Microbes- Friend or Foe

Figure 1.

Source. Microbes.

Microbes can be used as method of EOR however the area lacks research and this method has not been implemented yet but it does certainly have a great potential. It is a bio-based approach to improve the efficiency of oil recovery and allows to recover more oil from any reservoir like any other enhanced oil extraction technique. There are tow main strategies employed in Microbial Enhanced Oil Recovery (MEOR). Firstly nutrients (microbes) are injected or the activity of indigenous bacteria already thriving in the oil field is encouraged. And secondly, injecting specific bacteria into the reservoir together with a nutrient solution. (European Science Foundation,2010). Once injected, microbes produce harmless by-products such as slippery natural substances or gases once they interact with the oil making the oil more volatile and enabling it to come to the surface. (IPACT (International Journal of ChemTech Research),2013).

The research is currently focused to make MEOR technically and economically feasible as well as environmentally friendly or at least not harmful. Potentially some papers argue that this method has no environmental implication if applied in an appropriate way. Moreover this is believed to be a cheap process thus very economically sustainable in terms of oil recovery. Below are the potential advantages and disadvantages of using MEOR.

Advantages:

• ·      Both microbes and nutrients that require injection are cheap.
• ·      Increase oil production.
• ·      Existing infrastructure requires only slight adjustments.
• ·      Easy application of the method.
• ·      Less expensive set up than other EOR methods.
• ·      Low energy requirement for microbes to produce MEOR agents thus environmentally friendly as the method does not require prior combustion of fossil fuels to obtain energy to make the system work.
• ·      Potentially more efficient than other EOR when applied to carbonate oil reservoirs.
• ·      Microbial activity increases with microbial growth thus once injected, little further action has to be taken. Potentially the opposite of other EOR when constant additional action is required to keep the oil coming from the reservoir.
• ·      Cellular products are biodegradable thus it is environmentally friendly.

Disadvantages:

•      As any living thing, microbes require oxygen for aerobic processes such as aerobic respiration to allow cell growth. Oxygen is a corrosive agent for non-resistant topside infrastructure and pipes used.
• ·      Anaerobic MEOR is also not ideal as it requires large amount of sugar thus making the application of method more difficult due to costs especially in offshore fields where major transportation costs become involved too.
• ·      Exogenous microbes require facilities for their cultivation.
• ·      Whilst indigenous microbes require standardized frameworks and research facilities for evaluating microbial activities.
• ·      Microbial growth is only favored under certain conditions thus this method could be implemented only in specific reservoirs.
• ·      Microbial processes require preceding removal of debris and mud potentially blocking the channels where oil flows, which could potentially prove expensive.
• ·      Water floods may be required to increase microbial activity.
• ·      And finally and most importantly, microbes are a living thing that have not had an awful research done to them with regards to MEOR so a potential biological catastrophe could be created if microbial growth gets out of control.

Thus whilst the method has a lot of advantages the ecophysiology of microbial communities thriving in oil reservoirs lacks knowledge and requires a lot of research before the method can be implemented. There is currently a poor critical evaluation of the physical and biochemical mechanisms controlling microbial response to the hydrocarbon substrate and their mobility thus could lead to major harm to be caused to humans if the process gets out of hand as previously mentioned- a biological disaster. The real environmental impact that MEOR would cause has also not been assessed and thus remains a mystery. Furthermore the life cycle of said microbes under the reservoir conditions and their ability to multiply is also unknown. So whilst this method seems attractive, it also seems very daunting and scary if things were to go wrong. Considering it uses living things, there could be no return and it could prove irreversible once the microbes have been injected into the reservoir so significant amounts of research should be done regarding the safety of this method before implementation. Furthermore such a method would require a lot of convincing for the public as people generally get very freaked out and scared when hearing the word “microbes” as obviously it is associated with illnesses and all the negative things one could experience. Unless people understand biology, they are often unaware of the positive impacts and functions of microbes even such little things as enzymes that are used in our stomach to help digestion, which are also microbes. However the public will obviously have to be considered before anything such as this new technology is implemented.

Should the Scots Fear- Is the North Sea Oil Running Out?

So today’s question is whether the North Sea oil is running out. Whilst it is obvious that at some point, it will, in fact run out- it is yet a much harder question as to when exactly this will occur. Some sources such as The Economist argue that Britain’s offshore oil fields have already been producing oil for much longer than expected and thus it is no surprise that primary and secondary recovery oil is now reaching the end thus requires investment as well as all the current infrastructure is sucking money out of the UK economy due to its old age and the need to upgrade to new technologies. (Economist, 2014).

Whilst other sources argue that we have nothing to fear. According to different organizations, we have a very different amount of oil still left. Oil and Gas UK give a figure of 15 to 24 billion barrels boe thus claiming the energy will still be going beyond 2050 whilst the UK government claims that we are between 11.1 billion to 21 billion boe and The Wood Review reports between 12 to 24 billion boe of extractable oil. These are very different estimates and this is mainly due to the fact that as states in previous blog posts, it is very difficult to estimate the exact amounts of oil that is still left in a reserve thus there is a lot of uncertainty. Furthermore the UK may not want to make the actual figures public and may be keeping some oil as the nation’s reserve that is left for emergencies and security.

Having just faced The Scottish Independence, the UK remains shaken up about its oil. In the light of Scottish Independence, the amount of oil in reserves was exaggerated as obviously the arrogant Scots, wanting to become independent, closed their eyes and did not want to admit that the oil is running out. Leaving out all the other economical and political reasons as to why Scotland becoming independent would have been the worst idea ever, it is worth mentioning that all the monetary investments into the oil rigs (and can I highlight that the investments will have to increase by a great amount in the future to many enhanced oil recovery possible) were all supplied by the taxes that came from the UK tax payer- mainly made up of the population of people in England. Regardless of politics, it is hard to say how much oil is actually left in the North Sea and politics don’t help the matter making any conclusions on the subject more difficult however even the European Commissions Report on some EORs seems to mention the North Sea and that it will shortly run out of oil altogether although EORs are first to be used thus giving us a hint that the reservoirs have 5-15% more of extractable oil left within them. It does tell us that the area has been explored really carefully to find any possible oil reserves and there have been very few significant exploration successes and oil fields found since 1990.

While the first commercial extraction of oil on the shores of the North Sea was in 1851 when James Young retorted oil from oil shale mined in Midland Valley of Scotland, the first well was actually dug in 1964 in by the UK when the major exploration really begun. Regardless of how much oil remains in the North Sea, I think it is important to realize that it sure will run out before long making the UK economy struggle and alternative ways of obtaining energy should be explored. Below, is a video made by angry Scots, who in fact don’t believe that the oil will run out at all and think that there is some conspiracy against them and to try to convince people to vote “No” against the Scottish Independence. Perhaps people should be made more aware about the reality of oil running out.

https://www.youtube.com/watch?v=8v56WJQrG9Q

Enhanced Oil Recovery using Carbon Dioxide in the European Energy System and Carbon Capture and Storage as methods of battling Climate Change

Tertiary oil recovery is also sometimes known as enhanced oil recovery because many oil companies have now abandoned the conventional approach of oil recovery using primary recovery followed by secondary followed by tertiary in that order so sometimes the recovery is now started with tertiary oil recovery hence the name has been changed to enhanced oil recovery in literature. In this blog post I aim to analyze the environmental implications with a focus on climate change of one of the traditional methods of enhanced oil recovery using Carbon Dioxide, as well as the method’s other implications. This method requires injecting CO2 gas into the well to increase the pressure and thus make oil come up to the surface or to make CO2 mix with the remaining oil thus making it more volatile and also causing it to come up to the surface.

CO2-EOR can help in the reduction of CO2 emissions and simultaneously improve the security of energy supply. There are no current implications of this technique in Europe. Not implemented in Europe yet due to high costs of CO2 thus increasing the operating and capital expenses of offshore projects of oil extraction and making oil economically unprofitable to extract using this method. However Kyoto protocol is pressuring Europe to think seriously about decreasing CO2 emissions together with higher oil prices suggest that this method of oil recovery might be implemented in the near future. The oil fields in the North Sea are also running out of oil that may be extracted using primary or secondary recovery thus they either need to be abandoned or more investments made into them in terms of enhanced oil recovery. This technique is already quite widely used in the USA, which is known to increase oil recovery by 9-18% more from the reservoir beyond what is achievable using the conventional primary and secondary methods of recovery. For this blog post, one of the readings I did was examine the European Commission’s Report together with the Institute of energy on the potential of the implication of this technique in Europe. The report focused it’s study on the region in the North Sea which included 81 active oilfields and produces 73% of crude oil produces in the EEA (European Economic Area) at 4 million barrels of oil per day. These oil fields belong to UK, Norway and Denmark.

Crude oil production in the EU reached approximately 1.05 billion barrels in 2003 which corresponds to 4% of world oil production (European Commission, 2005). However we have to remember that Norway is not part of the EU hence these figures are not as easy to interpret as not all of Europe is included yet the report considered Norway when it was created as territorially Norway, is, in fact in Europe and it’s also part of the EEA. The inland consumption of oil in the EU in 2003 was at approximately 4.78 billion barrels hence 78% of oil (European Commission, 2005) was supplied by imports which increases the price of oil available for use in the EU. Most of the imports of this oil came from OPEC countries 40.3%, followed by Russia at 24.8% and Norway at 22.0%. Despite the high levels of imports of oil into the EU already, the European production of it is actually decreasing, which means the prices of the essential raw material- oil will rise further within the EU. This is shown by Figure 1 below. Furthermore, the fact that The North Sea is running out of the easily recovered oil adds an urgency to the matter as otherwise the already struggling EU economies will be effected. Thus in this blog post I examine the advantages and disadvantages of using one of the enhanced oil recovery methods with regards to Europe.

Figure 1.

Source: European Commission, 2005 Crude oil production, net gross consumption and import dependency in the EU during the period of 1990-2030.

At first sight, this method of oil recovery seems more eco friendly than other methods and if fact even helps the environment to a certain extent reducing the emissions of CO2 into the atmosphere and hence reducing the anthropogenic climate change. It includes injecting CO2 into the oil reservoirs to obtain the oil out of them, which means also creating underground CO2 stores. Carbon capture and storage (CCS) underground are currently a field of active research as little is actually known about the implications of such practice. But the main advantage is that CO2 is captured from power plants and other anthropogenic CO2 sources that massively effect climate change due to very high emissions of this GHG and it is injected into the oilfields that nearly reached the end of their lives. AS a result of this process CO2 is stored underground decreasing that country’s and global CO2 emissions and additional oil is produced thus creating income that helps the economy in this environmentally helpful process. This environmental fact certainly gives this method of oil recovery an advantage over other methods of enhanced oil recovery.

The energy industry itself creates very high pollution levels due to combustion of fossil fuels for energy production thus it is responsible for air, water and soil pollution so surely it should take at least some responsibility for its actions?! Furthermore oilfields are proven fluid traps, providing a certain level of certainty that they could serve as good CCS stores to try and mitigate the effects of climate change. If CCS was one of the techniques of mitigation of climate change, the oilfields (due to their economic profitability) are the geological reservoirs that have had the most research done to them thus there is better data available about them than any non-commercially profitable geological storage options for carbon such as aquifers. CO2 has to be stored in formations that occur at approximately 800m below the surface thus oilfields and aquifers are the best carbon storage options available on Earth CCS was used to combat climate change (Gough, 2006).

A saline aquifer is a geological formation in the rock found both below sea beds and ground and it consists of a layer of porous rock bearing saltwater. Oilfields are underground traps that used to store oil and gas or still do before it is extracted mostly without leakages over millions of years and they include already built infrastructure built around the sites already for the purposes of oil recovery that could now also be used for CO2 storage pumping.

Experience from CO2- EOR (Enhanced Oil Recovery) use in USA has shown that approximately 0.33 tones of CO2 are required to produce a barrel of oil miscible EOR operations and up to 0.8-1.1 tones per barrel of oil for immiscible CO2-EOR operations (European Commission, 2005). There are two types of oil EOR- miscible and immiscible which differ in the way and process oil is forced from under the ground but either way, it is evident that CO2 would be stored under the ground.

However there have also been studies done trying to assess CCS implications for our planet as well as humanity in general. They use SRES scenarios, which are Special Report on Emissions Scenarios produced by the IPCC and often used to model climate change in studies or what if studies under different future conditions due to climate change. I shall look at them more closely in my next blog post as they are fairly important. The good thing here is that the use of SRES by CCS studies also means that they consider climate change when looking at the implications of CCS as well as the fact they consider different projections of climate change and not just the implications of CCS today.

One of the worries of CCS is that although it makes CO2 “disappear” it is also not the ultimate solution of CO2 emissions and high anthropogenic production as we have to be careful not to just hide this problem “under the carpet”. The timescale of how long we can keep CO2 under the ground stored in these reservoirs is not certain and not enough research has been done into the area. The key security issue is the integrity of bedrock. As Figure 2 below shows, oil and gas cavity in bedrock or where CO2 is advised to be stored is covered by a cap rock, which is an impermeable layer of rock that acts as a seal. However longterm security relies on a continuous layer of cap rock extending far from the points of injection of CO2 into the ground through the oil wells. The oil wells themselves may represent weak points but these could potentially be monitored to avoid leakages and rapidly sealed if a leak was to occur but what if a leak occurred in some other place along the reservoir? The reservoirs sometimes extend over large geographical areas and hence it would be very difficult and expensive to monitor the whole thing over ground.

Source: European Commission, 2005. A typical “anticline” oil reservoir resulting from the upward folding of geologic strata (left) and a schematic of an oil occurrence within the reservoir (right).

Furthermore the specific store capacities of the reservoirs remain unknown. The potential capacity for storage in an aquifer are calculated from estimates of volumetric sweep efficiency (the displacement of water by CO2) based on modeled simulations of the reservoirs (Gough, 2006). However as we remember from the oil reserves blog post, it is very difficult to determine the size of the reservoir and the current technology does not provide detailed estimates thus they often change from the moment an oil reserve is discovered and all through its lifetime. Furthermore the pore volume that can be used for CO2 storage in the reservoir is very specific on each reservoir and depends on factors such as rate of injection, relative permeability, density and mobility of the fluids and rock heterogeneity. However this would require detailed research of each reservoir, which is currently lacking and thus only very generic estimates are used so it is uncertain how much CO2 we could actually “bury” under the ground and whether it is worth it. The extent of reversibility of CO2 back to the surface from the reservoirs also currently remains a mystery so the talk of using this CO2 in the future for new methods of energy creation and thus CCS being an early investment into something potentially very good for the economy remains a mystery.

Adverse impacts to human health and ecosystems are also a potential. Although CO2 is not toxic or too dangerous for humans in small concentrations, potentially leakages from the reservoirs can be very dangerous to humans because being a gas, CO2 would rapidly spread until the leak is discovered and high quantities of the gas have the potential to cause such severe conditions as asphyxiation (difficulties in breathing due to lack of oxygen) which potentially further leads to coma or death (Gough, 2006). The effects of CO2 that would be pumped into the reservoirs on any micro-organisms that might inhabit the reservoirs are also unknown thus potentially some ecosystems could get damaged although research suggests that oil and gas deposits would have already killed said ecosystems or caused them to adapt.

Finally there is also uncertainty that remains about the impacts on the large-scale earth systems due to CCS. There are some concerns that it would cause disruptions in the balance or weight distribution between ice caps and oceans thus effecting geology. Furthermore the increased pressures within the reservoirs could induce new seismicity in complete different parts of the world. So not only would we experience the effects of more natural disasters in terms of earthquakes and volcanic eruptions but also the whole environment on Earth is interlinked so by dis balancing the oceans, CCS could create a potential greater positive feedback to climate change compared to CO2 emissions into the atmosphere.

However despite all the uncertainties and under research of CCS, it is currently quite widely used in the USA for EOR and it is seen as a rather positive method of EOR compared to other methods so the question of why it is not yet implemented in Europe remains.

Firstly there are still some technical difficulties that remain with using this method in the North Sea such as the fact that in the US it is only used on the onshore oil fields whilst we are talking about offshore fields in Europe and hence the method requires research and monetary investment into this research as well as time before it can be implemented. Also the reservoir stratigraphy in the North Sea is very different to that in the US and it contains faulted blocks and steeply dipping beds. In the US the reservoirs are located in the low permeability and low dipping formations unlike the North Sea which are dominated by high permeability dipping reservoirs which means that gravity effects in the North Sea will be more important than viscous flow in the US so yet again more research into the effects of geology would be required (Gough, 2006).

Then there are also the economic reasons that not only would money have to be invested into all the extra research but also the costs of CO2 supply itself. Due to North Sea fields being offshore, there are no major combustion plants near by and thus infrastructure would have to be put in place to deliver CO2 to the oilrigs. Close monitoring of the wells would further be required to avoid the danger of leakages thus also increasing costs of recovery of oil this way. All of these make oil recovery this way potentially uneconomically viable for the purpose. Seeing as CCS is not yet seen as a major climate change mitigation policy, government has little incentive to invest in any of these projects either.

On top of all of these, environmental concerns by the public from such major new technology projects also remain and especially in the democratic countries of Europe where the public has a potential to stop such projects from going ahead thus they would require scientific proof and hence detailed research into the projects to convince them of safety and positive outcomes of such a project especially if public budgets were to be invested into these. Legal reasons also remain and albeit the fact there are no current legal limitations on the use of CO2 in EOR projects, there could be legal worries that CO2 is not used for EOR but with the aim of purely under researched CCS which has not yet been given a green light.

Overall, despite CO2 being a very questionable method of EOR with lots of uncertainties and potential disadvantages especially regarding CCS, I think CO2 as a method of EOR as well as just pure CCS is a very interesting topic that requires more research and potentially it is very important in mitigation of current climate change. Especially, let’s face it, humanity is not going to reduce its emissions of CO2 into the atmosphere any time soon or not to the significant amount that is needed to reduce climate change in our energy based society today thus some alternative solutions on what to do with all the CO2 produced in fossil fuel combustion are very important. Also I think that since USA have started using this method already, it obviously must be economically viable and profitable so Europe needs to do some research into it and seriously consider it especially on the verge of having to use EOR for oil extraction anyway or otherwise the European economy will be left lagging behind the USA one once again.