A Novel Approach for Under-Balanced Slim Hole Steering for Barren Carbonate Reservoirs Utilizing Real-Time Petrographic Data

Summary This paper highlights the importance of utilizing real-time petrographical data in steering slim-hole under-balanced holes in barren carbonate reservoirs. The design and geometry of the laterals hinder data collection with conventional active source tools such as density-neutron which makes porosity estimation impossible. Petrosteering has enabled active reservoir characterization through lithological identification using Dunham Classification and visible porosity estimation. The method requires collecting real-time drilling cuttings and preparing thin-sections within timely manner to evaluate lithology and porosity in the filed in order to pass instructions to directional driller to guide the bit into the desired zone. The method has also proven reliability in data precision, cost and time effectiveness, specifically when other means of bit-guiding data were not viable due to down hole limitations.