Enhanced Oil Recovery Essay Example for Free

Enhanced Oil Recovery Essay Oil and Gas refers to the naturally occurring liquid and natural gas specifically made up of long chain hydrocarbons and various organic compounds found beneath the surface of the earth in entrapments called reservoirs; the presence of oil and gas in these reservoirs is the reason humans survive everyday and carry out their daily activities effectively. Different activities are usually carried out to ensure that the oil and gas present in the reservoirs continue to support humans through their day-to-day activities; such activities include exploration, development, production and finally, abandonment and reclamation. This process is what is referred to as â€Å"the oil and gas process†. On completion of this process, numerous efforts are made to increase the quantity of oil that can be extracted again from the oil well and we refer to these efforts as â€Å"recovery†. There are three main types of recovery, primary recovery (solution gas, gas cap and natural water drive) secondary recovery (gas injection and water flooding) and tertiary recovery (enhanced oil recovery EOR, polymer flooding and steam flooding). In this article, analysis on the â€Å"enhanced oil recovery† technology and trends will be emphasized upon. Enhanced oil recovery becomes very vital when oil production has to be increased to obtain a recovery percentage of at least 75% (Rigzone, 2009). This can only achieved by using any of the four basic methods of EOR; these methods include chemical flooding, miscible gas displacement, thermal recovery and microbial EOR. Among these four mentioned, â€Å"Thermal methods are the oldest EOR methods, they have been developed over the last thirty years† (Elsevier, 1981). Miscible gas displacement also called â€Å"gas injection† by some engineers refers to the process of injecting CO2, natural gas and Nitrogen into a reservoir; â€Å"in miscible gas displacement, the gas is injected at or above the minimum miscibility pressure (MMP) which causes the gas to be miscible in oil† (Bandar, 2007). Chemical flooding also called â€Å"chemical injection† involves injecting chemicals such as a polymer directly into the reservoir to enhance the oil recovery. Thermal recovery introduces heat to the reservoir to reduce the viscosity of the oil. Many times, steam is applied to the reservoir, thinning the oil and enhancing its ability to flow (Rigzone, 2009). Over 50% of the tertiary recovery method employed by the United States of America is the thermal recovery method. The most common gas employed when â€Å"gas injection† is being used is the CO2 (carbon dioxide) gas. The two major reasons why carbon dioxide is used are because it is miscible with crude oil and also it is the cheapest of all the other miscible fluids present. Carbon dioxide injection into the reservoir based on previous experiences has shown that a recovery of up to 15% of the oil that was originally in the reservoir is achievable. With the injection of the carbon dioxide gas, changes occur in the reservoir such and temperature and pressure changes. Through the changes in temperature and pressure, carbon dioxide can form a solid, liquid, gas and supercritical fluid (Teledyne, 2007). Furthermore, when carbon dioxide has been injected into the reservoir, it begins to form a homogeneous mixture with the crude oil thus, the light hydrocarbons, which are present in the crude, mix with the carbon dioxide gas and this dissolves the oil. Upon miscibility of the carbon dioxide gas and the crude, the physical forces separating the liquid phase and the gaseous phase gives way and this helps the carbon dioxide gas move the oil from the rocks towards the wells for production. According to the USDOE, a very good example of an applied carbon dioxide gas injection technique is the  Wasson. Fields Denver Unit CO2 EOR project which has resulted  in  more than 120 million incremental barrels  of  oil through 2008 (2010). Moreover, carbon dioxide is not the only gas employed when the gas injection technique is employed. Nitrogen is another gas commonly used for gas injection basically to maintain the reservoir pressure; it can also be employed when gas cycling and gas lifting are to be employed. The minimum miscibility pressure of nitrogen depends largely on the pressure, temperate and the composition of the reservoir fluid. According to Schlumberger, â€Å"above the MMP, nitrogen injection is a miscible vaporizing drive. Miscibility of nitrogen can be achieved only with light oils that are at high pressures; therefore, the miscible method is suitable only in deep reservoirs† (2011). Both methods of miscible injection from past experiences have proved very effective. When oil has been effectively recovered from these reservoirs using the miscible gas, the gas that has mixed with the recovered oil is separated from the oil and re-injected into the reservoir to enhance the oil recovery once again. This process can be repeated until the reservoir is completely depleted and cannot produce any more oil. Note that nitrogen gas injection is used when dealing with reservoir containing light oils and also very economical allowing a recovery of up to 40%. A practical example of nitrogen gas injection is in the Cantarell oil field in Mexico. Upon application of this enhanced oil recovery methods, there was a noticeable increase in the oil production from 1. 9 million bpd to 2. 1 million bpd. Fig 1: Typical illustration of the miscible gas process using CO2 and water (University of Kansas, 1999) Chemical flooding can also be referred to as chemical injection and is the process whereby chemicals and polymers are injected into a reservoir to increase its â€Å"recovery factor†. EOR methods involving the use of polymers usually yield a recovery range of ~6% to ~30%. When these chemicals are injected into the reservoir, the oil that is trapped there is released thus it can flow freely into the production wells. Furthermore, â€Å"polymers help increase the effectiveness of water-floods and boost the efficiency of surfactants† (Duncan, Ferguson, Sudip and Neptune, 2011). The use of polymers in chemical injection further helps to enhance the competence of the surfactants and also the efficiency of the water flooding; to be precise, water soluble polymers are best used for this process. The polymer that is regularly utilised during the process is the partially hydrolyzed polyacrylamide and with development in technology, the quality has improved over time. In order to achieve the best results from the chemical injection process, there are certain characteristics that need to be in place. These characteristics include â€Å"high remaining oil saturation, low water-flood residual saturation, high permeability and porosity, high polymer concentration and slug size, fresh water and soft water and reservoir temperatures of less than 220F† (Gary, 2007). Favourable characteristics are not limited to these that have just been mentioned but if these characteristics are present, then the expected recovery from the reservoir in question would be satisfactory as up to ~30% recovery is achievable. Moreover, economics have shown that chemical flooding is not profitable when the price of the surfactants is compared with that of the price of oil; it usually cost a lot to obtain the surfactants needed to recover oil from reservoirs and in some cases, the chemicals which are injected into the reservoir are more expensive than the oil which they extract from that reservoir. Chemical flooding can prove to be very pricy and at the same time provide the engineers with the needed results. Thermal recovery is usually applied to reservoirs with depths lesser than 3000ft. These reservoirs usually contain very viscous oil. There are four main types of thermal flooding that can be applied to any reservoir; they include: Fig 3: The steam injection process (The Piping Guide, 2009) 1. Cyclic stem injection: Popularly known as the â€Å"huff and puff† technique, it differs from all other types of thermal flooding in that it uses a central well to carry out every function from the injection of steam to the extraction of oil. The technique is quite straightforward, steam is pumped into the well and the well is covered up for some time so that the steam can get to the reservoir rocks and upon arrival, the steam enhances the oil flow. To improve the oil flow further, this process can be repeated over again which leads to a new process called â€Å"steam drive†. 2. Steam drive: In this process, steam is re-injected into the reservoir constantly. Moreover, this process cannot be as effective as required if the reservoir rocks have fractures. If there were fractures, â€Å"the steam would simply head straight through those into the producing wells instead of working its way through the reservoir rock† (Anon. , 2008). After the steam is injected, underlying heat is formed and this eventually aids the oil to flow with ease. 3. Thermally assisted gas-oil gravity drainage: this process is best suited for highly fractured reservoirs. In this process, the steam is injected directly into these fractures to reduce the viscosity of the oil and allow it flow easily. According to the petroleum development Oman, the steam â€Å"just needs to get the oil flowing more easily. This then allows gravity to take effect, causing the oil to drain down into the fractures and then into horizontal producing wells that are situated towards the bottom of the reservoir† (2008). 4. In-situ combustion: In this process, a reasonable quantity of the oil in the reservoir is actually set on fire to act as a steam and gas generator. According to the petroleum development Oman â€Å"it’s the trickiest of the four main thermal EOR methods to get right. It is generally only used in a reservoir that has high permeability (i. e. fluids can flow easily through the reservoir rock) and even then only as a last resort† (2008). Some of the oil might be lost during burning but more can be recovered as a result of the steam that has been generated that drives the oil towards the producing well. MICROBIAL ENHANCED OIL RECOVERY (MEOR) Microbial enhanced oil recovery also known as microbial flooding refers to the process whereby microorganisms are injected into the reservoir to increase oil production from a well. The process of MEOR is a biological based technology in which these microorganisms react with the reservoir fluids in order to mobilize the oil and move it towards the production wells. Usually, MEOR is used in the third stage of EOR after 12% to 20% of the oil in the well has already been recovered. The characteristics of the reservoir in which the MEOR process is being applied will greatly have an effect on its success. There are two types of MEOR, â€Å"those in which the microorganisms react with reservoir fluids to generate surfactants and those that react with microorganisms to generate polymers† (Ronald, 2001). MEOR is an economical way of increasing oil production and as genetic technology keeps improving, it would become the most attractive and cheapest method of enhanced oil recovery as the improvement lowers the cost of oil production. Conclusively, certain strains of bacteria that exist and are used for the MEOR method sometimes do not survive due to the harsh conditions they encounter in the reservoirs but as mentioned earlier, microbiologists are working on a different strain of bacteria that can survive in the reservoirs irrespective of these harsh conditions. Enhanced oil recovery has an outstanding economic potential to increase oil recovery thereby maximizing profit. EOR also has it disadvantages that have negative effects on the ecosystem. Steam injection causes serious air pollution and also, polymer flooding which falls under chemical injection also leads to contamination of underground water which eventually makes it unfit for consumption. Furthermore, during the EOR process, a substance called â€Å"brine† is produced at the surface of the well; this substance is highly toxic and also radioactive. On exposure to humans, it can be very dangerous and highly detrimental. In my opinion, more research on how the chemical injection process can be carried out without affecting the underground water supply and also how the thermal process of steam injection can be done safely without a threat to the atmosphere. Regulations put in place to control the environmental impacts of EOR should be as strict as possible so that eventually, the eco-system is preserved and oil and gas companies can still maximize profit.

Ciceros De Amicitia Essay -- Friendship Death Love Essays

Cicero's De Amicitia Cicero’s De Amicitia brings a unique perspective to the topic of friendship and how it relates to death. The word amicitia comes from the Latin root word amor which is translated to mean â€Å"love†. In this day and age the word friendship has taken on a slightly different meaning from the ancient meaning. Cicero’s De Amicitia seeks to define what friendship is, its characteristics and principles. He has challenged us to reconsider what constitutes a true friend. Upon observing a typical friendship it becomes clear to us that this relationship is actually devoid of true love; the love in which Cicero speaks of. A genuine friendship is a rare and beautiful thing; a mutual relationship formed between two virtuous people of the same sex in which both individuals love the other as much if not more than themselves. â€Å"In the face of a true friend a man sees as it were a second self.† To love another person as much as you love yourself, to give without the expectation of receiving something in return is indeed an amazing concept. It is sometimes hard to comprehend its existence in this world where friendship is more for utility; â€Å"serve for particular ends - riches for use, power for securing homage, office for reputation, pleasure for enjoyment, health for freedom from pain and the full use of the functions of the body. But friendship embraces innumerable advantages.† The structural foundation upon which a friendship is built is a key determining factor concerning the quality, life and longevity of a friendship. When this foundation is weak and built on the selfish desires of those individuals, that friendship is ultimately put to the test. A utility based friendship is impermanent; giving way to the changing circumstances it faces over time as Cicero stated â€Å"For if it were true that its material advantages cemented friendship, it would be equally true that any change in them would dissolve it.† It does not have the qualities to endure and will fail to thrive in the face of such trials and tribulations as â€Å"conflicting interest; differences of opinion in politics; frequent changes in character, owing sometimes to misfortunes, sometimes to advancing years.† In this type of friendship the individual takes pleasure in each other’s company only in so far they have hopes of gaining an advantage from it. For Cicero, true friendship can only be achie... ...h act. â€Å"I am disposed to think, therefore, that in his case mourning would be a sign of envy rather than of friendship. If, however, the truth rather is that the body and soul perish together, and that no sensation remains, then though there is nothing good in death, at least there is nothing bad.† This statement shows a certain level of jealousy for you envy the freedom your friend has now achieved in death whereas you are still encased in your human form, your soul trapped and yearning for knowledge and wisdom. Feelings of joy would wash over the surviving friend if indeed their friendship were true. Feeling joyful that this person he has loved with all his heart and soul has moved on to a beautiful place, free from the human condition. Reading Cicero’s work has helped validate that which I have always felt to be true; not just of friendship but of death. I conclude with a passage in which Cicero touches on the purpose of forming friendships; †For it is not so much what one gets by a friend that gives one pleasure, as the warmth of his feeling.† One day I hope to understand through first hand experience rather than just through speculation and dissection of Cicero’s writing.

Who is Adrienne Rich

In these essays the writers back up there views with examples of how either man or woman has been oppressed throughout the history of education. While Adrienne Rich is talking mainly about the college system and David Thomas is talking about the school system in general, their views do conflict each other. Rich believes that women have been exploited throughout the history of time. Thomas on the other hand believes that by being forced to have women teachers has disadvantaged boys. Though these views do no directly conflict, they are pretty close. Rich tells why she feels that women have been oppressed and Thomas tells why he feels that boys have been disadvantaged. In Rich†s essay â€Å"What Does a Women Need to Know? † she argues that women have been demoralized throughout time. Rich says â€Å"when we think of what an independent women†s college might be: a college dedicated both to teaching women what women need to know and, by the same token, to changing the landscape of knowledge itself. (Rich 45) This means that she believes that women should be taught the skills that they will need to succeed in life as a wife and as a â€Å"self conscious, self-defining human being. † (Rich 45) She then gives examples of her life experiences and how her life experiences with men trying to force her to think and see things one way, and how she struggled to see things from a different perspective, â€Å"through the eyes of an outsider. † (Rich 46) She ends her speech by talking about how these women have to change the ways of the past and they have to step into the now and become educated of the past and present. She ends the speech with, â€Å"Get all of the knowledge and skill that you can in whatever professions you enter; but remember that most of your education must be self-education, in learning the things that women need to know and in calling up the voices we need to hear within ourselves. † (Rich 50) The David Thomas essay â€Å"The Mind of Man† is about how boys are shot down at an early age. In a writing from the Independent on Sunday Toney Mooney says â€Å"Women teachers find boys too noisy, too aggressive, too boisterous. Unconsciously or not, they consistently reinforce and reward more ‘feminine† behavior. If all this is true it is understandable that boys should not be as advanced as girls in the hands of woman junior school teachers. There is a direct relationship between a child†s academic achievement and a favorable response from the teacher. † (Thomas 339) To prove this fact there was an experiment done with seventy-two boys and sixty girls at kindergarten. They were taught to read on a self-teaching machine and then they were tested. The boys did better than the girls. Then they resumed normal classroom instruction by women teachers. The children were tested again and this time the boys† scores were lower than the girls. It is not a prejudice that women or men have against the children, it is a understanding of what the child is going through because the teacher has been in that position at one time in their lives. It is a common ground that the male teachers have with the male students and vice versa. Thomas talks about how a single sex environment is not always the answer either. He attended an all boys† boarding school and he was â€Å"taught in a system that was designed to bring the best out of boys, intellectually, creatively and on the sports field. † (Thomas 341) He says that it is a better venue to learn but he says, â€Å"I was painfully aware of the distorting affect that an all-male institution was having on my own emotional development and that of my classmates. (Thomas 341) He says that some people cannot handle this environment and it will lead to â€Å"disaster† (Thomas 341) In conclusion I would have to agree with Thomas. I am a little biased but women teachers have personally disadvantaged me. I also worked in a pre-school over the summer where the teachers are mostly women. I witnessed this discrimination first hand. I disagree with Rich because I think that today women and men pretty much stand on even ground. I think that there is more discrimination against men then there is against women.

ap us history dbq - 1672 Words

1.All of the following statements are true about Herbert Hoover’s responses to the Great Depression EXCEPT: B.:-) He saw the Depression as akin to an act of nature, about which nothing could be done except to ride it out. 2.Franklin D. Roosevelt’s New Deal program attempted or achieved all of the following EXCEPT C.:-) supported the creation of the Reconstruction Finance Corporation. 3.The â€Å"New Immigration† was made up primarily of D.:-) persons from Southern and Eastern Europe. 4.By â€Å"normalcy† President Warren G. Harding meant not only peace after the recent war but also C.:-) an end to idealistic crusades and efforts at large-scale reform 5.Which of the following words best describes the spirit of American†¦show more content†¦A.:-) Herbert Hoover 38.The â€Å"court-packing† scheme proposed by President Franklin D. Roosevelt on February 5, 1937 I. was triggered by Supreme Court decisions that undid much of the first New Deal II. was withdrawn when a majority of the Supreme Court justices retired III. became unnecessary when the Supreme Court began reversing previous decisions and upholding New Deal legislation IV. was replaced by a Judiciary bill that denied the president the power to enlarge the federal courts but conceded badly needed procedural reforms C.:-) I, III, and IV only 39.â€Å"There is no right to strike against the public safety, anywhere, any time,† was said by C.:-) Calvin Coolidge on calling out the Massachusetts National Guard during the Boston police strike 40.The Republican administrations of the 1920s would best be described as B.:-) supporting isolationism and laissez-faire business policies domestically 41.The Palmer Raids of the 1920s were a response to C. ? fears of communism follwoing after the Russian Revolution 42.The use of installment plans during the 1920s was significant to the economy because it D.:-) served as a catalyst for a new consumer-based economy 43.The Supreme Court decision of Schenck v. 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Uses all or all but