bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hoop-Stress Loading - A New Method of Determining the Tensile Strength of Rock
Authors: Hardy H. Reginald , Jayaraman Natesa I. 
Published: December 2007

Abstract
Although it is well known that rock commonly fails in tension under numerous field conditions, a satisfactory standard procedure for determination of the tensile strength of such materials has not as yet been established. With suitable precautions, direct-pull tests may be used; however, precise specimen preparation and extremely uniform and concentric loading must be utilized if meaningful results are to be obtained using this method. Recently, the authors completed a 3-year study in which a variety of methods for determining tensile strength were evaluated. One method, involving the hoop-stress loading of thick-walled hollow cylinders, was found to be particularly attractive. This paper describes the theory, apparatus, and test technique associated with this method.
In evaluating this new technique a number of specimens of Barre granite, Lauders and Indiana limestone, and Berea and Tennessee sandstone were tested. Reproducibility for each rock type was fund to be excellent, with the percentage standard deviation ranging from a maximum of 10.9 percent for Lauders limestone down to 0.9 percent for Berea sandstone. Values of tensile strength determined from hoop-stress tests were found to correspond closely to those determined by direct pull, provided the former were analyzed in terms of pull, provided the former were analyzed in terms of an equation based on a suitable elastic-plastic analysis. Under these conditions the ratio of hoop-stress to direct-pull tensile strength values ranged from 0.86 to 1.10 for the five rocks tested. Although studies on additional rock types are required, it appears that the hoop-stress loading method would be a strong candidate as a standard test for determination of the tensile strength of rock.

Introduction
Although it is well known that tensile stresses play an important role in the behavior of underground play an important role in the behavior of underground openings associated with petroleum, natural gas and mining operations, suitable techniques for the determination of the tensile strength of rock are limited.
Comparison of Methods for Analyzing a Water Drive Field, Torchlight Ten Sleep Reservoir, Wyoming
Authors: Stewart F.M. , Callaway F.H. , Gladfelter R.E. 
Published: December 2007

Abstract
In this paper oil initially in place is calculated by the various methods commonly used for analysis of water drive fields using data available as time progresses. Rate and pressure are predicted by means of the same methods using data available at the end of two years' history. These predictions are then compared with subsequent performance permitting an evaluation of the methods, which are Modified Schilthuis, Simplified Hurst, van Everdingen et al (1952), and the Electric Analyzer.

Introduction
Several variations of the material balance equation, differing in the term used to evaluate water influx, are in common use for estimating oil in place, predicting rate and volume of water influx, and forecasting producing rates and reservoir pressure in water drive reservoirs. The electric analyzer with an electrical network set up to simulate the oil reservoir and aquifer and their contained fluids may be used for the same purpose.
Examples of the application of one or another of these methods have appeared in the literature. The accuracy and reliability of the material balance for calculating oil in place have been covered. However, there have been few articles in which more than one method has been applied to an actual field allowing a comparison. It is felt that a field example, simple in nature, where the Modified Schilthuis, Simplified Hurst, van Everdingen et al (1952), and the Electric Analyzer have been applied would be of benefit in providing an evaluation of these methods as to their comparative usefulness and reliability in calculating initial oil in place and predicting performance.
Hindcasting Hurricane Waves in the Gulf of Mexico
Authors: Patterson M. M. 
Published: December 2007

Abstract
An estimate of wave heights is needed for risk and venture analysis, for platform design, and for operational planning. Very little reliable data on hurricane waves have been available for a number of years. The present hindcast system uses a moving, two-dimensional wind field to generates and propagate waves to a location of interest. The propagate waves to a location of interest. The wind-wave model is based on work reported in the literature by Wilson. Wave Program I uses a synoptic wind field based on measurements or observations. Wave Program II generates its own wind field based on the track, the time history of the radius to maximum Winds, and the barometric pressure of the storm. Wave Program III also pressure of the storm. Wave Program III also generates its own wind fields, but the storm is moved along a predetermined path. The results of all three hindcast methods have been compared with data gathered from Hurricane Carla. Other hurricanes have also been studied and each of the programs gives comparable results.

Introduction
The most critical environmental factor in deepwater platform design is the selection of wave heights to which the platform will be subjected. Regardless of the design theory, wave loading contributes a major portion of the environmental force on a deep-water platform. To date there has been little sound historical evidence of the magnitude of wave heights that could occur in the Gulf of Mexico. To overcome this problem the offshore oil industry has sought an answer by two related methods. The first method consists of several measuring programs to gather both wave force and wave height information. Since reliable measuring techniques have existed for only a short time, the second method consists of developing techniques to predict historical waves that probably occurred in the Gulf of Mexico. The purpose of this paper is to document Shell's efforts in hindcasting paper is to document Shell's efforts in hindcasting waves for hurricanes that have passed through the Gulf since 1900. In order to hindcast waves, it was necessary to find a mathematical simulation model that would generate waves from a moving wind field. Such wind fields may be taken from synoptic charts or developed from empirical equations based on hurricane data such as radius to maximum winds, central pressure, and forward speed.
A Study of Suction and Scouring of Bottom-Sitting Offshore Structures
Authors: Ninomiya Katsuya , Tagaya Kozo , Murase Yoshihide 
Published: December 2007

Two sources of difficulty with offshore submersible structures are suction and scour. It seems reasonable to suppose that the shape of the structure will influence the effect of these forces and the degree of damage they will inflict. Suction-breaker and scour tests have been conducted on models of five different shapes, and the results are presented here.

Introduction
When a submersible offshore structure sits on the soft, cohesive soil of the sea bed, it penetrates deeply into the soil. When the structure is freed from the bottom, a great suction force is created that not only makes the freeing operation difficult, but also can wreck or capsize the structure.
If the foundation soil is sandy, tidal currents or waves may cause scour around the legs of the structure, causing it to turn over, or may cause great local stress upon the structural members. The purposes of this investigation were to study the characteristics of suction and scouring, to develop an efficient suction breaker, and to examine a preventive method against scouring. Suction and scouring were investigated in an experimental tank, and the practical application of the suction breaker was field tested using a large model in the sea.

Laboratory Suction-Breaker Test Models and Testing Soil
To study the characteristics of suction and the effectiveness of a suction breaker, we designed and manufactured five types of small models (Fig. 1) made of steel and coated with paint, and having a bottom area of 219 sq ft.
Sea silt taken from the bed of Hiroshima Bay was reconsolidated and used as the testing soil. First the silt was agitated with water in a holding tank. Then a sheet of canvas was laid over the surface of the silt, and it was weighted down by perforated steel plates for 1 week. The pressure was approximately plates for 1 week. The pressure was approximately 1.5 psi. According to a Vane shear test, the mean cohesion of this soil was as follows.
Cohesion of the soil applied to the suction test:
C = 0.56 psi.
Cohesion of soil applied to the suction-breaker test:
C = 0.53 pk

Method of Testing
Suction Test. After the model penetrated the soil about 8 in. by means of loading, it was unloaded and leg alone for about 5 minutes. Then it was pulled up at a rate of 0.08 in./min; the pulling pulled up at a rate of 0.08 in./min; the pulling force was continuously measured by a tension meter the displacement gauge was read by a displacement gauge every 5 seconds.
Suction-Breaker Test. After the model had been sunk into the soil by means of loading as shown in Fig. 2, it was pulled up. When it had been pulled up about 0.8 in. (that is, when the contact pressure under the weight of the model was about zero), pressurized water was jetted by the pumping of the suction breaker until the model was completely pulled out. Items measured were the pulling force, the displacement, the pressure, and the flow rate of the pump.
JPT
P. 279
Relative Permeability Measurements Using Reservoir Fluids
Authors: Mungan Necmettin 
Published: December 2007

Abstract
Water-oil relative permeabilities measured using reservoir fluids and fresh, preserved cores are shown to differ considerably from those obtained routinely using relined fluids and extracted cores. Upon saturating the extracted cores with the reservoir fluids and allowing them to come to equilibrium, in this case for 6 days, the original relative permeability curves were reestablished.

Introduction
Ordinarily, relative permeabilities are measured using refined fluids and restored-state cores. On occasion, fresh core samples that had been flushed with a refined oil, without any other cleaning or extraction, have been used. To date, no relative permeability measurements have been reported permeability measurements have been reported using reservoir fluids and fresh preserved cores, although a number of published studies have dealt with the influence of core handling and other laboratory experimental factors on results of displacement tests. This is not surprising. Special procedures have to be followed for obtaining, procedures have to be followed for obtaining, preserving, and handling native-state cores; and preserving, and handling native-state cores; and companies are generally reluctant to permit any procedures that may increase the expense or the procedures that may increase the expense or the time required to complete a well. Consequently, suitable cores often are simply not available. Furthermore, only a very few of the petroleum production research laboratories have the facilities production research laboratories have the facilities for measuring interfacial tension, contact angle and relative permeabilities at the elevated temperatures and pressures normally encountered in reservoirs.
The following study provides, for the first time, relative permeability data obtained with fresh, preserved cores and reservoir fluids at reservoir preserved cores and reservoir fluids at reservoir pressure and temperature. Measurements were also pressure and temperature. Measurements were also made routinely with refined fluids and extracted cores to afford comparisons. Advancing and receding contact angles were measured as a function of time with the actual reservoir fluids on a solid surface representative of the reservoir rock to characterize the wetting equilibrium during the tests. Finally, a procedure was devised which, for the extracted procedure was devised which, for the extracted cores, yielded the original set of relative permeability curves. permeability curves.
Mathematical Simulation of Polymer Flooding in Complex Reservoirs
Authors: Bondor P.L. , Hirasaki G.J. , Tham M.J. 
Published: December 2007

Abstract
Simulation of polymer flooding in many complex reservoirs has requirements that preclude the use of either three-phase stream tube or two-phase finite-difference simulators. The development of a polymer flooding model used in a three-phase, polymer flooding model used in a three-phase, four-component, compressible, finite-difference reservoir simulator that allows the simulation of a variety of complex situations is discussed.
The polymer model represents the polymer solution as a fourth component that is included in the aqueous phase and is fully miscible with it. Adsorption of polymer is represented, as is both (1) the resulting permeability reduction of the aqueous phase and (2) the resulting lag of the polymer injection front and generation of a stripped polymer injection front and generation of a stripped water bank. The effects of fingering between the water and polymer are taken into account using an empirical "mixing parameter" model.
The resulting simulator is capable of modeling reservoirs with nonuniform dip, multiple zones, desaturated zones, gravity segregation, and irregular well spacing and reservoir shape.
Two examples are presented. The first illustrates the polymer flooding of a multizone dipping reservoir with a desaturated zone due to gravity drainage. The second illustrates the flooding of a reservoir with a gas cap and an oil rim with polymer injection near the oil-water contact. In this example, the effects of nonuniform dip, irregular well spacing and field shape, and gravity segregation of the flow are all taken into account. The two examples presented illustrate the versatility of the simulator presented illustrate the versatility of the simulator and its applicability to a wide range of problems.

Introduction
The design of a polymer flood for a complex reservoir requires a model that represents the reservoir features that have a significant effect on the performance of the flood. These features may include the presence of a gas cap or a desaturated zone due to gravity drainage in a dipping formation, the presence of an aquifer, irregular well spacing and reservoir boundaries, multiple zones, reservoir heterogeneities, and a well performance that is limited by state proration, injectivity, and productivity. These reservoir features are being productivity. These reservoir features are being represented by most compressible, three-phase, three-dimensional simulators. However, to model polymer flood projects, it is necessary to include a polymer flood projects, it is necessary to include a conservation equation for the polymer, and to represent the adsorption of polymer, the reduction of be rock permeability to the aqueous phase after contact with the polymer, the dispersion of the polymer slug, and the non-Newtonian flow behavior polymer slug, and the non-Newtonian flow behavior of the polymer solution.
A Rapid Accurate Unsteady-State Klinkenberg Permeameter
Authors: Jones Stanley C. 
Published: December 2007

Abstract
A simple, unsteady-state apparatus and appropriate theory have been developed for measuring the Klinkenberg permeability, Klinkenberg slip factor, and Forchheimer turbulence factor of core plugs. The technique is last and accurate and bas replaced nearly all steady-state gas permeability determinations made in our laboratory. The theory of operation, capabilities and limitations of the apparatus are discussed. New data are presented for more than 100 cores, correlating slip and turbulence factor vs permeability.

Introduction
Permeability is usually measured with air at mean pressures just above 1 atm. This steady-state determination is rapid, but it can lead to serious errors. For example, the low-pressure air permeability of tight core often differs from its permeability of tight core often differs from its permeability to liquid or high-pressure gas by 30 permeability to liquid or high-pressure gas by 30 to 100 percent or more. Correction factors (Klinkenberg slip factors) from correlations are available, but still, the corrected, low-pressure measurement can exhibit considerable error.
These errors are avoided by determining gas permeabilities at two or three mean pressures such permeabilities at two or three mean pressures such as 25, 50 and 100 psi, and then extrapolating to infinite pressure to obtain the equivalent liquid or Klinkenberg permeability. This method is generally reliable, but has two drawbacks it requires tedious rate measurements with a soap bubbler or other device, and the back-pressured flow system requires several minutes to reach steady state. Typical throughputs are 8 to 12 cores per day.
The desire to estimate accurately the injectivity into secondary and tertiary oil recovery prospects and to find the deliverability of very tight gas reservoirs has created a growing demand for reliable Klinkenberg permeability determinations in our laboratory. This demand made clear the need for a more rapid, yet accurate permeameter. On the premise that pressure measurements are made more premise that pressure measurements are made more conveniently and accurately than rate determinations, we developed a permeameter in which both rate and pressure drop across a core can be derived from pressure drop across a core can be derived from pressure measurements alone. The resulting pressure measurements alone. The resulting unsteady-state instrument is fast and accurate.
Transient permeability techniques have been discussed and other unsteady-state permeameters have been built and reported, but to our knowledge the instrument described herein is the only practical one for routine measurement of Klinkenberg permeability that does not require an empirical permeability that does not require an empirical correlation using cores of known permeability to construct calibration curves. It is also the only one from which Klinkenberg permeability, Klinkenberg slip factor and Forchheimer turbulence factor can be determined from a single run.
On Determining the Continuous Phase in Microemulsions
Authors: Dreher K.D. , Sydansk R.D. 
Published: December 2007

In light of recent advances in the use of micellar solutions (microemulsions) in oil recovery and well stimulation, it has become important to define accurately the physical properties of these systems. One aspect of such work is to distinguish between the disperse phase and the continuous phase, particularly at extreme concentrations of either water or hydrocarbon. Conventional techniques for making this distinction include the dye solubility method, the phase dilution method, the conductivity method, and the fluorescence method. However, a single test may give ambiguous results. We shall present here viscosity, conductivity, and miscibility data for a series of micellar solutions that are comparable in composition with those applied in the field.
Example 1 shows data obtained with a micellar solution prepared with a 420 equivalent weight (eq. wt.) petroleum sulfonate (of our own manufacture) to which was added 1-pentanol to produce a single-phase, optically clear system. Both conductivity and miscibility data indicate phase inversion between 2.2 and 2.3 volume percent 1-pentanol. Further, the data show that the inversion was from oil-external to water-external as the amount of 1-pentanol in the system increased. Continued addition of this cosurfactant (2.6 volume percent) led to separation of an aqueous phase. percent) led to separation of an aqueous phase. This observation is similar to those made by Winsor and Bowcott and Schulman, in that a system with the characteristics of a water-external micellar solution can exist in equilibrium with excess aqueous phase. Most of the brine had been expelled from the micellar solution, at 3 volume percent 1-pentanol. At this point, the conductivity decreased markedly; and the point, the conductivity decreased markedly; and the remaining micellar solution became miscible with hydrocarbon.
Example 2 shows data obtained with the same petroleum sulfonate and cosurfactant. However, in petroleum sulfonate and cosurfactant. However, in this case the micellar solution contained 70 weight percent brine as opposed to 30 weight percent of percent brine as opposed to 30 weight percent of Example 1. No evidence of phase inversion is present over the single-phase region, and both conductivity and miscibility data indicate a water-external system.
Example 3 shows the results obtained with a micellar solution prepared with a 470 equivalent weight petroleum sulfonate (commercially available).
Relative Permeabilities From Displacement Experiments With Full Account for Capillary Pressure
Authors: Helset H. M. , Nordtvedt J. E. , Skjœveland S. M. , Virnovsky G. A. 
Published: December 2007

Summary
Relative permeabilities are important characteristics of multiphase flow in porous media. Displacement experiments for relative permeabilities are frequently interpreted by the Johnson-BosslerNaumann method neglecting capillary pressure. The experiments are therefore conducted at high flooding rates, which tend to be much higher than those experienced during reservoir exploitation. Another disadvantage is that the relative permeabilities only can be determined for the usually small saturation interval outside the shock. We present a method to interpret displacement experiments with the capillary pressure included, using in-situ measurements of saturations and phase pressures. The experiments can then be run at low flow rates, and relative permeabilities can be determined for all saturations. The method is demonstrated by using simulated input data.
Challenges With Jointed-Pipe Underbalanced Operations
Authors: Saponja Jeff 
Published: December 2007

Summary
Successful underbalanced operations demand a systematic approach with integration of engineering, operations, production, reservoir, and geology. There are significant advantages to under-balanced drilling (UD). Formation damage can be minimized if proper circulating fluids and operating parameters are chosen; there is an opportunity for reservoir evaluation and characterization while drilling; lost circulation and differential sticking can be avoided, combined with improvements in drilling rate of penetration (ROP); and it also provides an alternative method of well control.
This paper discusses engineering challenges and considerations for underbalanced operations using multiphase flow as well as advances made during UD with rotary jointed pipe. Excluding air, mist, and foam, underbalanced techniques with multiphase fluids are reviewed. Much of the discussion and concepts also apply to coiled-tubing underbalanced operations.