Look for images or metaphors that the author uses consistently. What other sort of pattern can you identify in the text? How do you interpret this pattern so that your reader will understand the book, essay, poem, speech, etc. better?
What philosophical, moral, ethical, etc. ideas is the author advocating or opposing? What are the consequences of accepting the author's argument?
Explain how the work functions as a piece of rhetoric--how does the author attempt to convince his or her reader of something? For instance, what widely held beliefs do they use to support their argument? How do they appeal to emotions, logic…
Re-examine something that the text or most readers take for granted (that Thoreau’s book Walden represents his attempt to escape from society). Question this major premise and see where it takes you
Ask yourself if an author’s literary argument is inconsistent with itself or is in some way philosophically "dangerous," inadequate, unethical, or misleading.
Examine how characters are presented in a story. How do they help the main character to develop? Which characters are trustworthy? Which are not? Why are they presented this way?
Structure: How the parts of the book or essay follow one another; how the parts are assembled to make a whole? Why does the author start where they start, end where they end? What is the logical progression of thought? How might that progression be intended to affect the reader What effect might this progression of ideas have on a generic reader or on a reader from the time period in which the work was written? Does the piece move from the general to the specific or vice versa?
If you could divide the book/essay into sections, units of meaning, what would those sections be? How are they related to each other? Note that chapters, while they form obvious sections can themselves be grouped.
Referring to the text: In writing analytic papers that address any kind of literature, it is necessary to refer to the text (the specific words on the page of the book) in order to support your argument. This means that you must quote and interpret passages that demonstrate or support your argument. Quotation is usually stronger than paraphrase. Remember also that your purpose in writing an essay is not merely to paraphrase or summarize (repeat) what the author has said, but to make an argument about how the make their point, or how they have said what they have said.
Language: includes the way an author phrases his or her sentences, the key metaphors used (it’s up to you to explain how these metaphors are used, why these metaphors are appropriate, effective, ineffective, or ambiguous). Is the way a sentence is phrased particularly revealing of the author’s meaning?
Please title your paper and make the title apt and enticing--I LOVE a good title. It puts me in a good mood before I start reading.
Be clear about whether you’re writing about a book, an essay (non-fiction, short prose), a story (short fiction) a poem, a novel (book-length fiction), an autobiography, a narrative (as in Captivity Narratives) etc. Walden is a book comprised of chapters. Each of these chapters could also be called an essay. Within these essays, Thoreau sometimes tells stories. The book itself is not a story, but closer to a narrative, which is non-fiction.
Always go through at least two drafts of you paper. Let your paper sit, preferably for 24 hours between drafts sometime during the process of your writing.
Eliminatefirst person pronoun ("I") in your final draft (it’s OK for rough drafts and may help you write).
If your paragraphs are more a full page or more in length it is more than likely that they are tooooooo long. Probably you have too many ideas "in the air" at once. Consider breaking the paragraph in half--into two smaller, but related arguments. Your reader needs a break, needs more structure in order to be able to follow your meaning.
If several of your paragraphs are exceedingly short (4-5 lines), it is likely that you are not developing your ideas thoroughly enough--that you are writing notes rather than analysis. Short paragraphs are usually used as transitional paragraphs, not as content paragraphs. (Short paragraphs can be used in the rhetorical devise of reversal where you lead your reader down a certain path (to show them one side of the argument, the one you are going to oppose) and then turn away from that argument to state the true argument of your paper.)
Employ quotation often.One quotation per argumentative paragraph is usually necessary. Depending upon the length and complexity of the passage or topic you're dealing with, more quotations may be useful to prevent you from getting too far away from the text. Your quotations combined with your interpretations are your proof. Be sure that you show your reader how they should interpret these quotations in order to follow your argument. (Almost every quotation should be followed by an interpretation, a deeper reading of what is being said and how its being said. This interpretation demonstrates how the quotation supports the claim you're making about it). Pay attention to metaphor, phrasing, tone, alliteration, etc. How is the author saying what they are saying--what does that teach us about the text?
Remember to write directive (sometimes called "topic") sentences for your paragraphs. The first sentence of any paragraph should give your reader an idea of what the paragraph is going to say and how the paragraph will connect to the larger argument. It should have more to do with what you have to say about the materials than what the author him or herself has said.
Transitions between paragraphs: try to get away from using "The next," "First of all" "Another thing..." to connect your paragraphs. This is the "list" method of structuring a paper--not an integrated, logical approach. A really strong transition makes the logical connection between paragraphs or sections of a paper and gives the reader a sense that you’re building an argument. To make sure you are making a well-connected argument, ask yourself how the last sentence of each paragraph and the first sentence of the next are connected. Each of the sentences within your paragraphs should be related somehow (follow from, refer to, etc.) the one that precedes it, and the one which follows it. This will help the reader follow the flow of your ideas. The order of your paragraphs should reveal a developing argument.
On the most basic level, you should be able to consciously justify the presence and placement of every word in every sentence, every sentence in every paragraph, every paragraph in every essay. To repeat: in revising your papers after the first draft (which is always, inevitably to some degree confused because you are involved in the process of working your ideas out), you should be highly conscious of what you are doing and why you are doing it.
To summarize the most important physical, chemical reasons behind the phenomenon and processes described above give a short overview of laws of physics explaining them is given hereby. The topic is summarized in a detailed and substantial series of whitepapers and books [3–9].
The main reasons behind the capillary rise are the cohesion force among the molecules of fluids (e.g hydrogen bonds in water, or van der Waals forces in methane), and the adhesion forces between the fluid and the solid phases . Equilibrium is achieved when adhesion and cohesion forces become equal, as they are in Figure 1. Adhesion forces tend to lift the water, while cohesion forces are acting against it. The rise of the wetting fluid’s level can be calculated by Equation 1. (All of the abbreviations and units are indicated in a table named Units and Abbreviations after Acknowledgements, in the end of the whitepaper.) (1)where h is height, σ stands for interfacial tension, Θ for contact angle, r for radius, g for gravitational acceleration and ρ for absolute density. Equation 1 is a general equation for defining the capillary rise above FWL in an e.g water-hydrocarbon system.
According to Equation 1 the factors influencing capillary rise of water in a water-wet system are listed below, indicating the direction of proportion and source of information:
radius of the capillary tube (inverse)
From a rock fabric point of view these tubes are the equivalents of pore throats that are measureable. Basically the drainage capillary curve is the cumulative distribution function of pore volume belonging to decreasing diameter pore throat’s as capillary pressure increases.
acceleration of gravity (inverse)
The Earth’s average value for g is 9.81 m/s2 .
contact angle (inverse proportion, direct with its cosine)
Contact angle can be measured by several procedures, like USBM, Amott, imbibition, microscope, floatation methods . It has a high effect on the dynamic behavior of the reservoir, and it can change over time by aging due to the fact that some minerals tend to change their wettability on molecular level [3, 4].
interfacial tension (direct)
IFT is heavily dependent on temperature, it has to be considered to measure its value with reservoir fluids, but empirical equations, nomograms are also available in literature [10–16].
difference of fluid’s absolute densities (inverse)
Absolute densities can be measured in PVT laboratories or calculated using analytical and empirical equations [17–20].
Based on the workof Young and Laplace the pressures on two sides of a curved fluid surface are non-equal [21, 22]. Applying this fact to a capillary system it can be proven that in equilibrium the capillary pressure equals to the difference of measured pressures in the non-wetting and wetting phases, Equation 2 expresses this relation [7, 23–27].(2)
where capillary pressure (Pc) (bar) is expressed as the pressure difference of non-wetting (nw) and wetting (w) phases (cross-linked to Equation 1), ρ is absolute density (g/cm3), g is gravitational acceleration (m/s2), h is height (m), σ is interfacial tension (dynes/cm), Θ is contact angle (rad) and r is radius of the capillary tube (μm).
According to Equation 2, Pc (capillary pressure) can be explained as the pressure (or force) that would be sufficient to drive out the wetting fluid from the given size of pore throat. Supposing a theoretical rock type that has uniform pore throat size the capillary pressure can be calculated by solving Equation 2. That has to be overcome by buoyancy force to let the non-wetting phase enter the pore system and start draining the wetting one. The buoyancy force is provided by the difference of absolute densities, the higher the difference the lower the hydrocarbon column needed to reach the displacement or entering pressure. It means in practice that the same hydrocarbon saturation conditions can be acquired at lower heights in case of gas compared to oil reservoirs. Figure 2 gives a quick overview of the most important elements of a natural system and its tally from the laboratory.
A theoretical two-phase natural system is shown on the left, delineating the theory of capillary pressure and buoyancy forces. It is linked to the capillary pressure curve measured in the laboratory by contacts belonging to a hydrocarbon reservoir (based on ).
Figure 2 shows the superposition of physical processes resulting in equilibrium of capillary and gravitational (buoyancy) forces in a natural, single rock type, two-phase system. That equilibrium defines the initial saturation profile of a hydrocarbon reservoir. The initial saturation profile is a key parameter at reservoir geological and engineering calculations e.g in-place volume, technical volumes, recovery factors, and via them significantly affecting CAPEX, OPEX, NPV, revenue.
Free water level (FWL) is a flat, horizontal surface if the hydrodynamic system is in equilibrium and no significant underground water flow occurs. FWL is the surface, where the capillary pressure is zero, in other words where the water level would set in an infinite diameter water-wet capillary tube.
The phase contact (100% water level) is dependent on the lithology, to be more precise, on the largest pore throat of a given rock type. Phase contact’s (100% water level) height above the FWL (HAFWL) can be defined by the displacement pressure (pd) of the capillary curve. It is the minimum pressure that must be achieved to let the non-wetting phase enter the pore system through the largest pore throat. In the interval between the FWL and 100% water level of a given rocky type, the wetting phase is held by capillary forces against buoyancy even in the largest pore throats.
The producing water level (PWL) can be defined empirically to identify a proposed depth of the lowermost perforation producing with close to zero or zero water-cut. It must be emphasized, that this is a completely empirical approach.
Transition zone is the interval on the capillary curve from the phase contact to the starting point of the irreducible saturation (i.e the steep slope).
The irreducible water saturation (Swirr) is the portion of formation water that cannot be lowered by conventional production; it will not flow under depressions occurring while producing a reservoir. Although it has a significant role being the horizontal asymptote of the capillary curve. It shall not be confused with clay-bound, interstitial or connate water . One of the main goals of this paper is to introduce a new method of coupling irreducible water saturation with mercury injection capillary pressure (MICP) data.
Capillary and buoyancy forces play a significant role in numerous subsurface processes, and since they can be described by the rocks’ capillary curves, these data are crucial and extremely useful at several aspects of reservoir characterisation from petrophysics to reservoir engineering [16, 23–25]:
differentiating rock types,
determining initial water saturation profile,
defining in-place volumes’ spatial distribution,
estimating fluid contacts,
determining the maximum retainable hydrocarbon column (seal capacity),
predefining dynamic behaviour of reservoirs,
field development concept selection,
estimating the efficiency of EOR/IOR methods,
injection of fluids,
lifetime and processes of underground gas storages.
Drainage capillary curves reflect the process when non-wetting phase drives out the wetting phase (e.g secondary migration of hydrocarbon into a water-wet reservoir, water injection into oil-wet reservoir, gas injection into water-, or oil-wet reservoirs). While the opposite process i.e wetting phase’s saturation increase is called imbibition (e.g formation water(re)-entering a water-wet reservoir during production). Figure 3 is illustrating an example of drainage and imbibition curves, and capillary hysteresis. The latter phenomenon occurs mainly because of contact angle-hysteresis, a deviation of advancing and receding contact angles .
An example of drainage and imbibition capillary curves and capillary hysteresis .