Fault blocks not an issue for GSPC at KG-OSN-2001/3

Vol 10, PW 26 (03 May 07) Exploration & Production
     

Drilling continues smoothly at appraisal well KG#28 and exploration well KG#16 on GSPC offshore discovery block KG-OSN-2001/3.

By the middle of last week the drill bit of Saipem’s jack-up rig Perro Negro 3 had reached 4600 metres depth at KG#28 while that of Atwood Beacon had reached 5300 metres depth at KG#16. TD is variable because, “GSPC wants to reach basementâ€‌ which is expected to be somewhere around 5800 metres.

“Basement is still some time away,â€‌ we learn, “and drilling is now through the reservoir section in both wells.â€‌ An industry source tells PETROWATCH that KG#16 has yielded a significant â€کconceptual breakthrough’ for GSPC.

KG#16 lies just 5-km north east of the KG#8 discovery but is on a separate fault block. “Theoretically, the fault should have acted as a barrier preventing communication between both blocks,â€‌ says a source.

“Because of the presence of the faults the sands in both wells should have been at different levels and there should also have been pinch-outs.â€‌ But indications from drilling so far have thrown up a pleasant surprise.

“It is seen that sands are more or less at the same depths and continuous.â€‌ The presence of faults, we are told, is not hindering continuity of the sands.

“This is GSPC’s biggest finding from drilling KG#16.â€‌ GSPC’s main objective in all the wells on this block, says another source, is the Lower Cretaceous era sediments, 4200 metres downwards, where sand thickness ranges between 400 and 500 metres.

In contrast, the Upper Cretaceous sediments, between 3200 and 3500 metres depth, has sands with thickness of between 40 and 60 metres. Inspired by examples from the Gulf of Mexico and other regions, GSPC is confident of producing from the Lower Cretaceous sands despite high pressure/high temperature conditions.

Says a source: “Exxon is producing at a temperature of 500 degrees Fahrenheit and bottom-hole pressures of 20,000-psi.â€‌