Case Study: Bed Boundary Mapper Assists Geosteering for 100% Placement in Target Zone

PeriScope bed boundary mapper provides real-time LWD for Coastal Energy’s 1,170-ft lateral

Challenge: Maximize reservoir exposure in good quality sand within the target reservoir, using technology to gauge the wellbore’s distance to reservoir boundaries.

Solution: Use PeriScope bed boundary mapper to guide geosteering inside the reservoir with the PowerDrive X6 rotary steerable system (RSS).


  • Drilled 1,170-ft lateral section of first well 100% in target zone.
  • Avoided troublesome shale layer in the reservoir.
  • Drilled five wells for the whole project with a total of 6,506 ft in lateral sections placed 100% in the target zone using PeriScope data.

Horizontal development well drilled in Gulf of Thailand

Coastal Energy Thailand drilled its first horizontal well in the Songkhla field of the Gulf of Thailand. The well was drilled into the Miocene reservoir on the western side of the field. The operator needed real-time, reliable LWD data to guide geosteering of the lateral section within the reservoir for maximum exposure.

Obstacles detected by bed boundary mapper

The PeriScope bed boundary mapper was used in combination with the PowerDrive X6 RSS to smoothly steer the well within the high-quality reservoir target. After drilling 800 ft of lateral length in the middle of the target sand, the PeriScope inversion data indicated a conductive boundary 10 ft below the well path. This conductive boundary was interpreted as a possible shale layer in the middle of the reservoir. The decision was made to geosteer around this conductive boundary by slightly building the well path. The well placement team used PeriScope data to drill the lateral to TD, avoiding the shale layer.

Well geosteered 100% in target zone

The drilling system encountered the 1,170-ft net pay zone in the horizontal section and geosteered the well 100% inside the target zone with resistivity of more than 100 ohm.m. The lateral section was drilled at approximately 3,695 ft TVD, which is about 130 ft above the known water level.

After the success of this first well, Coastal Energy drilled four additional horizontal wells using the same technology, all of which were successfully placed in the target reservoir. A total of 6,506 ft of lateral sections were geosteered 100% inside the target zone with the help of PeriScope bed boundary mapping.

Download: Bed Boundary Mapper Assists Geosteering for 100% Placement in Target Zone (0.60 MB PDF)

Related services and products

Request More Information

PeriScope Service Guides Geosteering to Avoid Shale Layer

PeriScope inversion canvas shows the shale layer detected below the trajectory, which was successfully avoided.
PrevNextZoom1 of 1