bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abrasion Technology for Electric Submergible Pumps
Authors: King D. G. , Traylor F. T. , Stewart R. E. 
Published: December 2007

ABSTRACT
This paper describes the results of a five-year investigation of sand abrasion phenomena in conventional electrical submergible pumps (ESP). The investigation includes a review of the available literature on two body and three body wear processes in the presence of corrosive fluids, and the development of laboratory test methods from which baseline wear rates for conventional pumps can be established. These baseline wear rates are compared with performance data on pumps incorporating special wear resistant features. Preliminary field test results are also presented.
Compression of Wet CO2 in Reciprocating Compressors
Authors: Tanneberger F. J. , Feldmann J. L. 
Published: December 2007

Abstract
Compressing gaseous carbon dioxide (CO2) with a reciprocating compressor creates a potential for operational problems and inefficient performance. Ingersoll- Rand's (I–R) experience with compressing CO2, both in the field and in a closed test loop, has resulted in a number of recommendations for CO2 reciprocating compressor applications.
Simulation of Miscible Displacement Using Mixed Methods and a Modified Method of Characteristics
Authors: Ewing R. E. , Russell T. F. , Wheeler M. F. 
Published: December 2007

ABSTRACT
Numerical dispersion and grid orientation problems with adverse mobility ratios are two of the major difficulties in the numerical simulation of enhanced recovery processes. An efficient method for modeling convection-dominated flows which greatly reduces numerical dispersion and grid orientation problems is presented and applied to miscible displacement in a porous medium. The base method utilizes characteristic flow directions to model convection and finite elements to treat the diffusion and dispersion. The characteristic approach also minimizes certain overshoot difficulties which accompany many finite element methods for problems with sharp fluid interfaces. The truncation error caused by the characteristic time-stepping technique is small, so large stable time-steps can be taken as in fully-implicit methods without the corresponding loss in accuracy. A finite difference analogue can also be formulated.
Since the computed fluid velocities help to determine the time-stepping procedure in the characteristic-based method and since accurate velocities are crucial in the method's ability to conserve mass, very accurate Darcy velocities are necessary. A mixed finite element method solves for the pressure and the Darcy velocity simultaneously, as a system of first order partial differential equations. By solving for u = −(k/µ)Vp as one term, we minimize the difficulties occurring in standard methods caused by differentiation or differencing of p and multiplying by rough coefficients k/µ.
Using a combination of characteristic-based time-stepping procedures and mixed methods for accurate velocities, a variety of problems with variable (or random) permeabilities, adverse mobility ratios, and tensor dispersion models are examined. A study of viscous fingering is presented. Computational results on a variety of two-dimensional problems show minimal grid-orientation effects, reduced numerical dispersion, minimal overshoot at the front, and very low mass balance errors.
A Nine-Point Finite Difference Operator for Reduction of the Grid Orientation Effect
Authors: Shah P. C. 
Published: December 2007

ABSTRACT
The grid orientation effect is a long-standing problem plaguing reservoir simulators that employ finite difference schemes for solution. The nine-point finite difference scheme is a well known way of reducing this effect. The schemes available in the literature are applicable only to point distributed grid systems. However, most simulators used in practice employ block centered grid systems. In this report we present a derivation of a new nine-point scheme for the block centered grid systems. The derivation is based on physical consideration and hence is free from any problems such as asymmetry or negativity of interblock transmissibilities that arise in some published schemes. The scheme is applicable to nonuniform rectangular grids and to reservoirs with inhomogeneous permeability distributions; both isotropic and anisotropic cases are treated. The expressions resulting from the new scheme reduce to those published in the literature when a square uniform grid and homogeneous isotropic permeability are considered. The reduction in the grid orientation effect due to the new scheme is illustrated by a study of the steam-flood process in a five-spot pattern.
Fieldwide Simulation of the Anschutz Ranch East Nitrogen Injection Project With a Generalized Compositional Model
Authors: Wendschlag D. D. , Stephenson R. E. , Clark T. J. 
Published: December 2007

ABSTRACT
Anschutz Ranch East is a major rich gas condensate field located in the Western Overthrust Belt on the Wyoming-Utah border. The plan-of-depletion for the field involves injection of nitrogen to maintain reservoir pressure above the dew point of the in-place fluid.
Reservoir simulators were an essential tool in development of the Anschutz Ranch East plan of depletion. The fluid complexity dictated that a compositional simulator be employed which uses an equation of state. The preliminary simulation work was performed using a symmetry element, since data were initially very limited. As additional data became available, simulation efforts were directed towards modeling the entire field.
This paper discusses both the fieldwide and symmetry element simulations. The symmetry element approach was found to be adequate for comparison of various depletion schemes. Its limitations when extrapolating performance to the full field were identified. The performance of fieldwide simulations requiring up to 3.75 million words of storage was found to be efficient on scalar hardware.
A Comprehensive Well Management Program for Black Oil Reservoir Simulation
Authors: Wijesinghe A. M. , Leventhal S. H. , Mukherjee Hemanta , Laskey K. J. , Culham W. E. 
Published: December 2007

ABSTRACT
A comprehensive well management program developed for use with current state-of-the-art black oil simulators during the prediction phase of reservoir performance studies, is presented. The reservoir is modelled as a hierarchical system possessing field, group, and well levels of control at which production and injection specifications and constraints can be imposed. The program enables wellhead rate changes, shut-in and reopening of wells, workovers, stimulations, artificial lift, and the drilling of new wells to be executed automatically to maintain production and injection levels. It also has the capability to automatically maintain the average reservoir pressure within specified limits through injection and production rate changes. This program incorporates a high degree of functional logic and many new concepts, strategies, and options not reported previously in the literature.
In this paper, the logical structure of the program, its optional features, and the strategies employed at different levels of control to meet the reservoir management objectives are described and are illustrated through specific numerical examples.
A Reservoir Simulation Model With Platform Production/Injection Constraints for Development Planning of Volatile Oil Reservoirs
Authors: Wallace D. J. , van Spronsen Engel 
Published: December 2007

SUMMARY
The development planning of offshore oilfields, such as in the British North Sea sector, involves a variety of platform production/injection constraints. The operation of the platforms is governed by reservoir engeering, operational and production policy considerations. This paper describes the production/injection control system as incorporated into a volatile oil reservoir simulator for use as a field management tool.
Production and injection operations are controlled at three levels in an offshore oilfield: At the individual well level in which rates, well inflow performance, pressure constraints and well bore hydraulics play a role.At the platform level in which well rates have to be controlled within available capacities (oil/gas/water production, gas/water injection).At the field level in which total fluid production from the field is governed by pipeline/tanker capacity, allowing shortfall to be taken up by platforms operating with spare capacity.
To meet gas sales contracts and/or flaring constraints use is made of gas wells operating in a dual injection and production role ("gas-control wells").
Such gas-control wells enable surplus gas production to be reinjected or alternatively gas to be produced to meet a gas sales contract.
The paper further describes the possibilities of the well management package to implement a policy of voidage replacement or pressure maintenance in distinct reservoir partitions (zones). Pressure maintenance is defined as maintaining the hydrocarbon pore volume averaged pressure at datum. Such strategies interact with the total available injection capacity of the platforms and/or the distribution of capacity usage over the platforms.
Iterative Methods for the Solution of Linear Equations Based on Incomplete Block Factorization of the Matrix
Authors: Meyerink J. A. 
Published: December 2007

ABSTRACT
This paper presents a class of iterative methods for the solution of linear equations like those that arise in reservoir simulators. The methods are generalisations of the incomplete LU-factorisation technique introduced earlier.
It can be applied to equations generated by the usual 5- and 7-point finite difference approximations as well as to those generated by special 9-, 11-, 19-and 27-points approximations.
Application of the method to equations where the band structure of the matrix has been spoiled, e.g. by wells that are perforated in more gridblocks or by an irregular gridblock structure, is discussed and modifications for running efficiently on vector processors are given.
Numerical examples for well-known testproblems are presented and compared with results of other methods.
Incomplete Gaussian Elimination as a Preconditioning for Generalized Conjugate Gradient Acceleration
Authors: Wallis J. R. 
Published: December 2007

ABSTRACT
This paper discusses the application of preconditioned generalized conjugate gradient acceleration to fully implicit thermal simulation. The preconditioning step utilizes incomplete Gaussian elimination (IGE) to form an approximate factorization of the Jacobian matrix.
The implementation allows any finite difference approximationany grid block orderingassociated well constraint equationsany level of incomplete factorizationreduced system preconditioningconstrained residual preconditioning
Acceleration procedures include ORTHOMINORTHORES
IGE preconditioning and its implementation is discussed with respect to five, seven, nine or eleven-point finite difference approximations and optional well constraint equations. Numerical results were obtained using a thermal model allowing any number Nc of components. The model's implicit formulation requires the solution of a linear system of equations in which each grid block has Nc + 1 unknowns. Test problems involved combustion, steam drive and cyclic steam stimulation processes, some of which exhibited ill-conditioning, negative transmissabilities and high transmissability ratios. Numerical results indicate how different grid block orderings, different levels of incomplete factorization and different acceleration procedures affect convergence, storage and work requirements.
An Extension of Pseudofunction Concepts
Authors: Thomas G. W. 
Published: December 2007

ABSTRACT
In this work, we examine various pseudo function concepts that have appeared in the technical literature Emphasis is devoted to gravity-segregated vertical equilibrium (VE)4 and a dynamic pseudo function concept that requires no assumptions regarding the state of fluids in a reservoir. We extend the gravity-segregated VE concept to a system of N stratified layers and show that, in reality, the Hearn technique11 is a special case of this. We also relate it to previous work by Coats et al4 and van Poolen, et al10.
The dynamic pseudo function approach we postulate leads to the concept of sets of directionally dependent and time-dependent pseudo relative permeabilities. We discuss its connection with a similar work of Kyte and Berry8 and finally, present an example application of this extended idea.
New Method for Finding Hydraulic Diffusivity From Data in Underground Storage
Authors: Udegbunam E. O. , Tek M. R. , Wilkes J. O. 
Published: December 2007

ABSTRACT
A new transient well-testing procedure, which extends "pulse-testing" technology, has been developed for determining the hydraulic diffusivity (K/[μcϕ]) in underground-storage reservoirs. The method depends on the availability of cyclic pressure data from a pair of adjacent and communicating wells: A, the upstream or "forcing-function" well, and B, the downstream or "observation" well.
In general, the pressure fluctuations at well B will exhibit both an attenuated amplitude and a phase lag when compared with those at well A. The theory, which relates the two sets of fluctuations, relies on a solution of the diffusion equation, which governs pressure or potential variations with time and distance in a compressible medium.
To apply the theory to experimental observations, a Fourier analysis is performed on the transient pressures at both A and B. The method has been tested with field data and indicates good success in predicting the pressures at offset wells.
A Coupled Fracturing Model and its Application to Hydraulic Fracturing
Authors: Roegiers J. -C. , Ishijima Y. 
Published: December 2007

ABSTRACT
Although hydraulic fracturing has been used for several decades in the stimulation of hydrocarbon reservoirs, a thorough understanding of the interwoven phenomena is still lacking, especially in the case of porous media. This paper describes a two-dimensional numerical approach allowing the study of the fluid/rock skeleton interaction. The elastic stress analysis is coupled with the transient fluid-flow phenomenon. By introducing a failure criterion based on the critical stress intensity factor, quasi-static situations can easily be studied and instability conditions outlined.
This approach was used to interpret fracture initiation, fracture reopening as well as fracture closure after shut-in. The pressure/time curves generated for each of these phenomena clearly depend on the percolation characteristics of the fracturing fluid and the contact time as well as on the intrinsic properties of the rock mass.
Production Potential from Devonian Gas Shales: Effective Production Strategies
Authors: Kuuskraa V. S. , Wicks D. E. , Sawyer W. K. , Esposito P. R. , Komar C. A. 
Published: December 2007

ABSTRACT
The estimate of technically recoverable gas from Devonian shale in Ohio ranges from 6.2 to 22.5 Tcf, depending on stimulation method and pattern size selected. This estimate is based on (1) a compilation of the latest geologic and reservoir data, (2) analysis of key productive mechanisms, and (3) examination of alternative stimulation and production strategies.
The key findings of this study are: A substantial volume of gas is recoverable, although advanced technology will be required to reach economically attractive production rates in the state,Well spacing can be reduced by half from the traditional 150 to 160 acres per well without severly impairing per-well recovery, andDue to the high degree of permeability anisotropy in the shales, a rectangular, generally 3 by 1 well pattern leads to optimum recovery.
New Generation Fracturing Fluid for Ultrahigh-Temperature Application
Authors: Harms S. D. , Goss M. L. , Payne K. L. 
Published: December 2007

Abstract
This paper presents the results of laboratory tests on a unique combination of polymer, stabilizer and crosslinking chemicals that provide the extended thermal stability necessary for high temperature massive hydraulic fracturing. This fluid system was designed to improve the efficiency of MHF operations, With this thermally stable fluid, treatments may be designed using 20% less polymer than conventional fluids. The lower polymer loading helps lower costs and reduces the possibility of damage due to polymer residue.
High-Strength Proppants Behavior Under Extreme Conditions
Authors: Becq D. F. , Roque Claude , Sarda J. P. 
Published: December 2007

Abstract
Various types of propping agents have been tested in order to evaluate their behaviour at great depth. Several experimental procedures have been used: short duration tests with stress increase at constant temperature, long term tests at constant stress and temperature, tests with simultaneous increase of stress and temperature, with and without continuous flow of water or brine. The behaviour of the proppants having-the "average" density of 3.7 is satisfactory up to a temperature of 100 to 150°C and a stress of 70 MPa.
In order to simulate the steam injection or geothermal, or water producting wells, the propping agents have been tested first without stress at 200°C and 280°C in alcaline solutions at pH chosen from 10,5 to 11,5. At 280°Cthe behaviour of these materials is insufficient at pH 11,5 relatively satisfactory at pH 10,5 for the bauxites having a low silica content. At 200°C a stress of 10 MPa leads to a loss of mechanical strength, Whatever pH may be.
Initial Study of Temperature and Pressure Effects on Formation Damage by Completion Fluids
Authors: Allen F. L. , Riley S. M. , Strassner J. E. 
Published: December 2007

Abstract
An apparatus was selected and modified for formation damage studies at elevated temperatures and pressures. Procedures were developed to ensure reproducible results and are discussed in detail. Initial tests demonstrate a decline in formation damage with increased temperature when clear brine systems are used. The technique may be applicable for selection of drilling and completion fluids for field use.
Vapor-Liquid Phase Behavior Of The Helium-Methane System
Authors: Sinor J.E. , Schindler D.L. , Kurata F. 
Published: December 2007

Publication Rights Reserved
This paper was to be presented at the 40th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Denver, Colorado, October 3–6, 1965, and is considered to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the Journal of Petroleum Technology or the Executive Secretary. Such abstract elsewhere after publication in the Journal of Petroleum Technology or Society of Petroleum Engineers Journal is granted on request, providing proper credit is given that publication and the original presentation of the paper.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This report presents more extensive experimental vapor-liquid equilibria data for the helium-methane system than is found in the literature. A static sampling technique was used to obtain vapor and liquid compositions for six temperatures between -180C and -85C and pressures up to 2,000 psia. Data at 2,000 psia were extended to the critical temperature of the mixture.
Average scatter of the data from the smoothed lines is approximately 1 per cent of the helium concentration or 0.03 mole per cent helium, whichever is greater. Vapor compositions -140C, -160C, and -180C were analyzed by a different technique and scattered on the average from the smoothed curve less than 4 per cent of the methane concentration. Comparisons are drawn between the data of this study and the previously published work of Kharakhorin. The solubility of helium in liquid methane was found to be considerably less than the values indicated by Kharakhorin.
Experimental data are presented in tabular form and in various phase-composition diagrams. The behavior of the helium-methane system is seen tb be very similar to that of the helium-nitrogen system, with helium being much less soluble in methane than in nitrogen.
The data were satisfactorily correlated by means of the Krichevsky-Kazarnovsky equation. Extrapolations to higher pressures should be feasible.

VAPOR-LIQUID PHASE BEHAVIOR OF THE HELIUM-METHANE SYSTEM
Interest in conserving the only appreciable supply of helium has led to legislation enabling private industry to extract helium from streams of natural gases in which it occurs. The helium is purchased by the government for storage in underground formations. The separation processes used by all recovery plants now in operation depend upon low-temperature phase-equilibrium phenomena. Since helium is the least condensible of all gases, it is obtained by condensing all of the other components present in the natural gas. The helium-free natural-gas is then returned to the market stream.
Screening Tests to Evaluate Formation Damage in EOR Operations
Authors: Somerton W. H. , Chen S. P. , Schuh M. J. , Yuen J. P. 
Published: December 2007

Abstract
Tests have been run on cores from a number of California oil-producing formations, which are potential candidates for Enhanced Oil Recovery (EOR) operations, to evaluate the effects of disturbing fluid/rock equilibrium by injecting EOR fluids. The fluid-flow capacity of reservoir rocks may be severely affected by introduction of foreign fluids. In addition, loss of injected chemicals to the rock by adsorption, ion exchange, and mineral dissolution and by reactions with formation brines, may minimize the effectiveness of the EOR fluid injection.
Many of the cores tested did show serious reduction in fluid-flow capacity upon changing the ionic content and/or concentration of the injected fluid. This reduction is attributed to mobilization of and subsequent plugging by formation fines. Ultra-fine mineral particles have been noted in the effluent from fluid-flow tests. Some cores from two Southern San Joaquin Valley fields (Kern Front and Midway-Sunset), showed anomalous behavior in this regard. These cores showed a reduction of the effluent pH to as low as 4.0 when neutral NaCl solution was injected. This pH reduction which lasts for many pore volumes (PV) of injection, is attributed to H+/Na+ exchange, releasing H+ into the flowing fluid. These cores, although mineralogically similar to other cores from the same formation and, in one case, from the same well, show no reduction in permeability regardless of the nature of the injected fluid.
Screening tests have been developed to identify those cores which do not show permeability reduction to fresh-water injection. Similar tests have also been developed to demonstrate the effectiveness of stabilizing agents (dilute AlCl3 solution in this work) in reducing the susceptibility of cores to permeability reduction.
Log-Derived Stratigraphic Reservoir Description
Authors: McGinley T. R. , McKnight T. N. 
Published: December 2007

ABSTRACT
Definitive resolution of rock type in complex lithology enhances full development of hydrocarbon reserves. The suggested petrophysical model combines acoustic, neutron, bulk density and photoelectric effect in a descriptive four-mineral model that requires minimum log parameter decisions. Results are utilized to understand subsurface geology and design well completions.