Technical Trials

INJAZ UPS delivered a geosteering trial for Petrogas Rima for one of their horizontal wells in Tharish small field which was considered quite challenging after evaluating the pilot hole. The structure uncertainty, lateral variations in facies and close oil-water contact made the geosteering task further challenging.

Pre-Drill Recommendation

• Conventional gamma ray - resistivity – density/neutron tool suite is recommended to geosteer the horizontal section in Misfar target interval.

• With the above tool suite, the Density (Up/Down) or quadrant Image will provide useful information in determining relative stratigraphic position of wellbore with-respect-to formation.

• Placing density tool ahead of resistivity will give advantage to detect the boundary based on clear contrast of density. (If Res and GR in the same collar, Near bit Gamma would be helpful).

Fig. 1: Pre-well Model based on nearby type well.

Fig. 2: Multiple offset wells on curtain section with property log.

Post-Drill Evaluation

• TRS-5H2 was a flank side well.
• Pilot hole results were not promising.
• The good sand body M.5 was below OWC.
• TRS-5H2 log response was correlating better withTRS-4H1.
• TRS-5H1indicated that M.3 and M.4 units were not well developed with good sand facies.
• Good sand thickness was~1-1.5 m based on Logs response.
• 55% of the well was placed in thin sands within a challenging environment.

Fig. 3: At 1750m MD, the GR increased from 20 to 50api with 90°. Geosteering team requested to go deeper to reach from 1317.5m to 1319m TVDss to re-enter target zone.

Fig. 4: Geosteering team adjusted wellbore position swiftly with subtle changes in the structure and stratigraphy.

Fig. 5: Final Curtain Section

Appreciation Letter