Journal of Petroleum Research & Studies

This research presents a method for calculating stress ratio to predict fracture pressure gradient. It also, describes a correlation and list ideas about this correlation.
Using the data collected from four wells, which are the deepest in southern Iraqi oil fields (3000 to 6000) m and belonged to four oil fields. These wells are passing through the following formations: Y, Su, G, N, Sa, Al, M, Ad, and B. A correlation method was applied to calculate fracture pressure gradient immediately in terms of both overburden and pore pressure gradient with an accurate results.
Based on the results of our previous research , the data were used to calculate and plot the effective stresses. Many equations relating horizontal effective stress and vertical effective stress are obtained for each well and used to calculate fracture pressure gradient. Similar equations are found for group of formations that calculate fracture pressure gradient and to find the most accurate correlation among them.

Knowing the mechanical properties (Young’s modulus (E) (, Poisson’s Ratio (ν), Shear Modulus (G), Bulk modulus (K) and compressibility which is the inverse of Bulk modulus) of the rocks involve in a reservoir, are critical factors for reservoir characterization). Those properties affect a wide variety of applications into the petroleum industry; from drilling well planning and execution to production performance (sand production, compaction, subsidence, etc) passing through a wide variety of topics like wellbore stability, well completions and of course reservoir characterization. For these reasons, the knowledge of these properties is really valuable for people working in the petroleum industry and of course working in reservoir characterization.
This study was located in Berea town, Oklahoma, and it was intended to identify the geomechanical and acoustic properties of a sandstone sample. The Berea sandstone elastic properties are characterized using two methods: Quasi static and Dynamic. A detailed explanation of the sample preparation and the testing procedure is provided. Calculation results for both methods showed consistent values for the Young’s modulus being around 3,000,000 psi. The Poisson’s Ratio value is between 0.13 and 0.3. This study was performed in the PoroMechanics Institute (PMI) in the Sarkeys Energy Center at the University of Oklahoma, USA.
Monitoring equipment was used to obtain all the information necessary for the proper characterization of the rock. The results of this work are a good tool that can be used in future simulations such as hydraulic fracturing treatment, reservoir fluid flow or reserve estimation.

Before the production leaves the well head, it passes through a choke which serves to stabilize the optimum or desired flow rate against variations in flow line pressure.
In this paper, the aim is to develop new correlation to predict oil flow rate through chokes with critical flow for Iraqi oil wells. This study shows that there is a strict quantitative connection between three factors: upstream pressure, gas-oil ratio and choke size with oil flow rate at critical flow for one hundred production tests of Iraqi oil wells.
Many forms have been tried using nonlinear regression analysis to obtain the optimum form of correlation that gives minimum differences between the calculated and field data. Here, based on Iraqi oil wells data; new correlation has been developed for predicting oil flow rate through chokes at critical flow.
The proposed correlation exhibits more accuracy (only 4.523% average absolute error) than the existent correlations. The correlation coefficient of the new correlation is determined as 0.997. The cross plots of calculated and field data gives strong index of priority of new correlation for applying with Iraqi oil wells. The graphical presentation of the results of the new correlation for Iraqi oil wells states more matching with the field data that are not used in formulating the new correlation than Gilbert (1954), Baxendall (1957), Ros (1959), Achong (1961), Secen (1976), Pilehvari (1981), Osman and Dokla (1990), Owolabi, Dune and Ajienka (1991), Elgibaly and Nashawi (1996), Mesallati, Bizanti and Mansouri (2000) and Alrumah and Bizanti (2007) correlations.

The present study deals with the removal of oil from wastewater by organoclay. The organoclay was prepared by combination of Iraqi bentonite with quaternary amine (hexadecyltrimethyl ammonium chloride). The wastewater used in this study taken from the washing unit of fuel oil in the "South Baghdad Gas Power Plant". The operating conditions of batch process for removal of oil from wastewater by using the prepared organoclays were studied in details (quantity of organoclay, mixer speed and time of adsorption). Initial concentration of wastewater used in this study was within the maximum range 230-1512 mg/L. XRD and FTIR diagram of the prepared organoclay showed considered differences from those for natural bentonite which indicates the exchange of quaternary amine with Ca++ ions at the surface of bentonite. The concentration of oil in the wastewater decreased less than 10 mg/L after treatment with organoclay. Batch kinetics studies were conducted by using kinetic equations (Lagergren and Ho et al) and batch isotherm studies was conducted by using isotherm models (Freundlich, Langmuir and BET).

The Extraction behavior of nitrogen compounds (quionoline, indole, and pyridine) from a liquid hydrocarbon (nonane, C9) was studied by using batch and fixed bed activated carbon experiments. The adsorption isotherm curves and the extraction percentage were determined in batch experiments in the conditions of initial concentration 20,40,60,80,and 100 ppm of either of quionoline, indole, and pyridine, fuel/(AC) ratio of 20 wt/wt, room temperature 30 ± 1°C , and stirring time of 2h.
In the fixed bed experiments the breakthrough curves were determined as a function of the following variables:
 Bed height of activated carbon 3, 5, and10 cm.
 Initial concentration of nitrogen compounds 50, 75, and100 ppm.
 Flow rate of the feed (15, 25, and35) ml/min.
 Particle Diameter of activated carbon 1.5, 1.2, and1 mm.
The adsorption capacity increases with increasing equilibrium concentration of the nitrogen compounds in the liquid phase, which is a very favorable isotherm irreversible adsorption. Also the activated carbon has very high affinity for the nitrogen compounds in the order indole < quinoline < pyridine and the conversion values were (50, 46, and42) % respectively. In fixed bed experiments the time to breakthrough point decreases with:
 Decreasing in bed height.
 The increase in flow rate.
 The increase in initial concentration of nitrogen compounds.
 There is no effect of varying the particle diameter of the activated carbon because the experimental values of the activated carbon lies in the region of the large particle size and macrospore volume and there is no gradient in the particle size.

The corrosion behavior of carbon steel in circulating cooling water (C.T.) of Al Doura Refinery and performance of sodium nitrite (SN) and sodium hexametaphosphate (SHMP) inhibitor blend for inhibition of such corrosion process have been investigated at different temperatures, i.e., 303, 313, 323 K.
Weight loss experiment, under isothermal conditions, together with polarization method were carried out at 303, 313, and 323K using C.T., and make up with SN:SHMP (500:100) solutions. The results proved that the inhibition efficiency of the corrosion inhibitor used in this work is better than that obtained by the corrosion inhibitor used in C.T. of Al Doura Refinery and less effected by the change in temperature.

The present work was devoted to study the effect of operating parameters (e.g., superficial gas and liquid velocities, size of solid particles, volume percentage of particles loaded in column and type of particles) on foams, and to investigate the process of foam suppression.
The experimental apparatus was operated in continuous mode for the two phases (i.e. air and a solution of aqueous anionic surfactant). Sands which were considered as hydrophilic behavior particles were used as solid phase. A specific surface treatment was performed on hydrophilic sands particles to transfer it into hydrophobic one. These two versions of sands were used in the experimental setup respectively to study their effect on suppression of foams. The average gas holdup for the entire column was measured by means of the local gas holdup which was computed from the pressure difference in each segment of the column. Local solid concentration along the column was measured experimentally by analyzing the samples of mixture drawn from the sampling ports. From the present work it was found that: Flow regimes of multiphase system could be easily determined by utilizing local gas holdup profile measured by pressure drop transducer method. The transition from the homogenous to heterogeneous regime was advanced, from ug=4 to 2cm/s with increasing solid concentration from 10 to 20%v and decreasing average particle diameter from dp=(0.8) to (0.25) mm.
When a mixture of water/surfactant was employed in the bubble column, foam could be present depending on the input operating parameters. The fluid mechanism of foam suppression with hydrophilic particles was enhanced by a direct attack on the foam by hydrophobic particles (i.e. hydrophobic particles were more effective in retaining liquid–destroying foam than the hydrophilic particles). It was found that hydrophobic particles of 0.25 mm average diameter and 10%v loading in the reactor could reduce foaminess fraction from 0.85 to 0.15 if the liquid velocity was 0.3 cm/s. The foaminess fraction could be reduced to 0.0 if the liquid velocity increased to 0.4 cm/s. The results of this study may have abroad applications in petroleum and petrochemical industries where liquid hydrocarbons are processed.

The Fauqi oil field is located about 50Km north-east Amara town in Iraq. This field has two producing reservoir units, the Asmari and the deeper Mishrif. Fauqi field is an anticline crossing the Iraqi-Iranian border and approximately 15 km long and 6 km wide.
The Fauqi anticline is most probably segmented by several faults due to its location on Zagrous mountains area. Since, it is not possible to get full knowledge on the extent, orientation and segmentation of the field.
Production data used for the Material Balance analyses is comprised of a record, by well, of monthly cumulative oil production for the period 01 May 1979 – 01November 2007. The field was shut in due to the Iran-Iraq war between September 1980 and August 1998 and due to Gulf war between March to December 2003.
Twelve major modules, with different degrees of analytical sophistication have been used to prove oil initially in place (STOIIP) for Fauqi oil field throughout analyzing single well production history of FQ-8A. The accuracy for the obtained results has been investigated which show an acceptable degree of reliability.
Performing the twelve of different analytical and numerical calculation for the production history of Fauqi oil well Fq-8A, may assist to reduce the uncertainties in the reservoir calculation of the STOIIP especially in Asmari reservoir which show a considerable degree of uncertainty between the analytical (multiple column model) and the (full tank model) and also with the numerical calculation