FOCUS - Issue 4 by EAGE Suez

EAGE SUEZ ACADEMY TEAM'S MAGAZINE

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4d Seismic Time Lapse

4D Seismic The time-lapse, or 4D, seismic method involves acquisition, processing, and interpretation of repeated seismic surveys over a producing hydrocarbon field. The objective is to determine the changes occurring in the reservoir as a result of hydrocarbon production or injection of water or gas into the reservoir by comparing the repeated datasets.

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Drilling Problems and Their remedies While we drilling a well the are most common problems that face us such as lost circulation ,stuck pipe, Fishing . lost circulation. Its mean that I losses drilling mud in a permeable layer stuck pipe. During drilling operations, a pipe is considered stuck if it cannot be freed from the hole without damaging the pipe, and without exceeding the drilling rigâ&#x20AC;&#x2122;s maximum allowed hook load. What is the meaning of fishing? Sometimes, something gets into the hole that needs to be recovered .the processes of recovered any thing that go down to the well called Fishing.

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EOR Methods in Carbonate reservoirs About more 60 % of the discovered reservoirs are carbonate ones which need from us better studies and researches to maximize the recovery of this reservoirs types. The challenge in this reservoir is due to its heterogeneity and mixed wettability although it has good permeability. This article talks about some problems which we face during carbonate reservoir stimulation, reasons and solutions. The case study included shows the results from stimulating this reservoir.

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Oil distillation Oil is one of the most important natural resources on which we rely mainly on life, whether in homes, factories or as fuel for different means of transport. When crude oil is extracted, it must pass some separation processes to obtain its derivatives. , In this article we are talking about the simple stages of distillation process. Oil is one of the most important natural resources on which we rely mainly on life, whether in homes, factories or as fuel for different means of transport. When crude oil is extracted, it must pass some separation processes to obtain its derivatives. , In this article we are talking about the simple stages of distillation process.

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About us Focus is a magazine prepared by EAGE Academy committee members, and two issues were published until now. The first issue contained three topics the first was about earthquakes and the second discussed seismic processing. The third topic was about the relationship between geology and medicine. The second issue topics are environmental geophysics, and how to protect ourselves from earthquakes. It contained also an article to tell the students about the main work of academy committee.

Our team Editor in Chief Mostafa Ahmed Sobhy Academic Head Sara Abd allah Academic Team Khloud Hashem Esraa Fawzy Ahmed Mokhtar Mosa Mohamed Sameh Hamed Taha Yehia Mohamed Ramadan IR Head Omar Khaled Hassan IR Team Sherouk Mohamed Abdel-Razeq Sara khaled Hassan Sohaila Ahmed Abdel-hady Creative Director Aya Elgendy Graphic designers Noha Mohamed Mahran Hossam Nasr Mohammed Mohammed Amr | ISSUE 3 | FEBRUARY2017

4D SEISMIC TIME LAPSE edited by: Mohammed Shahin

Changes in a Reservoir Seen through 4-D Seismic Source: Schlumberger Four-D seismic can determine changes in flow, temperature, pressure and saturation. By scanning a reservoir over a given period of time, the flow of the hydrocarbons within can be traced and better understood. For example, as hydrocarbons are depleted from a field, the pressure and composition of the fluids may change. Additionally, geologists are interested in understanding how the reservoir reacts to gas injection or water flooding. Furthermore, 4-D seismic can help to locate untapped pockets of oil or gas within the reservoir. Typically, 4-D seismic data is processed by subtracting the data from one survey from the data of another. The amount of change in the reservoir is defined by the difference between the two. If no change has occurred over the time period, the result will be zero

D surveys are 3D surveys repeated in time, also called a time-lapse survey. It is considered best to leave the sensor array permanently in place for this to improve repeatability. The Time interval can be about 6 months to a year or two, and can go on for multiple years.

By comparing or animating the three-D images rapidly changes in the formation structure as a result of production can be observed, telling the interpreters where and how the hydrocarbons have been drained. Used to find oil and gas prospects, there are multiple types of seismic surveys that can be produced over reservoirs to understand the subsurface environment. Made up of reflection and refraction mapping, seismic surveys give geologists a better idea of what lies beneath the surface - or even below thousands of feet of water. One of the most intricate forms of seismic survey, 4-D (four-dimensional) seismic, is a type of geophysics. Also known as time lapse seismic, 4-D seismic incorporates numerous 3-D seismic surveys over the same reservoir at specified intervals of time. Studying multiple time-lapsed 3-D surveys, or threedimensional subsurface images, portrays the changes in the reservoir over time. 4

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References

•Koster, K. et al. 2000. Time-Lapse Seismic Surveys in the North Sea and Their Business Impact. The Leading Edge 19 (3): 286. http://dx.doi. org/10.1190/1.1438594 •Lumley, D.E., Behrens, R.A. and Wang, Z. 1997. Assessing the Technical Risk of a 4D Seismic Project. The Leading Edge 16 (9): 1287. http://dx.doi. org/10.1190/1.1437784 •Wang, Z. 1997. Feasibility of Time-Lapse Seismic Reservoir Monitoring: The Physical Basis. The Leading Edge 16 (9): 1327. http://dx.doi. org/10.1190/1.1437796 •Behrens, R., Condon, P., Haworth, W. et al. 2001. 4D Seismic Monitoring of Water Influx at Bay Marchand: The Practical Use of 4D in an Imperfect World. Presented at the SPE Annual Technical Conference and Exhibition, New Orleans, Louisiana, 30 September-3 October 2001. SPE71329-MS. http://dx.doi.org/10.2118/71329-MS.

•Jump up to: 5.0 5.1 5.2 Johnston, J.H. et al. 2000. Using Legacy Seismic Data in an Integrated Time-Lapse Study: Lena Field, Gulf of Mexico. The Leading Edge 19 (3): 294. http://dx.doi. org/10.1190/1.1438596 •Eastwood, J. et al. 1994. Seismic Monitoring of Steam-Based Recovery of Bitumen. The Leading Edge 13 (4): 242. http://dx.doi.org/10.1190/1.1437015 •Talley, D.J. et al. 1998. Dynamic Reservoir Characterization of Vacuum Field. The Leading Edge 17 (10): 1396. http://dx.doi.org/10.1190/1.1437858 •Wang, Z., Cates, M.E., and Langan, R.T. 1998. Seismic Monitoring of a CO2 Flood in a Carbonate Reservoir: A Rock Physics Study. Geophysics 63 (5): 1604. http://dx.doi.org/10.1190/1.1444457 •Greaves, R.J. and Fulp, T.J. 1987. ThreeDimensional Seismic Monitoring of an Enhanced Oil Recovery Process. Geophysics 52 (9): 1175. http:// dx.doi.org/10.1190/1.1442381 | ISSUE 4 | FEBRUARY2018

Drilling Problems and Their Remedies :

here are various common problems that might occur during drilling, and there are some uncommon ones, too. This chapter will describe the most commonly encountered drilling problems caused by downhole conditions. When any problem is encountered, the drilling staff must identify the root causes of the problem before a proper response to solve the problem can be formulated. If the root causes are incorrectly identited, it is unlikely that the correct response will be made, and the problem might remain unsolved. It can even make the situation worse. Identifying the root causes of problems covered in this article will be described, along with possible responses.

The main drilling problems:

1- Lost Circulation Lost circulation is defined as the uncontrolled flow of whole mud into a formation sometimes referred to as thief zone. shows partial and total lost-circulation zones. In partial lost circulation, mud continues to flow to surface with some loss to the formation. Total lost circulation, however, occurs when all the mud flows into a formation with no return to surface. If drilling continues during total lost circulation, it is referred to as blind drilling. This is not a common practice in the field unless the formation above the thief zone is mechanically stable, there is no production, and the fluid is clear water. Blind drilling also may continue if it is economically feasible and safe.

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Lost circulation zone and causes : Formations that are inherently fractured, cavernous, or have high permeability are potential zones of lost circulation. In addition, under certain improper drilling conditions, induced fractures can become potential zones of lost circulation. The major causes of induced fractures are excessive downhole pressures and setting intermediate casing, especially in the transition zone, too high. Induced or inherent fractures may be horizontal at shallow depth or vertical at depths greater than approximately 2,500 ft. Excessive wellbore pressures are caused by high flow rates (high annular-friction pressure loss) or tripping in too fast (high surge pressure), which can lead to mud losses. In addition, improper annular hole cleaning, excessive mud weight, or shutting in a well in high-pressure shallow gas can induce fractures, which can cause lost circulation.

Cavernous formations are often limestones with large caverns. This type of lost circulation is quick, total, and the most difficult to seal. High-permeability formations that are potential lost-circulation zones are those of shallow sand with permeability in excess of 10 darcies. Generally, deep sand has low permeability and presents no loss-of-circulation problems. In noncavernous thief zones, mud level in mud tanks decreases gradually and, if drilling continues, total loss of circulation may occur.

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Prevention of lost circulation : The complete prevention of lost circulation is impossible because some formations, such as inherently fractured, cavernous, or highpermeability zones, are not avoidable if the target zone is to be reached. However, limiting circulation loss is possible if certain precautions are taken, especially those related to induced fractures. These precautions include maintaining proper mud weight, minimizing annular-friction pressure losses during drilling and tripping in, adequate hole cleaning, avoiding restrictions in the annular space, setting casing to protect upper weaker formations within a transition zone, and updating formation pore pressure and fracture gradients for better accuracy with log and drilling data. If lost-circulation zones are anticipated, preventive measures should be taken by treating the mud with lost-circulation materials (LCMs).

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2- Stuck Pipe During drilling operations, a pipe is considered stuck if it cannot be freed and pulled out of the hole without damaging the pipe and without exceeding the drilling rigâ&#x20AC;&#x2122;s maximum allowed hook load. Differential pressure pipe sticking and mechanical pipe sticking are addressed in this section

2. Mechanical pipe sticking : The causes of mechanical pipe sticking are inadequate removal of drilled cuttings from the annulus; borehole instabilities, such as hole caving, sloughing, or collapse; plastic shale or salt sections squeezing (creeping); and key seating.

Causes of stuck pipe can be classiďŹ ed into :

1. Differential pressure pipe sticking Differential-pressure pipe sticking occurs when a portion of the drill string becomes embedded in a mud cake (an impermeable film of fine solids) that forms on the wall of a permeable formation during drilling. If the mud pressure, which acts on the outside wall of the pipe, is greater than the formation-fluid pressure, which generally is the case (with the exception of underbalanced drilling), then the pipe is said to be differentially stuck The differential pressure acting on the portion of the drill pipe that is embedded in the mud cake can be expressed as.

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3. Fishing : Sometimes, something gets into the hole that needs to be recovered. For instance, a spanner might drop down the rotary table or part of the drill string might break. These items prevent normal operations from continuing. The item that must be removed from the well is called a fish and activities to remove the fish are termed fishing. There are four main causes for fish in the hole

3- Washover and basket:

Within this class of tool there are three types: the fishing magnet, tools that use fluid movement to catch small bits of junk, and tools that use a barrel to go over bits of junk and then close below the junk.

a ) If there is a failure somewhere in the pipe in the hole that causes a break, the lower part of the string will drop into the hole b) If stuck pipe cannot be freed, it has to be cut or unscrewed downhole. c) Something falls into the well. d) Sometimes wells are worked over; they may require that the existing completion is replaced with another completion. Often the completion tubing has to be cut downhole and recovered in pieces. There are five classes of tool that can be used to remove a fish or junk from the hole. The choice of which one to use will depend on the circumstances. The five classes are each briefly described: OUTSIDE CATCH TOOLS If the junk has a round profile at the top, the preferred tool will normally be an outside catch tool. These tools are pushed over the top of the fi sh. When the fishing tool is moved upwards, it grips the fish and allows force to be applied.

INSIDE CATCH TOOLS Sometimes, a tubular ﬁsh has a large outside diameter, which prevents an overshot from going over it.

slow job because each stand of pipe has to have the wire fed through it before it can be connected to the wireline sometimes breaks, string at the rotary table. resulting in a tricky fishing job. Wireline is fi shed with a spear that has barbs on the side The spear is 2. Drilling, milling, and run into the top of the wire and smashing junk : rotated. The barbs catch on the wire Finally, In surface holes where and cause the wire to wrap around formations are soft, smaller the spear so that it can be pulled bits of loose junk can be drilled out. If a logging tool gets stuck, the with a steel tooth bit. Often what best way to fish it is by stripping happens is that the bits of junk over the wire. The wire is cut at the get pushed into the side of the surface and is fed through a special hole and are never seen again. tool that latches onto a profile at the Steel tooth bits are also capable top of the logging tool. This fishing of breaking up small bits of jun tool is then run in the hole over no other drill bit can do this. the wire so that the wire guides the fishing tool to the logging tool. It is a 1. Fishing for wireline and logging tools

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F EOR Methods in Carbonate Resevoirs edited by : Taha Yehia

uring the past decade, two-thirds of new hydrocarbon discoveries were made in carbonate reservoirs. More than 60% of the world’s oil and 40% of the world’s gas reserves are held in carbonates.The Middle East has 62% of the world’s proved conventional oil reserves; approximately 70% of these reserves are in carbonate reservoirs. The Middle East also has 40% of the world’s proved gas reserves; 90% of these gas reserves lie in carbonate reservoirs. Beside the great importance of carbonate reservoirs, they have specific characteristics which make dealing with them a real challenge. Unlike the relatively homogenous sandstone reservoirs, in which hydrocarbons are found within sand layers, carbonate reservoirs (limestone or dolomite), are made of materials such as shell or coral. These reservoirs are characterized by a matrix with a low permeability and high heterogeneity resulting from fractures or dissolution patterns, as carbonates may dissolve in the presence of water.

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luids present in these reservoirs often contain hydrogen sulphide and carbon dioxide, produced by chemical reactions within the carbonate reservoirs, this hydrogen sulphide is highly corrosive and toxic. Beside that tar mass which is heavy layers of hydrocarbons that are highly viscous, are also found in these reservoirs and can form permeability barriers. Because carbonate reservoirs have very high seismic velocities generating multiple reflections, obtaining good seismic images can be difficult. Also, it is extremely difficult to describe the wetting character of reservoir rocks as they have complex structures of a variety of minerals.This makes incorrect assumptions about reservoir wettability might result is unexpected formation damage. Unlike,sandstone reservoirs which have strongly water-wet, wettability is a further heterogeneous characteristic in carbonates. The aging of carbonate rock containing water and oil turns initially water-wet rocks into mixed-wet or even oilwet rocks. This means that oil can adhere to the surface of carbonate rock and it is therefore harder to produce. This article will discuss the main stimulation techniques in carbonate reservoirs, challenges we face in the stimulation process and its solutions.

Carbonate Stimulation : When the productivity of a well in a carbonate reservoir decreases as a result of formation damage or low natural permeability, the production team will attempt to increase productivity through intervention and appropriate treatments. If they decide to work over the well, they must identify and implement a treatment program that creates conductive flow paths between the reservoir and the borehole. This is the essence of carbonate stimulation.

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cids play a key role in boosting production or increasing injectivity in oil and gas fields. Stimulation of carbonate rocks usually involves a reaction between an acid and the minerals calcite (CaCO3) or dolomite CaMg(CO3)2 that is intended to enhance the flow properties of the rock.

Stimulation methods in carbonate sequences can be divided into two main groups:

Matrix stimulation involves pumping acids, solvents, or other treatment chemicals into the formationhydrochloric acid (HCl) is the most commonly applied stimulation fluid- at less than the reservoir fracture pressure. When acids are introduced into a carbonate formation, some of the minerals in the rock dissolve, which creates intricate, high-permeability channels or wormholes (Fig. 1).

Acid-fracturing stimulations, in contrast, are performed above the fracture pressure of the formation. A viscous pad (a fracturing fluid that does not contain proppant) is pumped into the formation at pressures above the fracture initiation pressure, which fractures the rock. Then an acid stage is pumped to etch the fracture surfaces. The acid also creates conductive wormholes at or near the fracture surfaces Figure 2. When the treatment is complete and the fracture closes, the etched surfaces provide high-conductivity flow paths from the reservoir to the wellbore.

2- UNEVEN DISTRIBUTION OF THE TREATING FLUID When injecting acids into a well with the goal of stimulating the production of a low permeability reservoir, the acids will naturally go into the more permeable parts of the geological formation. The solution is Diversion. Diversion is a technique used in injection treatments to ensure uniform distribution of the treatment fluid across the treatment interval. Injected fluids tend to follow the path of least resistance, and this may lead to inadequate treatment of the least permeable areas within the stimulation interval. Using diversion methods, engineers can focus treatment on the areas that require more stimulation. To be effective, the diversion effect should be temporary to enable the full productivity of the well to be restored when the treatment is complete. There are two main categories of diversion: mechanical and chemical. MECHANICAL METHODS Mechanical diversion techniques, such as ball sealers, packers, and straddle packer assemblies, are used to divert reservoir treatments to the target zone. Ball sealers and solidparticle diverting agents incorporated into the treatment fluid form a temporary plug in the perforations accepting the most fluid flow, thereby diverting the remaining treatment fluid to the less permeable zones (Fig. 3a). Packers and straddle-packer assemblies function by performing several short treatments over a longer interval to help ensure even treatment over the entire zone (Fig. 3b). LIMITATIONS though widely used, mechanical diversion methods may not always be feasible or recommended. They are often ineffective for stimulation projects in long horizontal or extended-reach wells.

CHEMICAL METHODS

In sandstones, matrix treatments are used to restore or improve the natural formation permeability around the wellbore by removing formation damage. This is accomplished by dissolving material that is plugging the pores or by enlarging the pore spaces. In carbonates, matrix stimulation creates new, highly conductive channels (wormholes) that bypass the damage. Matrix treatments are often applied in zones with good natural permeability to counteract damage in the near-wellbore area.

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CHALLENGES WE FACE IN THE STIMULATION PROCESS 1- WATER-BEARING ZONES ZONES One of the fundamental requirements for any stimulation program is that the increase in conductivity is restricted to the hydrocarbon zone. Acid or fracture stimulation of water bearing layers adjacent to the reservoir would lead to a sharp rise in water production with the associated issues of fluid handling, separation, and disposal. In extreme cases, stimulation of the water zone could end the economic life of the well.

Conventional chemical diversion methods include nitrogen foam, bridging agents such as benzoic acid flakes, and crosslinked polymer gels. These create a temporary plug in high-permeability carbonate zones so that the stimulation fluids are diverted into the low-permeability zones that require more treatment. Polymer-based gels are a well-established chemical diversion technique. These systems use reversible, pH-triggered cross-linker additives to alter the viscosity of the fluid during the acid treatment. SDA* Self-Diverting Acid is a polymer system mixed with HCl. When combined with fresh acid, the SDA fluid has a low viscosity to facilitate pumping. However, once this fluid enters a carbonate zone and the acid becomes spent, the polymer crosslinks and the fluid viscosity increases. The higher gel viscosity restricts the flow of fresh acid through the wormholes, and diverts it into the zones with lower permeabilities and, eventually, to all the zones requiring treatment (Fig. 4). LIMITATIONS Modern chemical diversion methods can be very effective, but may create problems if incorrectly managed. In some wells, for example, temporary plugs may become permanent, which damages the formation and reduces production from the zone that was supposed to be stimulated. | ISSUE 4 | FEBRUARY2018 15

ADVANCED TECHNOLOGY ClearFRAC polymer-free fracturing fluid, which is based on viscoelastic surfactant (VES) technology, and a high-temperature version of the system that can be used at temperatures to 135degC.VES surfactant fluids are polymerfree, so they do not damage the formation. Their enhanced, drag-reducing properties and significantly lower friction pressure enable the stimulation team to reduce the pumping requirements and treat deeper zones. There is a range of VES fluids for various applications. These include VDA diverting fluid, ClearFRAC hydraulic fracturing fluid, and ClearPAC* gravel packing fluid.

3- EMULSIONS AND SLUDGE During fracturing and matrix acidizing, the acid may come into direct contact with produced crude oil or well fluids. This may result in the formation of emulsions or sludge. Emulsions can be viscous and may block the treated formation and reduce oil production. Solution Reservoir engineers can add anti-emulsifying and antisludging agents to prevent these emulsions forming and demulsifiers to break emulsions once they have formed.

5-PREVENTING ACID DAMAGE TO WELL AND SURFACE EQUIPMENT The used chemicals and acids in stimulation treatments can cause damage to the completion equipment of the well Solution Corrosion inhibitors prevent acid damage to equipment both at the surface and in the well. The initial cost of corrosion inhibitors may seem very high—they are the single most expensive component of the materials used—but the cost of damage to pumping equipment and tubulars if they were not to be used would be even higher.

6-STIMULATION THROUGH HORIZONTAL WELLS FORM A REAL CHALLENGE

Case study: suCCess in saudi arabia Case study: suCCess in saudi arabia In Saudi Arabia, there has been were much greater than the average In Saudi Arabia, there has been significant greater than the from average11 production from 11 offset a significant change in a carbonate production offset wells that change in carbonate reservoir techniques, stimulation wells hadstimulated been stimulated without theVDA VDA reservoir stimulation hadthat been without the techniques, with away a shiftfrom awaypolymer-based from polymer- system (Fig.(Fig. 6). Water cut in the VDA-treated wells with a shift system 6). Water cut in the VDAbased stimulation fluidstoward towardnon-damaging non-damaging was much lower wells treated other stimulation fluids treated wellsthan wasinmuch lowerwith than in VDA systems. Saudi Aramco has used VES fluids systems. This was because the high-viscosity gel VDA systems. Saudi Aramco has used wells treated with other systems. This for VES a range of stimulation applications, including inwas the because water zones remained intact, whereas the fluids for a range of stimulation the high-viscosity gel in the matrix acidizing andincluding diversion in production and gel formed in the remained hydrocarbonintact, zones had broken applications, matrix acidizing water zones whereas water injection wells,inand acid fracturing high- and the acid toinmigrate further into the and diversion production andin water theenabled gel formed the hydrocarbon pressure, high temperature gas wells and watermatrix. This led to more effective stimulation of injection wells, and acid fracturing in zones had broken and enabled the acid injection wells. Saudi Aramco and Schlumberger zones higher This rates high-pressure, high temperature gas the to hydrocarbon-bearing migrate further into theand matrix. wells found and water-injection togas more effective stimulation of the engineers that the productionwells. rates ofSaudi the 5 ofled oil or production. Aramco and Schlumberger engineers hydrocarbon-bearing zones and higher wells after stimulation with VDA fluid were much found that the production rates of the rates of oil or gas production. 5 wells after stimulation with VDA fluid

Long, open hole horizontal wells provide an efficient way to develop complex carbonate reservoirs, but there are challenges in attempting to stimulate these wells due to the difficulty of proper distribution of the stimulation fluid through the well. Solution Mechanical isolation and individual treatments which allow treating each part of the well separately.

4-INSOLUBLE REACTION PRODUCTS When operators anticipate that a formation will contain large amounts of acid insoluble silts or other fines that could be released during acidizing, these solids can cause severe plugging of pore throats during flow back. Solution the acid should be treated with a siltsuspending agent. By keeping these solids in suspension, the operators can produce them out of the formation and avoid damaging the well’s performance.

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Oil Distillation Petroleum is considered one of the most important daily needs. It is used in most household appliances. Oil distillation is one of the processes used in preparation for direct use. Its main idea is the process of separating the liquid from the solution, depending on the difference in the boiling point. The material to be separated has a boiling point different from the other substances in the solution. By evaporation of a heterogeneous mixture of water and natural matter, and then the steam condensation process is carried out by cooling process.

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There are many types of distilleries used in oil refining, petrochemical industry, desalination, pharmaceutical industry and many others such as: 1. Simple or progressive distillation 2. Sudden distillation. 3. Frequent distillation using distillation towers. 4. Steam distillation. 5. Vacuum distillation.

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How distillation is done ? First Step :

When crude oil is extracted from the well, the water and associated salts are disposed of in several ways, because this water and these salts can cause serious and serious problems when oil distillates in a later step in the distillation tower. The water accompanying the oil if not removed , Distillation As the salts if it still produced acids in the tower which leads to erosion.

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Third Step : After obtaining these derivatives, they are not marketed directly because they are in fact not valid for use so far. In order to be usable, some improvements have to be made to make them suitable for the desired use.

Second Step : After removing water and salts, we move on to the main step in the process of refining oil, which is the process of separating oil into its components depending on the difference in the boiling point of these components. This separation process is known as distillation of oil because oil is separated and divided into specific components and known and specific uses. This step occurs in a huge tower known as a distillation tower where the oil is heated to degrees up to 400 degrees Celsius or slightly more in a special oven and then pushed with hot oil at the bottom of the tower. We also know that the oil consists of a large mixture of organic compounds each compound has certain characteristics and has a certain boiling point, the light organic compounds that are low in boiling will rise to the top of the tower such as methane and ethane. They will condense into special trays inside the tower and then be pulled out through special openings. Thus, the higher components in the boiling point will intensify slightly below. As we descend to the bottom of the tower, the boiling points of these components will increase until we reach the bottom of the tower, where we will find the heavy residues, the components with high boiling points. In general, the products (petroleum derivatives) obtained are different from refinery to refinery according to the design of the tower itself, as well as by the quality of oil is it light oil or heavy oil.

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In general, most of the petroleum derivatives produced by the oil distillation tower are as follows: Gases such as: methane, ethane, ethylene, propane, butane and others. 1) Light liquids: mainly gasoline (automotive fuel). 2) Kerosene: It is used as jet fuel, and a poor type of cheap fuel is used in industrial plants and homes. 3) Diesel: a heavier liquid than kerosene is used as fuel in factories, large engines and trucks. 4) Heavy liquids: An important source of petroleum industries, some of which can be converted to light derivatives such as gasoline through known oil operations such as thermal cracking and catalytic cracking. 5) The pitch: are the residues gathered at the bottom of the tower , With high molecular weight and used in the coating of concrete constructions, ship painting, paving and paving of roads.

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Other References: 1- Distillation: https://www.eia.gov/todayinenergy/detail.php?id=6970 2- Crude Oil Distillation - nptel. Journal of Chemical Education. Fenster 1967 44 (11), p 660 3- Drilling problems John Martin Shaughnessy (BP plc) | William Thomas Daugherty (BP America) | Rick L. Graff (Chevron Corp.) | Todd Durkee (Kerr-McGee Oil & Gas Corporation) PEH:Drilling Problems and Solutions - - PetroWiki 4- SPE-171126-MS_Viscous Fingering Stimulation Option Applied on Heavy-Oil Carbonate Reservoirs.(Javier Ballinas, Weatherford). 5- SPE 160887_Stimulation Strategies to Guard against Uncertainties of Carbonate Reservoirs. 6- SPE-169662-MS A Laboratory Study of Ionic Effect of Smart Water for Enhancing Oil Recovery in Carbonate Reservoirs. 7- Production Doubled in a Saudi Aramco Carbonate Reservoir_slb website. 8- SPE 93413_Stimulation Challenges and Solutions in Complex Carbonate Reservoirs. 9- An overview of hydraulic fracturing and other formation stimulation technologies for shale gas production (Luca Gandossi). 10- GEOLOGY OF CARBONATE RESERVOIRS_WAYNE M. AHR Texas A&M University. 11- www.researchgate.com. 12- www.onepetro.com. 13- www.slb.com.

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