The Gulf of Mexico’s Lower Tertiary plays represent one of the largest prizes of any offshore development in the world. “We believe this is the next frontier for the Gulf of Mexico,” said Robbie Pateder, senior director for Lower Tertiary integrated product team (IPT) at Baker Hughes. “Operators are moving from the shelf to prospect these larger fields. They are attracted to larger reservoirs with billions of barrels of untapped oil. According to industry data, the Lower Tertiary fields are estimated to have between 14 billion and 40 billion barrels of oil. These reservoirs offer greater opportunity for reserves and returns than that of shelf fields, but the challenges are just as great.

“Some of these challenges include extremes of water depths, well depths, pressures and temperatures; oil that does not flow naturally to the surface like it does in other reservoirs; and low average recovery factors.”

Responding to the industry’s need for ultradeepwater completion and production capabilities, Baker Hughes recently introduced its Hammerhead Ultradeepwater Integrated Completion and Production System.

Baker Hughes researchers started thinking about what it would take to produce these reserves. What is the current state of the technology to develop and produce these wells? How can the industry increase the recovery rate to make these fields more economically viable? It has been estimated that every 1% increase in reserves from these ultradeepwater plays will equate to additional revenues of $2 billion at $50/bbl oil.

“Based on customer feedback, the requirements for this new ultradeepwater system included withstanding temperatures up to 300 degrees Fahrenheit [149 C], pressures up to 25,000 psi, water depths up to 10,000 feet [3,048 m], and total well depths of 33,000 feet [10,058 m] while enabling long-term, high-volume production,” Pateder said.

Step-change in technology

It became clear to Baker Hughes that there was a significant disparity between the current state of technology and what is needed to develop ultradeepwater reserves, Pateder explained. Safe, economic development would require a step-change in technology—and a new approach centered on collaboration and integration. It would require a fully integrated wellhead-to-reservoir completion and production system built specifically for the Lower Tertiary geology, well conditions and production demands—a system that would help mitigate the risks of ultradeepwater wells, deliver the capability to complete and produce them and maximize the recovery rate.

“That is the challenge that we were facing,” he said.

Pateder’s group began conceptualizing the idea of this new system with customers about three years ago, he said. “We created a cross-functional IPT composed of as many as 95 dedicated members,” Pateder said. “Their first mission was to design and deliver the system, the Hammerhead system, in about three years, or about half of the time it would typically take for a project of its scope and complexity. The IPT—which is composed of members from design engineering, completion engineering, artificial lift, operations, customer service, reliability, quality and supply chain—operated outside the typical business cycle to ensure rapid design and development as well as accelerated manufacturing lead times.

“Our focus was to develop the next generation of completion technology driven by customer requirements and industry regulations. The design team looked at the requirements from an operator’s point of view and took an entirely new approach to development,” Pateder said.

“Typically the operators buy the individual components and/or systems from multiple suppliers, similar to a box of parts, and they take on the responsibility of integrating all of the components. We believe that our system-based approach will reduce or eliminate risk associated with multivendor integration and provide the increased reliability that customers require for these high-cost developments.

“Meeting this goal required intense teamwork, innovative thinking and extreme engineering,” Pateder said. “Many of our existing technologies offered a field-proven starting point from which we could work to develop the enhanced components required for the new ultradeepwater system.”

System design

Fully assembled, the Hammerhead system includes intelligent production capabilities, an upper completion, an isolation assembly and a lower completion system, and it is fully compatible with subsea boosting for increased recovery.

“The system has been designed and tested for HP/HT conditions; extreme stimulation capabilities; and high-rate, high-volume production for well cycles of 20+ years,” he said.

“The lower completion is run in the hole in a single trip and features a high-performance frack-pack system that can support extreme rates, pressures and temperatures,” Pateder explained. The frack-pack system is engineered to increase reliability and simplify operations in deepwater applications. Selective shifting profiles allow the lower portion of the isolation assembly to be run in the lower completion before any sleeves are opened, minimizing fluid loss into the formation. A mechanical barrier is included to maintain reliable well control during the upper completion installation.

“The lower completion is a unique new development where operationally we upgraded the performance,” Pateder said. “While our traditional systems were 10,000 psi to 12,000 psi differential pressure-rated, the lower completion in the Hammerhead system is 15,000 psi-rated. This gives operators additional ability to draw down the reservoirs to fully extract the hydrocarbons safely and reliably. For example, if you have 25,000-psi reservoir pressure, you can draw down to 10,000 psi if the well yields it naturally or through implementing artificial lift.

“We also needed to maximize the stimulation capability. The permeability in the Lower Tertiary formations is very low, so they require high treatment rates to make them productive. With traditional completion systems you could get 2 million to 3 million pounds of proppant to stimulate the well, but the new system has the capability of delivering 5 million pounds of proppant, or a million pounds per zone, at up to 50 barrels per minute. No other system on the market can support these rates and volumes, which are critical for maximizing reservoir connectivity and conductivity for optimal hydrocarbon flow.”

The lower completion also features a 5¼-in. minimum production inside diameter—the industry’s largest for a high-pressure 8½-in. drift completion, Pateder said. The system is capable of producing at rates up to 30,000 bbl/d for decades.

“For well control, we built an isolation assembly into the system,” Pateder said. “As we are going into the well, the assembly creates a barrier, allowing us to safely deploy the upper completion. The system’s intelligent production capabilities enable remote surveillance and control. We can deploy fiber-optic-based distributed temperature sensing into the lower completion to monitor pressure and temperature.

“The lower completion enables selective flow control using intelligent well system valves. We have flow control capabilities for two commingled zones,” Pateder said. “If you detect that the well is starting to produce water from a zone, for example, you can restrict flow from these zones and still continue to produce from the remaining zones, which helps increase ultimate recovery.

“The system also includes chemical injection capabilities to mitigate flow assurance problems that could occur, such as asphaltenes or scale production. All components are rated to 15,000-psi pressure differential to ensure reliable operation for the life of the well.”

Baker Hughes expects the Hammerhead system to improve recovery factors in the Lower Tertiary by 2%, which will translate to between $4 billion and $5 billion in additional revenues at current prices of $50/bbl to $60/bbl over the life of the well.

“Our next ultradeepwater system will offer even higher differential pressures and will incorporate Baker Hughes’ advanced in-well electrical submersible pump technologies to further improve reserves recovery,” Pateder said.

Comments