bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Investigation of Phase-Behavior/Macroscopic-Bypassing Interaction in CO2 Flooding
Authors: Gardner J. W. , Ypma J. G. J. 
Published: December 2007

AbstractCO2 core floods and related high-resolution, mathematical simulations in which viscous fingering is represented explicitly indicate a synergistic interaction between multicontact CO2/crude phase behavior and macroscopic bypassing that causes ultimate oil recovery (when the system has been swept) to be lower in unstable displacements than in stable ones. If this effect is present in field applications, corefloods in which fingering is absent should not be used as direct indicators of field-scale CO2 flood displacement efficiency because they will yield optimistic predictions, all other factors being equal in the laboratory and the field.
Interpretation of Differential Pressure in Laboratory Surfactant/Polymer Displacements
Authors: McCool C. Stanley , Parmeswar Ravi , Willhite G. Paul 
Published: December 2007

Abstract
Experimental data were obtained for two surfactant/polymer systems in which fluid mobilities and mobility control were studied through the analysis of differential pressure measurements. One system used nonane as the hydrocarbon phase, while the other system used crude oil from the Madison field, Greenwood County, KS. During the experimental studies, capillary-pressure effects were observed in differential pressure data when floods were conducted at reservoir rates and small port spacing. Capillary-pressure effects interfered with the measurement of the "true" or viscous pressure drop in oil/water banks and the transition region between the oil/water bank and surfactant slug. Pressure ports were designed to permit injection of small quantities of fluid at the rock surface during displacements to verify and to eliminate capillary-pressure effects.
Movement of fluid regions through the core was inferred from the differential pressure measurements along the core. Similar pressure perturbations at the ports were extrapolated to the end of the core and correlated with effluent fractions. In the nonane system, the microemulsion surfactant slug changed to a more mobile macroemulsion within the first half of the displacement. This macroemulsion moved through the last half of the core as a stabilized, constant velocity bank indicating good mobility control even though the apparent viscosity of the macroemulsion was less than that of the stabilized oil/water bank. In the crude-oil surfactant system, pressure data collected along the core indicated capillary-pressure effects at the leading edge of the oil bank and the formation of a viscous, less mobile region resulting from mixing of the microemulsion slug with resident fluids. Phase-behavior studies indicated the formation of a viscous lower phase as the microemulsion was diluted with brine. The formation and propagation of this viscous region during displacement leads to favorable mobility control illustrated by the pressure/ mobility curves as well as by good oil recoveries (80 to 95%).
Equilibrium Phase Compositions of CO2/Crude Oil Mixtures—Part 2: Comparison of Continuous Multiple-Contact and Slim-Tube Displacement Tests
Authors: Orr Franklin M. , Silva Matthew K. , Lien Cheng-Li 
Published: December 2007

AbstractResults of phase composition and density measurements for CO2/crude-oil mixtures at 32°C and four pressures are reported for a system in which liquid/liquid and liquid/liquid/vapor phase separations occur. The experiments demonstrate that a CO2-rich liquid phase can contain as much as 30 wt% hydrocarbons and show that a CO2-rich vapor phase at the same conditions extracts hydrocarbons less efficiently. Pseudoternary phase diagrams are presented that summarize the results of the detailed phase composition measurements.Results of slim-tube displacements at the same four pressures are also given. They indicate that displacement is efficient when the pressure is high enough that a liquid CO2-rich phase appears.Predictions of the performance of the slim-tube displacements based entirely on the experimental measurements of phase compositions and densities are obtained using a simple one-dimensional (1D) simulator. The simulation results clarify the roles of phase behavior and volume change on mixing in the siim-tube tests.Finally, the advantages and limitations of the slim-tube and continuous multiple-contact (CMC) tests are compared. We conclude that the CMC experiment yields more information useful for prediction of the performance of a CO2 flood.
Equilibrium Phase Compositions of CO2/Hydrocarbon Mixtures— Part 1: Measurement by a Continuous Multiple-Contact Experiment
Authors: Orr Franklin M. , Silva Matthew K. 
Published: December 2007

AbstractA new experimental technique that simultaneously measures compositions and densities of two phases in equilibrium is described. Because it operates continuously, the experiment can be performed more rapidly than conventional static-equilibrium measurements. Details of the experimental apparatus are reported, and results of test displacements for two simple CO2/hydrocarbon systems are compared with static-equilibrium phase composition measurements for the same systems. A simple analysis of the operation of the experiment is used to assess the experimental error that results from the continuous nature of the experiment and to suggest ways to reduce that error. Application of the experimental technique to a CO2/crude oil system is reported in a companion paper.1
Evaluation of an In-Situ Combustion Process by Postburn Core and Log Analysis
Authors: Joseph Conrad , Jay Charley B. , Eslinger Eric V. 
Published: December 2007

Summary
Evaluation of the performance of an in-situ combustion process applied by Cities Service Co. in the Bellevue field was made possible by analysis of postburn cores and logs from wells drilled within the flooded zone. postburn cores and logs from wells drilled within the flooded zone. Temperature-observation-well data and production performance were inadequate to describe the coverage and efficiency of the simultaneous air- and water-injection method applied.

Introduction
An attempt was made to monitor the coverage of the burn fronts generated by five injection wells in the Bellevue field using one temperature-observation well per injector. After 4 years' continuous injection, only one observation well ever had shown the high temperatures seen in laboratory combustion tube studies, and an accurate description of the burned zone could not be determined. After air injection was terminated, four wells were drilled within one pattern, obtaining openhole logs and cores of the producing formation. pattern, obtaining openhole logs and cores of the producing formation. Results from this postburn drilling program were used in constructing an approximate burned zone for the pattern, enabling better understanding of the combustion process and of the efficiency of the field project.

Reservoir and Laboratory Data
The combustion project is being conducted in the Bellevue field of northwestern Louisiana. This field, discovered in 1921, produces a 19API (0.9 g/cm3) crude from the Upper Cretaceous Nacatoch sand. Primary production from the field is estimated to have been less than 15% of the production from the field is estimated to have been less than 15% of the original oil in place (OOIP). The field is a 900-acre (4 × 10 6 m2) low-relief dome with pay thickness controlled by a water/oil transition at 212 ft. (64.6 m) subsea. The project area covered by this report is a 19-acre (77 × 10 3-m2) five-pattern demonstration conducted by Cities Service Co. under a cost-sharing contract with the U.S. DOE (Contract DE-AC03-76ET12057). In this area of the field the top of the Nacatoch is encountered between 109 and 174 ft (33.2 and 53.0 m) subsea, with dip to the northeast at 4.5 0. At this shallow depth, the Nacatoch is a highly unconsolidated sand with numerous thin, dense, fossiliferous limestone layers. These limestone layers are identified easily from bulk-density logs (Fig. 1) and essentially subdivide the pay section into four principal sand intervals (S1, S2, S3, and S4). The average porosity and permeability of the sand intervals are 33.9% and 700 md, with the sand having a 27.4% water saturation. Average reservoir pressure is only 40 psig (280 kPa).
JPT
p. 827
Critical Scaling Behavior of Microemulsion Systems
Authors: Huang John S. , Kim Mahn Won 
Published: December 2007

Abstract
We used dynamic light scattering to study the characteristic droplet size, r̄, in dilute single-phase microemulsions near the critical phase transition point. We found that there existed a general power-law dependence of r̄ on the reduced variable ΔZ=Zc−Z. Here Z stands for any thermodynamic and system variables whose critical value is denoted by Zc. The variables of interest in the present work are temperature and alkane carbon number (ACN). It is found that r̄∝ΔZ−ν where ν =0.75±0.1. This is observed both in water- and oil-internal microemulsions, independent of the surfactant properties.
This behavior, known as the scaling behavior, was analyzed in terms of generalized homogeneous functions with v as the degree of homogeneity. It turns out that only one of the reduced variables is an independent variable in these functions, greatly simplifying the description of the properties of microemulsions in the neighborhood of a critical phase boundary.
Fluid Flow and Structural Response Modeling Associated With the Mechanics of Hydraulic Fracturing
Authors: Advani Sunder H. , Lee June K. , Khattab Hussein A. , Gurdogan Oguzhan 
Published: December 2007

SummaryA review of hydraulic-fracture modeling is given. Equations governing pertinent fluid-flow, structural, and fracture-mechanics responses are presented. The finite-element method is used to discretize the field equations and to compute the fracture dimensions, fluid leakoff, and stress intensity factors. In addition, the effects of fracture-fluid properties, layered strata, and in-situ stresses are characterized, and numerical examples are presented.
Helical Postbuckling Configuration of a Weightless Column Under the Action of an Axial Load
Authors: Cheatham John B. , Pattillo Phillip D. 
Published: December 2007

Abstract
The helical postbuckled configuration of a weightless, circular column confined within a cylinder was used by Lubinski et al. in 1962 to develop frequently applied equations describing the deformation of oilfield tubing.1 This paper presents an extension of their work in the form of another expression for the relation between applied force and helical pitch in the buckled state. Based on simple laboratory experiments and stability arguments it appears that the previous force-pitch equation applies during load application and the one given in this paper applies during unloading.
Packing and Drafting in Natural Gas Pipelines
Authors: de Nevers Noel , Day Anthony 
Published: December 2007

Summary
Increasing and decreasing natural gas pipeline inventory (" packing" and "drafting" ) are examined mathematically. Any line segment's unsteady-state packing or drafting behavior depends on only two dimensionless parameters, packing or drafting behavior depends on only two dimensionless parameters, ( ) and ( ). The influence of ( ) is small, so that for any value of ( ) the behavior of all pipelines can be represented on a single plot; four such plots are shown for four different boundary conditions.

Introduction
Natural gas dispatchers use increase and decrease of the stored inventory of gas in their pipes as one method of matching time-varying demands with supplies, which generally have less time variation. In pipeline terminology, increasing the inventory (and hence the pressure) is called "line packing," while decreasing it is called "line drafting." This paper examines the limits of this procedure, asking both how much gas can be added to or subtracted from the inventory in a given pipeline segment, and how rapidly this can be accomplished.
How Rapidly Can the Inventory Be Depleted or Restored?
Although the questions of how large the inventory is and how much can be taken from it for any change in steady-state conditions can be answered very simply, the computation of how rapidly this can be accomplished requires a set of coupled partial differential equations and a numerical solution on a computer. Fortunately, as shown here, the nondimensional results can be summarized in ways that are fairly easy to use.

Mathematical Theory
It has been known since at least 1951 that the mathematical description of the unsteady-state flow of any gas in a long pipeline is governed by a material-balance equation,
............................(1)
and a momentum-balance equation,
............................(2)
The mass-balance and momentum equations, expressed with pressure, and mass flow rate, as dependent variables and length, and time, as independent variables and assuming that 's are much smaller than 's and ( / )'s, are
............................(3)
and
........................... (4)
respectively. The justification for dropping the terms as being much smaller than the others is that changes very slowly with changes in and other variables.
JPT
p. 655
Oil Recovery by Heat From In Situ Combustion
Authors: Breston Joseph N. 
Published: December 2007

Abstract
This paper presents a comprehensive and up-to-date review of the mechanics, operating variables and probable economics of the in situ combustion method of oil recovery. It distinguishes between the continuous burning and "heat wave" processes, and points out some of the advantages and disadvantages of each.
Although several useful papers have been published on the results of laboratory experiments, information on the results of field tests has been only fragmentary. In order to present a coherent picture of the present status of the in situ combustion method of oil recovery, the author has combined unofficial information on field tests with laboratory data to present some figures-at least some "ball park averages", for petroleum technologists who might be considering a trial of the process.

Introduction
In situ combustion basically consists of igniting the oil in porous reservoir rock with a suitable ignitor and driving a combustion zone through the reservoir toward producing wells with compressed air, with or without recycle gas. This process differs from other thermal processes in which heat is generated at the surface and injected into the reservoir via hot water, gases, or steam.
The in situ principle appeared in 1923 (first U.S. patent) and since 1948 10 field experiments have been conducted in various parts of the U.S., Canada and South America, including one test in Colorado oil shales. Approximately 10 pilot tests are currently being conducted and large commercial operations are planned by several companies.

Mechanism
During an in situ operation very little reservoir oil is consumed for the combustion front creates hot gases which force oil and water to producing wells. The produced oil is practically unaltered since it is not subjected to cracking temperatures. Actually, during most of the life of the operation, the fluids entering the producing wells are at or near the original reservoir temperature. Fig. 1 shows four coexistent but distinct transient regions which exist between the injection and producing wells.
The Static and Dynamic Interfacial Tensions Between Crude Oils and Caustic Solutions
Authors: Trujillo Edward M. 
Published: December 2007

Abstract
One method to achieve EOR is chemical alteration of the reservoir environment so that previously trapped oil can begin to flow freely. Under certain conditions, caustic or alkaline solutions can do this. The work reported here shows that interfacial tension (IFT) between various crudes and caustics increases with time because of desorption of the surface-active species from the interface. The desorption rate is temperature-dependent. Four kinds of crude oil were used—a California crude, a Wyoming crude, an Illinois crude, and an Alaska crude. Only with crude oils with a high concentration of crude acids, such as the California crude, is the ultralow IFT maintained for any reasonable period of time, namely 24 hours. The presence of calcium ions at concentrations of 200 ppm or more destroys the capability of caustic to reduce the IFT's, even for the California crude.
Mass-action relationships are presented that describe the equilibrium IFT at constant ionic strength between crude oils and sodium hydroxide solutions as a function of pH and calcium. Techniques are presented for evaluating time-dependent IFT's obtained by the spinning-drop apparatus. A transient mathematical model shows that IFT can increase by several orders of magnitude over a period of several days. Good agreement between the model and experimental data is obtained. The parameters obtained from these mathematical models describe crude reactivity to caustic more accurately than conventional crude acid numbers. The transient effects observed in the laboratory may or may not be significant in the field.
Microcrack Permeability in Tight Gas Sandstone
Authors: Ostensen R. W. 
Published: December 2007

Abstract
A model of stress-dependent permeability was developed on the basis of flow through cracks. The compliance of the cracks is controlled by elastic deformation of a Gaussian distribution of surface asperities, indented into the opposing crack face. The theory was applied to data from tight gas sand cores, with the following results.
The theory explains the Jones and Owens permeability correlation1 and predicts a modification of it that yields a better fit. The slope of the permeability/stress curve on a log-log plot is predicted to be about 1.0, which agrees with the data. The Jones and Owens Klinkenberg correlation supports a slit-like flow model and indicates that flow occurs along almost every grain boundary. The size of the surface roughness was computed from the Klinkenberg factor and the slope of the permeability/stress curve. It is independent of stress, as predicted by the theory. The porosity of tight sand cores decreases linearly with the log of net confining stress, in accordance with the Walsh-Grosenbaugh model of crack compressibility.
This detailed agreement supports the theory and indicates that the permeability of tight gas sand cores is due to microcracks.
On the Residence Time of Oil Mixed Into the Water Column by Breaking Waves
Authors: Naess Arvid 
Published: December 2007

Abstract
The main purpose of our paper is to present experimental results on the mixing of oil into the water column by breaking waves. During sea states characterized by frequent breaking it is believed that the breaking waves play a dominant role in the natural dispersion of an oil slick. When a breaking wave hits an oil slick, it will cause a mixing of oil into the water column. Because of buoyant effects, the oil particles tend to rise toward the surface again. This leads to a short-term balance between mixing and rising that is determined largely by the characteristic residence times of the oil particles in the water column. This particular problem is the subject of this paper.
Kinetic Study of Desulfonation of Disulfonated Alkyl Diphenyloxide Surfactants
Authors: Marriott R. C. , Kao C. I. , Kristal F. W. 
Published: December 2007

Abstract
Kinetic study of the desulfonation of Dowfax® surfactants, disulfonated alkyl diphenyloxide, is carried out in the temperature range of from 177 to 272°C, and a pH range of 2.0 to 7.0. The rate data support that the desulfonation is a step-wise reaction catalyzed by hydrogen ion. The desulfonation rate is first-order with respect to both surfactant and hydrogen ion concentrations. As a result, the pH of the reaction system has a very significant effect on the stability of the surfactants and may outweigh the effect of temperature. The half-life of disulfonated alkyl diphenyloxide at 235°C in a 5.5-pH buffer solution is 1,035 days, and at 272°C in a 7.0-pH buffer solution is 295 days. The results indicate that these surfactants can be used in most oil reservoir steamflood applications, especially when the rock formation may buffer the pH to about 7.0.
An Electromagnetic Survey Method for Directionally Drilling a Relief Well Into a Blown Out Oil or Gas Well
Authors: Kuckes Arthur F. , Lautzenhiser T. , Nekut A. G. , Sigal R. 
Published: December 2007

Abstract
This paper describes an electromagnetic method to facilitate drilling a well to intersect a target well casing. It has an important application in control of blown out oil and gas wells. By this method, a relief well was directionally drilled to intersect the casing of a blowout at 8,000 ft [2700 m]. The relative distance and azimuthal direction to the target casing can be determined when the relief well is up to more than 100 ft [30 m] from the blowout.
Laboratory Study of Diamond-Bit Hydraulic Lift
Authors: Winters Warren J. , Warren T. M. 
Published: December 2007

Summary
Hydraulic lift can have a major effect on the operation of diamond drill bits. The actual weight on bit (WOB) is less than the measured weight by the amount of hydraulic lift, or pumpoff force, acting beneath the bit. Pumpoff forces greater than 15,000 lbf [66.7 kN] have been recorded.
Historically, hydraulic lift has been recognized but not understood well enough to be accounted for reliably. The current hydraulic-lift theory has been developed and validated through a series of laboratory tests. Measurement techniques have been reduced to simple procedures for determining any bit's hydraulic-lift effect. Laboratory studies show that under identical conditions, the amount of hydraulic lift varies widely with bit design. Two parameters—the effective pumpoff area and apparent nozzle area—characterize a bit's pumpoff effect and are used to explain and to predict variations in hydraulic lift with diamond bits.
The "Checker Model," An Improvement in Modeling Naturally Fractured Reservoirs With a Tridimensional, Triphasic, Black-Oil Numerical Model
Authors: Bossie-Codreanu Dimitrie , Bia Paul R. , Sabathier Jean-Claude 
Published: December 2007

AbstractThis paper describes an approach to simulating the flow of water, oil, and gas in fully or partially fractured reservoirs with conventional black-oil models. This approach is based on the dual porosity concept and uses a conventional tridimensional, triphasic, black-oil model with minor modifications. The basic feature is an elementary volume of the fractured reservoir that is simulated by several model cells; the matrix is concentrated into one matrix cell and the fractures into the adjacent fracture cells. Fracture cells offer a continuous path for fluid flows, while matrix cells are discontinuous ("checker board" display). The matrix-fracture flows are calculated directly by the model. Limitations and applications of this approximate approach are discussed and examples given.