The latest addition to the stimulation-vessel fleet working in the Gulf of Mexico, is the BJ Blue Ray, owned by Hornbeck Offshore Services Inc., Mandeville, La., and operated by BJ Services Co.
The 265 ft long, 60 ft wide, 21-ft deep vessel is the first US flagged American Bureau of Shipping (ABS) classed "Well Stimulation" vessel built, according to BJ Services. It says it designed the vessel to support well completion and stimulation operations anywhere in the world, although it expects much of the work to be in the deepwater Gulf of Mexico.
First job
During its first job, the BJ Blue Ray pumped acid and a gravel pack (waterpack) in Taylor Energy Co.'s Well B-31 on a 16-pile South Marsh Island Block 31 platform in 130 ft of water. Taylor Energy is a privately-owned company headquartered in New Orleans.
Taylor Energy did the pumping job as part of the work for reestablishing oil production from the sanded-up well. The work involved washing out sand with coiled tubing, pulling out tubing, washing over the sand screen before retrieving it, running in a new 31/2-in. screen in 7-in. casing, and then pumping in acid and the gravel pack with the BJ Blue Ray.
BJ Services indicates that pumped fluids included:
- 3,500-gal of acid (1,500 gal of 10% HCl, 1,500 gal mixture of 7.5% HCl and 1.5% HF, and 500 gal of 5% HCl overflush).
- 3,500 lb of 40/60 resieved sand.
The sand slurry was pumped at a relatively slow pumping rate of 4 bbl/min because of concerns about the condition of the casing, according to BJ Services. The vessel can pump frac-pack treatments at rates up to 75 bbl/min.
Taylor Energy had planned for the vessel, on this same trip, to frac Well D-6 in South Marsh Island Block 73. But it said that, because the platform crane could not safely swing against the wind speeds to hook up the lines from the stimulation vessel, it decided to delay this frac job.
The BJ Blue Ray returned to port, even though it had held station for 12 hr and the crew reported that conditions on the boat were good and work could have continued, even in the 8-10 ft seas and 30-knot winds being experienced.
BJ Services sent out the BJ Blue Ray because of an approaching cold front that was forecast to cause severe wave and wind conditions.
Boat design
The BJ Blue Ray is the first stimulation vessel in the Gulf of Mexico with an ABS dynamic positioning DP-2 certification, according to Hornbeck Offshore Services.
ABS's DP classification indicates the degree of redundancy in the dynamic positioning system, with DP-0 having no redundancy and DP-3 having the most.
Other vessel features include:
- Fully enclosed pump room with six 2,000-hydraulic-hp pumps that BJ says provide several enhanced safety and reliability features. The enclosed room protects the pumps from the harsh offshore environment. The vessel also has a skid-mounted, 400-hydraulic-hp pump.
- Control room with touch-screen control systems and plasma job data and multiplex video monitors. The touch-screen controls provide redundancy because any one of the six units can operate all the stimulation systems. BJ personnel wrote all the purpose-specific software for the controls.
- Dual 60 bbl/min Cyclone III blenders that can be operated in tandem or alone with redundant and back-up capability. The blenders have independent power systems and all blender discharge piping is stainless steel to prevent fluid and reservoir contamination.
- Vertical mixing tank (VMT) array that is automated for accuracy on-the-fly or in batch mode.
- Storage for 1 million lb of proppant with above-deck silo for 400,000 lb. Below-deck sand can be blown into silo at 15,000 lb/min.
- A treatment pressure rating to 15,000 psi.
- Storage for 13,000 gal of raw acid and 6,500 gal of solvent. The acid can be blended either batched or on-the-fly at 0.25-25 bbl/min.
- Two 350 ft Coflexip reels with one containing a 3 in., 15,000-psi hose and the other one a 4 in., 10,000 psi hose.
- Dynamic positioning provided by a drop-down bow thruster, tunnel bow thruster, and two tunnel stern thrusters.
- Berths with 32 bunk beds.
