Collaboration delivers first Lower Tertiary smart completion system

Originally appeared in World Oil® MAY 2014 issue, pgs 43-48. Posted with permission.

The Lower Tertiary play in the Gulf of Mexico (GOM) is a proving ground for E&P technologies capable of withstanding harsh HPHT conditions. The vast ultra-deepwater play is an oilbearing reservoir with 1,200-ft gross sand thickness. At water depths ranging from 8,200 ft to 8,900 ft, the reservoir depths are greater than 26,000 ft TVD, with reservoir temperatures greater than 250°F and pressures exceeding 19,000 psi. The formation is composed of stacked thin beds of sand and fine-grained siltstone intervals that have, effectively, no vertical permeability and an occasional cap of thick salt/sediment layers. The region also provides an opportunity to achieve industry firsts by applying advanced technologies at record depths.

Since the start of production from its Lower-Tertiary Cascade and Chinook (C&C) fields in 2012, Petrobras has relied consistently on advanced technology applications. Located in the Walker Ridge area, 180 mi off the Louisiana coast, the fields are tied to the GOM’s first floating production, storage and offloading (FPSO) vessel. These fields represent the outer limits of ultradeepwater development.

By the end of 2013, Petrobras completed five wells (three wells in Cascade and two in Chinook), each of them producing from two separate pay intervals—an upper interval known as Wilcox 1 and a lower interval called Wilcox 2. While these wells have been producing as expected, their completion designs have not afforded Petrobras the opportunity to accurately measure the production contribution from each individual interval. The operator has relied on the use of tracers to qualitatively measure production from all of the zones, and on multiphase flowmeters at the wellhead to monitor the total, commingled production from each well.

This limitation, and the need for more quantitative measurements of each interval’s flow characteristics, prompted Petrobras’ reservoir group to call for the development of an intelligent well completion. Such a system, the first of its kind in the Lower Tertiary, would allow for a more quantitative understanding of each pay interval’s contribution to the overall production, while providing greater zonal control.

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Intelligent Well Systems

Intelligent well systems remotely monitor and control oil and gas production or water and gas injection. They let you change the flow from/to individual zones without intervention.

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