bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow of Viscoelastic Fluids Through Porous Media
Authors: Gaitonde Narendranath Y. , Middleman Stanley 
Published: December 2007

This paper was prepared for the Society of Petroleum Engineers Symposium on Mechanics of Rheologically Complex Fluids, to be held in Houston, Tex., Dec. 15–16, 1966. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Introduction
This communication presents an extension of an earlier study by Christopher and Middleman of the applicability of a non-Newtonian generalization of the Blake-Kozeny equation to the laminar flow of non-Newtonian polymer solutions through porous media. The earlier work, done with dilute aqueous solutions of carboxymethylcellulose, indicated that the model put forth correlated data with an average error of 18 per cent and a standard deviation of the friction factor of 0.21 over a range of three orders of magnitude in a modified Reynolds number.
A survey of the literature available at that time indicated some evidence of viscoelastic effects, in contrast with the conclusions drawn by Christopher and Middleman it was decided to extend the earlier study by examining a more elastic fluid, polyisobutylene dissolved in toluene. In addition, data were obtained for tubes packed with sand, and for tubes packed with binary mixtures of glass spheres. We still fail to see viscoelastic effects.
The basic experimental techniques, and the methods of reducing and correlating the data, are as described by Christopher and Middleman and in more detail by Christopher and by Gaitonde. Polyisobutylene [PIB L-100, Enjay Co.] solutions in toluene were run at 25.0 deg C. Power-law parameters were obtained from capillary viscometry performed over a range of shear rates corresponding to the shear rates achieved in the porous medium. Table 1 shows the solution properties, including the zero-shear viscosities of the solutions and the viscosity average molecular weight of PIB L-100.

CORRELATION OF DATA
Fig. 1 shows the friction factor-Reynolds number correlation of the data obtained using tubes packed with glass spheres of a narrow size range. The data are correlated with an average error of 9.8, per cent and a standard deviation of 0.14 by
........................................(1)
where
........................................(2)
and
........................................(3)
Restructuring for Long-Term Survival
Authors: Hassell R. L. 
Published: December 2007

Abstract
The past ten years in the energy business have tended to be typical of the industry--cyclical--with periods of great optimism followed by years of even greater pessimism. The true nature of our industry has never been more evident nor the opportunities for success or failure greater.
During ten years, we have seen a very active period of industrial restructuring throughout the United States: from automobiles and airlines to steel, banking and farming. The bankruptcies, consolidations, joint-ventures, mergers and hostile takeovers seem to be in the headlines daily.
We in the energy industry have experienced all of this and more as the problems/opportunities this last decade have brought many to their knees. But now there is, according to some, "a light at the end of the tunnel," "price stability" and "guarded optimism." Surely, we are now on the road to recovery, aren't we?
The Role of Natural Gas in the European Gas Market and East-West Energy Trade
Authors: D'Andrea L. A. 
Published: December 2007

Abstract
The importance of energy for economic growth and regional co-operation has held a promiment role in the activities pursued by the Economic Commission for Europe (ECE). The ECE was created by the United Nations in 1947 for the purpose of promoting co-operation and strengthening relations among member countries, with varying economic and political systems, in virtually every economic activity.
Over the years, the Energy Division of the ECE has been intimately involved in analyzing and evaluating energy developments and markets in the ECE region; and in serving the needs of member governments in their endeavour to promote regional co-operation. In the context of east-west relations, energy trade has played a prominent role in the economic interchange that has prevailed in the recent decades, and natural gas has become an increasingly important fuel commodity in the development of trade relations across most member states, and in trade relations between east and west. Drawing upon the experience and knowledge available in the ECE Energy Division in these matters, this paper provides an insight on the importance attached to natural gas in the energy markets of Europe, and the reliance placed on gas trade to sustain increased demand for natural gas in European gas markets.
The ECE consists of thirty-four member countries (Table 1), of western and eastern Europe, including the USSR, Canada and the United States. Unless otherwise noted, reference to Europe in this paper excludes North America.
Superpressured Gas Reservoirs: Case Studies and a Generalized Tank Model
Authors: Prasad R. K. , Rogers L. A. 
Published: December 2007

Abstract
Pressure decline data from 21 superpressured gas reservoirs in the Gulf Coast were reviewed to determine the characteristic slopes of the P/Z (pressure divided by the gas non-ideality factor) vs. cumulative production plots. Twelve of the reservoirs were substantially depleted. The data were fit with one or two straight lines which would indicate a change in the reservoir pressure support mechanism. The slopes of the plots were reviewed in particular to determine whether the apparent compressibility at reservoir pressures above the hydrostatic level was different than the apparent compressibility below the hydrostatic level, as proposed by Hammerlindl and others. Only four of the plots could reasonably be fit by two straight lines which indicated that the rock compressibility correction factor proposed by Hammerlind1 and others, that changes at the hydrostatic pressure point is not general and the method cannot be used indiscriminately.
To better identify the factors that cause downward curving P/Z plots the gas law equation for a gas/aquifer reservoir was rewritten in a generalized form with additional coefficients included the fluid and rock compressibility changes with pressure and gas exsolving from solution. The P/Z plot calculated by the generalized model departs from a straight line, and curves downwards depending on the compressibilities and aquifer size. The generalized equation, with appropriate expressions for the non-ideal factors, can be solved analytically or with numerical computer methods to fit both the shape and position of the decline data. An example fit, using both the two straight line method and the generalized tank model, to a reservoir with a curving P/Z plot is given.
Inert Gas in Tønder Aquifer Storage: A Complete Preliminary Computer Study
Authors: Labaune F. , Knudsen J. E. 
Published: December 2007

ABSTRACT
Inert gas may be injected into underground gas storages as a part of the cushion gas, and thus provide significant reduction of the project cost. This is being considered for the Tønder aquifer gas storage project in Denmark. Two alternative strategies have been investigated, central or peripheral injection of the inert gas.
The 3-D studies were split into two 2-D stages, in order to reduce the simulation costs. In the first stage, the horizontal distribution of the natural gas and of the inert gas was computed on an XY model of the Tønder structure. For the second stage, that part of the model where most of the mixing occured was selected, and its parameters defined for the XZ simulation.
From this study, a strategy was defined for the following step of the project, involving technical choices. The paper concludes with a discussion of these next steps planned for implementing the inert gas technology at the Tønder storage.
Expansion of a Successful In-Situ Combustion Pilot in the Midway Sunset Field
Authors: Williams R. L. , Jones J. A. , Counihan T. M. 
Published: December 2007

ABSTRACT
This study focuses on Santa Fe Energy's operating and monitoring experience of the expansion of a successful fireflood pilot in the Midway-Sunset Field1. The pilot had run for eight years, while the expanded project has been in various stages of operation since 1982. This study will review the rationale behind the facility installation and the various, unanticipated start-up problems that were encountered. A detailed discussion of the remedies for injector and producer damage, as well as our experience with bottomhole temperature, gas analysis, production and injection monitoring systems will be presented. The positive cash flow and project economics through 1986 are encouraging and effectively summarize Santa Fe Energy's efforts in fireflood technology to date.
Self-Powered Pumps for Watered-Out Trapped Gas
Authors: Elliott G. R. B. , Yates T. M. , Yates D. , McDaniel M. , Houseman B. L. , Elliott R. D. 
Published: December 2007

ABSTRACT
The high-pressure gas in underground reservoirs can be used to provide the energy to pump brine underground and away from a well, thereby preventing premature watering out of water-drive gas wells. Use of such work has been demonstrated with modified 5-in turbine pumps acting as motors in an above-ground 500-gallon system. Such pumping work can also be used in secondary recovery of petroleum and in recovery of dissolved or hydrated natural gas.
A Novel Approach to Flow Control for Chemical Injection and Continuous Sampling
Authors: Shelton M. S. 
Published: December 2007

ABSTRACT
Multilocation injection of a single chemical has historically been accomplished by the use of multihead or small, pneumatic positive displacement pumps. Certain expense-incurring problems exist with these systems. A new approach to chemical injection reduces the number of metering pumps required for multilocation injection and associated installation, operation and maintenance expenses.
Characteristics of Metal-Polymer Interactions in Fracturing Fluid Systems
Authors: Kramer J. , Prud'homme R. K. , Norman L. R. , Sandy J. M. 
Published: December 2007

ABSTRACT
A series of model derivatized guar polymer samples were crosslinked with three different metal-ion crosslinkers in order to better understand the complex chemical reactions involved in producing fracturing fluid gels. The gels were studied using steady shear viscosity and dynamic oscillatory measurements. Dynamic oscillatory measurements are often more sensitive probes of the structure of crosslinked gels than are steady shear viscosity measurements and, therefore, both viscosity and dynamic oscillatory measurements are needed to fully characterize fracturing fluids. We present examples of fluids with nearly identical viscosities but different moduli-- indicating different network structures in the gel. The gels considered represent commonly used fracturing fluids such as titanate crosslinked hydroxypropyl guar (HPG), titanate crosslinked carboxymethyl hydroxypropyl guar (CMHPG), and aluminum crosslinked CMHPG. The effect of molar substitution of hydroxypropyl groups (MS level) on HPG crosslinked with two titanate crosslinkers is presented. The effects of MS and degree of substitution of carboxyl groups (DS level) changes for CMHPG gels crosslinked with titanates and aluminum ions are also presented.
An explanation of the mechanism involved in titanate crosslinking is offered from evidence gathered from NMR and dynamic light scattering experiments.
Recompletion Workover Program at the Kuparuk River Field
Authors: Woodling G. S. 
Published: December 2007

ABSTRACT
An aggressive workover program was undertaken from 1984 to 1987 at the Kuparuk River field on the North Slope of Alaska to recomplete older single completions with the more versatile selective single design. The two oil producing horizons ("C" and "A" Sands) have contrasting reservoir properties which complicate reservoir management. The recompletion allowed fracture stimulation of the "A" Sand which was easily damaged during drilling. In addition, selective zone management in each production or injection well maximized reserves development under waterflood and gas reinjection.
Eighty-six (86) of the field's 529 wells (16%) have been recompleted since 1984 at a total cost of $68 million (1987 dollars). This case history summarizes oil rate benefits and workover cost trends for use in future evaluation of remaining Kuparuk workovers. An economic evaluation approach for justifying injection workovers in a limited-capital environment is also included.
A Combination Gas Field Development Model Evaluated with Field Data
Authors: El-Feky S. A. 
Published: December 2007

ABSTRACT
For a gas field a close relationship exists between the production and marketing phases. Accordingly, the design of an optimum development plan for a natural gas field always depends on the field parameters, such as total natural gas reserves, the individual well productivity, the dependence of production rates on the equipment capacity and the state of depletion of the reservoir, and the gas sales contract. To maintain total field output at the required gas sales contract level, additional infill wells are drilled.
This paper presents a model for abnormally pressured gas-condensate reservoirs that can predict the delivery rates from individual wells to meet a gas sales contract, set the completion schedule for additional infill wells, and determine the requirements for compression facilities.
The model combines certain facets of previously published ones in a manner that required development and use of some new and some little-known relationships. Analytical methods for calculating gas compressibility factor, dew-point pressure, volume percent liquid formed during retrograde condensation, and other gas properties have been included.
The volumetrically calculated original gas-in-place was allocated between wells based on their production histories. Individual well deliverability was evaluated using a semi-steady state quadratic flow equation with the real gas pseudopressure function. The loss in productivity sustained by producing wells due to condensate accumulation around the well-bore, change of permeability with pressure, and the effect of pressure on formation compressibility have been considered.
Performance matching for individual wells in one of the Middle East gas fields has demonstrated that the resulting approach, which was designed for computer solution, is as accurate as the necessary available data will permit.
Laboratory Measurements Relevant to Two-Phase Flow in a Tight Gas Sand Matrix
Authors: Chowdiah P. 
Published: December 2007

ABSTRACT
True drainage measurements of specific water permeability, gas entry pressure, critical gas saturation and effective gas permeability at in-situ stress conditions have been conducted on several tight sandstones, mostly from the Mesaverde formation. The results have been used to develop some general rules useful in making meaningful estimates of both drainage and imbibition relative permeability curves for use in reservoir simulation.
A Correlation for the Increase in Gas Gravity During Pressure Depletion of a Dissolved Gas/Oil Reservoir
Authors: Ostermann R. D. , Qadeer S. , Dehshani K. 
Published: December 2007

ABSTRACT
A correlation is presented to predict the increase in solution gas gravity experienced during pressure depletion in solution gas drive reservoirs. Correlations are also presented for predicting the change in CO2 and N2 content of dissolved gas during depletion. The application of these correlations to standard PVT correlations is demonstrated.
Modeling the Performance of Fractured Wells in Pattern Floods Using Orthogonal, Curvilinear Grids
Authors: Fleming G. C. 
Published: December 2007

ABSTRACT
Previous investigators have used orthogonal, curvilinear grids to simulate oil recovery processes in repeated well patterns. These grids are radial in the vicinity of the wells, allowing accurate resolution of the near well region. This paper extends the applicability of curvilinear grids to include patterns with vertically fractured wells, where elliptical coordinates provide better representation of fluid flow near the fracture. Appropriate curvilinear coordinate systems are obtained from an analytic solution for steady, unit mobility displacements. This solution encompasses a variety of pattern geometries, including fractured five and nine spots, line drives, staggered line drives and single wells. The analytic potential for unfractured wells in these patterns is available in the literature, while the extension to fractured wells is developed in this work. Unit mobility flow rates and areal sweep out in fractured well patterns can be easily obtained from the analytic solution. Examples are given for line drives and staggered line drives, for different fracture lengths and pattern aspect ratios.
Pore volumes and transmissibilities are calculated from the analytic potential, and are incorporated into a thermal reservoir simulator. Excellent agreement is demonstrated in comparing the curvilinear formulation with Cartesian grids for a miscible displacement at a mobility ratio of 40 in a five spot pattern, and a steamflood in an inverted nine spot pattern. The fracture formulation is verified against published numerical solutions for the performance of finite conductivity, vertically fractured wells in single-layer reservoirs. Fewer grid blocks are required by the curvilinear grid to obtain the same accuracy as a Cartesian grid.
The main advantage of using a curvilinear model lies in the ability to accurately describe flow around the well, while simultaneously modeling the flow at a distance. Several applications have been chosen to demonstrate this capability. An adverse mobility, miscible line drive between fractured wells demonstrates that the large fluid flux near the injection well fracture tip has a strong influence on areal sweep. This is also shown in a steamflood between horizontal wells, where curvilinear and Cartesian grids predict significantly different recoveries. Finally, a waterflood in an inverted nine spot pattern, shows the importance of accurately modeling fractured injection wells.
Selection of a Hospital Cogeneration System
Authors: Miller G. S. , Branson M. W. 
Published: December 2007

ABSTRACT
Stable natural gas prices and increasing power costs are making gas fired cogeneration systems economically attractive to hospitals. This paper presents analytical methods for preliminary evaluation of the economic feasibility of a proposed cogeneration plant. Equations are developed which permit rapid estimation of: generator size, cogenerated power cost, economic payback, additional hospital gas consumption due to cogeneration, and cogeneration cycle efficiency.
The Effect of Changes in Pricing and Other Economic Factors on Estimates of Gross Reserves
Authors: Letendre S. B. , Wright D. R. 
Published: December 2007

ABSTRACT
Oil and gas reserves are projected based upon a number of fluctuating variables such as operating conditions (including curtailments), product prices, operating costs, and production trends. Most of these factors have a direct relationship to the future net revenues and payout times. However, the corresponding effect of changes in these parameters on the gross reserves is quite often buried beneath the surface of associated changes in future revenues. Even though the estimates of gross reserves that could be recovered may not change for a particular well, the economic gross reserves and associated future revenues could change dramatically due to economic and/or operating conditions. An increase, or decrease, in pricing and/or operating costs can alter the volume of oil or gas reserves which are reported. When reserves reports are prepared, it is necessary that the oil and gas producer understands the relationship between gross reserves and economic gross reserves as presented herein. The purpose of this paper is to further investigate and define the effect that changes in economic factors, especially pricing, have on the calculation of economic gross reserves. Three typical Appalachian Basin reservoirs (Clinton, Big Lime, and shallow oil productive sand) are used in this paper to depict the effects of changes in economic conditions. Variations in operating conditions such as curtailments are also briefly addressed to examine associated changes in future revenues and payout times.
Application of Nodal Analysis in Appalachian Gas Wells
Authors: Frear R. M. , Yu J. P. , Blair J. R. 
Published: December 2007

Abstract
Many small independent operators are currently using a cookbook style of production operation and performance evaluation. The result reduces the opportunity of producing at the well's top performance which will curtail the current revenues. A promising innovative Nodal analysis technique is being applied to two Appalachian gas wells using a microcomputer. The objective of this paper is to present the optimization studies and their effects on production operations.
Wade #2 well was drilled and completed in 1985 in Harrison County, West Virginia. The well was hydraulically fractured in 3 zones, Benson, Balltown, and Speechley and the stimulation seems to be working well. A 2-3/8 inch tubing string was run to a depth of 4774 feet. The well was loading with fluid and producing at a diminishing rate. It is suspected that oil is being produced in the upper zone which causes damage in the lower zones (gas zones). If the oil is isolated from the other zones, the gas will not have enough pressure to produce by itself. The Nodal analysis suggests that the well's production will be improved if an intermittent gas lift "rabbit" is installed for the production stream. The well will then be producing efficiently in different zones.
Pratt #1 well was drilled and completed in late 1985 in Lewis County, West Virginia. The well was stimulated in two zones, Balltown and Speechley, with hydraulic fracturing. Since the engineer believed the well could be a better well from the logging data, a deep penetration stimulation was conducted on this well. Unfortunately, the well started producing water, and the oil and gas rates dropped because the fracture had gone into the water zone in the neighboring area. If a casing log is run in order to find out the exact location of the water zone, the well needs to be cement squeezed, reperforated and re-stimulated in the new zone. However, this method would be very costly. The Nodal analysis was applied for this well. Clean-up and stimulation will be necessary to remove the wax and formation damage. Again, an intermittent gas lift is recommended to replace the sucker-rod pump. With all these recommended changes, the well will be producing at its optimized rate. In addition, both wells' new designs will have an economic advantage over the old design without excessive extra cost.