Published: 07/08/2015
Published: 07/08/2015
Finding and efficiently developing new hydrocarbon reserves involves operating in increasingly hostile downhole conditions. In the Lower Tertiary play of the Gulf of Mexico, operators face ultrahigh absolute bottomhole pressures that push the limits of conventional downhole test tools.
When operating in this environment, the operator wanted to run a TCP shoot-and-pull string, perforate the well and reverse tubing fluid to ensure well control, and then pull out of hole before beginning gravel-pack operations. However, since the operator wanted to test two types of IPC stands with different thicknesses, the coating’s integrity needed to be tested prior to the gravel-pack operation.
Conventionally, testing the coated pipe would require an extra run, or "flex trip", prior to perforating. During such a test, only single-shot tubing tests and reversing tools could be used due to the absolute-pressure limitations of conventional multicycle dual valves. Because of this, the operator analyzed an alternative option that would eliminate the need for a flex trip and test the coated pipe during the perforating run, while keeping the main multicycle tester and circulating valves in the string. This option would provide greater flexibility, address safety concerns, and control the well after perforating.
Schlumberger proposed using the IRDV intelligent remote dual valve that is rated to 30,000-psi absolute ID and OD pressure. The IRDV dual valve combines two fullbore multicycle valves—a tester valve and a circulating valve—that can be cycled independently or sequentially for increased flexibility. This feature met the operator’s requirement that both valves remain downhole to ensure well control. The dual valve also enhances safety with lower-pressure, nitrogen-free operation and minimizes operating time by using automatic valve sequence commands.
The reservoir was perforated using both a 25,000-psi HSD high shot density perforating gun system and 25,000-psi eFire electronic firing heads. Then, the IRDV dual valve was used to successfully pressure test the string up to absolute pressure of 28,400 psi at depth. This enabled evaluating the coated pipe condition prior to gravel-pack operations in a single run, thereby eliminating the need to perform a flex trip, saving costly rig time in the extreme ultradeepwater environment. The circulating valve reversed out the workstring volume at 1.11 m3/min [7 bbl/min]. With these results, the operator metall of its test objectives within outlined parameters.
Challenge: Confirm integrity of coated IPC test stands while ensuring safety by applying ID pressure in tubing-conveyed perforating (TCP) shoot-and-pull string without removing muticycle tester and circulating valves.
Solution: Deploy the ultrahigh-pressure-rated IRDV intelligent remote dual valve, which combines nitrogen-free, hydrostatically powered testing and circulating valves in a single tool.
Result: Successfully tested the coated pipe in the TCP shoot-and-pull run after perforating, saving a flex-trip run and associated rig costs.
