The buzz in the US continues to be centered on tight oil and shale formations onshore…and for good reason. Growth in crude oil production from those resources, spurred by technology and efficiency gains (among a host of other reasons), increased from 12% of total US production in 2008 to 35% in 2012. Moreover, estimated growth from unconventionals onshore could propel the US as a net exporter of crude oil and petroleum products by 2040, according to one scenario in the US EIA Annual Energy Outlook 2014. A more conservative scenario, the Reference case, estimates that total US crude oil production will reach 9.6 MMb/d in 2019 – some 3.1 MMb/d more than in 2012 and near the historic high in 1970. Over the same period (2012-2019), tight oil production is estimated to grow by 2.5 MMb/d, to 4.8 MMb/d or 50% of the US total.
EIA estimates that production from Lower 48 offshore will vary between 1.4 and 2.0 MMb/d through 2040. Most of the production growth from US offshore areas is from a number of deepwater Gulf of Mexico projects that are scheduled to come onstream by the end of 2015.
The point here is to illustrate the impact that technology advances are having on US onshore resource development, and to raise the following: Could technology advances deliver similar results offshore? In other words, are there any "unconventional" approaches under development for offshore that could deliver a step-change in production growth?
Advances in HP/HT equipment and services and improvements in subsalt imaging could offer significant upside in the production curve. But, the one approach that is considered as having the greatest potential to add meaningful growth to the global reserves base is EOR application to conventional offshore oil resources.
Recently formed alliances are proof of this emerging trend. Baker Hughes and Aker Solutions are teaming to develop technology for production solutions that will boost output, increase recovery rates, and reduce costs for subsea fields. This follows the formation of OneSubsea – a Cameron and Schlumberger joint venture – also tasked with improving recovery subsea.
A number of major operators are allocating resources for EOR R&D as well. BP, for example, is developing LoSal, or low salinity, which is injection water treated to reduce the total dissolved solids from seawater's typical 35,000 ppm down to a few thousand parts per million. The process also targets a reduction in the total divalent ion concentration to a point below that of the connate reservoir water. These two steps combine to help release the formation oil from the reservoir rock surfaces.
BP says its LoSal EOR technology has the potential to improve the outcome of water-flooding by 5 to 10%.
Another approach is microbial EOR (MEOR).Offshore contributing editor Dick Ghiselin shares an interesting case study in his column on its application on the Statoil-operated Norne field in the Norwegian Sea. The process aims to stimulate the growth of indigenous or injected bacteria, which can help to improve oil recovery by mobilizing residual oil trapped in the pore space. As a result, recovery at Norne is approaching 55%.
Meanwhile, DNV GL has launched a joint industry project to develop a wind-powered subsea water injection system. The concept is being promoted as an alternative for production sites where reservoir characteristics and system design allow for raw seawater injection, and there are long distances from the host platform to the satellite injection well.
This is just a small sample of recent developments in EOR for offshore application. If the technology is widely accepted, the results could be, well, unconventional.
|David Paganie • Houston|
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