Extending the Life of Deepwater Fields

By Stephen Rassenfoss 6 May 2014

Block 17 is nearing the end of one era of development and beginning its next.

The prolific offshore area has been developed with a series of megaprojects, from commissioning of the first Floating Production, Storage, and Offloading (FPSO) vessel, the Girassol, in 2001, to the Pazflor in 2011. Now Total is working on the last major field development plan in Block 17 that will include an FPSO, Clov.

“This will be the end of megaproject development” there, said Pascal Carrier, vice president projects for Total Exploration and Production Angola, during a lunchtime presentation titled “Deepwater Brownfields: Yes, We Have to Tackle It Right Now” at the Offshore Technology Conference in Houston. For the operating partners and its partners there, the focus will shift to optimizing the production plateau.

The future for Block 17 will depend in large part on a Total arm known as Project Brown Field (PBF), which was created with a goal of creating an organizational model for future long-term work sustaining older fields, known as brownfield development. While this group within the international oil company has a total budget that is on a megaproject scale, it needs to think small, with a relatively small number of people managing a huge number of contracts for many incremental efforts that must remain within the tight budgets that come with older fields, where the potential yields are modest compared to new field development.

The organization within the organization was created to embody a diverse team seeking to extend the production plateaus of the fields, where the natural decline rate averages 10% a year, Carrier said. Current projects by the two-year organization are expected to reduce that to 5% a year, and work in the early planning stage could further pare that rate.

By 2019, work to extract more production from the current fields and extend production to smaller, satellite fields is expected to account for 26% of the total output from Block 17, up from 14% in 2015. The challenge is getting more out of the economically marginal projects at a profitable price per barrel. Using a variety of strategies, this independent-minded organization is doing projects for 30% to 40% less than it would have cost within the existing organization, Carrier said.

There are 210 people managing projects with a total capital expenditure budget of USD 8 billion. This megaproject scale work is run by a group where 60% of the staff is working on at least 2 projects. Success will require maintaining the mentality of an independent oil company looking for lower-cost ways to produce more by considering a lot of options. Projects so far include drilling infill wells, adding subsea pumping systems, removing bottlenecks for oil process, and tying in nearby fields into the FPSOs.

The range of skills required has been broad, with an organization chart covering the skills found in a typical oil company. Essential for PBF is managing large numbers of contracts and reducing engineering costs by applying “copy and paste” equipment choices when possible, Carrier said, adding that the organization is charged with using “new technology when value is added.”

Also needed are the communication skills of service company employees to sell different ways of doing things to operating personnel running the fields. Those personnel have ideas based on their experience about how best to manage fields, and those ideas need to be considered when setting priorities and identifying solutions.

A primary concern when planning brownfield upgrades is lost production. PBF people are required to work with existing staffers to minimize shutdowns while replacing critical systems, such as a major upgrade to increase the capacity of the water-oil separation system on the Dalia FPSO, where the growing volume of water limited the oil output.

Pre-assembled modules were installed to speed installation, and early planning focused on anticipating potential problems in connecting the new equipment. “We need to work earlier in the process to validate plans,” Carrier said.

Looking forward, Total is expecting the PBF organization to shape megaprojects to come to anticipate the most effective brownfield development. That has not always been the case. While one of the PBF projects installed massive multiphase subead pumps to extend the output on wells serving the Girrisol FPSO, some of the other wells considered for pumps were ruled out because it was too late in their life to justify the large investment in pump modules, each of which draws 2.4 mm watts, Carrier said.

PBF’s mandate includes working with development teams on Angola Block 34 to ensure early development there will be compatible with future plans to sustain long-term production there.

Stephen Rassenfoss is the Emerging Technology Senior Editor for the Journal of Petroleum Technology.