bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Experimental Study of Gas Solubility in Oil-Based Drilling Fluids
Authors: O'Bryan Patrick L. , Bourgoyne Adam T. , Monger Teresa G. , Kopcso Debra P. 
Published: December 2007

Summary
Experimental data are provided for the solubility of C1, C2, CO2, and a natural gas mixture in base oils and emulsifiers used to prepare oil-based drilling fluids over a range of temperatures. In addition, an empirical correlation for predicting gas solubility in oil-based drilling fluids at low to moderate pressures is presented and a field application is outlined.
A Weight- and Space-Saving Seawater-lnjection System Design
Authors: Gran H. G. , Matthews R. R. , Johnson D. , Sollesnes G. 
Published: December 2007

Summary
This paper describes an integrated and compact seawater-injection system built around backwashable cartridge filters and catalytic deoxygenation. Suspended solids are removed by a high-efficiency cartridge filter in which the cartridges are regenerated by a proprietary acid rinse. Dissolved oxygen is removed in a single stage to a level of 20 ppb by use of dissolved hydrogen over a palladium catalyst. A combined-cycle power plant makes the unit self-contained. A unit for treating 150, 000 B/D [23 850 m3/d] of seawater is estimated to weigh 260 metric tons [260 Mg] (operating), or about 35% of a comparable "conventional" system using media filters and vacuum deaeration. Space requirements are reduced proportionally.
Transient Response of Nonhomogeneous Aquifers
Authors: Mueller T.D. 
Published: December 2007

Abstract
Many investigators have used the response of the "dimensionless aquifer" to a unit pressure drop or a unit fluid-withdrawal volume to calculate the performance of an aquifer in supplying water influx to an oil reservoir. In the past, these response functions have been calculated with the aid of the Laplace transform. With the advent of ultra high-speed digital computers, it becomes practical to solve for the response functions with finite-difference techniques. The computer method also permits extension of the dimensionless-aquifer concept to include the nonhomogeneous aquifer wherein the permeability and other properties vary as a function of the space co-ordinates. This paper gives results of calculating the response functions for a series of nonhomogeneous aquifers. Response functions are presented for both linear and radial aquifers whose thickness, permeability-viscosity ratio and porosity-compressibility vary. These functions are new and should prove useful to the petroleum engineer in analyzing the behavior of nonhomogeneous aquifers. Results are presented in the form of charts that can be easily used by the field engineer.

Introduction
Aquifers which surround many oil and gas reservoirs have the ability to supply water influx to such reservoirs as oil and gas are withdrawn. This water influx, called natural water drive, provides one of the most effective driving mechanisms for the production of oil and gas. In producing a reservoir, therefore, it behooves one to make the maximum use of natural water drive. To achieve the maximum use, the reservoir engineer must be able to predict the performance of an aquifer under a variety of production schemes that may be proposed for the reservoir. Unfortunately, the physical properties which dictate aquifer behavior often are known only within limits. Seldom do wells penetrate the porous strata of the aquifer.
Density Modeling for Brines as a Function of Composition, Temperature, and Pressure
Authors: Kemp Nantelle P. , Thomas David C. , Atkinson Gordon , Atkinson Betty L. 
Published: December 2007

Summary
Electrolyte solutions containing high concentrations of salts, such as NaCl, KCl, CaCl2, CaBr2, and ZnBr2, have several important applications in the oil field. The so-called "heavy brines" are used as solids-free completion fluids. Brines are also a major constituent of many drilling-fluid systems, including both water- and oil-based muds. This paper describes the density behavior of brine solutions containing single salts and salt mixtures under various temperature and pressure conditions. Examples are given for using the derived density model to calculate both downhole differential pressures for brine completion fluids and the solids content in brine muds.
Study of Gas Reservoirs Subject to Water Drive on Electronic Differential Analyzer
Authors: Yoo H.D. , Katz D.L. , Tek M.R. 
Published: December 2007

Abstract
The behavior of gas-storage reservoirs subject to water drive is investigated through analog simulation on an electronic differential analyzer. The simulation technique developed on an LM–10 computer permits the prediction of reservoir volume or pressure resulting from the movement of water in the surrounding aquifer.
The method developed on the analog computer consists off-setting up an appropriate transfer-function circuit and feeding the arbitrary time-varying boundary conditions as an input signal. The input may be specified as gas reservoir pressure, pore volume or the water flux.
Several cases studied include an isolated gas reservoir on a limited aquifer, interference among three reservoirs adjacent to a common aquifer and the growth of gas-storage volume on an aquifer.
It is concluded that the method developed on an electronic differential analyzer provides an excellent technique to simulate and investigate the behavior of gas reservoirs subject to water drive. The agreement between the reservoir performance as predicted from the simulation technique and as measured from actual field data is found to be better than the range usually encountered in predicting water-drive behavior.

Introduction
It is generally known that some gas-storage reservoirs are located on top of blanket sands of large extent, saturated with brine called aquifers.
Because the volume of the body of water associated with aquifers is usually very large and water is compressible, the cyclic pressure variations encountered in normal storage service inevitably cause unsteady, compressible flow conditions in the adjacent aquifers.
The solution to radial diffusivity equation for a limited aquifer for constant terminal conditions has been known since the early 1930's. The solution for the constant terminal conditions for an infinite aquifer was published in 1949.
A Numerical Solution to the Unsteady-State Partial-Water-Drive Reservoir Performance Problem
Authors: Henson Walter L. , Wearden Paul L. , Rice John D. 
Published: December 2007

Abstract
Solutions to the unsteady-state partial water-drive reservoir performance problem can be obtained through the use of analogue computers or high-speed electronic digital computers. The solutions that have previously been resolved for use on digital computers, however, demand a knowledge of the aquifer parameters. Generally, the analogue computers now in use do not require this knowledge.
A solution is presented herein where the aquifer performance, expressed in terms of difference equations, is related to the reservoir performance as expressed by the modified Schilthuis material-balance equation. A numerical procedure for a medium-sized digital computer also is presented in which a solution to the set of equations defining the aquifer and reservoir performance is obtained and the aquifer parameters (permeability and sand thickness) are automatically optimized while simultaneously matching the known pressure behavior. Predicted pressure behavior can be calculated using rates from any assumed future production practice. The procedure provides an output format which presents the cumulative, incremental and average rate of natural water influx, the per cent gas-cap expansion, the calculated reservoir pressure, the measured reservoir pressure, and the difference between the measured and calculated pressures.
Results of a test problem are presented in comparison with results obtained by the Bruce Analyzer, Ohio Oil Co.'s Pace General Purpose Analogue Computer, and Sun Oil Co.'s Single-Pool Electronic Reservoir Analyzer. These results indicate that unsteady-state reservoir performance for a single-pool system can be adequately simulated by a numerical method employing a digital computer and that the special-purpose analogue computer can be supplanted by this method.
Development of Large, Nickel-Based Alloy 925 Composite-Block Trees for Extreme-Corrosion, Fire-Resistant Applications on Offshore Platforms
Authors: Haeberle Timothy , Kovach Paul J. 
Published: December 2007

Summary
This case study presents the development of the first large components to be manufactured from nickel-based Alloy 925 for oilfield use: nine composite-block trees used on an offshore production platform producing gas/condensate containing H2S, CO2, and chlorides. Details are provided on the material selection process and the manufacture (forging, heat treating, and machining) of the composite blocks and smaller equipment. This report introduces Alloy 925 as a candidate for future oilfield applications, providing performance benefits for special design requirements.
Improving Wellhead Performance With Programmed Cement Shortfall
Authors: Britton J. S. , Henderson G. 
Published: December 2007

Summary
Subsea wellheads can be subjected to extreme external loads when a drilling or production riser remains connected during storm or vessel drive-off conditions. In addition, vortex shedding from high currents and wave action on drilling and production risers can subject the wellhead to high-cycle fatigue loads. These extreme external and high-cycle fatigue loads can cause failure of the wellhead system when a fully cemented annulus between the 30-in. [76-cm] structural conductor pipe and 20-in. [51-cm] surface casing is not achieved. This effect of cement shortfall is most damaging when the cement level is just below the wellhead-body/conductor-housing region. Purposefully setting the cement level far below the mudline can be a cost-effective solution to the unintentional cement-shortfall problem.
Droplet-Settling vs. Retention-Time Theories for Sizing Oil/Water Separator
Authors: Arnold Kenneth E. , Koszela Paul J. 
Published: December 2007

Summary
This paper discusses two techniques for sizing oil/water separators. Droplet-settling theory, based on Stokes' law governing water-droplet movement through a continuous oil phase, is used to develop sizing equations for both horizontal and vertical separators. Retention-time theory, which calculates theoretical fluid-retention time within the separator by relating liquid flow rates to vessel geometry, is also presented. Published separator data comparing vessel sizes to allowable capacities are analyzed using both sizing techniques.
Hydrocyclones: A Solution to Produced-Water Treatment
Authors: Meldrum N. 
Published: December 2007

Summary
Progressing into deeper water and more hostile environments in the search for new oil and gas reserves has placed an increasing demand on the industry to develop lighter, more compact, and more efficient process equipment to replace their traditional counterparts. A recent application of cyclone technology for liquid/liquid separation of oil from produced water has shown considerable promise during extensive field testing. This paper outlines the basic construction and principle of operation of the deoiling hydrocyclone and discusses system design, early operational experiences, and test results from the first full-scale commercial application of the four-in-one hydrocyclone concept on the Murchison platform. In addition, and of perhaps more significance, early results from field tests of the larger 60-mm [2.4-in.] cyclones on the Hutton tension leg platform (TLP), where conventional equipment was adversely affected by platform motion, are discussed.
Development and Results of the Hale/Mable Leases Cooperative Polymer EOR Injection Project, Vacuum (Grayburg-San Andres) Field, Lea County, New Mexico
Authors: Hovendick M. D. 
Published: December 2007

Summary
This paper presents a case history of the design, implementation, and results of a tertiary polymer EOR injection project conducted by Phillips Petroleum Co. in their Hale and Mable leases located in the Vacuum (Grayburg-San Andres) field, Lea County, NM. Polymer is being injected at a relatively low concentration, and the paper concludes that, given the reservoir rock and fluid properties prevalent in the Hale and Mable leases, a low-concentration polymer flood is just as effective as a higher-concentration flood as long as the total pounds of polymer injected is the same.
Type- and Decline-Curve Analysis With Composite Models
Authors: Olarewaju Joseph S. , Lee W. John , Lancaster David E. 
Published: December 2007

Summary
This paper presents applications of new type curves generated with a composite model for the analysis of radially damaged and stimulated wells. These type curves can be used to estimate the depth and degree of damage or stimulation. Some of the type curves include phase redistribution, and the production type curves can be used to forecast incremental production from the stimulation of damaged wells.
The Value and Analysis of Core-Based Water-Quality Experiments as Related to Water Injection Schemes
Authors: Todd A. C. , Kumar Tarkeshwar , Mohammadl Shahrokh 
Published: December 2007

SummaryThis paper describes an experimental study of formation damage associated with low-concentration particle invasion in water injection schemes. Depth-of-invasion results are presented, the importance of core preparation is stressed, and the results from conventional cut-faced plugs are compared with those from the broken-faced plugs used in this study.
Innovative Devices for Testing Drilling Muds
Authors: Zamora Mario , Lai Damon T. , Dzialowskl Andrew K. 
Published: December 2007

Summary
There are ample incentives and opportunities to improve current mud-testing equipment and to develop new instruments to measure mud properties not previously tested. This paper discusses three innovative devices for testing drilling muds: the automatic shearometer unit, the high-temperature/high-pressure (HTHP) dynamic filtration tester, and the filter-cake penetrometer. Each discussion includes a summary of previous technology, current API standards (if available), equipment description, and selected case studies.
Alternative Flow-Pattern Maps Can Improve Pressure-Drop Calculations of the Aziz et al. Multiphase-Flow Correlation
Authors: Al-Najjar Hazim S. H. , Al-Soof Nimat B. Abu 
Published: December 2007

Summary
An improvement in pressure-drop calculations of the Aziz-Govier-Fogarasi multiphase-flow correlation is presented. This improvement was achieved after several combinations of different flow-pattern maps with the correlation were attempted.
Field data taken from 15 flowing oil wells of an Iraqi oil field and the published data of Poettmann and Carpenter and Chierici et al. are used for testing the performance of the various combinations. The introduction of ± 15% uncertainty in the values of bubblepoint pressures and solution GOR's predicted by the Vasquez fluid-property correlation appears to have insignificant effects on pressure-drop calculations. The effects of changing the direction of pressure-drop calculations confirms the findings of the work of Gregory et al.
Although all the attempted combinations show an improvement in pressure-drop calculations over the original correlation, the Duns-Ros flow-pattern-map combinations produce the best results. Its overall absolute average percent deviation for the Iraqi oilfield data set is 3.05%, compared with 7.23% for the original correlation. Also, the percent of calculated pressure-drop points deviating by more than ± 5% from the observed points is reduced from 52.5% for the original correlation to 17% for this combination.
Calculating Effective Absolute Permeability in Sandstone/Shale Sequences
Authors: Deutsch Clayton 
Published: December 2007

Summary
Two averaging algorithms are proposed for determining block effective absolute permeability. The experimental relationship between the effective permeability, the volume fraction of shale, and the anisotropy of the shales is first observed through repeated flow simulations. A power-averaging model and a percolation model are proposed to fit the experimentally observed relationship. The power-averaging model provides a surprisingly easy and efficient way to calculate block effective absolute permeability. A simple graph is given to determine the averaging power from the geometric anisotropy (aspect ratio) of the shales for both vertical and horizontal steady-state flow. The effective absolute permeability can then be calculated with the averaging power, the volume fraction of shale, and the component sandstone and shale permeabilities. The effective permeability of a sandstone/shale sequence is affected when the shales are large with respect to the size of the gridblocks. A correction for large shales relative to small gridblocks is also proposed.
Experimental and Simulation Study of High-Temperature Foam Displacement in Porous Media
Authors: Friedmann François , Chen W. H. , Gauglitz P. A. 
Published: December 2007

SummaryHigh-temperature surfactant foams are simulated by modifying gas-phase mobility in a conventional thermal simulator. Both surfactant-alternating-gas (SAG) and gas/liquid-coinjection processes are modeled. Foam generation by leave-behind and snap-off as well as foam coalescence and trapping mechanisms are incorporated in the model by an equation for the number density of foam bubbles; gas-phase relative permeability and apparent viscosity are modified according to the bubble density. Pressure and saturation data of laboratory corefloods are successfully history matched with simulation results. Field-scale sensitivity studies of the steam-foam-drive process demonstrate how the coalescence rate affects the extent of steam diversion.
An Experimental Investigation of the Fireflooding Combustion Zone
Authors: Kumar Mridul , Garon A. M. 
Published: December 2007

Summary
In a laboratory study, an automated, linear-traversing, sampling probe enabled real-time gas analysis and temperature measurements within the combustion zone. Results showed that the combustion-zone thickness was on the order of 1 in. [25 mm] for a nominal injected air flux of 20 scf/hr-ft2 [1.7 × 10-3 std m3/s·m2]. The combustion-zone thickness was found to be kinetically controlled. The combustion reaction could not be represented by the commonly used first-order, Arrhenius kinetics; however, the actual kinetics of combustion is unimportant for performance prediction because the combustion-front velocity is oxygen-flow-rate-controlled.
Cold Lake Cyclic Steam Stimulation: A Multiwell Process
Authors: Vittoratos E. , Scott George R. , Beattie Craig I. 
Published: December 2007

SummaryCyclic steam stimulation (CSS) typically is thought of as a single-well process. At Cold Lake, however, where steam injectivity is achieved by fracturing the formation, considerable interwell communication is observed. The result is usually the watering out of a producer by condensed steam from a neighboring injector. These interwell interactions greatly complicate steam-injection scheduling for commercial projects involving hundreds of wells but do not seem to reduce bitumen production in early cycles. Field experience indicates that steaming rows of wells sequentially with 50% overlap in injection time between adjacent rows significantly reduces water transfer between wells, increases the conformance of the injected heat, and reduces the field's tendency to form communicating well couplets. Exploratory numerical simulations show that the impact of steaming strategy on bitumen production is not significant until later cycles.
High-Temperature Relative Permeabilities for Athabasca Oil Sands
Authors: Poilkar M. , Farouq All S. M. , Puttagunta V. R. 
Published: December 2007

SummaryAn experimental study of Athabasca bitumen/water relative permeabilities revealed little or no temperature effect on the relative permeabilities to water and bitumen over a range of 100 to 250°C [212 to 482°F]. Comparable results were obtained with both steady- and unsteady-state relative permeability measuring techniques. It was determined that the oil-phase relative permeability curve was convex. Measured curves were also compared with those obtained by history matching.
Production From Naturally Fissured Reservoirs Intercepted by a Vertical Hydraulic Fracture
Authors: Naceur K. Ben , Economides M. J. 
Published: December 2007

Summary
A model is developed to simulate the behavior of naturally fissured and anisotropic reservoirs intercepted by a hydraulically induced vertical fracture of finite or infinite conductivity. The method is based on a numerical discretization of the formation, which is represented by a double-porosity model, for which transient interporosity solutions for pressure and cumulative production are presented. It is shown that matching the pressure behavior for those formations with homogeneous isotropic models leads invariably to a fracture length that is smaller than the actual fracture length.
Steamflood Material-Balance Applications
Authors: Peake W. T. 
Published: December 2007

Summary
A simple steamflood material balance derived from a two-zone reservoir model is presented. Alternative forms of the material balance include the effects of an initial hydrocarbon gas saturation, PV compressibility, and a hot-water zone. In example applications, the material balance is used to calculate the amount of fluid migration from a 16-pattern steamflood pilot and the steam injection rate within a regular five-spot pattern.
Steamflooding in a Waterdrive Reservoirs Upper Tulare Sands, South Belridge Field
Authors: Dietrich James K. 
Published: December 2007

Summary
A steamflood project in the strong edgewater-drive Upper Tulare reservoir at South Belridge recovered about 31% of the original oil in place (OOIP) at a cumulative steam/oil ratio (SOR) of 2.7 vol/vol. Seven years of downdip steam injection depressed water influx and created an oil bank updip from the injectors. Response continued under the influence of returning aquifer water and heat scavenging after the injectors were shut down.
Numerical reservoir simulation of the historical steamflood performance indicated that the high production/injection capacity (P/I) ratio induced early water encroachment and partial quenching of the growing steam zone. Restarting downdip steam injection at much higher rates after 6 years without injection was shown to recover more oil than continuing the steamflood with either a seven-spot or inverted nine-spot pattern.
An efficient steamflood operating policy in an edgewater-drive environment involves overproducing in the oil column to reduce reservoir pressure combined with high-rate downdip pumping of the aquifer to reduce water inflow during steam injection. Downdip steam injection rates greater than 100 B/D-acre and P/I ratios of about 1.4 STB/STB emerged as reasonable operating parameters in several projects.