Journal of Petroleum Research & Studies

The possibility of improving the oil production rate for Mishrif formation in Nasiriyah oil field, located in Thi-Qar Governorate – southern province of Iraq, proposed in this paper. Electrical submersible pump (ESP) and gas lift techniques were applied to one well (NS-Y) in the studied reservoir. Firstly, the mathematical model has been built and validation has been done using PIPESIM software in order to select the best correlation (Duns & Ros correlation) for the pressure gradient calculation in the wellbore. The effect of decreasing reservoir pressure and increasing water cut on production rate has been studied through the evaluation of the well performance. The production rate was decreased to 1917 STB/D when reservoir pressure reached to 2750 psi, and flow rate decreased to 1210 at water cut 60%. Therefore, the artificial lift techniques were applied to increase the oil production rate. The result showed that Gas lift system contributed to increase production rate to (3198) STB/D at reservoir pressure equal to 2750 psi, while using the ESP system improved oil production rate to (2800) STB/D at reservoir pressure 2750 psi. The results also showed that gas lift system contributed to increase production rate to (3805) STB/D at water cut 60% and ESP raised the production rate to 3087 STB/D at water cut 60%. The comparison between them showed that the gas lift technique gave the highest production rate at different reservoir pressure and water cut.

In field separation facilities operation, operators tend to determine the optimum conditions to maximize revenue.
The object of this study is to investigate the present number of separation stages and their optimal conditions for degassing stations of oil Field.
A computer program model was written to predict the optimal conditions for oil field gas-oil separation stations subject to a given crude oil composition , flow rate and feed temperature and pressure using flash calculations with modified Soave-Redlich-Kwong Equation of state.
Nine Bottom-hole well samples of reservoir crude oil was collected and subjected to PVT analysis commonly performed on crude oil, Surface stage separators gas samples at steady condition were taken and analyzed by gas chromatography apparatus to determine the gas composition.
A good agreement was found by comparing theoretical and experimental prediction for gas composition.
The results indicate that the present five separation stages is the optimum number and the values obtained for these optimum stages pressure are (514.7,119.7,42.7,26.7,14.7 psig) for Summer and (464.7,119.7,42.7,26.7,14.7 Psig) for Winter where the current operation pressures are (614.7,119.7,42.7,26.7,14.7 psi) for Summer and Winter. The total liquid yields in stock tank reaches (1.29, 1.31 %) for summer and winter respectively and the stock tank API Gravity reaches (0.41, 0.42) for summer and winter respectively.

In this paper, the artificial intelligent technique represents fuzzy logic, had been employed to generate missing well logs for three common logs sonic, neutron and density. A total Input data of 432 readings represent both depth and porosity, which belong to Buzurgun member were used to build fuzzy model. Input data were divided into two groups including training data 308 data points, which represent FQ-6, FQ-7, FQ-20 and FQ-21wells; and testing data 124 data points which represent FQ-15. Performance of model were evaluated by using two statistic aspects such as root mean square error and correlation coefficient. The results show that this technique offer more accurate and reliable missing logs. Fuzzy logic is used as a powerful tool in oil industry in Iraq because it is more flexible and realistic for evaluation, by employing the sufficient data for training and testing.

One of the principle concepts for understanding the hydrocarbon field is the heterogeneity scale; this becomes particularly challenging in supergiant oil fields with medium to low lateral connectivity in carbonate reservoir rocks.
The main objective of this study is to quantify the value of the heterogeneity for any well, and propagate it to the full reservoir. This is quite useful specifically prior conducting detailed water flooding or full field development studies and work, in order to be prepared for a proper design and exploitation requirements, which fits with the level of heterogeneity of this formation.
The main tool used for these purposes is the application of the famous Lorenz coefficient method, in conjunction with the Dykstra Parsons technique for calculating the degree of heterogeneity for any well.
The starting point for this kind of complicated studies needs to start from the basics. In order to understand the big picture and be able to plan properly for the scope to be delivered. Utilizing analytical tools like the ones mentioned above becomes quite necessary, if not crucial, to the success of full field modelling and choosing an optimum water flood pattern and design.
This work covers the methodology for quantifying and calculating the level of heterogeneity in a given reservoir.
The Dykstra-Parsons Coefficient or the variation of Dykstra Parsons (VDP) is commonly used in calculating permeability variation. The method of calculating begins by sorting the property of interest and make the other property fixed value (to calculate permeability you have to make porosity a fixed value for all calculations) and make permeability in order of decreasing magnitude.
For each of the values calculate the percentage of values greater or the ‘cumulative probability’, so that the probability of X is P(x≤X). Then plot the original permeability values on a log probability graph with the cumulative probability values. The slope value and the intercept of the line of the best fit, for all data are used to calculate the 50th and 84th probability values or by variation layering system to calculate the variation of P10, P50 and P90, which are used to find VDP.
This methodology has been tested successfully in the stated super giant oil field, in which the reservoir is a carbonate rock formation. The reservoir is areally extensive reservoir and not of a great thickness.
The importance of this step is to conclude a utilizing heterogeneity calculation method before conducting any detailed reservoir simulation study. It can save a lot of time and effort by providing guidance to the path, which needs to be followed, and sheds light on the critical elements to be looked after. This also can help to uncover many insights on the reservoir itself, hence allowing the engineer to plan for the necessary voidage replacement and water injection rates to sustain the reservoir pressure and pattern development based on the magnitude of heterogeneity those results from this procedure.
The suggested method, in combination with geological and petrophysical information available, can be applied to majority of the reservoirs. This combination is paramount to ensure optimum time and planning is followed for each reservoir development study that involves for example water flooding.

The produced water or wastewater resulting from the oil reservoirs in Basrah Petroleum Company / Zubair 1 Warehouse causes very high pollution in the land. The aim of this study is to find possible ways to treat such produced water and to remove turbidity through coagulation, flocculation, sedimentation and adsorption. Experimental tests of the properties for natural produced water such as turbidity, pH, TDS, TSS, and oil content found out that oil content = 137 mg/L and turbidity = 122 NTU. The produced water is treated with two types of coagulant poly aluminum chloride, alum and with two other types of adsorbent (Bentonite , Zeolite (Cation and Anion)). The coagulation, flocculation and sedimentation experiments are performed using a Jar-test device and adsorption experiments , and a magnetic stirrer device are used at different times, speeds, and concentrations.
It is found through the practical results that the best dosages of (poly aluminum chloride and alum) are (3, 35, 6.75, and 30) mg/L to obtain R% (96.3, 93, 99, and 98.9), respectively.
It is found from the experimental results of adsorption that the best results of weight adsorbent, stirrer time and stirrer speed to obtain maximum removal efficiency are (6 gram anion zeolite ,15 minute and 920 rpm) R% (98 , 97.8 and 99.2), respectively .
It is found that the best results are poor at different parameters, except when it is used (2) gram of bentonite obtained R% of turbidity weight, stirrer time and stirrer speed by bentonite and zeolite (cation and anion) were (2 gram) . Finally, it was found that removing the oil content by adsorption (97.8) is better than coagulation (96.3). And the results for removing turbidity by coagulation (99) is better than adsorption (97.4) .

This study is an attempt to investigate the effect of nanomaterials on the water base drilling mud properties. Two types of nano materials were investigated, are Multi Walled Carbone Nano Tube (MWCNT) and nano silicon oxide (SiO2).The investigated properties of drilling mud with the rheological properties (Plastic viscosity, yield point, Apparent viscosity and Gel strength), filtration ,and lubricity test are investigated. In addition, effects of high temperature on these properties were studied. All tests are conducted according to API specification and proceed in Petroleum Research and Development Center (PRDC).
The experimental results show that a significant improvements in the lubricity test and the rheological properties such as yield point, filtration properties of the MWCNT and nano silicon oxide modified drilling fluid compared with the base drilling fluid. Also a significant improvement in the rheological properties at using combined of nanomaterials (MWCNT and nanoSio2) and reduction of filter loss at using nanosilicon oxide compared with fluid loss reducer.

The aim of this study is to determine the deposition of the asphalt that occurs during the oil production process at reservoir pressures. Finding the two refractive index one for crude oil (STO) and the second for live oil using models and mathematical equations and using the results of physical tests of reservoir oil (PVT).
Asphalt is a part of heavy sections in crude oil and can be polarized during production process. Asphalt is defined based on its solubility in solvents or can be defined at which dissolve in aromatic solvents and do not dissolve in paraffin solvents or is a function of the solubility of asphalt in crude oil.
Most of the world's oil fields suffer from the problem of deposition of asphalt that accompanies the process of production of crude oil in all stage from the area near the opening of the well, tubing pipe, surface equipment, transport pipes, and even reservoirs, causing many problems such as damage to the oil reservoir .In addition it case blockages in production pipes, conveyor lines and equipment. Many companies in the world have studied this problem through many methods and models to understand the conditions of deposition of asphalt and its causes to find appropriate solutions. The most important reasons for the deposition of asphalt are the changes in the pressure and temperature and components of crude oil during the production process and electrostatic shear stresses.
The northern region (Kirkuk, Khabaz, Jambur) suffers from the problem of asphalt deposition, which causes, blockage in the pipes and production equipment where they are treated by cleaning the clogged parts with solvents and mechanical processes, and this requires efforts, time and cases losses in production. The aim of this paper is to identify the problem, and find solutions for it, and appropriate treatment methods, methods of predicting the problem, and avoiding or hindering it.
In determining the reservoir pressures at which the deposition of the asphalt in the oil production process occurs with the refractive index of the crude oil, the problem can be solved and the optimal solution of the deposition can be achieved by using several solvents to dissolve the asphalt deposits of the wells. Toluene is a substance that can be used with its own safety measures (toluene is a volatile light substance).
It is also preferred to use the technique of coiled tube, in the absence of toluene it is possible to use kerosene reformate white elite.