<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.

An Essential Skill Many Graduates Lack

An Essential Skill Many Graduates Lack

What comes to mind when we talk about skills future employers want to see in recent graduates is; communication, problem solving, leadership, creativity, and adaptability skills. While such skills are undoubtedly in demand, an essential skill many employers want graduates to have which you might not even have thought about is called quantitative reasoning skill. You are probably wondering what quantitative reasoning skill is all about? To give you a little bit of understanding, consider the following example:

You are given a calculation based question to solve, and you are asked to take a decision based on the result you get from your calculation. The decision might be to either invest in a new business opportunity or not, or to choose a product based on the product’s price and quality and the list goes down. The skill required to take such decisions is called quantitative reasoning.

What is quantitative reasoning skill?

Quantitative reasoning skill ( QR ) is the ability to understand and use quantitative information to come to a solid conclusion. It involves the application of basic mathematical, and critical thinking skills to draw justified conclusions from facts and evidence available at hand. QR is considered among the most important intellectual skills such as communication fluency, information literacy, and analytical thinking that all university graduates should acquire.

Why QR is so important?

The importance of QR skill comes from the fact that it is a real world skill that future employers want you to have. Whether you are taking engineering, science, or even arts major, quantitative reasoning is a skill everyone need these days. There is no major I can think of that does not need a quantitative understanding. Whether you are still student, recent graduate or even having a career right now, cultivating this skill is a crucial factor that will determine how successful you will be.

But, do all graduates have this important skill?

As a recent graduate, I can tell you the answer. Not all students who graduate have this skill. And even those graduates who have QR skill, it may not be as strong as required by employers. The issue comes down to few reasons. First of all, students are often not informed by the academia about the importance of this skill in their career readiness and life in general. Therefore, they can not develop something they do not know its benefits for them or why they need it in their career.

The second reason is the misconception that QR skill is already thought in math classes. The truth is, there is a huge difference between QR and math. It is true that QR utilizes the basic mathematical skills in getting the calculation result, however it is more about the meaning of the calculation results rather than how to perform the calculation itself. As a result, academic subjects are more into recalling math procedures rather than encouraging students to think critically about problems in real-life contexts.

How do you cultivate and develop QR skills?

For you to have the ability to understand and use statistical data to make informed decisions, you must first have a sense of numbers, measurements and what they really represent. This is due to the fact that your accurate sense of numbers and measurements backed by a strong mathematical knowledge base is what will enable you to make accurate conclusions.

Once that put in place, the next step is to practice quantitative reasoning in diverse settings. Find problems that require you to think critically, analyze data, interpret numbers to reach decisions based on those results you get from solving such problems. A better way is to practice solving problems in real-life contest. That means taking problems from current real-life events. This will surely motivates you to go beyond recalling procedures and solving mathematical problems to think critically about the result you get and relate what you learn to the real life.

As a student or recent graduate or even having an entry level career, you need QR skills more than any other skills in your daily life and your career readiness. Strong quantitative reasoning skills will allow you to make sense of complex situations in your everyday life and enable you to make informed choices and decisions. It is never too late to learn something new, if you have that skill, make it better, and if you do not have it, go and cultivate it.