VisiTrak service navigated 2,838 feet of pay sand without pilot hole
An operator drilling in the Carapebus reservoir off the shore of Brazil requested that Baker Hughes, a GE company (BHGE), drill an 8-½-in., 3,340-ft (1,018-m) horizontal section in the reservoir’s facies 1 sand. The heel of the well was in an area below seismic resolution.
The Carapebus reservoir is a series of gravity flow channel deposits on the continental slope margin of the Campos Basin. The reservoir is subdivided into 3 facies types, with facies 1 being the only productive sand type. The thickness and distribution of the facies 1 sand within the reservoir was poorly known.
The plan was to drill a 12-¼-in. hole to the top of the Carapebus reservoir and set 9-5⁄8-in. casing. The well inclination would then be built to land at 90° and maintain position in the target zone before drilling into the lower sand.
Total depth was at the start of a deep channel that cut across the well trajectory. The minimum net sand interval was set at 984 ft (300 m) with a KPI minimum of 1,509 ft (460 m).
BHGE used a logging-while-drilling (LWD) suite of services, including its VisiTrak™ reservoir navigation and analysis service, AziTrak™ deep azimuthal resistivity service, and LithoTrak™ advanced LWD porosity service, to detect, measure, and visualize the reservoir. Inversion modeling software was also used for real-time of multiple bed boundaries.
Density and gamma ray images from the LithoTrak and AziTrak services also provided real-time dip measurements to help geosteer through the well. Two nearby horizontal offset wells, each targeting separate sands, were used for the pre-well modeling.
Download the PDF to read the full case study.
- Two horizontal offset wells available for pre-well modeling
- Sand distribution in well landing area was unclear due to seismic interpretation limitations
- Total planned length of horizontal section was 3,340 ft, with a minimum required net sand of 984.3 ft
- Drilled horizontal well successfully without a pilot hole
- Mapped target sand thickness while following the upper surface of the sand
- Mapped correct reservoir using real-time inversion results after crossing faults
- Drilled 75% net-to-gross sand along a 3,343.2-ft (1,019-m) horizontal section