Improve geosteering and stay within the sand body
The operator faced drilling challenges where the development wells shift from targeting the center of the sand body to the end. In the previous two wells, because of the large sedimentary changes and sand body discontinuities, the NTG ratios were lower than expected. The average thickness of sand bodies is approximately 8 m. With previous technology, the depth of investigation was around 2 to 3 m, making it difficult to clearly depict the whole sand body. The rapidly changing reservoir structure makes geosteering and staying within the sand body more challenging.
Increase reservoir understanding and make informed decisions
Schlumberger recommended using the PeriScope Edge service, which increases the depth of investigation to 6 m. The service doubled the detection range in the field compared with previous-generation technology. The tool mapped the whole sand body, increased reservoir understanding, and enabled the operator to make informed decisions for maximizing the NTG ratio for each well, which greatly improved the productivity of the wells.
By providing higher-resolution mapping, the PeriScope Edge service revealed the internal layering and quality variation within the reservoir, optimizing the well path and production. PowerDrive Archer high build rate rotary steerable system enabled the operator to effectively steer the horizontal section of the wells to handle the abrupt structure changes and target multiple sand bodies in one well.
Optimize well path
PeriScope Edge service was first used in the reservoir section of Well A. The service mapped the top of target sand 2.1 m away and the base of target sand 5.2 m away as soon as it came out of the casing shoe. PeriScope Edge service mapped the top and the base of the sand body throughout the section, clearly showing the pinchout of the sand body. The well was drilled for 256 m inside the sand body, with 50-m/h average ROP while achieving 100% NTG.