UNIVERSITI TEKNOLOGI MARAFAKULTI KEJURUTERAAN KIMIARESERVOIR ENGINEERING LAB(CGE 617)

NAME & STUDENT NO:ABDI ZIL IKRAM BIN ABDUL AZIZ(2013612392)EXPERIMENT:CLEANSING AND SATURATION DETERMINATION DATE PERFORMED:16 APRIL 2015SEMESTER:4PROGRAMME/ CODE:EH223GROUP:4A

Checked by:

1.0: Fluid saturation definition:Saturation is the measure of the fluid volume present in the pore volume of a porous medium. By definition, the saturation of a fluid is the ratio of the fluid volume to the pore volume or the rock. Fluid saturation = Geologist noted that the rock pores are saturated with water at the first place before eventually being displaced by the presence of hydrocarbon as the hydrocarbons mihrate ujp dip into traps due to having density less than watwe density. Therefore, more than one fluid is usually present in the reservoir. For the two phase case, only one of the two saturation independent, the other must make the sum of the saturation equal to unity (1).2.0: Fluids saturation method comparison:2.1: Direct injection of solvent.The solvent is injected into the sample in a continuous process. The sample is held in arubber sleeve thus forcing the flow to be uniaxial.

2.2: Centrifuge FlushingA centrifuge which has been fitted with a special head sprays warm solvent onto thesample. The centrifugal force then moves the solvent through the sample. The usedsolvent can be collected and recycled.

2.3: Gas Driven Solvent ExtractionThe sample is placed in a pressurized atmosphere of solvent containing dissolved gas. The solvent fills the pores of sample. When the pressure is decreased, the gas comes outof solution, expands, and drives fluids out of the rock pore space. This process can berepeated as many times as necessary.2.4: Soxhlet Extraction

A Soxhlet extraction apparatus is the most common method for cleaning sample, and isroutinely used by most laboratories. As shown in Figure (1.1a), samples to be cleaned areplaced in a porous thimble inside the Soxhlet.Electric or gas heaters are used to vaporize the solvent. The hot vapors meet the samples inthe thimble and dissolve the oil and water. Vapors are condensed and cover the sample untilover-flown back to the solvent flask. The extraction process continues for several hours and isterminated when no more oil remains in the samples. This is recognized when the condensingvapors remain clean because no oils is left in the cores to be dissolved.After the extraction, samples are dried in an electric oven. Sometimes vacuum may also beapplied to the oven. A complete extraction may take several days to several weeks in the caseof low API gravity crude or presence of heavy residual hydrocarbon deposit within the core.Low permeability rock may also require a long extraction time.The dried samples are kept ina desiccator sealed with grease and has some moisture absorbents at its bottom .

Figure 1 shows a Soxhlet extraction apparatus2.5: Dean-Stark Distillation-Extraction

The Dean-Stark distillation provides a direct determination of water content. The oil andwater area extracted by dripping a solvent, usually toluene or a mixture of acetone andchloroform, over the plug samples. In this method, the water and solvent are vaporized,recondensed in a cooled tube in the top of the apparatus and the water is collected in acalibrated chamber (Figure 1.1b). The solvent overflows and drips back over the samples.The oil removed from the samples remains in solution in the solvent. Oil content iscalculated by the difference between the weight of water recovered and the total weightloss after extraction and drying.2.6: Vacuum distillationA sample is placed within a leakproof vacuum system and heated to a maximum temperature of 230 0C. Liquids within the sample are vaporized and passed through a condensing column that is cooled by liquid nitrogen .

Conclusion:

The direct-injection method is effective, but slow. The method of flushing by using centrifugeis limited to plug-sized samples. The samples also must have sufficient mechanical strengthto withstand the stress imposed by centrifuging. However, the procedure is fast. The gasdriven-extraction method is slow. The disadvantage here is that it is not suitable for poorlyconsolidated samples or chalky limestones. The distillation in a Soxhlet apparatus is slow, butis gentle on the samples. The procedure is simple and very accurate water contentdetermination can be made. Vacuum distillation is often used for full diameter cores becausethe process is relatively rapid. Vacuum distillation is also frequently used for poorlyconsolidated cores since the process does not damage the sample. The oil and water values are measured directly and dependently of each other. In each of these methods, the number ofcycles or amount of solvent which must be used depends on the nature of the hydrocarbonsbeing removed and the solvent used. Often, more than one solvent must be used to clean asample. The solvents selected must not react with the minerals in the core. Some of the commonly used solvents are:- Acetone- Benzene- Benzen-methol Alcohol- Carbon-tetrachloride- Chloroform

3.0: Choose one method and describe in details the experiment.3.1 Procedure:1. Weigh a clean, dry thimble. Use tongs to handle the thimble.2. Place the cylindrical core plug inside the thimble, then quickly weigh the thimble and timble the sample3. Fill the extraction flask two-thirds full with toluene. Place the thimble with sample into the long neck flask.4. Tighten the ground joint fittings, but do not apply any lubricant for creating tighter joints. Start circulating cold water in the condenser.5. Turn on the heating jacket or plate and adjust the rate of boiling so that the reflux from the condenser is a few drops of solvent per second. The water circulation rate should be adjusted so that excessive cooling does not prevent the condenser solvent from reaching the core sample.6. Continue the extraction until the solvent is clear. Change solvent if necessary.7. Read the volume of collected water in the graduated tube. Turn off the heater and cooling water and place the sample into the oven (from 105 to 120 ), until the sample weight does not change. The dried sample should be stored in desiccators.8. Obtain the weight of the thimble and the dry core.9. Calculate the loss in weight WL, of the core sample due to the removal of oil and water.10. Measure the density of a separate sample of the oil.11. Calculate the oil, water and gas saturations after the pore volume Vp of the sample is determined.

3.2 Apparatus:1. Dean-stark apparatus2. Rock sample(core plug)3. Solvent (usually used toluene)

The Dean-Stark distillation provides a direct determination of water content. The oil and water area extracted by dripping a solvent, usually toluene or a mixture of acetone andchloroform, over the plug samples. In this method, the water and solvent are vaporized,recondensed in a cooled tube in the top of the apparatus and the water is collected in acalibrated chamber.

Figure 2 shows a Dean-Stark Distillation-Extraction apparatus.

3.3 Data and calculation:Sample No:Porosity :WorggWdryGwg/cm3og/cm3Vwcm3WoGVocm3Vpcm3SoSwSg

Where,Worg: Weight of original saturated sampleWdry: Weight of desaturated and dry sample

3.4 Equations:WL= Worg - WdryWo= WL - WwVb= (D/2)2 LVp= VbWhere D and L are diameter and length of the core sample respectively.

3.5 Summary:The aim of this experiment are to study the procedure in cleaning of the cores samples from residual fluid and to determine the oil and as saturation of core sample using dean stark distillation extraction method. But, there was a problem and we cannot carry out the experiment. However, we manage to do the research about this method.We supposed to heat the hydrocarbon solvent which is toluene at its boiling point which is 1100C. The vapour produce move upward and the rock sample become engulfed in the vapour. Then begin to extract oil and water present in the rock sample. The rising vapour will condense and collected in the graduated tube.The condense liquid in the graduated tube will consist of two liquid phase which are mixed hydrocarbon and water. Due to higher density, water settles at the bottom of the graduated tube while solvent overflow and drop back over the rock sample. The process continues until no more water is collect in the receiving tube.