Rigless Subsea Well Abandonment using SWAT™
- Suspended Well Abandonment Tool

Client: over 20 operator companies

Since its development in 1996, InterAct and the Acteon team have abandoned over 130 subsea wells for over 20 operators in the North Sea using the SWAT, the Suspended Well Abandonment Tool.  SWAT, the world’s first vessel-oriented abandonment tool, allows for rigless, riserless, diverless operation in up to 600 feet of water depth.  The tool is designed to perforate, circulate and cement multiple casing annuli while maintaining strict well control.

InterAct provides a full range of services associated with SWAT deployment and subsea well abandonment, including feasibility studies, permitting, risk analysis, abandonment procedures, vessel contracting, and project execution of the downhole abandonment, wellhead severing and site clearance.

Subsea Well Abandonment Rig Sharing (SWARS) Program

Client: a Consortium of six oil companies

InterAct was the management contractor for the SWARS Program, which successfully plugged & abandoned 23 subsea wells on California state tidelands.  This work was performed for a consortium of six oil companies who coordinated their individual P&A projects through a multi-operator agreement.

InterAct was tasked with facilitating this coordination, final permitting & compliance, rig selection & mobilization, contracting, program scheduling, field supervision, public interface, and reporting. Execution work included preliminary site surveys and wellhead inspection, preparation of wellheads for re-entry, well P&A work, recovery of seafloor debris, and removal/salvage/disposal of wellhead/pipeline components. The fieldwork utilized an Adriatic Class jackup rig (mobilized from West Africa). The SWARS Program field work was completed one month ahead of schedule, and the entire program cost was approximately $5MM below budget.

Assessment of Decommissioning Liabilities

Client: UK Operator

InterAct provided a UK operator with an assessment of the decommissioning liabilities for its European subsea wells. The study listed the operator’s inventory of 128 European subsea wells up to the end of 2007. InterAct analysed, categorised and provided costs for the wells according to five abandonment strategies.

Using its knowledge of the latest industry technology, InterAct complemented the study with current best available information on the capabilities being brought to the market by the latest generation of monohull vessels.

North Sea Well Abandonment Studies

Using its knowledge of the industry guidelines, InterAct has developed well-abandonment designs for three subsea wells in the northern North Sea.

From the available data, InterAct was able to build a detailed picture of each well and to propose an abandonment design detailing plug placement to permanently abandon the wells in accordance with Oil & Gas UK guidelines. The wells were categorised for vessel-based abandonment, and an outline abandonment procedure was developed, supported by an engineering risk review.

Santa Barbara Channel Subsea Debris Removal Program

Client: California State Lands Commission

InterAct provided comprehensive project planning, management, permit acquisition, regulatory compliance, contracting, and field supervision services for the recovery of 41 sea floor targets (including 31 well heads and casing) along the coast of California from Point Conception to Ventura County. The project required locating, demolishing, rigging (by divers and remotely operated vehicles), retrieving with a small derrick barge, and eventually disposing of all targets. Precision navigation was required for all operations. All targets were retrieved ahead of the project schedule and below the project budget without any environmental or safety incidents.

BP Cook Inlet Submarine Pipeline Re-Abandonment

Client: BP

InterAct managed the “re-abandonment” of a 10-inch oil submarine pipeline following the discovery of a leak from a 28-year old previously abandoned pipeline.  InterAct managed fabricators, equipment vendors, and diving contractors using a multiple vessel spread to attach an underwater pig launcher complete with barge mounted pump skids, gel tanks, and hose reel. Offshore diving and pumping operations were conducted in the central Cook Inlet region known for swift currents and high tidal variations. InterAct provided technical and management support to BP during multi-agency briefing/planning meetings, which included Cook Inlet Spill Response Inc., Alaska Department of Environmental Conservation, Regional Citizens Advisory Group, BP Incident Management Team, and U.S. Coast Guard.