Journal of Petroleum Research & Studies

Ethylene refrigeration for gases separation at low temperature and high pressure for olefin production is an important technique in the chemical industry. Since small changes in the operating conditions of such a process can have a significant influence on its economics, optimization is desirable. The present work was aimed to propose and establish a mathematical model for the ethylene refrigeration system of the ethylene plant in Basrah petrochemical complex NO.1 (PC1) and reformulated as a geometric programming problem using Visual Basic for predicting:- (overall efficiency of the ethylene refrigeration system {% }and percent of energy saving %E). Through the formulated model shaft work consumption by the centrifugal compressor, refrigeration effect and coefficient of performance of the system were obtained and other parameters concerning the system. The results of simulation showed a good agreement with the manufacturer manual.In this study the effect of four factors as independent variables on the overall refrigeration system efficiency and percent of energy saving were studied ;evaporator low pressure (PL) in the range of (1-3)bar ,compressor discharge high pressure (Ph) in the range of ( 28-32)bar ,condenser degree of sub-cool temperature (Tsub-D) in the range of (6-22)0C and evaporator degree of superheat temperature (Tsup-D) in the range of (1-5)0C. And the optimum conditions that aimed to minimize the thermodynamic irreversibility i.e (maximize overall refrigeration system efficiency) and also lower operating cost i.e (maximize percent of energy saving) evaporator low pressure (PL) (2.8 bar), compressor discharge high pressure (Ph) (28.7 bar), condenser degree of sub-cool temperature (Tsub-D) (190C), and evaporator degree of superheat temperature (Tsup-D) (3.40C). At these conditions the overall refrigeration system efficiency is (81.8%) and percent of energy saving is 51.18% with respect to conditions in the factory.

Production of low sulfur content of untreated naphtha from Al -Qayarah Refinery units has been studied in this research by using oxidation, oxidation-adsorption, and adsorption methods. The influence of time, temperature, sorbent type on sulfur reduction was investigated. The results showed that oxidation- adsorption was an efficient method for the desulfurization of naphtha where high removal efficiencies of about 93% were obtained. Also, it was concluded that by increasing temperature (up to 60C), and time (up to 5 hr) led to decreasing sulfur content from 1194ppm to about 76ppm. The results indicated that the best sequence of sulfur removal on sorbent materials were as follow: Ni/AC˃ AC ˃ Ni/γAl2O3˃ γAl2O3.

The present numerical study compares between spray characteristics of diesel and soybean oil methyl ester (SME biodiesel) under non-evaporating sprays. The spray structure of diesel and biodiesel fuel (soybean oil) in a common rail injection system are investigated and compared with that of available experimental data used image processing and atomization performance analysis. The proposed approach for the liquid phase based on the statistical properties of sprays be used to describe the liquid and gas phases in an Eulerian-Eulerian approach. The main concept for this model is the possibility of describing a poly disperse spray by using moments of a drop number size distribution function. The main reason for less spray tip penetration in
the (SME) comparing with diesel because a larger droplet diameters is the higher density, viscosity and surface tension of (SME). The effect of fuel properties on the near nozzle structure is studied. The comparisons are referring that the spray drag, breakup and collision processes are promoted.

The research aims at investigating the corrosion behavior of low Carbone steel pipelines welds and mechanical properties of weldment . The corrosion behavior was investigated in crude oil and water extraction from oil to study the effect of water chemistry on corrosion employing electrochemical and weight loss measurements.
Corrosion and erosion-corrosion have important role in oil fields especially in oil pipelines . The experimental work tests of erosion- corrosion were done using special device which was designed and manufactured according to (G 73) ASTM . The work tests were achieved using traditional weight loss technique to measure weight loss rates in (mpy) Unit, the tests above were done in pumped media and pumped media had constant pressure of 1 bar, flow rate Q = 36 L/min, temperature ≈25 ºC and pH = 6.56 for erosive-corrosive media.
Weight loss method was used in which test specimens of carbon
steel, with a known weights, were immersed in the oil for a total exposure time of 60 days. The weight loss was measured at an interval of 10 days, whereas in water specimens immersed for 30 day at an interval 2 days. The corrosion rate was determined using (mpy) unit. Metallographic observations and micro-hardness measurements were also performed on specimens taken from the parent metal, heat affected zone and weld metal. The obtained results clearly indicate a degradation of the mechanical properties of steel welds.

Equivalent Radius (EQR) is a relatively new normalized capillary pressure method for modeling of the saturation height function. In this method petrophysical data such as well logs, special and routine core analysis have been used in an integrated manner.
The main purpose of this study is to investigate dynamic behavior of the fluid flow through porous media with a new integrated technique for saturation height function modeling. Amongst different methods, EQR method that originally developed by Engstrom in 1996 has been selected for further study. Although this method can model the initial water saturation with high accuracy but it only can be applicable for low permeability formations. However, there is still an incomplete understanding its application for other rock units with higher degree of porosity and permeability. For this purpose, we present a Modified EQR (MEQR) based on iterative curve fitting procedure. To demonstrate the capabilities of MEQR method, one of the Iranian oil field data located in southwest of Iran with quite high degree of permeability in its porous sandstone layers has been used.
It is shown that this technique can accurately predict the initial water saturation in all rock types and in each cell of the reservoir with very good correlation coefficient achieved in comparison with interpreted saturation well logs.
Keywords: Saturation Height Function, Equivalent Radius (EQR), normalized capillary pressure, dynamic behavior

The aim of this research is to investigate the extraction of lead (Pb) from soil of Al-Doura oil refinery in Baghdad/Iraq. Ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and Hydrochloric acid (HCl) solution were used as extractants. Soil washing method was practiced in two ways, batch extraction and column extraction experiments. A set of batch experiments were carried out at different conditions of extractant (Na2EDTA, HCl) concentration, contact time, pH and agitation speed. From the batch experiments, the maximum removal percentages of Pb that have been obtained were 70 % using Na2EDTA (0.1M) at pH 4 , agitation speed 200 and at equilibrium time 4 hours and 65 % using HCl (1M) at pH 1.08 , agitation speed 200 at equilibrium time 5 hours.
Column experiments were conducted at different conditions of extractant (Na2EDTA, HCl) concentration, contact time and flow rate. The maximum removal percentages of Pb were 78% using Na2EDTA (0.1M) at pH 4 , flow rate 30 ml/hr and equilibrium time 8 hours and 75% using HCl (1M) at pH 1.08, flow rate 20 ml/hr and equilibrium time 10 hours.
The column extraction proved that the extractant volume required to achieve high removal efficiency is less than that of the batch extraction, but requires a longer contact time.
The experimental data of batch and column extraction were applied in four kinetic models; first order, parabolic diffusion, two constant and Elovich model to find best fit model for extraction system. For batch extraction, the parabolic diffusion and two-constant models gave the best correlation {coefficient of determination (R2)} with experimental data using HCl and Na2EDTA respectively. While for column extraction, Elovich model gave good correlation with experimental data.

Determination of permeability is an essential component of reservoir characterization process which is among the key input parameters into a flow simulation models. Permeability modeling in carbonate reservoirs is still a challenge in the world. Permeability is directly determined in the laboratory from core analysis. Alternatively, it can be determined by analyzing well test or well logs. Due to high cost associated with coring and some technical problems, few wells in any given field are cored whereas most wells have wire-line logs.
In this study detailed core analysis data including core porosity and core permeability supplemented by well logs and well test data to predict a continuous log derived permeability in un-cored wells in a heterogeneous carbonate reservoir in south west of Iran. The Mishrif reservoir in the studied field consists of limestone and interbedded shale. The field has 3 wells that have recovered cores. Permeability prediction was applied by several methods including: fuzzy logic, neural networks, clustering, empirical methods and regression analysis. These different methods were used to determine the optimal approach for utilizing in the field under study. To test the permeability prediction, the techniques were calibrated in 2 cored wells and blind tested in remaining cored well to see how well estimated permeability fitted the actual core permeability. Among all permeability modeling methods applied in the field, it turned out that electrofacies method and after that artificial neural network have the highest degree of association. Fuzzy logic and regression techniques are average in modeling permeability and empirical methods are not capable for predicting permeability in studied heterogeneous carbonate reservoir. The core analysis from 3 cored-wells was applied to determine permeability in 51 un-cored wells.

The Permian –Triassic Chia Ziri formation holds oil and gas reserves in exploration blocks in Iraq .Paleozoic is the most under explored succession in Iraq including important Permo-Triassic sequences.
Several wells was penetrated the Chia Ziri fm. in Iraq, three wells in NW Al-Jazira area (Kd-1,Mt-1 and As-1) and south west desert blocks in the two wells (Dn-1 and Wk-1). The Chia Ziri fm. represents a Permian transgression over varied topography in Iraq.
Lithologicaly, the formation is comprised of both carbonate & siliciclastic. The depositional setting was in subtidal to supratidal “shelf platform" with multiple digenetic events which control the reservoir characteristic. However,
The main source rock for entire Paleozoic plays in Iraq is Lower Silurian Akkas formation and lower Chia Ziri shaley parts.
Paleozoic is the most under explored succession in Iraq including important permo-Triassic sequences. The Permian –Triassic Chia Zairi formation holds oil and gas reserves in Iraq.
Several wells was penetrated the Chia ziri fm, in Iraq, three wells in Nw Al-jezira area and south west desert blocks
Lithologicaly,the formation is comprised of both carbonate &siliciclastic,The depositional setting was in subtidal to supratidal" shelf platform" " with multiple digentic events which control the reservoir characteristic.
The main source rock for entire Paleozoic plays in Iraq are Lower Silurian Akass Fm and lower chia Zairi shale parts.

In my work , I investigates the effect of initial temperature of diesel fuel upon engine performance and emissions by using CI engin , with different diesel fuel cetane number ( 56 , 54 , 53 ) , from the results it showing us that the brake power is increasing with the engine speed and the increasing is (64.66 %) at maximum load with respect with brake power at minimum load ,also measuring the brake torque and it is found from the results the brake torque is increasing with the engine speed at minimum and maximum load and from the results it is found that the brake torque is increasing about (63.902 %) when compare it with brake torque at minimum load ,fuel consumption(kg/hr) is increasing with the engine speed but decreasing when increasing cetane number with the following values (6.631%,7.843%,9.15%) for cetane number ( 53,54,56 ) , and the brake specific fuel consumption also decreasing about (6.065%,6.98%,8.654%) for Cetane number (56,54,53) respectively , the thermal efficiency it is found to be increased with the engine speed and for different fuel cetane number with the following percentage (5.96%,6.837%,8.498%) for Cetane number (53, 54 , 56) respectively, The ( CO2 ) emissions is increased with the engine speed and when the Cetane number increased about (11.35%,9.457%,11.065%) for cetane number (56,54,53) respectively , The (CO) emissions is decreased when the Cetane number increased about (24.165%,20.581%,21.7%) for Cetane number (56,54,53) respectively , The (HC) emissions is decreased by increasing fuel Cetane number about (8.695%,10%,9.586%) for Cetane number (53 , 54 , 56) respectively.

Since from the past, drag has been identified as the main reason for the loss of energy in pipelines and other similar transportation channels. The contribution of this drag is due to mainly viscous of the flow as well as friction against the pipe walls. These energy losses can be identified through pressure drop, which will results in more pumping power consumption.
Due to their very high viscosity heavy oil cannot be transported as such in pipelines and required additional treatments [1].
This work studied flow increase (%FI) in heavy oil at different flow rates (2 to 10 m3/hr) in two pipes (0.0381 m & 0.0508 m) ID. By using different additives (toluene and naphtha) with different concentrations (2, 4, 6, 8 and 10) %wt at 27ᵒC.
The results of this study showed Increasing values of FI % and Maximum Dr% of 40.48% and 37.03 % were obtained using heavy oil containing 10% wt of naphtha flowing in pipes of 0.0508 and 0.0381 m I.D. at 27°C respectively.
Increasing values of %Dr with increasing of Reynolds number, fluid velocity and additive concentration, the used additives (toluene and naphtha) reduce the high viscosity of used heavy oil, and naphtha is more efficient as viscosity reducer than toluene.
All these results show treatment heavy oil and improvement their transport in pipelines.

Petrophysical properties of the Mishrif reservoir at Noor oil field have been done. Based on the interpretation of the open hole data from wells (No-1, 2, 3, 4, and 5) .Which have been calculated total porosity, effective and secondary porosity, water and hydrocarbon saturation (moveable and residual hydrocarbon) in invaded and uninvaded zones. Depends on the calculated of petrophysical properties, Mishrif Formation can be divided into eight reservoir units (RU-1 to 8), separated by eight caped rock units (barrier) (Bar-1 to Bar8). Three-dimensional reservoir model of oil saturation was constructed using the Petrel Software, (2009). Distribution of these petrophysical properties for each reservoir unit within the studied field has been done. The results showed that the best reservoir units are the second, fourth and first reservoir unit. It’s worth mentioned here that the heterogeneity of the thicknesses of these units and its individual direction. In addition, observed that the oil saturation increases towards the north of the field at the well (No-5) and the center of the field at the well (No-4).

Iraqi Rice husk (IRH) was used to produce nanosilica by precipitation method. The prepared silica nanoparticles samples were characterized using different analytical techniques, these included FTIR, XRD, SEM ,AFM and and,TEM. X-Ray fluorescence (XRF) was used for the quantitative determination of chemical composition of rice husk which revel that it contains 94.22% silica, after acid leaching it gave 99.04% silica. at 700 oC. FTIR showed bending and stretching absorption bands Si-O-Si at (797) cm-1, (1078) cm−1. X-Ray diffraction shows a strong broad characteristic peak of nano pure silica at ≈ 22°. Electron microscope image characterize particles size of~ (60) nm in spherical shape and agglomerated form. The observation by Atomic Force Microscope shows that the average diameter of particles 88.87 nm.The prepared nanosilica from rice husk has a surface area of(194m2/g) and pore volume of (0.275 cm3/g).
Nanosilica pozzolanic material was used as cement admixture in oil field cement to improve compressive strength. The nanosilica cement admixture compressive strength was increase 8%, 9% and 4% at 1.5%, 2%, 2.5% nanosilica percentage adding respectively by weight of cement at 38 oC and 0.1%, 9%, 7% compressive strength percent increase at 60 oC.
Keywords: Iraqi rice husk, Nanosilica, Oil well, cement-admixture.

EPS is a major constituent of plastic waste. Reuse of waste EPS which is non-biodegradable, to useful products is a way of effective waste management. Oil is one of the most important energy sources but oil spill accidents often take place during the oil utilization process, resulting in threats to the environment. We reported the use of EPS waste to obtain an adsorbent material to cleanup crude oil spill from water. The effects of major factors such as sorption time, adsorbent surface areas, kind of surface (smooth or rough) and thermo-modification and mechanical modification (punching holes) were investigated on laboratory experiments and presented at ADIPEC 2014( Abu Dhabi International Petroleum Exhibition & Conference, 10-13 Nov., 2014, Session 52 Environment, SPE 172000-MS). The laboratory experiments carried out with about 0.9 g EPS sorbent for oil sorption times of 5 to 120 min at 350 g oil only and at 100 g oil over 500 mL water. The sorbent were punched with holes of 1.65 mm diameter. To verify the above laboratory experiments a field study for oil spill cleanup at crude oil pond from a rupture pipeline in Basrah was conducted. About 40 g EPS waste of small pieces (0.100-0.200 g) packed in 40x30 cm mesh net plastic bags. More than 40 bags were placed on the surface of a pond containing the spill crude oil over water. The pond was of about 6 meter diameter with oil layer of about 1.0 cm thickness. The bags were agitated manually after placing it on the oil surface to increase oil distribution to all EPS pieces. Oil sorption Capacity (OSC) of EPS in the field application increased with the increasing of the sorption times. The oil sorption was measured after 30 min sorption time and then every 15 min till 150 min. OSC of 43- 53 g oil/ g EPS sorbent for a sorption time of 30- 150 min respectively, were determined. The OSC are about 4 times the maximum OSC of the laboratory tests. The increasing in OSC of field application over laboratory tests due to utilization of all EPS 6 surfaces in place of one surface in laboratory tests, using lower density EPS and high density crude oil. The use of EPS waste in oil spill cleanup will reduce pollution in two ways, remediation of oil spill and reduce the landfill area due EPS waste.