bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oil Spill Contingency Planning in the North Sea
Authors: Daniels J.T. 
Published: December 2007

The North Sea is one of the world's important commercial fishing areas; yet the introduction in the early 1970's of oil-producing operations into the North Sea has not been hampered by particularly restrictive legislation or critical public opinion. If anything, the public and their governments have welcomed the oil public and their governments have welcomed the oil industry to their respective countries. The happy situation that prevails in the North Sea area has not been achieved without a great deal of effort by the oil companies and the governments; the way in which this effort was organized and directed forms the basis of this article.

Work of the North Sea Offshore Operating Committee
While the first plans for offshore oil production were still being drawn up, and the majority of oil fields in the North Sea were in the discovery phase, the industry, through the various North Sea country offshore operating committees, was setting up committees to study the problems associated with oil production in the marine environment. The first work of these committees was to accept the fact - one that is still not accepted universally - that oil spills were possible from the offshore oil fields and to study feasible methods of cleaning up an oil spill. This was done by first reviewing the published data and house reports of the classic oil spills such as that from the Torrey Canyon and the spill in the Santa Barbara Channel. From analysis of these spills it became evident that any plan or method would have to cover a wide range of individual company management structures or be extremely restrictive on any specific company's management. Accordingly, the groups restricted their studies to equipment and methods of cleaning up oil spills and gave only general advice on how individual company plans could be drafted to suit the available jointly owned equipment. All the conventional methods of cleanup were evaluated and it was decided that the only one that could be relied upon to be effective was dispersing the oil with chemical dispersants. (The North Sea groups are striving to develop methods that will pick up oil in the hostile North Sea, and are giving advice to operators and governments regarding improved operating practices that will minimize spillage.) Generally speaking, no mechanical equipment available today can collect or retain oil in seas that exceed 10-ft wave height. Therefore, the present plans of nearly all the North Sea Offshore Operating Committees are based on using oil-dispersing chemicals. The chemicals to be used were selected after consultation with, and on the recommendation of, the national government laboratories who were undertaking large-scale tests of dispersants. On successfully obtaining suitable supplies of approved dispersant, the next step was to decide on methods of application.
P. 1153
Analysis of Naturally Fractured Reservoirs From Sonic and Resistivity Logs
Authors: Aguilera Roberto 
Published: December 2007

This study was an effort to find a reliable means of detecting and analyzing fractured systems from logs. It appears from the cases considered that the porosity exponent m is an adequate criterion to detect such a system and that the parameter P, a function of formation resistivity and sonic velocity, provides a reliable means of distinguishing the hydrocarbon-bearing zones.

Introduction
Detection and evaluation of naturally fractured reservoirs is becoming more important every day. This investigation was undertaken to try to find a reliable means of detecting and evaluating fractured systems from sonic and resistivity logs. A theoretical model developed for detection purposes indicates that for such systems the porosity exponent m (commonly referred to as cementation factor) should be relatively small, ranging between 1.1 and 1.3. This criterion has been successfully used in recognizing natural fractures in different wells of the Altamont trend. (It must be pointed out that the method is limited to gross sections where a statistically significant number of zones is available, some of which are 100 percent water saturated and fractured.) For evaluation purposes a previously defined parameter, P, has been used. This parameter is a parameter, P, has been used. This parameter is a function of formation resistivity and sonic velocity. By determining the mean value of P at a water saturation of 100 percent, it is possible to evaluate the resistivity index, I, for hydrocarbon zones, and hence values of water saturation. This technique has also been used in wells of the Altamont trend. For illustration, analyses of a commercial well and of a noncommercial well are presented.

Theory
The idealized model considered in this study is presented in Fig. 1. It is similar to the one presented by Warren and Root to analyze pressure behavior in fractured reservoirs and to the one presented by Towle to study the relationship between formation resistivity factor and porosity. In this model it was assumed that the spacing between parallelpipeds represented the fractures. This assumption does not appear to be unreasonable. Since porosity is defined as the ratio of the void space in a porosity is defined as the ratio of the void space in a rock to the bulk volume of that rock, porosity could be expressed for the case of this model as(1)= 1 - X 3
where
= porosity, fraction, X = length of the block, fraction.
The resistance of each block is given by the equation(2)r = RL/A,
where
R = resistivity L = length of current path A = cross-sectional area of the current path.
As defined by Archiel the formation factor is given by(3)F = Ro/Rw,
JPT
P. 1233
A Simple Method for Determining Well Pressure in Closed Rectangular Reservoirs
Authors: Cobb William M. , Dentist Walter L. 
Published: December 2007

In 1968, Earlougher et al., introduced a "buildingblock" concept, using a constart-rate well producing from the center of a closed square, to generate solutions for pressure behavior in several rectangular systems. Tables of the dimensionless pressure drop function for the square system are presented in Ref. 1, along with illustrations of the technique. Their procedure, while a step toward reducing laborious procedure, while a step toward reducing laborious computations, can sometimes be quite tedious. This note describes a further simplification for obtaining dimensionless pressures for these other rectangular systems at the producing well; other points within these systems are not considered. Conveniently, Earlougher et al. have tabulated the Matthews-Brons-Hazebroek pressure correction function, PDMBH, for 16 closed rectangular systems. These correction functions provide the basis from which the dimensionless wellbore pressure drop functions can easily be obtained. In a recent comprehensive review of pressure buildup analysis, it was shown thatwhereSolving Eq. 1 for pD yieldsIt is clear from Eq. 5 that pD is a function of pDMBH, tDA, and A/rw2. Thus, given pDMBH and A/rw2 for a particular system, pD as a function of tDA can be particular system, pD as a function of tDA can be calculated directly. Columns 2 and 3 of Table 1 present the pD and pDMBH data of Ref. 1 for the case of a well in the pDMBH data of Ref. 1 for the case of a well in the center of a square with it value for A/rw of 2,000. The pD data tabulated in Column 4 are obtained by direct substitution of tDA and pDMBH of Columns 1 and 3, respectively, into Eq. 5. As can be seen, the solutions in Columns 2 and 4 are identical. For dimensionless times less than those given in Table 1, pD can be obtained from pD can be obtained fromFor times greater than those given in Table 1, pD can be obtained bywhere CA is the reservoir shape factor, and is be Euler constant - approximately 1.7811.
P. 1305
Effect of Gas Slip on Unsteady Flow of Gas Through Porous Media - Experimental Verification
Authors: Wallick G.C. , Aronofsky J.S. 
Published: December 2007

Abstract
This paper presents an experimental verification of numerical solutions of the differential equation describing the transient flow of an ideal gas through a porous material including gas slip effects. Several experiments previously proposed by one of the authors are described together with the correlation of the experimental results with the numerical solutions. Excellent agreement is shown between experiment and theory, thus demonstrating the validity of both the basic assumption made in the derivation of the differential equation and of the numerical solutions of the differential equation.

Introduction
In a recent paper, one of the authors has discussed a numerical solution of the differential equation describing the unsteady flow of an ideal gas through a porous material. This paper was primarily concerned with the effect of gas slip on the flow behavior. In steady state measurements, Klinkenberg and others have observed that the apparent gas permeability of a porous material may be expressed as a linear function of the reciprocal average pressure of the form,
(Equation 1)
where the intercept is a constant for a given porous material and the slope is a constant for a given porous material-gas combination.
A number of numerical solutions of the resultant differential equation were presented and specific flow experiments were proposed as a means of testing the numerical solutions. The purpose of the present paper is to describe the results of several of these experiments and the correlation of the experimental data with the results of the numerical analysis. Reference should be made to the previous paper for details of the mathematical and numerical analysis.
Flash Calculations as Performed on the IBM Card Programmed Calculator
Authors: Organick Elliott I. , Meyer Henry I. 
Published: December 2007

Abstract
One of the fundamental and perhaps most tedious of all calculations in petroleum engineering has been the so-called "flash calculation." High speed computing machines have been playing an increasingly important role in the oil industry, and it is natural that one of our first job assignments for these machines would be to relieve the engineer by performing flash calculations for him.
One of the machines currently available which is particularly suitable for this work is the International Business Machines Corp. Card Programmed Calculator, or CPC. Two CPC procedures developed for flash calculations are reported. In each case the machine is made to print a composite, compact, and accurate record of the entire calculation (see Figs. 1 and 2).
The first procedure, or program, is applicable primarily for separator calculations. This program may be used conveniently and efficiently in calculating optimum separator pressures and temperatures in single and in series staging of well effluent feed streams of up to 11 components. Machine time is four minutes per stage. The second program is designed primarily for reservoir flash calculations at elevated pressures or for process calculations at very low temperatures where the equilibrium constants vary significantly with the composition of the feed stream. This latter method will handle mixtures containing up to in 20 components in seven minutes of machine time.

Introduction
During the past three years there has been generated an enormous interest among engineers and scientists regarding the application of high speed digital computers to the solution of problems of research and industry. Computer manufacturers have managed to keep pace with this interest by developing machines capable of handling economically the most prodigious of calculations conceived by would-be customers. In general. however, these machines, announced by more than 15 manufacturers, are not yet generally available and will not be for at least another year.
Combustion-Drive Tests
Authors: Showalter W.E. 
Published: December 2007

SHOWALTER, W.E., UNION OIL CO. OF CALIFORNIA, BREA, CALIF.

Abstract
This paper discusses some of the results of combustion-drive tests which were made in a test cell using a sand bed 10 in. in diameter × 10-ft long. The test method is illustrated and described.The relationship between the API gravity of the in situ oil and the amount of air required for combustion drive is discussed n detail. Other things constant, the air requirement for combustion drive increases as the API gravity of the in situ oil decreases. If the test results apply to actual reservoirs, the lowest-priced oils may cost the most to recover by this method.Information is shown which indicates that the effect of pressure on the amount of hydrocarbon burned is not large. A method of predicting air requirements from the API gravity of the in situ oil is presented.

Introduction
Combustion drive is the term used to identify the process of interstitial or in situ burning as an oil recovery method. Part of the in situ oil is burned to generate the energy needed to produce the remainder of the oil. Combustion drive as an oil recovery mechanism remains an economic uncertainty in spite of all the work that has been done by the industry in both laboratory and field. This paper will show some of the results of tests which were made in a test cell for the purpose of studying the nature of the combustion-drive process. It will present data which indicate that the API gravity of the in situ oil is a significant indicator of the amount of air required to drive a burning front through oil sand. Air requirement varies inversely as the API gravity of the in situ oil.

EXPERIMENTAL
The tests were performed in a cell which utilized a cylindrical sand section 10 in. in diameter × 10-ft long. The thin-walled metal pipe which held the sand was wound with twenty external electrical resistance heaters which, by means of an automatic controller, maintained adjacent sections of the wall of the pipe at temperatures equal to the temperatures of the contained sand. Each heater covered 6 linear in. of the pipe. By this means lateral heat loss from the sand section was minimized, thereby causing the sand section to simulate more closely a horizontal increment of a combustion-drive reservoir.Fig. 1 shows a schematic diagram of the test assembly.Thermocouplestomeasurethetemperature in the sand were located every 6 in. along the length of the sand section. The pipe containing the sand was enclosed in a cell designed for an operating pressure of 500 psig. The inlet air pressure was controlled at the inlet, and the gas flow rate was controlled and measured at the outlet of the cell.The oil sand used for the tests was prepared by mixing first water and then oil with the non-consolidated sand using a closed mixer similar to a cement mixer. Table 1 shows a screen analysis of the sand. Ninety percent of the sand was 100 mesh or finer. This sand was a mixture of 80 per cent No. 120 Nevada White Sand and 20 per cent Tennessee Hi-Fusion Moulding Sand No. 3. The Nevada sand was a clean silica sand.
SPEJ
P. 53^
Estimating the Coefficient of Inertial Resistance in Fluid Flow Through Porous Media
Authors: Geertsma J. 
Published: December 2007

Abstract
The object of this paper is to introduce an empirical, time-honored relationship between inertia coefficient - frequently misnamed "turbulence factor" - permeability, and porosity, based on a combination of experimental data, dimensional analysis, and other physical considerations. The formula can be used effectively for, among other things, the preliminary evaluation of the number of wells in a new gas field and the spacing between them.

Introduction
It has long been recognized that Darcy's law for single-phase fluid flow through porous media,Equation 1
in which ?=superficial velocity
µ=fluid viscosity
k=formation permeability
p=pressure head,
is approximately correct only in a specific flow regime where the velocity ? is low. Single-phase fluid flow in reservoir rocks is often characterized by conditions in favor of this linearized flow law, but important exceptions do occur. They are in particular related to the surroundings of wells producing at high flow rates such as gas wells.
For the prediction or analysis of the production behavior of such wells it is necessary to apply a more general nonlinear flow law. The appropriate formula was given in 1901 by Forchheimer1; it readsEquation 2
in which ?=density
a=coefficient of viscous flow resistance 1/k
ß=coefficient of inertial flow resistance.
This equation indicates that in single-phase fluid flow through a porous medium two forces counteract the external force simultaneously - namely, viscous and inertial forces - the latter continuously gaining importance as the velocity ? increases. For low flow rates the viscous term dominates, whereas for high flow rates the inertia term does. The upper limit of practical applicability of Darcy's law can best be specified by some "critical value" orf the dimensionless ratio.Equation 3
which has a close resemblance to the Reynolds number. Observe that ß/a has the dimension of a length.

Inertia and Turbulence
As the Reynolds number is commonly used as an indicator for either laminar or turbulent flow conditions, the coefficient ß is often referred to as the turbulence coefficient. However, the phenomenon we are interested in has nothing to do with turbulence. The flow regime of concern is usually fully laminar. The observed departure from Darcy's law is the result of convective accelerations and decelerations of the fluid particles on their way through the pore space. Within the flow range normally experienced in oil and gas reservoirs, including the well's surroundings, energy losses caused by actual turbulence can be safely ignored.
Determination of In-Situ Mobility and Wellbore Impairment From Polymer Injectivity Data (includes associated papers 6412 and 6413 and 6414 and 6415)
Authors: Tinker G.E. , Bowman R.W. , Pope G.A. 
Published: December 2007

Polymer injection and filtration field tests being carried out inthe East Coalinga field have been used to determine the degree ofin-situ mobility control and to furnish measurements and determine the nature of wellbore impairment. These tests also have been usedto develop criteria for describing solution quality using polyacrylamideand two grades of biopolymer.

Introduction
Water and polymer field-injection tests are beingconducted to furnish data for a planned pilot projectin the Temblor Zone II reservoir in the East Coalingafield, Calif. The pilot project will evaluate therelative merits of polymer flooding and waterflooding.A waterflood would have an unfavorable mobility ratioof 14.0, but this could be reduced to 1.5 with polymerflooding. Fig. 1 is an index map of the Coalinga fieldshowing the pilot project area.To choose the most suitable polymer for this project, it was necessary to determine the injection characteristicsof both polyacrylamide polymer and biopolymers. Theinjection field tests were supported by field filtrationtests and laboratory studies to define polymer viscosityand filtration properties. The field tests consistedof injecting both polymer solutions and pure water atdifferent times for periods of weeks to generate comparison data for polymer and water for determining thedegree of in-situ mobility control and possible wellboreimpairment.

Polyacrylamide Injectivity Test
Polyacrylamide polymer (Pusher 700) was originallyselected for field testing at the Coalinga field because, at the time of the test, more was known about thispolymer. To achieve maximum mobility control usingpolyacrylamide, and because it was readily available, afresh-water (300-ppm NACI) source was developed forthe project. This water caused severe wellbore damage (20-fold decrease in permeability) from clay swellingand dispersion during initial water-injection testing;therefore, the test well was chemically treated with theDarley treatment to prevent this damage.The properties of the unconsolidated sand and thefluids involved with the tests are as follows:
Property Hx Sand Jv Sand Dept, ft 1,660 1,750Thickness ft 8 17Permeability, md 470 230water at Sor, md 165 80Porosity 0.28 0.28Oil gravity, deg.API 20 20 20Reservoirtemperature, deg.F 100 100Oil viscosityat reservoirtemperature, cp 25.0 25.0Water viscosityat reservoirtemperature, cp 0.64 0.64
The injection system for the polyacrylamide testwas carefully designed to prevent mechanical shear oroxygen degradation of the polymer at the surface. Fig.2 is a plot of water and polymer injectivity vs cumulative injection.
JPT
P. 586^
High Strength Granular Sealing Material Increases Efficiency of Primary Cementing and Squeeze Cementing
Authors: Einarsen Charles A. 
Published: December 2007

Abstract
The use of high strength granular materials in cement slurries has proved beneficial for cementing casing and squeeze cementing operations in Permian in Basin oil and gas wells. The addition of 1 to 4 lb of ground walnut shells to each sack of cement made possible successful high column cementing jobs in fields where high fill-ups normally cannot be obtained because of lost circulation. In squeeze cementing operations the number of cementing stages required for shutting off water was reduced by the addition of walnut shells to the last 50 per cent of the volume of cement slurry.

Introduction
The high hydrostatic head, created in the annulus when cementing casing, frequently is the cause of loss of slurry into weak formations or formations containing fractures or vugs. Common precautions taken to reduce this loss are reducing the density of the slurry adding effective sealing agents to the slurry, or both. One phase of this paper concerns the use of high strength granular sealing materials in cement slurry to seal openings into formations so that the slurry may be pumped to the desired level behind the casing. In squeeze cementing operations neat cement often fails to effect a complete seal because of the tendency of the slurry to enter only the weakest zones. This is indicated by the number of stages frequently required to stop the flow of water or gas. The intrusion of cement slurry into each perforation in a water or gas producing zone is probably necessary to eliminate flow completely, and a high final squeeze pressure may be a means of assuring entry of cement into each perforation or zone of weakness. The second phase of this paper concerns the use of high strength granular materials in cement slurries to obtain a high final squeeze pressure.