Tracking floating production in Mexico

Bruce Crager profiles some of the floating production vessels already being used offshore Mexico, and highlights what is yet to come.

FPSO Yùum K’ak’Náab is currently operating in the KMZ oilfield in the Bay of Campeche. Photos from Pemex.

Pemex currently has over 232 fixed production platforms in water depths shallower than 200m with no hydrocarbon production in water depths deeper than 200m.

There is a huge offshore development contact between US and Mexico. It stretches from the US-Mexico land border on the coast SSE into the east-central Gulf to the “donut hole” where the US and Mexico have signed a boundary treaty to divide their portion. Cuba is the other party to this area and treaties are still being negotiated for its boundaries.

Pemex assigned 169 blocks to CNH, which will be offered for leasing. Most of these blocks are offshore.

Due to the relatively shallow water depths and the relative closeness of producing blocks to shore, there is only one floating production facility installed offshore Mexico, the FPSO Yùum K’ak’Náab. There is also one large FSO and three well test vessels.

The FPSO Yùum K’ak’Náab (YKN) vessel was converted from a tanker to an FPSO in 2007 by BW Offshore. It is currently operating in the KMZ oilfield in the Bay of Campeche. The vessel is one of the largest FPSOs in the world and can store up to 2.2 MMbbl. It is turret moored in 100m water depth and cannot be disconnected in hurricanes. The process system includes the capability for 200,000 b/d processing as well as blending, mixing stabilized heavy and light oil of API 13 and 21, from other locations. It has an oil throughput of up to 600,000 b/d. It can also handle 120 MMcf/d of gas including H2S in the gas phase (approx. 400 ppm). The gas is sweetened with an amine plant and used for fuel.

The FSO Ta’ Kuntah is operated by Pemex in the Cantarell Field in the Bay of Campeche. The vessel was converted from an ultra large crude carrier (ULCC) tanker and installed in 1998. The vessel was originally owned and operated by MODEC, who sold it to Pemex in 2013. It can handle 800,000 b/d and store up to 2.3 MMbbl. The vessel is permanently moored in 75m of water using a SOFEC external turret that is connected to two flexible lazy-S risers. Ta’ Kuntah has both side-by-side and tandem offloading capabilities and can offload from both locations simultaneously.

FSO Ta’ Kuntah is operated by Pemex in the Cantarell Field in the Bay of Campeche.

The FPSO Crystal Ocean was built in 1999 by Kvaerner Govan and is owned by Rubicon Offshore. It is one of the smallest FPSOs in the world and one of the few to have a dynamic positioning system. The vessel can handle up to 40,000 b/d and uses DP3 with a disconnectable turret. It is operated as an extended well test (EWT) vessel by Blue Marine for Pemex.

The Toisa Pisces is a well test and servicing vessel owned and operated by Sealion Shipping Ltd It was first used in Mexico in 2002 and has a length of 106 m with a 27-m beam.

The Bourban Opale is another well testing vessel that is owned by Bourban Ships AS and operated by Sealion Shipping Ltd. The vessel started working in Mexico in 2006 and has a length of 91m with a breadth of 19m.

Future FPSO Plans

Pemex has plans to add a number of FPSOs in the future. A replacement FPSO for FSO Ta’Kuntah. The Ta’Kuntah is located in the Cantarell field, which is beginning to produce water. One solution is to remove the existing FSO and replace it with an FPSO able to handle water production. The produced water would be removed from the oil, cleaned to meet discharge requirements and dumped overboard.

FPSO Crystal Ocean is operated as an EWT vessel by Blue Marine for Pemex.

The Ayatsil-Tekel field development will produce heavy crude oil from several fields discovered between 120-145km northeast of Ciudad del Carmen, a 1100sq km region in the southern Gulf of Mexico. The FPSO being designed for this development will handle crude from 16-21° API gravity, be able to process and treat 50,000 b/d of water and compress and dehydrate 25 MMcf/d of gas. It will be able to handle the sour crude with H2S up to 24% mol and CO2 up to 18% mol. Crude from adjacent platforms with be blended on the FPSO. Associated gas will be used for fuel on the FPSO with some fuel gas going back to the fixed platforms. The double hull vessel will be moored in 120m water depth using a disconnectable turret to avoid hurricanes. It will be able to store at least 1.5 MMbbl of crude. The contract for the Ayatsil FPSO is scheduled to be signed by the end of 2Q 2015.

In addition to the FPSO, the field will require a EWT vessel capable of processing and separating up to 15,000 b/d of crude with densities of 6-14° API gravity. The processing system will be able to handle H2S up to 30% mol and CO2 up to 20% mol, and be able to store 500,000 bbl while on location. The vessel will use a hybrid DP2 system for station-keeping and operate in 80-700m water depths. The contract for this EWT vessel is scheduled for signing by the end of 1Q 2015.

Bourbon Opale Well Testing Vessel is owned by Bourbon Ships AS and operated by Sealion Shipping Ltd. Photos from Pemex.

A subsea well will be drilled and completed at each location, which will be tested prior to the arrival of the EWT vessel. A drilling rig will complete the well, including a downhole pump, and install a subsea tree. Subsea installation vessels will then install a production riser, control umbilical, and power cable for the downhole pump between the subsea tree and a buoy that will connect to the EWT vessel when it arrives. While the vessel is testing this initial well, a drilling rig will drill and complete a second well, and install a separate subsea tree. A second set of production riser, control umbilical, and power cable will be installed and connected to a second buoy.

When the first well test is complete, the EWT vessel will move to the second well, connect to the buoy, and begin testing this well. A drilling rig can then go back to the first well, recover the subsea tree and downhole completion, and plug and abandon the well. The first set of production riser, umbilical, and power cable along with the associated buoy can also be recovered. All of the recovered equipment can be refurbished and reused on a future well. This “leapfrog concept” will be continued for years at locations in varying water depths. It is expected that each well will be tested for at least six months.

Other FPSOs are likely to be required for other locations offshore Mexico. This includes any deepwater locations such as those near the Mexico/Texas border. As Pemex contracts with other operators as partners, it is likely that these operators will bring floating technology with them for Mexican projects. In addition, the Round One lease sale should result in leases won by a number of international operators, who bring experience with floating production systems and subsea tiebacks.

The Ayatsil-Tekel region will be the site of EWT operations.Image from Pemex.

Conclusion

Mexico has a rich history of offshore production based on many years of Pemex activities. In the past, these fields were located in shallow water and were developed using fixed platforms with pipelines to shore in most locations. As new operators move into the Mexican market and as new fields are developed in deeper waters, it is likely that the use of floating production systems, particularly FPSOs, will increase.

Since 2010, Bruce Crager has served as executive vice president, expert advisory group for Endeavor Management located in Houston. He leads the firm’s group with a focus on offshore, subsea and marine activities. He has 40 years’ experience in offshore drilling and production, primarily in management positions. Since joining Endeavor, Bruce has consulted for many clients, including Addax Petroleum, Afren, Audubon Engineering, Barra Energia, Cal Dive, Cameron, ENI, Maersk Oil and Gas, Petrobras, Pemex, Ridgewood Energy, Shell and VAALCO Energy. Bruce holds a BS in Ocean Engineering from Texas A&M University and was selected as a Distinguished Graduate of TAMU’s Zachary Department of Civil Engineering in 2008. He also holds a MBA from the University of Houston, has co-authored 4 patents, and has written numerous technical and management articles.