Sharif Digital Repository

In this research various treatment methods of produce water are discussed and categorized in two groups namely; Basic and advance methods. Four basic treatment methods including; hydro cyclone, flotation, settling and membrane filtration and also four advance treatment methods including; nano filtration, ultra filtration, oxidation and adsorption are considered to compare and to select the most proper ones. To compare the treatment methods a multi criteria decision method namely Analytical Hierarchy Process (AHP) is applied twice to choose the most proper basic and advance treatment methods. The criteria are suggested according to the local conditions of Kharg Island and the similar... 

Capillary Imbibition is an important mechanism in producing oil from matrix blocks in fractured reservoirs. In a water-wet fractured reservoir, if the rise of water level in fracture is in a way that at all the moments the water front in fracture is lower than that in the matrix block we expect co-current imbibition. Iranian reservoirs have large matrix blocks and co-current imbibition can be expectable. Till this time, not many investigations have been done on co-current imbibition in and out of our country, Iran. In this thesis, an experimental investigation on co-current imbibition will be done for different conditions. The main goal of this thesis is the study of co-current imbibition in... 

The nature of fluid flow in hydrocarbon reservoirs is very complex because of the complicated sedimentary processes. Proper modeling of distribution of these heterogeneities is crucial, affecting all aspect of fluid flow. The conventional approach to investigating the impact of geological uncertainties on the prediction of reservoir performance is to build a detailed geological model using geophysical, geological and petrophysical data, upscale it and finally perform flow simulation. Because of uncertainties in the data, it is necessary to construct a number of possible geological models and then run flow simulations many times to get a reliable model. This approach is computationally very... 

In the recent two decades Lattice Boltzmann method has been introduced as a class of computational fluid dynamic methods for fluid simulation. In this method instead of solving Navier-Stocks equation, Boltzmann equation is solved to simulate the flow of a fluid. This method originally was developed based on uniform grids which makes lattice Boltzmann a time consuming technique. This feature already exists in the case of simulation of fluid flow in porous media. To eliminate this limitation some research has been done on methods to formulate lattice Boltzmann on unstructured grids. On the basis of this research a method on non-uniform grids has been selected. Here using object oriented... 

Determining the best location for new wells is a complex problem that depends on reservoir and fluid properties, well and surface equipment specifications, and economic criteria. Various approaches have been proposed for this problem. Among those, direct optimization using the simulator as the evaluation function, although accurate, is in most cases infeasible due to the number of simulations required. This study proposes a hybrid optimization technique (HGA) based on the genetic algorithm (GA) with helper functions based on the polytope algorithm and the neural network. Hybridization of the GA with these helper methods introduces hill-climbing into the stochastic search and also makes use... 

Most of the Iranian oil reservoirs are reaching end of their natural production life, hence they are suitable candidates for EOR common processes like gas injection and WAG injection. Studies have shown that gas and WAG injection can be applied for optimal oil production. Past studies have been mainly on gas and WAG injection in immiscible or fully miscible conditions and there is a limited amount of data available on performance of these methods in near miscible conditions. Miscible injection is not feasible in old Iranian oil reservoirs due to their depleted pressure. Moreover injection in lower pressures is attractive from both economical and operational standpoints since this reduces the... 

Water in oil emulsion usually forms during natural water encroachment or enhanced oil recovery processes due to the reaction between asphaltenic and naphthenic acid part of oil with brine in some heavy oil reservoirs. This results in major production challenges because of high w/o emulsion viscosity which leads to significant pressure drops. Therefore, it is essential to investigate the dominant mechanisms of w/o emulsion flow in porous media to overcome the production challenges. In the present study, w/o emulsion behavior is investigated through both static and dynamic tests. The w/o emulsion was prepared through mixing of a crude with brine using magnet stirrer. Emulsion stability... 

The assessment of fluid transport in porous media is the main subject in oil reservoirs to understand the oil recovery efficiency. The efficiency of Enhanced oil recovery (EOR) processes depends on the surface properties and wetting behavior of oil reservoir rocks which are also affected by the electrokinetic behavior of solid part of the porous rock. Streaming potential measurement is one of the techniques to determine the electrokinetic properties. The streaming potential measurements using electrodes have recently been introduced in oil field applications and there are still significant uncertainties during the measurements and interpretation of streaming potential results. The Primarily... 

Oil reservoir simulation serves an important role in forecasting oil production. This forecast, in turn, helps to devise a production scheme for hydrocarbon reservoirs which is one of main objectives of reservoir management team. In this research, using the idea of logarithmic distribution of reservoir fluid pressure around a wellbore, a new method for simulation of naturally fractured reservoir is developed. This method is shown to be more fast and accurate than conventional methods in reservoir simulation. In this method Dual-Porosity formulation is used for description of fluid flow in fractured reservoirs. The governing equations then were discretized by Galerkin Finite element method in... 

Nowadays, foaming agents have wide applications in drilling, cementing, fracturing and oil displacement in the petroleum industry. Typical applications are to make light fluids for drilling operations in naturally fractured reservoirs where lost circulation is a problem. Compared with conventional and aerated drilling fluids, foamy mud is a compressible and relatively homogeneous mixture. A great flexibility for pressure control is thus possible. In this study, a new foaming agent of Yas-Khorramshahr Company is introduced to drilling fluids. Stability of this agent at different concentration and in presence of Salt and crude oil is tested. Also common drilling muds are lightened and... 

Smart wellsareunconventional wells with down-hole devices installed on their production tubing. Such wells allow us to continuouslymonitor flow rates, pressures, temperature and periodically adjust down-holevalves setting without any production intervention. This makes smart well technology to be considered as one of the most significantbreakthroughs in reservoir management technologies. So, modeling and simulating smart wellsautomated action represents a challenge in forecastingtheir performances.One of the easiest ways to model such wells is to transform theminto a multi-segment well with the ability tocontrol each segment independently. By using the commercial reservoir simulator,... 

This research was done for feasibility evaluation and understanding correct microbial enhanced oil recovery(MEOR) procedure for carbonate reservoirs. With the aim of cost reduction and possible activation of smart water mechanisms, sea water used as a base for MEOR process. Two biosurfactant producing strains were isolated from oil contaminated water and soil, and one halotolerant strain, from sea water. Optimization of biosurfactant yield was conducted and two new definitions for optimum point, by considering economical and technical facts, were proposed. Partial characterization of produced biosurfactant was carried out through FTIR and NMR analysis and the produced biosurfactant was... 

Effective stress variation is one of the main issues in petroleum and gheothermal reservoir development. These stress variation could cause formation damage, sand production, sloughing shale and various modes of borehole instability like induced fractures and borehole wall shearing. In petroleum engineering, drilling a borehole is the first step in reservoir development. The wellbores are implemented to produce or inject fluids such as water, oil, gas and chemical fluids used during secondary and tertiary recovery processes. Upon drilling a borehole, reservoir pore pressure, rock and fluid temperature and mechanical stresses change which induces borehole instability and variations in rock... 

One of the main challenges in characterization and simulation of larg scale porous media is spatial heterogeneity and variability of porous media properties such as porosity, density, and lithology at different scales. These information can be achieved at different scale from coring, well logging or seismic data. Well logs are an efficient way to obtain rock and fluid properties of geological patterns specially water resources and hydrocarbon reservoirs. One of the characteristics of geophysical well logs is their complex behavior which seems to imply a multifractal nature.In this study we investigate multifractality and presence of long range correlations in petrophysical well log data such... 

Nowadays, due to limitation of production from conventional oil reservoirs, enhanced recovery from heavy oil reservoirs are of great concern. In heavy oil reservoirs, only 5% of initial oil in place (IOIP) is producible due to high viscosity. Water flooding increases oil recovery just up to 10% which is due to improper mobility ratio. One of popular methods for increasing oil recovery is injection of chemical materials. Chemical methods are used in reservoirs that have high degree of heterogeneity like heterogeneous and layered reservoirs. These heterogeneities cause diversion and loss of injected water which leads to remaining of oil in its place. Using surface active agents, as a popular... 

The discrete fracture network and continuous fracture network are among the most widely used methods to model naturally fractured reservoirs. Each method faces particular limitations. The recently introduced recovery curve method (RCM) is believed to meet the limitations of the common methods. In the RCM the recovery curves are used to more realistically describe matrix-fracture interactions. It is necessary to present appropriate solutions to apply the RCM in the real fileds and also to evaluate it based on the historical production data. In this work at first, the basics of the RCM are presented then with a simple column model this method is validated. Then in a column model and a field... 

The available investigations show that gravity drainage mechanism in fractured reservoir make a high recovery factor in comparison with other mechanisms. In recent years, the forced gravity drainage assisted by gas injection is also introduced; despite of its importance there is no comprehensive modeling study in the literature. The fractured reservoir is simulated frequently by dual porosity models in which the transfer function is the key issue for this method of simulation. This study makes an effort by comparison of different transfer functions with fine grid simulation results of a single block model, in order to evaluate their ability for simulation of forced gravity drainage... 

Heavy oil reservoirs contain huge amount of initial oil in place in the world. Thus, enhancement of their production attracts lots of attention. Primary and secondary oil recovery methods have just little effects on the production of these reservoirs, thus, using innovative chemical methods which lead them to increase their mobility is recommended to improve their oil recovery efficiency. One of these proper and novel methods which has been established recently to enhance oil recovery is ASP1 flooding that can significantly increase oil recovery from petroleum heavy oil reservoirs. In addition, considerable numbers of reservoirs especially heavy oil reservoirs are fractured reservoirs. In...