VictorJuiz/thesis huggingface dataset:
A Simple Cyclic Steam Analytical Model for Heavy Oil, Pressure Depleted Reservoirs
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Since the discovery of cyclic steam a number of mathematical models describing the phenomenon have been proposed. These models range from the very simple analytical expressions t o complex numerical reservoir simulators requiring the use of super computers. While thermal simulators provide the most powerful tools for predicting performance of cyclic steam operations, their use is not always justified. Often availability of data, time pressure and economic constraints require that much simpler analytical models be used.In this study a review of existing analytical models for cyclic steam is presented and a new model is proposed. The proposed model incorporates many of the ideas from existing models with some refinements. The flow rate of oil in the model is influenced by oil viscosity, effective permeability heated zone radius, formation dip angle, porosity, mobile oil saturation and thermal diffusivity of reservoir. The reservoir temperature changes with time are modelled and they cause the oil rate to decline during the cycle. The model also accounts for the heat remaining in the reservoir from previous cycles. The model equations are kept as simple as possible and correlations are incorporated t o minimize data requirements.The results from the proposed analytical model are compared with some field data and with another analytical model. The agreement with the reported data is good. The limitations and uses of the model are discussed.
A Study on Designing the Surfactant-Gas Slug for Optimum Foam-Drive Performance
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Foam drive has been demonstrated to be a success as an enhanced oil recovery method in laboratory experiements as well as in field tests. Foam drive, as with any other EOR method, may not be suitable for all types of reservoirs nor putting surfactant solution in haphazard mannerdoes ensure success in otherwise suitable reservoirs.Unfortunately, very little research has been published i n t h e areas of selection criteria and slug design, despite its importance. This study attempts to increase the awareness of the importance of proper slug design and highlights some of the important parameters, on a qualitative basis.A homogeneous two-dimensional flow model, 1 ft high by 4 ft long by 1/4-in. thick, filled with unconsolidated Brea sand, having a permeability of 14 darcies and a porosity of 35%, was used for this study. Experiments were evaluated on the basis of visual observations and material balance. The model was saturated with Decane at irreducible water saturation, and this oil was subsequently displaced by a surfactant-gas mixture at a constant gas rate of 1 standard cc per minute. Both qualitative and quantitative results have shown that simultaneous gas and surfactant injection gives almost complete areal sweep and twice as much recovery as obtained by either pre-formed foam injection or slug type injection and suggests t h a t increased recovery can be obtained by proper slug design.
Analysis of a Streamline Model for Waterflooding
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This report examines the Program STRMLN, a streamline model for waterflooding, developed by Professor Caudle's group at the University of Texas at Austin.The streamline model is based on the stream or flow lines generated by the line source and line sink solutions to the diffusivity equation. Each streamline represents a channel of flow, the velocity of the fluid flow within each channel being a function of the mobility distribution along its path. Through the use of image well techniques, reservoir boundaries are mathematically produced, thus confining the flowlines between injector and producer. This makes the program easily adaptable to arbitrary reservoir shapes and well patterns.Because this method focuses completely on the fluid and not the medium in which it flows, gross simplifications are required. These simplifications being incompressible flow in a homogeneous reservoir of constant thickness. This program therefore is a meeting point between a more complex 3-D commercial simulator and simple hand calculations.The purpose of this report was to obtain, implement, document, and compare the program. For comparison,the question of a model's reliability to simulate a reservoir accurately and therefore be fit as a basis for comparison, may arise. Intuitively, fluid flow models should be the most reliable since they simulate in entirety the unsteady state displacement of one fluid by another. Because of this, the miscible displacement data obtained by Dyes, Candle, and Erickson (19541, and the exact solution as determined by Maghsood Abbaszaden-Dehghani (1982) are used. Having area sweep efficiency data versus displaceable pore volumes injected as a basis, the streamline model for varying program parameters and reservoir characteristics is compared.
Pipeline Transportation of Waxy Crude Oils; Rheology of Synthetic Waxy Crude-Water Slurries
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

One potential method for pipeline transportation of highly waxy crude oil is to produce a slurry from the waxy oil and water with a small amount of surfactant. Synthetic waxy crude oil was prepared with white oil and paraffin wax, and slurries were produced using Triton X-45 as the surfactant in order t o study their rheological properties.In the measurements with the Fann VG meter, rapid drops in the shear stress were often observed at constant shear rates. Due to these drops, the higher water concentration or the higher surfactant concentration tend t o give the lower shear stresses, but this tendency reverses itself as the shear rate becomes higher.It is presumed t h a t the emulsion and then the slurry inverts from a water continuous type to an oil continuous type as the waxy oil concentration increases. This inversion is stimulated with higher temperatures or higher shear rates, which cause the above opposing tendencies.It is also presumed that water rich layers are gradually formed with time on the rotor and bob surfaces of the viscometer, generating slip near the surfaces and thus the drops i n the shear stress.
Application of Reservoir Simulation and Linear Programming to Optimization of Primary and Secondary Oil Recovery
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The optimization of field operations under a given set of technical and economic constraints has been a key topic of study in the last years in petroleum engineering research. It turns out, however, that no method allying satisfactory accuracy to reasonable computing cost has been designed. This report attempts to demonstrate that an "optimum control procedure" may be applied to any industrial oil and/or gas reservoir at low cost and at acceptable accuracy level. Both primary and secondary recovery processes will be considered.The method proposed here is an original approach to the problem and is presented in two main sections. First, the modelling phase provides one with an analytical linear model of the reservoir. This phase is performed by referring to a reservoir simulator model as the experimental basis and by using a multiple variable regression analysis for fitting the experimental data. Second the optimization phase is performed by using a linear programming algorithm, a procedure which is very easy to work with. Non-linear effects, such as those generated by the presence of gas, are approximated by performing several procedural iterations.The application of this method to the case of a hypothetical full scale reservoir demonstrates the validity of the optimum control procedure. Furthermore, it allows one to anticipate acceptable results when considering' the case of any real oil and/or gas reservoir that features a large number of producer and injector wells.
Chemical Tracer Retention in Porous Media
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This report is concerned with the characteristics of chemical tracer retention in reservoir rock. In most of the previous work done concerning tracer behavior in reservoirs, the retention parameter was not quantified and thus neglected in the material balance calculations. In order to gain a more precise understanding of reservoir tracer behavior, the process of tracer retention in reservoir rock has been investigated.
The Prediction of Oil Saturation Using the Carbon/Oxygen Log
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Stanford University Petroleum Research Institute
Thesis

This project investigates the nature of Carbon/Oxygen Log gamma-ray spectra. It presents an attempt to improve the signal-to-noise ratio of the C/O and Si/Ca parameters used by Dresser-Atlas to determine oil saturation. Two techniques were developed to subtract the Compton background from the spectral data. Neither technique significantly improves the accuracy of the cased-hole prediction of oil saturation. However, it has been shown that it is possible to develop a satisfactory correlation for oil saturation on a well-by-well basis. This correlation can then be used to generate oil-in-place from the C/O and Si/Ca ratios.
The Relationship Between Viscosity Ratio and Dispersion Coefficient in Unconsolidated Sand
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The purpose of this report is to determine the relationship between viscosity ratio and dispersion coefficient in unconsolidated sand. A summary of the work done on miscible displacement is presented. A detailed description of the experimental equipment is included. From preliminary experiments, absorbance differences between vacuum oil and kaydol at 400 nm will be used as a method of analysis.
The work of Dr. Moshe Spitzer : leader in modern Hebrew printing and publishing
Keywords: publishing
Hebrew imprints
typefaces
Thesis

Dr. Moshe Spitzer (1900-1982 ) was a recognized leader in the art and production of the modern Hebrew book. He had complete authority on all the technical aspects of book production and is considered by all who knew him either personally or through his work to have innate and intuitive taste. In this paper I have undertaken a study of Dr. Moshe Spitzer's life and work and examined the forces that gave his career as designer and publisher its special nature.
A Simulation of a Natural Gas Reservoir Producing at Constant Wellhead Flowing Pressure Subject to Non-Darcy Flow Effect and Formation Damage
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This study investigates the transient response caused by a well located in a circular gas reservoir, closed or subject to constant pressure at the outer boundary, when producing at a constant wellhead flowing pressure and when formation damage and high-velocity flow are present.The work consists basically of the solution of the vertical flow equation that depends on the friction factor, wellhead flowing pressure, bottom hole pressure, and flow rate, combined with the solution for the gas reservoir flow equation, considering non-Darcy flow and formation damage effects.Since the flow rates in gas reservoirs are usually high, the flow in the production pipe is considered turbulent and the friction factor independent of the Reynolds Number.The reservoir flow equation is developed in terms of real gas potential m(p), and since it is a nonlinear partial differential equation, numerical techniques are used to solve it. An iterative process in flow rate is applied, since knowledge of flow rate is necessary to compute the bottom hole flowing pressure.The effects of non-Darcy flow, formation damage, and pressure dependence are analyzed and the results presented in terms of dimension-less flow rate and dimensionless cumulative production versus dimension-less time.The results obtained compare well with the classical constant- property solutions, at early and intermediate times, but at late times when the reservoir limit begins to affect the transient behavior, a deviation is observed. The non-Darcy flow affects the transient response at late times, while at early times there is not much influence.
Calculation of the Performance of Dry Steam Wells
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

This study presents a procedure for the calculation of the performance of dry steam wells, including wells under conditions of critical flow. The procedure uses the technique of Cullender and Smith (2) to calculate pressure drop i n the well. Calculation of the Mach number for maximum flow uses the technique of Thomas et al (9). Transient heat loss is calculated after Ramey (1). The overall convective heat transfer coefficient is evaluated using the Reynolds analogy of heat and momentum transfer. A computer program has been developed to calculate the performance and graph pressure and temperature profiles in flowing steam wells. Calculated and observed performances of some dry steam wells are presented. General graphs useful for well completion design are also presented.
Flow Metering of Geothermal Wells
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The fundamentals of horizontal, multiphase flow are sufficiently understood and reduced to practice to provide an adequate basis for measurement of geothermal well fluids. The fundamental momentum and energy balances which provide a basis for measurement are reviewed herein. A number of practical correlations for horizontal two-phase flow have been developed. Two methods are in wide use for geothermal systems: the James lip-pressure method, and separation of liquid and gas with separate single-phase metering.Geothermal reservoirs of a wide variety have been discovered and developed. These produce fluids ranging from single-phase gas, to single-phase liquid, to two-phase liquid and gas. The equipment use for metering these geothermal fluids has been discussed in the literature and provides a basis for planning new geothermal developments.
The Design and Construction of a Reservoir Conditioned Relative Permeameter
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Numerous studies have been conducted which deal with the effect of different factors on multi-phase flow through porous media. Because of the importance of thermal recovery techniques, researchers have included temperature as an important parameter of investigation. Studies have been completed which investigated the dependence of both absolute and relative permeability on temperature. However, the studies have not yielded consistent results. The existence and nature of a temperature dependency is still subject to discussion. Thus, a continuing need exists to further examine this phenomenon. Most researchers do agree that a temperature dependency does in fact exist; however, it is the nature of the behavior which has not yet been precisely defined.
A Study on Dykstra-Parsons Curves
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The Dykstra-Parsons method for prediction of oil recovery by water flood is a well known technique which has been used by the petroleum industry since 1945. The present work carries their study further, solving the same problem of finding coverage for certain values of permeability variation having water-oil-ratio and mobility ratio as fixed parameters. This work however, instead of using 50 layers, uses 200 layers. Also a more precise theoretical approach to the problem is given. Because of these differences, the answers are not exactly the same when one compares the resulting curves.In a second part, the author deals with empirical simplifications, with relative success. The idea here was to collapse the curves obtained in the first part above. This work includes a general discussion of the theory, a computer program with the results, the curves of coverage versus permeability variation for fixed values of water-oil-ratio and the empirical simplified curves.
A Study on Dykstra-Parsons Curves
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

The Dykstra-Parsons method for prediction of oil recovery by water flood is a well known technique which has been used by the petroleum industry since 1945. The present work carries their study further, solving the same problem of finding coverage for certain values of permeability variation having water-oil ratio and mobility ratio as fixed parameters. This work however, instead of using 50 layers, uses 200 layers. Also a more precise theoretical approach to the problem is given. Because of these differences, the answers are not exactly the same when one compares the resulting curves. In a second part, the author deals with empirical simplifications, with relative success. The idea here was to collapse the curves obtained in the first part above.This work includes a general discussion of the theory, a computer program with the results, the curves of coverage versus permeability variation for fixed values of water-oil ratio and the empirical simplified curves.
The Effect of Temperature and Salinity of Flowing Fluid on the Absolute Permeability of Sandstone
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Past works in the area of relative permeability and its variation with temperature indicate absolute permeability may also be a temperature dependent reservoir parameter.To study the temperature dependence of absolute permeability, an apparatus - designed and modified to allow for constant rate and temperature variation measurements - was constructed. The equipment was designed to allow for the constant confining pressure around the core assembly necessary to simulate actual reservoir conditions.
Unsteady-State Pressure Distribution in a Reservoir with a Pinch-Out
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

An analytical solution has been obtained for the unsteady-state pressure distribution in a reservoir with a pinch-out. The solution was obtained by means of a source function. The derivation assumed a constant rate production from a well in the vicinity of a pinch-out.The results showed that in both fully penetrating and partially penetrating situations, three flow regimes existed: (1) an early time radial flow period where the well behaved as a line source in a homogeneous infinite medium, (2) a transition zone, and (3) a long-time regime where there was spherical flow and an approach to steady flow.The distance of the pinch-out from the well as well as the angle of convergence of the overburden and underburden can be estimated from the long-time data.Times t o spherical flow and limiting pressure drops are calculated and presented in tables.
Limitations of the Dp/q Approximation in the Analysis of Pressure Drawdown Interference with Variable Flow Rate
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Conventional drawdown interference analysis assumes that the producing well flows at a constant flow rate. Several methods have been developed to handle variation of flow rate during the test.In this work, the method of superposition of continuously changing rates was used to generate dimensionless pressure solutions based on the instantaneous rate for a variety of functional forms of rate variation.Curves relating dimensionless pressure , dimensionless time, and a correlation parameter defined by reservoir properties and rate variation were constructed. Error curves were constructed that can be used as diagnostic tools to determine the validity of the Dp/q approximation.When the method of stepwise change in rate is t o be used in analyzing the data, it was shown that the pressure data at the end of the step period should be used. An equation has been developed to determine the duration of the flow rate in each step change to provide desired accuracy.
The Design, Construction and Operation of a Sand Pack Model to Study the Use of Foam as a Permeability Blocking Agent
Keywords:  Department of Petroleum Engineering
School of Earth Energy &amp; Environmental Sciences
Thesis

Non Newtonian fluids a r e often injected into a reservoir as part of an enhanced oil recovery process. Thermal recovery techniques and air injection have led to the flow of foams in porous media. In the state of California, a large portion of the oil reserve is in the form of heavy oil. Thermal recovery techniques, such as the injection of steam or insitu combustion, a r e the most effective means of recovering heavy oils.One of the major problems encountered in thermal recovery projects is the tendency of the injected fluids to pass through higher pemeability zones, missing the lower permeability zones. A second problem is gravity override. These two problems cause the thermal recovery projects to affect only the more pemeable and higher elevation zones. The most practical method of correcting this problem is to selectively block the fluid flow into the higher permeability and higher elevation zones.The injection of a permeability blocking agent would accomplish this. Scaled reservoir models have been used to study the effect of permeability variation and gravity override on oil recovery performance in frontal drive operations. Dyed fluids have been used so that the gross movement of the injected fluid can be observed.The purpose of this project was to design and construct a vertical sandpack model. The model will be used to evaluate the performance of foaming agents in permeability blocking.