Page 84: of Offshore Engineer Magazine (Sep/Oct 2015)

83 85

planned, as well as pre-investment in key can store, mix and pump polymer.

Others have been considering offshore polymer EOR facilities. As a result, it hopes schemes, with Statoil working on pilots at it can maximize recovery to above 30%.

Key to the project has been improving

Heidrun, Norway, and Peregrino, Brazil. liquids handling capability. The Glen

BP now looks set to join the polymer party.

Adding EOR to

Further to its multi-billion pound rede- Lyon, due onstream in 2016, will have velopment of the Schiehallion and Loyal 320,000 b/d liquids capacity. It will be

BP has been making ? elds, known as the Quad 204 project, needed. Some 380,000 b/d of water injec-

Northwest Europe strides in LowSal

West of Shetland, BP has been consider- tion capacity will be installed to sweep

Quad 204 enhanced oil recovery ing introducing polymer EOR. The Quad the ? eld and maintain pressure, with 204 project involves a newbuild FPSO, the vessel having a capacity to produce techniques and the 270m-long Glen Lyon, which will 130,000 bo/d.

Bright Water. It now become the North Sea’s largest unit once For Quad 204, which had been under operational, onto which BP is planning to a water ? ood scheme since 1998 (with has its sights set on pre-invest in key polymer injection facili- 50%+ water cut in places), a large part polymerized water ties. If the subsequent polymer project of the bene? t of polymer is that, through for its Quad 204 goes ahead, it will be the ? rst deepwater reducing the mobility of the water, less subsea polymer EOR project. water will be produced, freeing up valu- development. Elaine able plant capacity for more in? ll wells

Maslin found out more.

Quad 204 or tieback opportunities.

Quad 204 is 175km West of Shetland. “When you inject regular water in to

Schiehallion was discovered in 1993, nshore, enhanced oil the ? eld, the water ? ngers through the and Loyal a year later, with production However, it is also expensive and typi- recovery(EOR) using polymers is reservoir and leaves oil that has not been

O starting in 1998 from the Schiehallion cally most cost-effective on more viscous an established practice. Offshore swept, which can get left behind,” says

FPSO, which the Glen Lyon replaces. oil? elds or, where oil in place is large, on it is a different ball game and, until now, Scott Thomson, area subsurface man-

Schiehallion and Loyal together had moderately viscous ? elds. not quite mastered by the industry. But, ager, BP. “If you use polymer, instead of more than a billion barrels in place and To date, polymer use for EOR offshore after a string of projects, mostly pilots, creating ? ngers, the polymerized water recovery to date had been about 15%. has been limited to a handful of proj- operators are getting to grips with off- moves in a more piston-like and ef? cient

Recognizing the greater potential of the ects. Since 2003, CNOOC has been using shore polymer EOR. manner. That is the traditional industry area – BP has produced ~400 MMbo to polymer from platforms on its heavy oil EOR technologies are attractive application of polymer ? ood. date and thinks there’s a similar amount ? elds in Bohai Bay, offshore China, ? rst because they can help operators increase “Quad 204 is a bit different,” Thomson to be had – and both the falling ef? ciency as a pilot and then extending it across their reserves – without having to spin says. “Our new wells will bene? t from and limitations of the original Schiehallion 27 wells on three oil? elds by 2010*. the exploration bit. According to France’s the traditional mechanism of piston-like

FPSO, the operator, with partners Shell

Total was ? rst to take polymers on a Total, global conventional recovery rates sweep, but because we have already pro- and OMV, decided to redevelop the ? eld ? oating production, storage and of? oad- are about 32% of oil in place; improving duced several millions of barrels from the through the Quad 204 project, investing in ing (FPSO) vessel deep offshore with its this performance by 5% could add some ? eld and we have been injecting water the new, higher capacity Glen Lyon FPSO, polymer EOR pilot on the Camelia ? eld 300 billion of additional reserves. for some time, there are huge chunks subsea infrastructure renewal, a seven-year offshore Angola in 2010-11, with a skid- Polymer EOR is like water ? ood, but of the ? eld where the water has already drilling program, with at least 20 new wells mounted injection pilot on the deck of it involves increasing the viscosity of broken through at the producers. “We are less interested in delaying water the water using polymers to stabilize the the Dalia FPSO. More recently, Chevron, breakthrough in these areas and more ? ood front and help divert water from in the UK North Sea, has been trialling interested in capturing some of the oil that high-permeability zones (potentially polymer EOR on the Captain heavy oil has been left behind via the mechanism of already swept) to improve sweep ef? - ? eld, a project which has led to plans for viscous cross ? ow,” he says. Viscous cross ciency and aid additional oil recovery. a new bridge-linked platform on which it ? ow happens when pressure gradients cre-

BP’s FPSO taking shape in South Korea. Glen Lyon ated by the polymer-? ood force water into

Photo from BP. parts of the reservoir that were previously bypassed by ? ngering.

Using polymer will also have another, signi? cant, bene? cial effect. Despite being set to be the biggest FPSO in the

North Sea, the Glen Lyon will still have limitations, i.e. there’s only so much water you can produce. This would mean that production has to be choked back. “We want to reduce the fractional ? ow of water into our facility and polymer helps us do this,” Thomson says. “The polymer effectively slows down the water in the reservoir and means the water cut is reduced at the surface. With less water coming to the surface, we can open up

September 2015 | OE oedigital.com 86 086_OE0915_Geofocus3_Quad204_1.indd 86 8/19/15 11:32 PM