Sharif Digital Repository

A novel mathematical-based approach is proposed to develop reliable models for prediction of saturated crude oil viscosity in a wide range of PVT properties. A new soft computing approach, namely least square support vector machine modeling optimized with coupled simulated annealing optimization technique, is proposed. Six models have been developed to predict saturated oil viscosity, which are designed in such a way that could predict saturated oil viscosity with every available PVT parameter. The constructed models are evaluated by carrying out extensive experimental saturated crude oil viscosity data from Iranian oil reservoirs, which were measured using a "Rolling Ball viscometer." To... 

Following three generations of buyback contracts, the new model of Iranian petroleum contracts (IPC) was introduced by the Iranian cabinet to incentivize investments in the country. This paper analyzes the fiscal terms of the contract with technical information from one of the candidate fields for licensing. The financial simulation shows that, in general, the IPC resembles more a service contract than a production sharing contract as the contractor’s take is relatively low—below 5% across different scenarios of crude oil price. Second, the IPC is progressive in that as the overall profitability of the project improves the government takes an increasing share of the economic rent. The... 

During transient tests, both pressure and temperature are changed depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating effects are the main dynamic factors causing flowing bottomhole temperature to differ from the static formation temperature at that depth. When a gas well is shut in, JT cooling effect is vanished and this causes a sharp increase in sandface temperature. As effect of wellbore storage ends, wellbore temperature gradually cools down due to heat conduction with near wellbore region. This paper demonstrates a new technique for using temperature transient data in gas wells in order to determine end of wellbore storage. Also, effect... 

This review aims to bring together the studies on petroleum reservoirs' sand production control in a comprehensive guide for the researcher to compare various methods for the chemical consolidation of sand. Sand production can be considered one of the major challenges in the petroleum production industry, causing severe operational issues. This study introduces various methods to control and prevent sand production in petroleum wells and evaluates their advantages and performance in tabular form. The use of chemical procedures is considered to be more efficient in counteracting the production and migration of sand. Various chemicals and polymers have been proposed for this purpose. These... 

This article discusses the distribution of total petroleum hydrocarbons (TPH) contamination in soil within areas of the South Pars Gas Complex (S.P.G.C.), located on the northern shore of the Persian Gulf. To assess the potential risk to groundwater, in situ contaminant mobility was also examined in vertical soil profiles. Sampling was conducted in two rounds, and TPH was determined in accordance with standard methods of TPH analysis. The maximum detected concentration was 10268±785 mg/kg in the area of the waste disposal site. Significant heterogeneity in natural attenuation of different hydrocarbon compounds during transport in the soil was observed. Although the groundwater samples did... 

Volumetric and equilibrium calculations for the natural gas and oil defined by a large number of components are not feasible in applications like compositional reservoir simulation. Therefore, the fluid mixture is grouped to reduce computational load and to make faster calculations. However, for several reasons, it is required to have the detailed fluid composition rather than the lumped one. In this work, an improved delumping method is presented to retrieve the phase composition of the detailed mixture based on the grouped mixture thermodynamic calculations. The method is based on previously proposed delumping techniques for non-cubic equation of state (Assareh et al. in Fluid Phase... 

The soil slurry-sequencing bath reactor (SS-SBR) was studied to treat poorly graded sand with clay (SP-SC) contaminated by aged petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) with concentrations of 23000 mg/kg and 750 mg/kg respectively. An 8 L bioreactor was operated with a 10% solid concentration (0.1 kg dry soil/L slurry). The fill period was relatively instantaneous, and the draw period lasted approximately 1 minute so the react period comprised essentially the entire cycle time. In the draw period a fraction of slurry (10%) was removed from the SS-SBR weekly and it was replaced with untreated slurry. This volumetric replacement strategy provided 70 days hydraulic... 

In this paper, lean blow-out limits in a double swirl GT model combustor were investigated experimentally for liquid petroleum gas fuel. The lean blow-out curve was extracted for different combustor configurations. While burner could operate reasonably under ultra-lean conditions, two different sets of operating conditions, one with a low flow rate and another one with high flow rate, are identified and studied in terms of lean blow-out and pollutant. Results showed that while the flame structure was similar in both cases, the chamber responses to geometrical changes and also preheating are minimal at the low flow rate. That means confinement and injector type have desirable effects on... 

Refineries are amongst the most energy-intensive and polluting industries in the world. Biotechnology may serve as an alternative low-cost and environmental-friendly tool to the current costly, toxic and hazardous refining processes. In this study, the compositional redistribution of a heavy hydrocarbon cut is investigated under biological conversion using native microbial consortia. The native consortia were obtained by batch enrichment method applied on oil-polluted soil samples from oil refineries of Iran. The bioconversion experiments were conducted with 20% and 40% (v/v) of the heavy cut as the sole carbon source and 10% (v/v) of the consortia broth in 250 ml flasks containing a mineral... 

The coning phenomenon usually occurs in water and gas cap drive reservoirs. Water coning in Iranian hydrocarbon reservoirs is one of the most important problems that affects the cumulative production, operation costs and causes environmental problems. Before producing from a reservoir, its fluids are in equilibrium and their contact surfaces remain unchanged, but after starting production from the reservoir, when the viscous force overcome gravitational force in vertical direction, contact surfaces will displace and coning will occur. So, the production rates will be controlled in a range that prevents entering water and gas to the production well. For this reason, investigation and modeling... 

The coning phenomenon usually occurs in water and gas cap drive reservoirs. Water coning in Iranian hydrocarbon reservoirs is one of the most important problems that affects the cumulative production, operation costs and causes environmental problems. Before producing from a reservoir, its fluids are in equilibrium and their contact surfaces remain unchanged, but after starting production from the reservoir, when the viscous force overcome gravitational force in vertical direction, contact surfaces will displace and coning will occur. So, the production rates will be controlled in a range that prevents entering water and gas to the production well. For this reason, investigation and modeling... 

In this study, heat oil conversion experiments using steam and formic acid as a hydrogen carrier be carried out in a batch reactor at T = 380 degrees of Celsius and P = 165 bar. Material balance and product distribution were calculated after the process. Properties of crude oil before and after thermal conversion, including viscosity, API gravity, SARA measurement, and elemental analysis, were analyzed. It has been presented that the use of formic acid as a hydrogen carrier solvent reduces the formation of coke and gaseous products and enhances the performance of liquid products. Also, the viscosity of the refined oil decreased by 23.2% due to the addition of formic acid compared to the... 

During transient tests, both pressure and temperature are changed depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating effects are the main dynamic factors causing flowing bottomhole temperature to differ from the static formation temperature at that depth. When a gas well is shut in, JT cooling effect is vanished and this causes a sharp increase in sandface temperature. As effect of wellbore storage ends, wellbore temperature gradually cools down due to heat conduction with near wellbore region. This paper demonstrates a new technique for using temperature transient data in gas wells in order to determine end of wellbore storage. Also, effect... 

The application of the renewable energy sources, especially solar energy, for thermal enhanced oil recovery methods as an economical and environmental valuable technique has received many attractions recently. Concentrated Solar Power systems are capable of producing substantial quantities of steam by means of focused sunlight as the heat source for steam generation. This paper aims to investigate viability of using this innovative technology in fractured reservoirs to generate steam instead of using conventional steam generators. A synthetic fractured reservoir with properties similar to those of giant carbonate oil reserves in the Middle East was designed by using commercial thermal... 

Parameters of the PC-SAFT Equation of State (EoS) for pure components are generally determined by matching the saturation pressure and liquid density experimental data. These experimental data are unavailable for petroleum cuts and plus fractions of the petroleum reservoir fluids. In this work, new correlations as functions of specific gravity and molecular weight were developed to estimate the PC-SAFT parameters of petroleum cuts with unknown composition. It was shown that the proposed correlations accurately estimate the PC-SAFT parameters of the pure components published in the literature. Then, the obtained correlations were used and the PVT experimental data for various real reservoir... 

In this paper we present new methods to estimate the effective permeability (keff) of heterogeneous porous media with a wide distribution of permeabilities and various underlying structures, using percolation concepts. We first set a threshold permeability (kth) on the permeability density function and use standard algorithms from percolation theory to check whether the high permeable grid blocks (i.e., those with permeability higher than kth) with occupied fraction of “p” first forms a cluster connecting two opposite sides of the system in the direction of the flow (high permeability flow pathway). Then we estimate the effective permeability of the heterogeneous porous media in different... 

Iran's petroleum industry is facing challenges including maturity of hydrocarbon fields, growing population of the nation that demands additional revenues from petroleum exports, and international economic sanctions that have limited access to technology sources. Restrictions from international technology providers have led managers of the industry enterprises to try to develop their needed technologies inside the country. The Ministry of Petroleum has supervised this and as a result, a technology planning systems has been developed and implemented since 2009. In this paper, an overview of the Iranian petroleum industry is provided from a technology planning perspective. The focus has been... 

The vapor extraction process (or VAPEX) uses vaporized solvents injected into a horizontal well to form a vapor chamber within the reservoir. Vapor dissolves in the oil and enhances the oil production by decreasing the oil viscosity in heavy oil reservoirs. To evaluate the process we conduct a simulation study on an Iranian heavy oil reservoir called Kuh-e-Mond. In addition, a semi-analytical investigation of the VAPEX process has been performed. The idea is to perform VAPEX simulation for a laboratory model and find a methodology to compare the results of the simulator with the semi-analytical Butler's model. In particular, a semi-analytical dimensionless correlation for production rate... 

The vapor extraction process (or VAPEX) uses vaporized solvents injected into a horizontal well to form a vapor chamber within the reservoir. Vapor dissolves in the oil and enhances the oil production by decreasing the oil viscosity in heavy oil reservoirs. To evaluate the process we conduct a simulation study on an Iranian heavy oil reservoir called Kuh-e-Mond. In addition, a semi-analytical investigation of the VAPEX process has been performed. The idea is to perform VAPEX simulation for a laboratory model and find a methodology to compare the results of the simulator with the semi-analytical Butler's model. In particular, a semi-analytical dimensionless correlation for production rate... 

Effect of several auxiliary carbon sources such as crude oil, different precultures, and quality of adding crude oil in treatment of petroleum wax deposits by an isolated bacterial strain, BBRC9012, was investigated. First and second experiments which compered effect of molasses, glucose and crude oil, indicated that glucose and molasses causes more microbial growth, biosurfactant production and bioemolsification than crude oil. Both optometry and Surface tension measurements showed that using molasses-BHB preculture for wax treatment is not suitable and when crude oil is used as auxiliary carbon source a one day lag phase is unavoidable. It was also shown that when crude oil is added to...