bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Conductivities of Porous Rocks Filled with Stagnant Fluid
Authors: Kunii D. , Smith J.M. 
Published: December 2007

Abstract
Effective thermal conductivities of sandstones filled with stagnant fluids were measured using a steady-state technique. Data were obtained for seven sandstone samples, taken from four different locations and ranging in permeability from 18 to 590 md. The measurements with gases (helium, nitrogen, air and carbon dioxide) covered a pressure range from 0.039 psia to 400 psig. Data were taken for four liquids - n-heptane, methyl alcohol, 79.8 weight per cent glycerol-water solution and pure water at atmospheric pressure.
The experimental results were used to evaluate the theoretical equations for predicting stagnant conductivities developed earlier. The low-pressure measurements permitted evaluation of the consolidation parameter hpDp/ks (necessary to utilize the theory) for the various types of sandstones. Using these characteristic values, the theoretical equations correlated well with the experimental conductivity data for the several fluids and rock samples.

Introduction
An aspect of heat transfer in solid-fluid systems of considerable current interest is the effective thermal conductivity of porous media. The stimulus for study of the subject arises from the need for sound procedures for designing thermal methods of petroleum production. The general system occurs when there exists a flow of fluid through the pores of the solid material. However, a logical starting point in developing a theory for predicting the effective thermal conductivity in the general system is to attack the special case when the porous solid is filled with stagnant fluid. Since the flow rates anticipated in thermal production processes are very low, such stagnant conductivities k are also of practical significance.
Applications of Convolution and Deconvolution to Transient Well Tests
Authors: Kuchuk F. J. 
Published: December 2007

SummaryThis paper presents the application of convolution and deconvolution interpretation methods. Two well-test field examples, interpreted with these methods, suggest that the downhole flow rate is crucial for system identification and parameter estimation and that the wellbore volume below the pressure gauge and flowmeter must be taken into account. A new generalized rate-convolution method is presented to obtain the reservoir pressure. This new method gives better results than both the Horner and modified Horner methods. A new formula also is presented to determine the vertical permeability for partially penetrated wells.
Temperature Profiles in Underground Combustion
Authors: Baker P.E. 
Published: December 2007

Introduction
In this paper, approximate analytical expressions are derived for the temperature profile developed in the underground combustion method of oil recovery. A qualitative description of the process may be found in a paper by Tadema. The flame front is regarded as a moving source with a constant rate of heat generation. Heat transfer is by conduction and convection.
Previous publications, of which a few are cited here, have also attacked this problem and have presented solutions pertaining to different methods of approximating or idealizing the process studied. The present paper also treats an idealized case: linear flow is assumed for heat and fluids, and vaporization and condensation effects are neglected. The results obtained are similar to those derived by Bailey and Larkin, but are obtained by an entirely different procedure. The method used here should give considerably greater insight into the physics of the in situ combustion process.
Four types of cases are considered, distinguished by thermal and fluid-flow properties of the system. A constant rate of heat generation and constant rate of flame-front advance are assumed. Flamefront temperature is determined for each case using a heat balance which involves the entire temperature profile. The applicability of the different solutions to real systems is discussed after they are all presented. Again, this is done for the purpose of understanding better the physics of the process. Consideration of the nonapplicable solutions and of the reasons for their not applying is significant. In a paper by Cooperman, the only case solved is one considered here as not applicable.
Well-Test Analysis for Solution-Gas-Drive Reservoirs: Part 1—Determination of Relative and Absolute Permeabilities
Authors: Serra Kelsen V. , Peres Alvaro M. M. , Reynolds Albert C. 
Published: December 2007

SummaryFor transient radial flow to a well producing a solution-gas-drive reservoir, it is shown that estimates of effective phase permeabilities as functions of pressure can be obtained directly from the measured flowing wellbore pressure and the flow rates. Rough estimates of effective permeabilities as functions of oil saturation also can be obtained. It is also shown that a semilog plot of pressure squared vs. time can be used to estimate effective permeabilities and the skin factor.
Study of the Potential for an Off-Bottom Dynamic Kill of a Gas Well Having an Underground Blowout
Authors: Gillespie John D. , Morgan Richard F. , Perkins Thomas K. 
Published: December 2007

Summary
This paper reports on an analysis that links expected reservoir performance with wellbore hydraulics. The dynamics of counterflow of the kill fluid and gas below the kill string can play a significant role in the expected behavior during a dynamic kill. The design concepts and techniques presented should be applicable to any well that requires the kill string to be run or snubbed into the well or one in which the string is a significant distance off bottom at the time of a blowout and cannot be lowered to bottom.
Visualization of Xanthan Flood Behavior in Core Samples by Means of X-Ray Tomography
Authors: Hove A. O. , Nilsen Victor , Leknes Jørgen 
Published: December 2007

Summary
This paper presents examples of xanthan corefloods visualized by X-ray tomography. Water and aqueous xanthan solutions are distinguished from each other by addition of sodium iodide (NaI) at different concentrations. One reservoir sandstone and one outcrop (Rosbrae) sandstone core samples were used. The reservoir sample was naturally divided into two longitudinal zones differing in permeability by about 20-fold. The Rosbrae sample was homogeneous, with a permeability of 450 md. Miscible xanthan/water displacement tests were performed on both plugs. Immiscible displacement of light refined oil by xanthan was performed on the homogeneous sample.
Effects of CO2 Flooding on Wave Velocities in Rocks With Hydrocarbons
Authors: Wang Zhijing , Nur Amos M. 
Published: December 2007

Summary
Compressional- and shear-wave velocities were measured in the laboratory in seven sandstones (porosities ranging from 6 to 29%) and one unconsolidated sand (37% porosity) saturated with n-hexadecane (C16H34) both before and after CO2 flooding. CO2 flooding decreased compressional-wave velocities significantly, while shear-wave velocities were less affected. The magnitude of these effects was found to depend on confining and pore pressures, temperature, and porosities of the rocks. The experimental results and theoretical analysis show that the decreases in compressional-wave velocities caused by CO2 flooding may be seismically resolvable in situ. Therefore, seismic—especially high-frequency, high-resolution seismic—methods may be useful in mapping and locating CO2 zones, tracking movements of CO2 fronts, and monitoring flooding processes in reservoirs undergoing CO2 flooding.
Assessment of a Vertical Hydrocarbon Miscible Flood in the Westpem Nisku D Reef
Authors: Da Sle W. J. , Guo D. S. 
Published: December 2007

Summary
In 1981, a vertical hydrocarbon miscible flood was implemented in the Westpem Nisku D pool, one of 40 isolated carbonate pinnacle reefs in a trend located west of Edmonton, Alta., Canada. A solvent composed of methane and 15% ethane-plus components was injected into the reservoir, which is maintained at a pressure of about 4, 800 psig [33 MPa]. Positive indications of the location of the solvent/oil interface have been obtained from interface logging [pulsed-neutron-capture (PNC) logs] in a producing wellbore and from special analysis of core from an infill well recently drilled into the pool. Two types of chromatographic analysis of residual oil and a conventional core residual oil determination were done. The results show that the flood is gravity stable and has excellent volumetric conformance. The special core analysis provided information on the quantity and composition of residual oil saturation (ROS) in the miscibly swept zone. On the basis of these flood performance data, an estimate of ultimate recovery has been prepared.
Laboratory Measurements of CO2-Foam Mobility
Authors: Lee Hae Ok , Heller John P. 
Published: December 2007

SummaryMobility control of high-pressure CO2 floods by use of foam is a promising oil recovery technique. Critical information for the use of CO2 foam as a thickened displacement fluid is the ratio of the combined CO2/surfactant-solution flow rate to the pressure drop in the swept region. This foam mobility can be measured in laboratory experiments. In this work, a high-pressure apparatus was designed and carefully calibrated to measure foam mobilities at various flow rates. These measurements were made during simultaneous flow of the dense CO2 and surfactant solutions through core samples. Dependence of CO2-foam mobility on several variables was observed. The effect of aqueous surfactant concentration on CO2-foam mobility was explored thoroughly. The dependence in this case was such that foam mobility decreased steadily as surfactant concentration increased until a minimum mobility was attained at some particular concentration well above the conventional critical micelle concentration (CMC). The effect of foam volume fraction showed that mobility decreases with increasing fraction of surfactant solution. Also, it was found that the relative mobility (mobility divided by rock permeability) of CO2 foam was higher in Rock Creek sandstone than in Berea sandstone. Shear-thinning behavior was observed under some conditions in our experimental range of total flow rate.
Miscible Displacement: Recovery Tests With Nitrogen
Authors: Glasø Olstein 
Published: December 2007

Summary
High-pressure slim-tube tests and phase-behavior studies were performed with reservoir fluid and three-component hydrocarbon mixtures. The amount of methane and intermediates in the reservoir fluid were varied while other parameters that affect the oil recovery were kept constant. The effects of displacement velocity, temperature, and length of the packed column on slim-tube recovery were also investigated. The results obtained show that the amount of methane and intermediates in the reservoir fluid has a significant effect on minimum miscibility pressure (MMP). The results suggest very strongly that a reservoir fluid with a low methane content needs a long path length to develop miscibility with N2 (a large fraction of the oil is bypassed in the first part of the column). The slim-tube oil recovery, and hence the average microscopic displacement efficiency of the process, is shown to increase significantly with slim-tube length when injection pressure and other variables are kept constant. The results from simulation tests of phase behavior and fluid flow in the slim tube confirmed some of the conclusions made from the experimental results obtained in this work. An N2 MMP correlation was developed from displacement test data reported in the literature and in the present study.
An In-Situ Combustion Reservoir Simulator With a New Representation of Chemical Reactions
Authors: Le Thiez Pierre A. , Lemonnier Patrick A. 
Published: December 2007

Summary
Numerical simulation of in-situ combustion processes poses numerical problems related to the representation of chemical reactions in the burning zone. This paper presents a new approach to the description of the combustion front. The fully implicit thermal compositional model developed to simulate oil recovery by wet or dry forward combustion is formulated to handle three dimensions, three phases, gravity and capillary forces, heat transfer by convection and conduction within the reservoir, and conductive heat loss to adjacent strata. Two options are available. The first includes four components and one fuel combustion reaction. The second allows any number of components and several reactions. The first option emphasizes description of the combustion front with a new formulation that uses a heat-release curve to improve numerical stability and to give accurate temperature distribution with large gridblocks. The paper compares different representations of chemical reactions and includes results of a sensitivity study on the mesh size. Thermal-balance considerations are given for wet or dry combustion to provide calculated values of the peak temperature and steam-plateau characteristics. The thermal-balance results agree well with those predicted by the numerical model.
Analyzing Aquifers Associated With Gas Reservoirs Using AlF's and Type Curves
Authors: Targac Gary W. , Wattenbarger R. A. , Startzman R. A. 
Published: December 2007

Summary
An aquifer-influence function (AIF) can be calculated from a gas reservoir's production and pressure histories. The AIF is unique for an aquifer and can be analyzed to determine aquifer size and other information. Two AIF type curves were developed for aquifers with partially sealing faults and then applied to 32 U.S. gulf coast gas reservoirs.
Light-Oil Steamflooding: A Laboratory Study
Authors: Sarathi Partha S. , Roark S. Doug , Stryker Arden R. 
Published: December 2007

Summary
Experiments were conducted in a 2D elemental model to determine the response of light crudes to steam injection and to verify reported numerical simulation results. The results showed that light-oil steamfloods are typified by an early production response to steam injection and that recovery efficiencies are strongly influenced by the chemical nature of the crude. The data also indicated that gravity override of steam remains a potential problem in light-oil steamflooding and that as much as 65% of oil in place (OIP) can be recovered economically by steamflooding light oils.
The Effects of Shear History on the Gelation of Polyacrylamide/Chromium(VI)/Thiourea Solutions
Authors: Bhaskar Ravi K. , Stinson Jeffrey A. , Willhite G. Paul , Thiele John L. 
Published: December 2007

SummaryThe influence of shearing during gelation on the gelation rate of a polyacrylamide/chromium(VI)/thiourea solution was studied. Gelations were carried out under steady-state shear, oscillatory shear, and programmed shear. When shear rate was constant throughout the experiment, gels formed more slowly at high than at low shear rates. This behavior is opposite to that observed with polyacrylamide/chromium(VI)/bisulfite solutions, where increased shear rates led to faster gelations. The gelation mechanism is believed to involve at least two chemical reaction steps: reduction of chromium(VI) to chromium(III) followed by crosslinking of the polymer by chromium(III). in gelation with bisulfite as the reducing agent, chromium(III) is generated rapidly, and the rate-determining step (which may be polymer-diffiision controlled) is probably the crosslinking of polymer by chromium(III). in contrast, chromium(III) is generated relatively slowly in gelation with thiourea as the reducing agent, and the rate-determining step appears to be the redox reaction.The conclusion that the rate of gelation and strength of the gel formed for the gelation of Polyacrylamide by chromium(III) are strongly influenced by the total shear history of the solution has important implications for design of field applications of gelled polymers in EOR. The evaluation of gel characteristics in quiescent botfle tests, a common practice, may not be sufficient to determine whether a gel of the desired strength can be obtained in situ because all gelling solutions must be subjected to considerable shearing during injection.
Application of Geological Modeling and Reservoir Simulation to the West Saertu Area of the Daqing Oil Field
Authors: Abib Osmar , Moretti F. J. , Mel Cen , Yuzhe Yang 
Published: December 2007

Summary
An integrated geological and engineering study was conducted for a representative section of the Saertu and Putaohua reservoirs in the West Saertu area of Daqing, the largest oil field in the People's Republic of China. This paper discusses various aspects of the study related to reservoir geology, field development, geological and reservoir simulation modeling, production history matching, and reservoir performance predictions. Geological and reservoir simulation models developed during this study are being used routinely in Daqing as part of a plan to improve reservoir management of the West Saertu portion of the field.
Estimating Skin Decline and Relative Permeabilities from Cleanup Effects in Well-Test Data With Buckley-Leverett Methods
Authors: Larsen Leif , Kviljo Knut , Litlehamar Terje 
Published: December 2007

Summary
This paper examines relationships between backflow of water from the invaded zone and changes in skin owing to reduced water saturation and the associated change in mobility for homogeneous reservoirs. Effects studied are governed by initial saturation profiles, relative permeabilities of water and the produced reservoir fluid, basic reservoir and fluid parameters, and the producing rate. Buckley-Leverett-type displacement is assumed in the skin zone, and production and skin-zone data needed to determine relative permeability characteristics by extensions of standard techniques are given. Methods to determine such characteristics by matching observed and computed skin-decline data are also presented.
An Experimental Study of Non-Newtonian Polymer Rheology Effects on Oil Recovery and Injectivity
Authors: Gleasure Richard W. , Phillips Colin R. 
Published: December 2007

Summary
Pseudoplastic non-Newtonian polymer solutions were examined for their enhanced oil recovery performance. Detailed results are reported for xanthan gum (XAN), Kelzan XCD™, and a viscoelastic polyethylene oxide (PEO), Polyox OF-50™. Increases in the power-law coefficient resulted in improved displacement efficiency. Effects were also observed in the injectivity-index parameter results.
Successful Application of Drilling Technology Extends Directional Capability
Authors: Schroeter D. R. , Chan H. W. 
Published: December 2007

Summary
This paper presents an operational overview of the application of measurement-while-drilling (MWD) directional equipment, polycrystalline-diamond-compact (PDC) bits, a top-drive drilling system (TDS), and low-toxicity oil-based-mud (LTOBM) technology for cost reductions in the drilling of long-reach directional wells in the South China Sea offshore Malaysia. Guidelines are provided for improved hole cleaning, for monitoring oil mud properties, and for drillstem tripping practices to minimize hole problems and costly stuck-pipe incidents.
Tubing-Conveyed Perforating: Operating Experience
Authors: Bowler G. V. , Suparman Dadang 
Published: December 2007

Summary
In 1981, Huffco Indonesia, a production-sharing contractor to Pertamina, was the first company in Indonesia to use tubing-conveyed perforating (TCP) in its well completions. This paper draws conclusions on the benefits of using a TCP technique over wireline perforating techniques. Of the 75 TCP jobs done, less than 10% can be considered failures. The results achieved with various amounts of underbalance are compared with published results. TCP is considered the most effective perforating technique currently available.
A Slug-Length Distribution Law for Multiphase Transportation Systems
Authors: Bernicot M. F. , Drouffe J.-M. 
Published: December 2007

Summary
A probabilistic approach is used to analyze the formation of slugs in nearly horizontal pipelines. Knowledge of the probability amplitude for a liquid bridge in the formation zone allows derivation of the slug-length distribution law. The method is suitable for simulating complex situations, including unsteady flows. For horizontal steady flows, a simple model of this probability, expected to be valid in large-diameter pipes or for long slugs (tail of the distribution), yields a Gaussian law, which is distinct from the log-normal law. Frequency, mean length, and variance depend on only one parameter, which may be predicted from theoretical study (not included here). This new length distribution law is verified against experimental data obtained with an air/water test loop (42 mm in diameter and 400 m long) installed in the Beauplan production laboratory in France and is compared with the log-normal distribution law.
Steam-Soak Performance in South Oman
Authors: Rice S. A. 
Published: December 2007

Summary
With about 2 × 109 stock-tank m3 [12.6 × 109 STB] of medium/heavy oil originally in place (OOIP) in south Oman, considerable scope exists for increasing oil recovery by thermal methods. The viability of thermal recovery in south Oman was tested with a steamflood pilot in the Al Khlata sands of the Marmul field and a 2-year steam-soak project to test the applicability of steam soak in five south Oman oil fields producing heavy oil. This paper describes the performance of the latter project. The wells selected for the test program included a wide range of south Oman reservoir and oil characteristics—i.e., the main reservoir drive mechanisms of depletion, solution-gas, and edge- and bottomwater drive, the reservoir sandbody types, and oil viscosities from 80 to 4000 mPa·s [80 to 4, 000 cp]. Steam-soak operations were successful, and oil production accelerated significantly, with an average stimulated production rate twice that before stimulation. Acceleration was less marked in wells where reservoir energy is limited or where the primary (cold) water cut is more than 30%. At primary (cold) water cuts &gt;50%, no increase in oil production rate was observed. The process was simulated numerically for several wells, with the results in close agreement with performance. Improved understanding of the process resulting from the simulation allowed the most important factors influencing performance to be identified and aided process optimization in the field test. Two small-scale steam-soak projects currently are being assessed for implementation in the early 1990's.