bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mobilization and Banking of Residual Oil in High Salinity Reservoir Systems with the Use of Aqueous Surfactant Solutions of Ethoxylated Carboxymethylates
Authors: Kraft Harald R. , Pusch Guenter 
Published: December 2007

Abstract
Highly saline reservoir brine and crude oil with ethoxylated carboxymethylates and cosolvents show a complicated phase behavior. Easily obtainable and well defined indicators are therefore required to characterize phase conditions, which prevail in displacement processes.
The phase inversion temperature (PIT) has been investigated with respect to its ability to discern phase transformation in oil-brine- surfactant systems.
PIT proved to be very sensitive to changes in salinity, ionic strength, water-oil ratio and surfactant concentration, which simultaneously are responsible for phase inversion of chemical systems in the porous medium.
Core flood tests using an ethoxylated carboxymethylate as surfactant have shown that a rapid formation and production of a continuous oil phase in form of an oil bank can be achieved by a composition of the system in the boundary region of phase type III and II+ according to the terminology of NELSON and POPE.
However these flood conditions may cause increased pressure gradients during the flood at the trailing end of the oil bank.
Viscosity measurements on the emulsion in a low shear viscosimeter demonstrated that the increase of viscosity of a water-in-oil emulsion can be attributed to the increase of the WOR.
In displacement processes this may be provoked by viscous fingering of the mobility buffer into the mobilized oil bank.
The length and profile of the oil bank is controlled by phase conditions and viscous forces in the transition zone of the mobility buffer.
By addition of a suitable alcohol as a cosolvent to the surfactant slug or to the mobility buffer the temperature range of the stable displacement process could be extended without loss of recovery efficiency and the pressure gradients observed during the flood were in the normal range.
Comparison of Vertical, Slanted, and Horizontal Wells Productivity in Layered Gas-Condensate Reservoirs
Authors: Jamiolahmady M. , Ghahri P. , Victor O. E. , Danesh A. 
Published: December 2007

Abstract
The performance of a horizontal (highly slanted) well (HW) or a slanted well (SW), is generally believed to be better than that of a vertical well (VW) due to its greater exposure to the reservoir. However, the costs of drilling and completion are more and the options for monitoring, control and intervention often limited. Gas-condensate reservoirs are increasingly considered as suitable candidates for drilling SWs or HWs. These reservoirs pose special challenges selecting one type or the other due to the complex nature of fluid flow in porous media exhibited by these low interfacial tension systems, which are different from those of conventional gas-oil systems.
In this study we have investigated the performances of SW, HW and VW in both single-layer homogenous and layered gas-condensate reservoirs. ECLIPSE 300 compositional reservoir simulator, which includes our inhouse relative permeability (kr) correlation accounting for the coupling (increase in kr by an increase in velocity and interfacial tension) and inertial (decrease in kr by an increase in velocity) effects, has been used to conduct a series of sensitivity analysis on a single-well model resulting in some important practical guidelines. The effect of fluid properties and that of reservoir anisotropy (vertical to horizontal permeability ratio, kv/kh) have also been studied.
For homogenous systems, HW and SW have higher productivities. The improvement due to increase in lateral reach is less pronounced at lower kv/kh values especially for SW. In the case of layered reservoirs, the productivity of SW is adversely affected by the extended cross flow from low permeability to high permeability layers. In this case the impact of position of layers and that of kv/kh is more pronounced for SW and both at lower kv/kh. The decrease in velocity around the wellbore of HW decreases the impact of kr velocity dependency on production.
North Burbank Unit 1,440-Acre Polymer Flood Project Design
Authors: Trantham Joseph C. , Moffitt Paul D. 
Published: December 2007

Abstract
Substantial areas of the North Burbank Unit, Osage County, Oklahoma, gave poorer than average response to waterflooding. After studies showed that the performance of these areas could be traced to greater than field average heterogeneity, a pilot polymerflood was conducted during the period from 1970-1979. Good response to polymerflooding, followed by economic evaluation of proposed expanded operations, led to the design and implementation of a 1440 acre commercial scale project.
The project involved injection of fresh water preflush during the period from September, 1980 to late April, 1981. Then a liquid emulsion type polyacrylamide was blended to 500 ppm in fresh water and injected at a total rate of 63,000 BPD until approximately 4.4 percent of the pore volume had been injected. This was followed by a water spacer, and a 0.8 percent (PV) slug of aluminum citrate containing 500 ppm of aluminum was injected as a cross-linking agent into those two-thirds of the injectors which were expected to present no injectivity problems. Following injection of a second water spacer, 500 ppm polymer injection was resumed.
Plans call for injection of polymer at 500 ppm until the total amount reaches 15 percent of pore volume. This will be followed by polymer slugs of 250 ppm (10 percent of pore volume) and 50 ppm (15 percent of pore volume), fresh water (20 percent of pore volume), and finally drive (produced) water. Any localized channeling problems will be handled by treating individual injection wells with crosslinking agents such as aluminum citrate.
Methods of scaling up pilot results to the 1440- acre commercial project, site selection, design of the fresh water preflush, estimation of aluminum citrate requirements, and project costs are discussed.
Investigation of High-Temperature Fluid Loss Control Agents in Geothermal Drilling Fluids
Authors: Carney Leroy L. , Guven Necip , McGrew George T. 
Published: December 2007

ABSTRACT
This paper is a report on research work recently accomplished on examination of various polymers for the purpose of controlling the fluid loss in drilling fluids when subjected to temperatures of up to 371°C (700°F). Investigations have shown that attapulgite and sepiolite will transform to smectite under downhole conditions of temperature and pressure.
While this improves the rheology and fluid loss, to some degree, of a system containing attapulgite or sepiolite when subjected to high temperature, there is a need to further lower the fluid loss.
A series of polymers, copolymers and terpolymers have been evaluated for further control of both rheology and fluid loss.
These systems prove to be superior to conventional water base systems used in oil and gas drilling.
The clay constituents of the fluids have been examined with both x-ray diffraction and electron microscopy. The newly formed smectite has been dehydrated and rehydrated to make up a system for high temperature drilling.
Improvements are noted in the process of dehydrating and rehydrating the newly formed smectite for obtaining viscosity for temperature stable fluids.
The newly formed smectites coupled with high temperature stable polymers have resulted in the formation of a temperature stable drilling fluid for use in geothermal drilling.
The Laboratory Development and Field Testing of Steam/Noncondensible Gas Foams for Mobility Control in Heavy Oil Recovery
Authors: Dilgren Richard E. , Deemer Arthur R. , Owens Kenneth B. 
Published: December 2007

ABSTRACT
Steam foam formulations were developed to reduce steam mobility in the steam drive process. Several commercially available alkylbenzene sodium sulfonates and alpha olefin sodium sulfonates appear promising. Other foam components were nitrogen and sodium chloride. Ottawa sand packs were the primary screening tool used in the laboratory. Reduced steam foam mobility in the field was evidenced by significantly increased flowing bottom-hole pressures for the injectors. An increased rate of oil production was also observed.
The Thermodynamics of Evaporation and Condensation in Porous Media
Authors: Udell Kent S. 
Published: December 2007

ABSTRACT
The thermodynamics of a single component, vapor-liquid system subjected to capillary pressures characteristic of porous rock have been examined. Van der Waal's equation was coupled with the Gibbs-Duhem differential expression for the chemical potential and integrated. The resulting expression for chemical potential as a function of pressure, temperature and specific volume provided the key to the understanding of the thermodynamic equilibrium between the wetting liquid and its vapor across the capillary pressure discontinuity.
Through this analysis it was found that when capillary pressures are present, thermodynamic equilibrium can only exist if both liquid and vapor phases are in a superheated state. This result is consistant with Kelvin's equation for vapor lowering. Furthermore, the superheated liquid phase, which is in a metastable state if no vapor or capillary pressures are present, is in an unconditionally stable state if capillary pressures are imposed. The degree of liquid superheat was found to be a function of contact angle, interfacial tension, effective pore radius and heat of vaporization.
Using water as an example, quantitative values of liquid and vapor pressure lowering are presented for various pressures and pore radii. It was found that for porous media of pore size distribution similar to that of reservoir rock, the vapor thermodynamic equilibrium pressures and temperatures do not differ significantly from the steam table values. Significant liquid pressure lowering does result. Also the transition from capillary condensation to thin film adsorption may be identified from the liquid pressure lowering curves. Applications to other systems in thermodynamic equilibrium with a porous media are discussed.
Loudon Surfactant Flood Pilot Test
Authors: Bragg J. R. , Gale W. W. , McElhannon W. A. , Davenport O. W. , Petrichuk M. D. , Ashcraft T. L. 
Published: December 2007

Abstract
A successful surfactant (microemulsion) flood pilot test has been completed by Exxon in a watered-out portion of the Weiler sand, Loudon Field, Fayette County, Illinois. The microemulsion system tested was designed to be effective in the presence of high-salinity formation water containing 104,000 ppm (mg/1) total dissolved solids (TDS) without use of a preflush. The test was conducted in a single, 0.68-acre 5-spot operated to approximate a confined pattern. Approximately 60 percent of the waterflood residual oil present in the pilot pattern was recovered. Extensive data for determining sweep and displacement efficiencies were obtained from observation well logs and fluid tracers. Although problems were encountered with bacterial degradation of biopolymer and with produced oil-water emulsions, the test is considered to be a technical success and confirms the effectiveness of the high-salinity microemulsion formulation. Additional pilot tests are needed to determine the effects on oil recovery of microemulsion bank size and well spacing.
Overview of Regulating Burdens and their Affect on Various Areas of the Industry
Authors: MacDowell Peter 
Published: December 2007

ABSTRACT
The world of regulatory affairs is in its usual state of disarray and flux, with promises of reform echoing from the electorate while compliance procedures are being enforced in the field at an ever increasing level. The difficulty encountered by industry in planning future operations and expenditures in regard to regulatory affairs is a real problem and no facet of the industry is immune from these concerns. An overview of these burdens and their effect on various areas of the industry will be discussed.
Offshore Operations on Great Salt Lake
Authors: Woodhall Robert J. 
Published: December 2007

ABSTRACT
Amoco recently drilled 15 exploration wells and ran production tests from floating barges on the Great Salt Lake, Utah. To compensate for the lack of critical lake data and the lack of conventional offshore equipment, Amoco embarked on a comprehensive engineering effort to plan for drilling operations.
Engineering studies included: wind and wave measurement; sub-bottom technical data evaluation; design of a drilling barge with the associated anchoring system; and later, performance monitoring and redesign to meet a second drilling phase.
The unique environment and remote location presented some very interesting engineering challenges which require innovative solutions. This paper discusses the overall planning effort, as well as documenting solutions and results for this frontier offshore operation.
Information from this operation has reference value to operations in similar remote frontier areas.
Foam Fracturing in the Uinta Basin — A Field Study of the Dakota and Wasatch Formations
Authors: Goelitz R. , Evertz G. E. 
Published: December 2007

ABSTRACT
The Dakota and Wasatch formations of the Uinta Basin in northeastern Utah and northwestern Colorado have been historically difficult to clean up following a fracturing treatment. Recovery of normal water-based fluids has been averaging 20 to 30%, with much rig time spent in swabbing before the wells were put on production. Because of low recovery and the potential for clay problems, a number of techniques and fluids were tried without any significant improvement. Since these formations were very low in permeability, .05 to .2 md, deeper penetration through fracturing remained a high priority for treatment success. To achieve this penetration, relatively large volumes of treating fluids were needed. Foam fracturing was then instituted as a means of controlling the amount of water put into the formation. The first treatments were relatively small and sand concentrations of two pounds per gallon were the maximum that could be achieved. The results were encouraging enough to warrant the continued use of foam as a fracturing fluid. With the advent of equipment to achieve higher concentrations of sand at the formation and better materials to stabilize the fluid itself, foam fracturing matured into a much more viable means of treating both formations.
The immediate advantages of foam are obvious. There is 65 to 75% less water put into the formation that has to be recovered and the possibility of damage due to swelling or migrating clay is reduced. The reduced damage is the result of smaller volumes of water and easier handling, of clay control agents, KCl and/or chemicals. A very important aspect of this technique is a faster and improved cleanup, which can be attributed to less water, more energy and lower hydrostatic head.
Modern Techniques and thorough Evaluation Yield More Consistent Stimulation Results in Frontier Formation
Authors: Hodges J. E. , Paoli B. F. 
Published: December 2007

ABSTRACT
A study was made of stimulation treatments being conducted in the Frontier Formation, southwestern Wyoming. The purpose of the study was to determine why some treatments were successful while others resulted in inadequate production increases.
The initial step was to gather as much data as possible from treatments previously pumped. Although this information helped to pinpoint trends in the field, it was of little value in determining the cause of stimulation failure. In an effort to get more information, rninifracture treatments were pumped on new wells to determine fracture parameters. Bottom-hole pressures were also monitored during all pumping operations. Applying current technology to these data led to a better understanding of how the fracture was propagating. On previous jobs, post-fracture temperature logs consistently indicated "in-zone" treatments, which could not be supported by the interpretation of bottom-hole treating pressures. The assumption that fractures were confined in the pay zone was also disproved by post-fracture, pressure buildup tests. These tests indicated that effective propped fracture lengths were far shorter than calculated fracture lengths. The key to successful stimulation was found to be controlled fracture height throughout the fracture.
Our goal was to build an artificial barrier the length of the fracture using 100-mesh sand. Other techniques applied included lower pump rates, lowering breakdown pressures to avoid unwanted fracture geometry, and gut shooting the pay zone to predetermine the point of fracture initiation. Production results to date show a definite increase in the percentage of successful stimulation treatments.
Design, Application, and Future of Polycrystalline Diamond Compact Cutters in the Rocky Mountains
Authors: Cerkovnik Jerry 
Published: December 2007

ABSTRACT
The Rocky Mountain Region has proven to be one of the greatest challenges to manufacturers of bits utilizing Polycrystalline Diamond Compacts (PDC) as cutting elements. Constant advancements in bit design, and further exploration of possible drilling applications has proven to the industry that PDC bits have a place in Rocky Mountain Drilling. The knowledge of what makes a PDC bit drill is essential for everyone connected with the application of this bit. An understanding of terms such as back rake, side rake, exposure, and profile, is necessary to correctly select the right style of bit.
The type of chip generated by the cutter is dictated by the characteristics of the rock being drilled. We can control this generation of cuttings by orientation of the cutter face. This orientation is controlled by exposure, side rake, back rake, and cutter density. Differing profiles can enhance directional characteristics and improve the cleaning of the bit. Setting up a proper hydraulics program for the bit, thee rig, and the formation is critical in optimizing bit performance.
Running procedures used with PDC bits are similar to those used in diamond drilling, which includes careful setting of a bottom hole pattern, light weights and low RPM's while reaming. Drilling weights and RPM's are determined by optimum rates of penetration, keeping in mind that the shearing action of the PDC cutter requires considerably less weight than conventional bits to fail the rock. With the increasing performance and success rate achieved in just the last year, the future of PDC drill bits is very promising in the Rocky Mountain Region.
Mathematical Simulation of Natural Gas Condensation Processess Using the Peng-Robinson Equation of State
Authors: Nagy Zoltán , Shirkovskiy Arkadiy I. 
Published: December 2007

ABSTRACT
On the basis of its simplicity and the data obtained by a great number of tests and comparative analysis, we consider the Peng-Robinson (PR) equation of state to be the most suitable to calculate the condensation processes of natural gas, further on to set up the equations of material and heat balances.
In case of mixtures, the accuracy of the PR equation of state was mainly influenced by the correct selection of the interaction coefficients.
The paper presents the calculation correlations of the thermal and thermodynamic properties published uncompletely before, as expressed with the parameters of the PR equation of state.
The simulation of natural gas processes could be made more robust by introducing new differential characteristics. Such is the partial derivative of temperature change owing to pressure change (∂T/∂P), that can be effectively used to calculate expansion and compression processes to reduce the number of iteration steps. This term has been calculated using the derivatives (∂Z/∂T)p which can easily be determined from the PR equation of state.
Using the experiences obtained by the application of the PENG-ROBINSON AGA PROGRAM we have developed a module for calculation of phase equilibria and thermodynamic properties of fluid systems. This is the main module of our program MODEL-TECH (constructed in module structure) which is suitable to calculate separators, heat-exchangers, heat sources, heat drains, Joule-Thomson effect, expansion turbines, compressors, detander-compressor units, arbitrary columns and simulation processes of any degree of complexity built from the above elements.
Offshore Exploitation of Refrigerated Natural Gas Liquids
Authors: Castel Elisabeth J. , Baggio Jean-Louis 
Published: December 2007

ABSTRACT
Producing refrigerated Natural Gas liquids will improve offshore associated Gas recovery.
The following system includes production, storage and loading of Natural Gaz liquids cooled down to atmospheric pressure.
Natural Gaz liquids are cooled down using a NGL refrigerant cycle and stored in floating or gravity concrete membrane tanks. Loading is carried out using a distant loading terminal with separate mooring and loading devices. The whole system was designed to meet requirements for safety, easy maintenance and use of existing technology. Detailed engineering of the elements was performed including process calculation, structural analysis and risk analysis.
An application of the system will be presented and an appraisal of its cost given.
Deconvolution With Propagated Geometric Factors
Authors: Thadani Suresh G. , Merchant Givlamabbas A. 
Published: December 2007

ABSTRACT
The deconvolution process is basic to the improvement of the thin bed response of induction logging tools. Past approaches to this problem (Smith, Bostick 1964) have focussed on the design of inverse filters based on the Doll Geometric factor (Doll 1949). As is well known, the Doll Geometric factor does not accurately model the response of the induction tool particularly in formations with conductivities greater than 1 mho/meter. Recently (Thadani, Hall 1981), new techniques based on the solution of Maxwell's equations have been developed that permit the computation of propagated geometric factors i.e. geometric factors that fully incorporate propagation effects. These techniques make it possible to accurately compute the vertical investigation characteristic or response function of the induction tool in a large class of cylindrically symmetric formation geometries, including the thin invaded bed formation model.
In this paper, it is shown by the application of the above techniques that the response function of the induction tool is a function of both the formation parameters and the relative position of the tool with respect to the formation. In particular, it is shown that the shape of the response function becomes asymmetric with respect to the center of the tool as the conductivity of the formation increases. Synthetic data computed by using the above techniques is used to evaluate the performance of inverse filters based on the Doll Geometric factor for various formation geometries including the thin bed formation model. Currently, various deconvolution filters are being developed using response functions based on propagated geometric factors. The paper will include the results of an evaluation of these filters on various cylindrically symmetric formation geometries.
Petroleum Industry Technical Manpower Requirements for the Next Decade
Authors: Early P. J. 
Published: December 2007

Abstract
It is a pleasure to take part in this SPE session on Resource Management in a Changing Environment. My topic -- Manpower -- has recently been a serious problem for our industry. Thus, it is appropriate that your Program Committee included this discussion of technical manpower requirements over the next decade.
You have already heard forecasts on energy supply and demand, future capital requirements, and the technological direction our industry will take. These interrelated subjects also will influence future manpower requirements, but I will try to avoid ground already covered.
This dynamic interplay makes forecasting difficult, and I do not intend to make specific, year-by-year predictions about personnel needs.