PTS) probe, Acoustic Televiewer (ATV/ABI) w/ Natural Gamma-Ray detection, and Mechanical Caliper — all rated to withstand at least 120°C (248°F). Additionally, COLOG now offers digital video inspections in wells with temperatures up to 90°C — an increase of 20°C over previous capabilities.
COLOG has deployed its high-temperature logging suite at several geothermal projects across the United States — from the freezing high-deserts of Nevada, to the humid jungles of Hawaii. With a suite of probes engineered to withstand temperatures of up to 350°C (662°F), combined with our custom-fabricated wellhead protection equipment and years of borehole surveying expertise, COLOG is outfitted to safely and efficiently collect high-quality geothermal well data that you can trust.
Overview of the Pressure-Temperature-Spinner (PTS) Probe
A staple in geothermal well characterization, the Pressure-Temperature-Spinner (PTS) probe is capable of reliably collecting data in boreholes conditions up to 350°C (662°F) and 10,000 psi, through the use of special vacuum flask technology. Pressure and temperature data are collected via a silicon-sapphire transducer and a fast response resistance temperature detector, respectively. A robust continuous/inline spinner flowmeter is affixed to the end of the probe, allowing for flow profiling under ambient or stressed conditions. COLOG’s PTS probe provides a real-time view of the data as it is collected via a surface readout (SRO) module mounted in the logging cabin, enabling operators to validate sensor performance, verify data quality, and monitor measurement trends as they are acquired. This real-time feedback allows the logging team to detect anomalies, confirm tool response, and make immediate operational adjustments to ensure accurate and reliable data is collected.
Overview of High-Temp Accoustic Televiewer (ABI/ATV)
COLOG’s high-temperature Acoustic Televiewer acquires a continuous high-resolution, oriented image of the borehole wall in uncased, fluid-filled conditions. The probe is rated for 120°C (248°F), and is able to collect image data in boreholes as small as 3” in diameter, to as large as 12” in diameter. Acoustic Televiewer data plays a key role in geothermal reservoir characterization by providing data used for fracture analysis, structure modeling, flow modeling, and well construction design. Our high-temperature televiewer probe also has an integrated NaI(Tl) scintillation crystal, allowing the probe to simultaneously collect natural gamma-ray data that can be used in the delineation of shale and sandstone layers, or radioactive formations.
Overview of Wellhead Protection
For surveys to be conducted in completed geothermal well installations, COLOG maintains its own dedicated wellhead protection equipment. This custom-fabricated assembly is equipped with a blowout preventer (BOP), wireline lubricator and hydraulic pack-off, ensuring surface operations are performed under controlled conditions, mitigating risks associated with high-temperature and high-pressure well discharge. The assembly also integrates hoisting provisions and a sheave mounting cradle, and is designed to interface with flanged steel piping commonly utilized on geothermal wellheads. By providing our own wellhead protection equipment, COLOG can streamline field operations, maintain compliance with safety requirements, and deliver quality data without reliance on third-party equipment.