Description:

• Two (2) subsea wells located in Garden Banks 385 providing oil production to the Shell Auger TLP via two (2) dual looped 12x8 pipe-in-pipe flowlines linked by a short 3,500-foot infield 12x8 pipe-in-pipe flowline and two (2) wet-insulated 6” steel catenary risers.
• The dual subsea flowlines tie-back to Auger approximately 10.5 miles away, creating the fifth subsea development to tie-back to Auger. Peak production is expected to reach 32,000 barrels of oil per day.

Technology:

• Installation of a pipe-in-pipe (PIP) flowline system without the use of steel pipe bulkheads. Specialized installation procedures and tooling were utilized allowing the outer casing pipe to slide unimpeded over the inner casing pipe during offshore welding and installation operations.
• Installation of water stop seals and other installation procedures employed to eliminate moisture of any kind entering the PIP flowline annulus during offshore installation operations.
• Use of specially designed SCR Installation Mast for SCR transfer operations between the DB50 and the Auger TLP.
• JRM first-time installation of a second-end pipeline termination sled conducted during continuous J-Lay installation operations.
  

Scope:

• Installation contract for the construction of two (2) pipe-in-pipe (PIP) flowlines and one (1) infield PIP flowline comprised of 8.625” x 1.158” API 5L X70 SMLS carrier pipe and 12.750” x 0.500” API 5L X52 HFIW casing pipe. The 8.625” carrier pipe was insulated with 1.3-inch thick jacketed polyurethane foam.
• Flowline construction activities included the installation of three (3) PIP flowline initiation sleds located in 2,500 to 2,620 feet of water using pre-installed suction piles located adjacent to the two (2) subsea wells; the installation of one (1) infield PIP flowline termination sled located in 2,620 feet of water; and the installation of two (2) 6.625” x 1.067” API 5L X70 SMLS steel catenary risers (SCR’s) located in 2,860 feet of water and insulated with 3.5” of Glass Syntactic Polyurethane (GSPU) insulation.
• Installation engineering work was performed by JRM Engineering in Houston, TX. All flowline installation activities were performed by the Derrick Barge No. 50 (DB50) utilizing J-Lay installation methods. All welding work was performed by the JRM Vermatt Bug-N-Band Automatic Welding System (JBBS).

Innovations:

• Industry-First 13.5-ksi 12x8 PIP Flowline System
• Purpose-Built SCR Installation Mast Eliminating Need for Drill Rig Assistance During SCR Pull-In Operations
• Longest 15-ksi EH Umbilical Installation (By Others)