<a href="http://youngpetro.org/2013/03/06/how-is-it-possible-to-produce-oil-from-sand/"><b>How is it possible to produce oil from sand?</b></a> <a href="http://youngpetro.org/2011/10/09/people-engineers-and-spe-members/"><b>People, Engineers and SPE Members</b></a> <a href="http://youngpetro.org/2012/12/19/if-i-were-a-prime-minister/"><b>If I Were a Prime Minister…</b></a> <a href="http://youngpetro.org/2012/12/26/polish-shales-delayed/"><b>Polish shales delayed?</b></a> <a href="http://youngpetro.org/2013/01/11/russia-continues-the-policy-of-states-companies-monopoly/"><b>Russia continues the policy of state companies’ monopoly</b></a>
 

Gas Condensate Banking Effects

Gas Condensate Banking Effects

Gas condensate reservoirs have been classified between volatile oil and wet gas reservoirs. It means that the reservoir temperature is between the critical temperature and the cricondentherm (maximum temperature at which gas-liquid phases can coexist). Gas condensate reservoirs exhibit a complex behavior due to the existence of a two-fluid system (it is a single-phase fluid at original reservoir conditions) composed of reservoir gas and liquid condensate. When the pressure of the reservoir falls below dew point due to production, the original single-phase (gas phase) literally disappears because of the formation of condensates (liquid phase). The behaviours of such systems are complex and still not fully understood, especially in the near-wellbore region, where the largest pressure drops occur. It is important to mention that two kinds of gas condensate reservoirs exist: rich gas condensate reservoirs (e.g. Alen field – Equatorial Guinea) and lean gas condensate reservoirs (e.g. Arun field – Indonesia, Camisea field – Peru).

Gas Condensate Blockage

Condensate banking formation is a major problem when producing gas condensate fields. From the first day a gas condensate field is being produced, heavy components (valuable components) in the reservoir condense near the wellbore and continue growing over time. These condensate liquids are formed because the reservoir pressure falls below dew point (point where the first drop of liquid appears), and reduce the productivity over time. Productivity losses of around 50% (or even more) have been registered. Taking for example the case of the Arun field in Indonesia, where after 10 years of production a significant loss in well productivity occurred.

In technical literature, many authors proposed the existence of flow regions (from 2 to 4). Beyond the discussion of the existence of 2, 3 or even 4 flow regions in the reservoir, in this article we will focus only in the near wellbore region, where the principal phenomena occur due to condensate banking. Generally speaking there are two main factors that affect well deliverability when producing gas condensate reservoirs: Coupling and Forchheimer effects.

In the near wellbore region, where the gas flow rate is higher, an important effect called Forchheimer effect appears which produces higher pressure drawdown which results in major gas condensation that fills up the pore throats, and  consequently the gas relative permeability is reduced, decreasing the well deliverability. However, when condensation reaches a critical saturation, a “positive effect” occurs, which is called the coupling effect, that essentially explains the increment of the condensate relative permeability with increasing velocity and decreasing interfacial tension.

The evidence is overwhelming, it does not matter whether it is a rich or lean gas condensate reservoir, with production over time, the quantity of liquids in the near wellbore region will increase, affecting the well deliverability which is translated as a reduction in the production. Working to avoid a high pressure drawdown in retrograde gas condensate reservoirs has become an important topic today.

Corrosion and it’s remedy

Corrosion and it’s remedy

In simple words corrosion is defined as ruination of material because of its reaction with environment. It should be made clear here that for corrosion material does not have to be metal only and this vast term is not restricted to metals alone. On the other hand ruination of wood, rubber and paint due to exposure to sunlight is also considered to be corrosion.
Stress Corrosion Cracking (S.C.C) happens when mechanical stresses occur in the presence of corrosive environment and this phenomenon can cause serious problems. It is common observation that corrosion is always detrimental but interesting fact is that in some cases corrosion is beneficial and desirable like while anodizing of aluminum used to obtain a protective corrosion product on the surface and uniform appearance.
Chemical machining is widely used in aircraft’s industry. In this process unmasked areas are subjected to acid treatment and excess metal is dissolved. This process is adopted in situations where parts are hard and difficult to machine. Analysis of corrosion in Oil & Gas industry is of prime importance because of two main reasons:
1. To maintain continued and extended production to avoid loss of revenue.
2. To avoid catastrophic failures of facilities and avoid irreparable loss of life.
To control corrosion many industries are spending several billion dollars so one can realize the devastation caused by this phenomenon. Corrosion can be classified as either Sour or Sweet depending upon environments. Usually sour corrosion is caused due to the presence of high sulphur contents and its compounds in oil and gas industry.
Most common corrodents are:
1. Acid gases
2. Brine
3. Aggressive soils
4. Anaerobic bacteria
To control corrosion following corrosion measures may be taken:
1. Chemical Inhibition
2. Chemical Control (removal of dissolved gas)
3. PH control
4. Oxygen Scavenging
5. Cathodic Protection
6. Thickness measurement (Ultrasonic thickness meter)
7. Control of physical factors (Shocks etc)
It is important to calculate cost effectiveness of any of corrosion control measures before applying it and this can be calculated only in case of proper monitoring, the effectiveness of corrosion control program can be judged only in case of its proper monitoring.
At the end in Oil and gas industry it is difficult to total elimination of corrosion one can feel comfortably satisfied if the rate of corrosion is retarded up to safe extend.

 

References:

http://www.npl.co.uk/upload/pdf/beginners_guide_to_corrosion.pdf

http://www.npl.co.uk/upload/pdf/basics_of_corrosion_control.pdf

http://www.ce.berkeley.edu/~paulmont/241/Corrosion.pdf

The Story of Oil Sand

The Story of Oil Sand

Is it possible to produce Oil from Sand? Yes!
Canada has 3rd largest Oil reserves in the World and 97% of Oil reserves are tapped in sand called “Oil Sand”. Out of “173 Billion Barrels” of oil reserves “167 Billion Barrels” are present in the Oil Sands.
So here Question comes what are Oil Sands?
Basically Oil Sands are naturally occurring mixture of “sand, clay, water and bitumen” lies in the category of Unconventional Petroleum deposits. According to National Energy Board of Canada Bitumen main component of oil sands which can be refined into diesel fuel is defined as “A highly viscous mixture of hydrocarbons heavier than pentanes which, in its natural state, is not usually recoverable at a commercial rate through a well because it is too thick to flow”.
Canada’s oil sands have drawn attention for more than 200 years. Historical background date back as far as 1715, when “James Knight”, wrote in his journal about “gum or pitch that flows out of the banks of a river” (The Athabasca). Efforts to exploit the oil sands resource began in the early 20th century.
Oil sands are recovered using two main technical methods:
1. Open Pit Mining
Large shovels scoop the oil sands into huge trucks which transfer it to crusher.
Large pieces of clay are broken down at crusher units.
Oil sand is then mixed with water & transported to plant via pipeline.
Bitumen is separated from other compounds.
Recovery rate through this process is 90% —— useful & cost-effective.
20% Oil sands are present close to earth’s surface.
2. In-Situ Drilling
In situ drilling accounts for 80% of oil sands reserves because mostly these reserves are located below 200ft from surface.
Advanced technology (Directional Drilling) is utilized to inject steam, combustion or other sources of heat into the reservoir which warms the bitumen so it can be pumped to the surface through recovery wells.
Majority of in situ operations are performed through steam-assisted gravity drainage, or SAGD.
Steam is pumped underground through a horizontal well to liquefy the bitumen, which is then pumped to the surface through a second recovery well.
Recovery rate is 50—65%
Another method is Cyclic Steam Stimulation in which steam is pumped down through a vertical well to liquefy the bitumen, which is then pumped to the surface through the same well.
Recovery rate is 30—-40%.
Crude oil which is derived from the oil sands is usually sent to refineries across North America to make gasoline, diesel, aviation fuel and other consumer products and then utilized commercially.

http://www.oilsandstoday.ca/whatareoilsands/Pages/RecoveringtheOil.aspx
http://www.oilsandstoday.ca/whatareoilsands/Pages/History.aspx
http://www.oilsandstoday.ca/whatareoilsands/Pages/QuickFacts.aspx
http://www.oilsandstoday.ca/whatareoilsands/Uses/Pages/default.aspx
http://www.canadiangeographic.ca/magazine/jun08/feature_tar_sands.asp
Image Source Oilandgasiq.com

Russia cancels the planned South Stream gas pipeline

Russia cancels the planned South Stream gas pipeline

Vladimir Putin, the president of the Russian Federation, announced that his country resigns from the plans of building South Stream Gas Pipeline.

It was a strategic project both for Russia and for European countries (mainly Bulgaria, Hungary, Slovakia, Serbia and Austria). After the crisis in Ukraine, when the delivery of gas to these countries was threatened, it seemed that South Stream is necessary. The reason is that it was to pass by Ukraine and was to guarantee energy security of the southeastern Europe. The project was very important not only for the economies of these countries, but also for the biggest E&P companies of the region: OMV (Austria) and ENI (Italy). South Stream was to be the second largest investment in the field of pipelines in Europe in the last years. The first was Nord Stream, which was a sticking point in EU, connecting Russia and Germany, passing by Estonia, Lithuania, Latvia, Poland, Belarus and Ukraine.

The official reason of abandonment of the plan is that the position of European countries in the matter of the investment is not constructive. For example, the investor has not received all the necessary permissions for the construction in Bulgaria. But Bojko Borisow, the prime minister of Bulgaria asserts that his country supports the investment and the preparations still go on.

Specialists and politics indicate other reasons which might lead to such a decision of Russian authorities.

First of all, after the crisis in the eastern Ukraine and the annexation of Crimea, Russia has to face more and more political and economical problems, although its authorities will never admit it. Some European politics, especially from Ukraine, convince that it is only a political decision and its aim is to punish EU.

The second reason arises from the first one. Political and economical sanctions of EU and US put on Russia brought about serious financial problems to Russian companies, amongst them for the state-owned Gazprom. Maybe the South Stream is too big a burden to bear by the giant.

The third reason may be the price of oil and gas, which is falling down for many days. It is not profitable to invest in such a huge project (its costs are estimated to €40 bn), when the situation is uncertain and unstable.

The next reason is the potential modification of the strategy of Gazprom. The company creates new contacts in southeastern Asia and some people claim that soon some plans of building a gas pipeline to China will be prepared. It can be realized in about 5 years. Such change of strategy can be essential for the future of Gazprom as the approach of European economies also changes its course. European Union is making efforts to start a common energy policy. It looks for new sources of energy (mostly renewable energy, but also nuclear power) and for new contractors of oil and gas. Europe opens its doors for LNG (liquefied natural gas) through construction of LNG terminals in Świnoujście (Poland), Klaipeda (Lithuania) and Omisalj (Croatia). The investments will enable Europe to receive LNG from Qatar and North Africa. From 2019, when the Trans Adriatic Pipeline will be finished, also gas from Azerbaijan will enter Europe.

Thus, Europe will get independence from Russian oil and gas and the Old Continent will no longer need so many pipelines transporting Russian gas. Even given that Soyuz and Brotherfood crossing Ukraine will be cancelled, Jamal and Nord Stream will be enough to provide Europe with gas from Russia.

 “It may a bluff, to pressurise the Bulgarian, Serbian, Hungarian and Austrian governments to unite behind accelerating the project and make a better case for it to the European Commission” – says Martin Vladimirov, an energy specialist at the Centre for the Study of Democracy in Sofia. It may be true, because for Gazprom abandonment of the project can be the first step to loss the European market.

What can we, common gas users, do? I think we can take a bucket of popcorn and wait for the continuation of the matter.

Was Russia’s South Stream too big a ‘burden’ to bear? |BBC News Europe

Pictures:
www.gazprom.com