فهرست مطالب

Journal of Petroleum Science and Technology
Volume:1 Issue: 1, Spring 2011

  • تاریخ انتشار: 1390/05/15
  • تعداد عناوین: 8
|
  • M. Assareh, M.R. Pishvaie, C. Ghotbi Pages 3-14
    Equations of state should be tuned to reservoir conditions by PVT tests for phase behavior modeling. This tuning is achievable via an optimization method. In this work, simulated annealing algorithm is applied as a global optimization method to parameter optimization for PC-SAFT from the statistical associating fluid theory incorporating hard chain as reference fluid. The optimization parameters are determined by minimizing the calculated phase behavior of a synthetic petroleum mixture and real petroleum fluids from Iranian oil and gas reservoirs, based on their PVT-tests. We examined several tests, assumed to be representative of reservoir processes, such as differential liberation and constant composition expansion for oil samples and constant volume depletion for gas condensate sample. In petroleum systems, new petroleum fraction characterizing correlations were developed and validated according to PVT data and other equations of state. The results showed a high degree of accuracy for these newly developed correlations. It is observed that for the synthetic mixture and real reservoir fluids, considering the parameters obtained using the annealing technique, the solutions are theoretically justifiable. For real samples of petroleum fluid, the results are acceptables such results provide a measure of confidence that the annealing method does converge to the global minimum in the majority of the studied systems.
    Keywords: Petroleum Fluids, EOS Tuning, PVT, Test, Non, linear Parameter Optimization, Simulated Annealing, PC, SAFT
  • R. Behin, H. Sharifi Galiuk Pages 15-23
    Displacement of oil and water in porous media of reservoir rocks is described by relative permeability curves, which are important input data for reservoir performance simulation and drive mechanism studies. Many core studies, such as multiphase relative permeability, capillary pressure and saturation exponent determination, depend on the volume fractions of multiphase fluids present in the studied rock samples. X-ray scanners are increasingly used for measurement of fluids saturation in the core samples during core studies, mainly due to expanding need of modeling and measuring reservoir condition fluid flow behavior and its being safer issues than other radioactive sources like gamma ray. Incorporating X-Ray in situ saturation measurements into the relative permeability, capillary pressure and intrinsic wettability characterization of reservoir rocks may improve reservoir management and productivity prediction. This paper describes two phase immiscible fluid flow behavior of oil displaced by water through water wet porous media interpreted by X-ray data utility, according to saturation profile shapes incorporated by history matching of oil production and differential pressure history in low oil to water viscosity ratio fluid flow. In situ saturation profiles have been obtained with 1% saturation accuracy. The in situ saturation profiles confirm wettability character of reservoir rock samples and are an indication of the fact that initial water saturation and non-wetting oil phase values are controlled by reservoir rock wettability characteristics. The immovable water saturation increases because of oil snap-off and when light oil enters a water wet porous media, even increasing the oil injection rate cannot overcome van der Waals forces throughout water molecules. The saturation profiles have been shaped rather flat after water breakthrough. These profiles attribute to the recovery of the bulk of oil before breakthrough in low viscosity ratio displacement through water wet rocks. Besides, overlapping of various after bump saturation profiles indicates that there is no significant difference between remaining oil saturation and residual oil saturation in water wet reservoir rocks.
    Keywords: Relative Permeability, X-ray In situ Saturation Monitoring, Wettability, Saturation Profiles, Irreducible Water Saturation (IWS), Residual Oil Saturation (ROS), Viscosity Ratio
  • N. Hajilary, A. Ehsani Nejad S. Sheikhaei, H. Foroughipour Pages 24-30
    This paper includes the significant on-site experience of the authors related to problems faced in amine systems with fresh amine and their possible solutions in phases#2&3 of South Pars gas complex. The amine system was designed as a closed circuit system with the primary objective of removing H2S, CO2, and other acidic components from gaseous hydrocarbon streams. Amine plant operational problems such as excessive foaming, intense corrosion and capacity reduction are observed in gas sweetening unit. Heat stable salt (HSS) accumulations were found to be one of the main reasons for corrosions. Since there are no MDEA purification facilities in phase#2&3, it was decided to replace old MDEA solution with fresh MDEA. However, there are some problems that many plants have experienced after amine replacing or construction. In this paper, practical strategies with experimental data were proposed to overcome these problems.
    Keywords: Amine Replacement, HSS, MDEA, Corrosion, Degradation, Regeneration
  • A. Moghadassi, N. Amini, O. Fadavi, M. Bahmani Pages 31-37
    A kinetic model of a fixed bed tubular reactor incorporating catalyst deactivation was developed for the ISOMAX unit of Arak refinery. The kinetic parameters for the hydrocracking reactions over the commercial catalyst were determined using initial activity plant data i.e. when the catalyst is fresh. Catalyst deactivation was then taken into account by means of deactivation function based on plant data. The catalyst deactivation function is defined in terms of normalized time (BPP) of operation. Effect of catalyst deactivation on the product yield has been investigated. Steady state material and energy balances were then developed for an extended four lumped kinetic network. To determine the effect of reaction types on the rate, we calculate frequency factor for each individual bed with constant activation energy and heat of reaction. Furthermore, we calculate the frequency factor for individual beds, for the first one to estimate the rate of reactions in the different beds. The results show that the reactions in the first and second bed are faster than those in the 3rd and 4th beds. The comparison between model conversion and experimental conversion of the unit indicates that the model is capable of predicting product yield with an error of less than 5%.
    Keywords: Lumped Kinetic Model, Catalyst Deactivation Function, Normalized Time, Production Yield, Frequency Factor
  • M. Tavakol Moghadam, S.K. Bagheri Pages 38-45
    In recent years, an increasing number of Chemical Engineering Software (CES), which play an important role in improving efficiency in the petroleum industry, has been introduced to the market. Generally, software is the product of intellectual creativity, but protection of the intellectual property residing in software is the subject of some controversy. This paper explores the legal protection of software products and its evolution over time. The approach of selected countries to software protection is reviewed in comparison with the Iranian legal regime in the same field. Important concepts that need to be considered in acquiring effective protection of CES are presented. Software-related patent classifications were reviewed and US inventions relating to them were collected using a professional patent data base. Finally, the CES inventions in each classification were investigated in comparison to the total number of software patents. Consequently, the most referable classification for CES invention has been determined in this paper.
    Keywords: Software, Chemical Engineering, Petroleum Industry, Intellectual Property, Legal Protection
  • M. Rashidzadeh, A. Ahmad, S. Sadighi Pages 46-54
    Catalyst deactivation is usually indispensable, although the rate at which it occurs varies greatly. At first, this article discusses the causes of deactivation in a commercial hydrocracking unit called Isomax. Then, a 5-lump kinetic model including catalyst decay function for hydrocracking of vacuum gas oil in a commercial plant is proposed. The model considers vacuum gas oil (VGO) having boiling point higher than 380oC (380+°C), diesel (260-380°C), kerosene (150-260°C), naphtha (IBP:150°C), and gas as products. By using selective catalyst decay function in the kinetic model, the effect of the catalyst deactivation on the yield of products over time is studied. The prediction of the model during 1.5 years is in good agreement with the actual commercial data. The average absolute deviation (AAD%) of the model for the strategic products like naphtha, kerosene and diesel are about 1.784%, 1.983% and 1.971%, respectively. Also it is observed that the estimated parameters are consistent with the reported characteristics of amorphous catalysts.
    Keywords: Catalyst deactivation, Life model, Hydrocracking, Isomax
  • A. Aleghafouri, M. Mahdyarfar, M. Mohsen, Nia, A. Mohajeri, M. Asghari Pages 55-59
    Adsorbed natural gas (ANG) by Granular Activated Carbon (GAC) has been widely investigated as an alternative to CNG and LNG technologies for storage and transportation of natural gas. In the present work, a theoretical and experimental study was conducted to accurately determine the amount of adsorption of CH4 by GAC. To carry out the experiments, the volumetric method was used up to 4 MPa at constant temperature of 298 K. Also, various adsorption isotherm models were used to model the experimental data collected from the experiments. The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported. The results shows that the amount of CH4 adsorbed is dependent on the physical characteristics of activated carbons. Moreover, the Toth, two term TVFM and Sips isotherm models show good agreement with the experimental data.
    Keywords: Adsorbed Natural Gas, Activated Carbon, Adsorption Isotherm
  • R. Mostafaee, M. Mohammadinia, F. Mirzaee Tabesh Pages 60-67
    Bibi Hakimeh oilfield consists of more than 145 oil producing wells. Its Oligomiocene Asmari reservoir is dominantly made of limestone. The act of a reverse fault on the north flank of Bibi-Hakimeh Field caused a significant thickness reduction in Gachsaran formation in the way that in some drilled wells, members No. 2, 3, 4, 5 and 6 of Gachsaran cap rock have been totally eliminated. This causes locating Asmari reservoir in a shallower level and therefore lowers reservoir temperature in the North flank already have made the reservoir suitable for a microbiological enhanced recovery. The long term production of this reservoir caused a significant reservoir pressure drop. Therefore; the recovery has been performed using Basilus with Ex-Situ method. In this case study, the feasibility of surfactant production in several oil wells has been accomplished. A high temperature resistant Basilus has been selected to evaluate the production ability of biosurfactant. This bacterium has been chosen after performing all morphological, biochemical and genetic studies. This bacteria shows a good resistance against the temperature in such manner that its emulsification, surface tension and inter surface tension abilities do not change after 15 min in an autoclave process at 120° C. In the next step, the temperature, pH, Carbon, N2 and other factors have been optimized for biosurfactant production. Considering the lithology of the reservoir using this type of bacterium. This can be a good way to produce lipopithidic biosurfactant by Ex-Situ method in Asmari to enhance oil recovery. The basilus, which has good resistance against temperature and acts well in pressurized environments, can be considered as a good candidate for tertiary enhanced oil recovery process. The best method to produce basilus in B5 is the Formislink method.
    Keywords: Bibi Hakimeh Oilfield, Asmari Reservoir, Oil Recovery