Using the natural bacteria in a reservoir, Glori Energy’s microbial EOR technology – Activated Environment for the Recovery of Oil (AERO) – could change the fortunes of mature fields worldwide
Ready for the flood
AERO is also amongst the most inexpensive EOR systems to operate. The indigenous bacteria themselves are naturally suited to each reservoir, meaning they are unlikely to perish. Neither are they costly to produce or maintain, given the relatively low OPEX of the nutrients needed to encourage their growth.
Likewise, the system can also be set up with minimal changes to the existing waterflood facilities and with a very small footprint. The equipment is a simple injection skid with associated pumps and compressors, “around 6 feet by 9 feet [1.8m x 2.75 m] and essentially plug and play,” an appealing factor for space- and weight-conscious platform operators. Injection water must be below 14% salinity, meaning the system is suitable for the majority of on- and offshore work.
This process is straightforward, adds Pavia: “We go into the reservoir, analyse the oil and the water and the microbes, take them into the lab and design a custom set-up of nutrients that allows them to become active again.”
Senior vice president of operations, Ken Nimitz, outlines how Glori works with each client to determine an MEOR strategy. Fields are first assessed for suitability, “based on various criteria – reservoir primers if you will – things like permeability, API gravity of the produced oil, etc.” Optimal reservoir conditions for AERO deployment are typically a permeability of around 75mD or more and temperatures below 222°F (100°C).
The next step is for a Glori technician to visit the site and take samples to assess the reservoir bacteria and their environment. “There are a lot of companies that take samples for chemistry, geo-chemistry, things of that nature,” Nimitz says, “But very few take samples for biology.”
These samples are then analysed in the company’s Houston lab, typically for a few weeks, where fluid chemistry screening and nutrient analysis are performed to identify the nutrient mix that will foster the bacteria, evaluating their compatibility with oil as a carbon food source and their behaviour as a surfactant.
At this point, Glori can make a recommendation. Once a nutrient package is designed, it conducts “a minimum 12-month pilot project to demonstrate the increased production and enhanced recovery,” Nimitz continues. “At which point we’ll demonstrate an uplift and we’ll be able to evaluate the new decline rate.” The system is constantly monitored in real time via remote systems at the injector wellheads, meaning the company can ensure the right nutrients are being fed at the right rate.
Across the board, the results are promising. “We typically see an uplift of 40-60% in production and then a reduction in the established decline rate of approximately 50%,” says Nimitz.
Neither is this is a “wait and see” technology – Pavia cites a far greater effectiveness compared to past “huff and puff,” shut-in MEOR techniques. Glori’s business development director Natalie Kiser adds that operators can “see uplift of up to 60%, in as little as 6-8 weeks.”
The upshot is that AERO can provide a rapid turnaround in reservoir production. The whole consultation process, from initial study to the injection of nutrients, typically takes around six months.
Proven in the field
Glori has no shortage of experience in deploying the technology. Having worked to develop it with Statoil in its onshore fields since 2009 – Pavia talks of “a wonderful collaboration” – Statoil’s version of the technology is currently being evaluated in its Norne field, the results of which have shown considerable promise.
AERO’s track record extends to dozens of deployments, spanning multiple continents and working with everyone from E&P independents to national oil companies (NOCs) and “everyone in between.” A project with Brazilian national operator Petrobras is under way after studying a number of great candidates from their extensive portfolio, while a major 2013 project in Alberta has enabled exceptional life extension – the customer is estimating “At least half a decade, probably longer,” says vice president sales & marketing Daan Veeningen – not to mention a number of successful projects onshore US where Glori has been an operator.
Its confidence in the technology extends to a dedicated acquisition unit, which buys into maturing and declining fields with the purpose of turning production and asset life around. This, Veenigen says, is Glori “putting our money where our mouth is.”
These results are repeatable, Veeningen continues: “The reduction in decline rate [as a result of AERO] is typically 50%, [while] the improvement in production rate is somewhere between 50 and 70%. These economics are really appealing for our customers.” Such a dramatic life extension together with improvements in oil cut is also good news for anyone interested in deferring plug and abandonment costs for a vital few years for offshore platforms.
In the case of the Alberta project – a field which had previous production decline of 34% – the latest available data show production has risen to 63 barrels per day after 18 months of injection, over four times the pre-AERO predicted rate of 15 bpd. In fact, Nimitz enthuses, “I think we’ve yet to define the new decline rate because production continues to increase, and that’s been a little over two years.”
It should also interest those with their eye on the bottom line. AERO is provided as a monthly service, but “the best [cost] metric is per incremental barrel, and we aim for a cost of no more than US$10 per barrel,” says Nimitz. Because of its highly competitive CAPEX and OPEX costs – in the hundreds of thousands of dollars or less – the system can be used on small reservoirs producing less than 100 bpd.
“There are a lot of people that are aware of [MEOR’s] history and are sceptical about microbial approach, but we have some phenomenal field results now,” says Pavia. Glori believes it has the technology today which can change the fortunes of hundreds of maturing fields across the world. And seeing their results, we would be inclined to agree.