Deepwater drilling activities require contingencies for temporary abandonment of the well, sometimes necessitated by wellhead change outs or riser work, and sometimes by Mother Nature.
Existing mechanical solutions can struggle with restrictions inside the riser or seabed structure, but an inflatable temporary packer such as the one recently introduced by TAM International has more clearance than conventional systems.
“The beauty of the inflatable system is we have a lot of range, and we can expand to a larger diameter. Any restrictions you have to run through, whether it’s the riser, LMRP or BOP, could limit options for mechanical systems,” says Marty Coronado, development engineering manager. “Inflatables are well tailored toward the large casing sizes.”
The Temporary Suspension System (TSS) provides a secondary barrier to the wellbore if drilling operations must halt in the face of a looming hurricane or for planned equipment work, Coronado says. Consisting of the SSP Packer, High Performance Ball Valve, Fishing Neck, Hydraulic Release Running Tool and Multi-Cycle Circulating Valve, the TSS is geared toward larger casings.
The drillstring can be partially pulled out of the hole and the TSS run in the hole to 500 feet to 1,000 feet below the mudline, a ball is landed on the shearable ball seat, and the packer is inflated with the rest of the drillstring hanging off the bottom of the packer. A positive pressure test and/or a negative inflow test can be run to confirm good pressure integrity in the system before disconnecting by using another ball dropped to the running tool. The retrieval BHA is run into the well to continue drilling, latches onto the fishing neck, turns the ball valve to test for any pressure buildup below the packer, which is monitored in the drill pipe at the surface. When the pressure is equalized across the packer, the packer is released and the retrieval BHA pulled out of hole.
This approach, Coronado says, makes it possible to get the packer in the hole as soon as possible while leaving as much drill pipe in the hole as possible.
Coronado says TAM developed the system because deepwater operators wanted more capabilities and flexibility for temporary abandonment. TAM drew on existing technologies like the inflatable packer, but developed from scratch the ball valve, packer chassis and multi-cycle circulating valve.
Part of the challenge TAM faced in developing the tool, says Tim Davis, director of technology, is that not every operator wanted the tool to do exactly the same thing.
“We had to engineer in flexibility to accommodate each operator’s preference for how they wanted the operation to go,” Davis says.
Some of that flexibility is apparent in the well control contingencies, as well as the ability to conduct multiple tests to ensure safe operations, Coronado says.
When it’s time to resume drilling operations, the TSS retrieval involves an overshot connecting over the ball valve, and opening it. The action creates a communications path from below the packer to the drill string to indicate gas influx or pressure build up. The operator can decide whether to pull the packer out of the hole or first circulate out any gas that has come into the drill pipe through the choke line or use the circulating valve to spot heavier weight fluid above the packer before releasing it.
“They wanted maximum flexibility in being able to circulate and do some inflow testing, and we needed a way to open that communication path, so we developed the multi-circulating valve,” Coronado says.
This system is available in 7.88 inch OD for casing sizes up to 13 3/8 inches, in 13 3/8 inch OD targeted for casing sizes of 16 inches and 18 5/8 inches, and in 15.1 inch OD, for 18 5/8 inch and larger casing.
“We are building tools right now as fast as we can, and shipping them to our Broussard location,” Davis says, so they are on hand during the Atlantic hurricane season, which started June 1 and runs through November 30. “We have contracts to have the tools on-site in multiple sizes during hurricane season.”