bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Symmetric, Positive Definite Formulation of a Three-Dimensional Micellar/Polymer Simulator
Authors: Gupta A. Datta , Pope G. A. , Sepehrnoori K. , Thrasher R. L. 
Published: December 2007

SummaryAn efficient approach to compositional simulation is described. Application to micellar/polymer flooding resulted in a significant saving in computation time. A new method was developed to impose precisely the outflow boundary condition arising from continuity of flux across the reservoir/wellbore interface. In a manner analogous to classic well models, the above condition was used to define produced concentrations from the wellblock concentrations. Effects of numerical dispersion in multidimensional, multiphase, multicomponent flow and the effectiveness of a dispersion control scheme are also discussed.
Moving Elements for Transport Processes
Authors: Carey Graham F. , Mueller Alan , Sepehrnoori Kamy , Thrasher Richard L. 
Published: December 2007

Summary
We consider a class of convection-dominated flows fundamental to reservoir simulation and their approximate solutions by use of finite-element techniques and moving meshes. Both the solution field and the coordinate functions enter as primary unknowns in the resulting problem statement. Hence the mesh evolves with the solution, and the method is particularly well-suited to those problems where tracking of sharp solution fronts is important. Examples of particular interest related to petroleum reservoir simulation are the model convection/diffusion, Burgers, and Buckley-Leverett equations, which are considered in the numerical studies. We consider effective solution techniques and system integration, as well as questions related to the use of constraints for limiting the permissible distortion of the mesh.
A New Approach to Limited Compositional Simulation: Direct Solution of the Phase Equilibrium Equations
Authors: Lo Tak Sing , Youngren Gary K. 
Published: December 2007

Summary
A new method for solving the phase equilibrium in limited compositional models is presented. It is a direct solution algorithm based on simplified thermodynamics and can be easily implemented in existing simulators to model such mechanisms as retrograde condensation, oil stripping by gas cycling, and miscible and immiscible gas drive. In field-scale studies, the simplification in phase behavior is more than compensated for by the increase in simulator efficiency. Examples are given to illustrate the method's use in large-scale gas cycling.
Experience in the Use of 13% Cr Tubing in Corrosive CO2 Fields
Authors: Crolet J.-L. , Bonis M. R. 
Published: December 2007

Summary
This paper discusses the following points in detail: the reasons for using 13% Cr steel tubing in corrosive offshore wells; the corrosion resistance to be expected with this material; the precautions to be taken both at the completion design stage and during practical implementation; the economic evaluation that can be made after 8 years of experience and that covers 140 wells; and the rationalized use of 13% Cr steel tubing based on early prediction of the corrosivity of future wells.
Inhibitor Film Persistence Measurement by Electrochemical Techniques
Authors: Choi H. J. , Cepulis R. L. 
Published: December 2007

Summary
A technique that uses corrosion-potential, Φcorr, measurements was developed to evaluate rapidly the film persistence of commercial adsorption-type inhibitors for downhole tubular treatment. It was demonstrated that the Φcorr measurement revealed the progressive change with time of inhibitor film in aqueous moving fluids. The advantages of Φcorr measurements are that film effectiveness can be monitored continuously with a simple device and that they are nonintrusive.
Additional results of the tests showed that dissolved O2, CO2, and fluid flow drastically degraded the effectiveness of inhibitor film, and higher concentrations of inhibitors provided better performance. These indicate that simulation of process conditions is a prerequisite when the film persistence of commercial adsorption-type inhibitors is determined in a laboratory.
Effects of Commonly Used Oilfield Chemicals on the Rate of Oxygen Scavenging by Sulfite/Bisulfite
Authors: Braga T. G. 
Published: December 2007

Summary
The effect of common oilfield biocides, corrosion inhibitors, scale preventives, and alcohols on the rate of O2 scavenging by sulfite/bisulfite is described. Emphasis is placed on the effect of the functional group of each of the chemical types. An attempt is made to explain the results in terms of the free-radical mechanism.
Natural Gas Hydrates in the Alaskan Arctic
Authors: Godbole S. P. , Kamath V. A. , Ehlig-Economides C. 
Published: December 2007

Summary
The occurrence of in-situ natural gas hydrates in the arctic North Slope of Alaska is governed by several thermodynamic and geologic parameters, such as mean annual surface temperature, geothermal gradients above and below the base of the permafrost, pore-fluid salinity, permafrost base depth and temperature, subsurface pressure, and composition. Accurate knowledge of these parameters is necessary to determine the depths and thicknesses of zones of potential hydrate occurrences. The role of the parameters Is discussed in this paper. To determine the hydrate-stability zone, a nomogram has been developed and has been used for several Alaskan wells. For further delineation of gas hydrates, the neutron-transit-time crossplots have served as a valuable tool. To quantify gas hydrate deposits in terms of thickness, porosity, and saturation; use of neutron- and sonic-porosity-correction factors and Pickett crossplots is recommended.
A Comparison of Steamflood Strategies: Five-Spot Pattern vs. Inverted Nine-Spot Pattern
Authors: Ziegler Victor M. 
Published: December 2007

SummaryThis paper describes the use of a black-oil, thermal simulator to compare steamflood development using five-spot and inverted nine-spot patterns. The input data selected were representative of a homogeneous heavy-oil reservoir. This study considered three different development strategies: conventional pattern steamflooding, pattern steamflooding with infill drilling, and steamflooding with infill drilling and pattern realignment.Comparison of pattern steamfloods indicates that at close well spacing (1.25 acres/well [0.5 ha/well]), the inverted nine-spot recovers more oil than the five-spot. Steam breakthrough and oil production are accelerated for the nine-spot relative to the five-spot pattern. At larger well spacing, however, oil recovery from the five-spot pattern exceeds that from the nine-spot. Conversion of a five-spot pattern to an inverted nine-spot increases and accelerates oil recovery. Processing of multiple sands will improve the effectiveness of this infill drilling strategy.A development strategy using inverted nine-spot patterns on large well spacings (2.5 to 5.0 acres/well [1 to 2 ha/well]) that yields improved oil recovery compared with conventional five-spot steamflood development was identified. This strategy uses infill drilling and pattern realignment to improve steamflood performance.
Visualization of Laboratory Corefloods With the Aid of Computerized Tomography of X-Rays
Authors: Hove A. O. , Ringen J. K. , Read P. A. 
Published: December 2007

Summary
This paper presents the use of X-ray tomography to inspect a series of laboratory core-displacement tests. Saturation profiles in thin longitudinal planes of view (slices) in the core are followed as a function of time.
Immiscible and miscible displacements in single core plugs and butted composite plugs are presented. Effects of heterogeneity of the core, dispersion of flood fronts, and end effects are observed and discussed. The technique has a large potential to improve the understanding of fluid displacement processes in laboratory core experiments.
Semilog Analysis of Gas Well Drawdown and Buildup Data
Authors: Reynolds A. C. , Bratvold R. B. , Ding W. 
Published: December 2007

Summary
The pseudopressure function is well understood and widely used for analyzing gas well drawdown and buildup data. The usefulness of the pseudotime function for analyzing buildup data with drawdown type curves has also been established. Unfortunately, the pseudotime concept is often incorrectly applied when drawdown data are analyzed by semilog methods. This work provides information on appropriate definitions of dimensionless time that yield accurate analysis of data obtained under radial flow conditions. From the practical viewpoint, the most important result is that two Horner time ratios exist—one based on a normalized shut-in time and one based on shut-in pseudotime—that yield an accurate analysis of buildup data, including the correct determination of average pressure using the liquid Matthews-Brons-Hazebroek (MBH) functions.
Field Performance of Ultralightweight Cement Slurry Compositions Used in the UAE
Authors: Murali B. N. , Tanner C. H. 
Published: December 2007

Summary
Operators in the UAE have achieved a high degree of success with a high-strength microsphere (HSMS) cement additive to deal with lost circulation during drilling and/or cementing. Slurries made with the additive maintain good strength properties at low weights.
Multiple Regression Approach To Optimize Drilling Operations in the Arabian Gulf Area
Authors: Al-Betairi Emad A. , Moussa Mohamed M. , Al-Otaibi Saud 
Published: December 2007

Summary
This paper reports a successful application of multiple regression analysis, supported by a detailed statistical study to verify the Bourgoyne and Young model. The model estimates the optimum penetration rate (ROP), weight on bit (WOB), and rotary speed under the effect of controllable and uncontrollable factors. Field data from three wells in the Arabian Gulf were used and emphasized the validity of this model. The model coefficients are sensitive to the number of points included. The correlation coefficients and multicollinearity sensitivity of each drilling parameter on the ROP are studied.
Fractured Reservoir Evaluation Using Monte Carlo Techniques (includes associated paper 16991 )
Authors: Sears G.F. , Phillips N.V. 
Published: December 2007

Summary.
Pro forma cash-flow analysis of petroleum ventures usually isconsidered as a dterministic model. In the last 10 years, Monte Carlo analysishas allowed the introduction of probability distributions of input variables inplace of single-valued functions. Reserve determination and rate scheduling inthese current Monte Carlo techniques have relied on the volumetric formula, which works well in nonfractured reservoirs.
Recent massive drilling in fractured reservoirs has rendered this approachunusable. This paper develops a variation of the Arps rate-cumulative equationas a basic model for the determination of the distribution of original reservesand the decline rates. Continuation of the Monte Carlo technique into netpresent value analysis and internal rate of return (IRR) is also developed.

Introduction
Estimating the profitability of petroleum ventures is a risky business atbest. The prices of oil and gas are not the least of many uncertain variablesin any standard cash-flow model. Friedman used the idea of Monte Carlosimulation in competitive bidding strategy. Hertz popularized teh idea of MonteCarlo modeling to treat uncertainty in a business situation. Several authorshave applied this concept to petroleum ventures, particularly in the earlystages of development of a reservoir or even during exploration. The basicmodel used in these calculations has always been the volumetric model outlinedbelow. That approach works well in conventional reservoirs where porosity, netthickness, and recovery factor can be measured or estimated. In tight ornaturally fractured reservoirs, however, the volumetric approach fails becausethe hydrocarbons are not in an isotropic, homogeneous matrix as in conventionalreservoirs but instead are confined largely to the fracture system. A MonteCarlo model for fractured reservoirs using the general approach is outlinedbelow, but it is based on the Arps rate-cumulative and rate/time empiricalequations. The model is used to determine both the distribution of reserves andthe extraction schedule that woudl result. These lead to computation of the netpresent value of the reserves.
The volumetric formula is based on the equation (Equation 1)
P. 71^
Casing Heading in Flowing Oil Wells
Authors: Torre A. J. , Schmidt Z. , Blais R. N. , Doty D. R. , Brill J. P. 
Published: December 2007

Summary
Casing heading, an unsteady flow in oil wells completed without packers, occurs when both gas and liquid superficial velocities are low. A hydrodynamic model is presented that simulates laboratory data for the cases considered. Results confirm that heading occurs for low superficial gas and liquid velocities and that choking re-establishes stability.
The Petroleum Engineer's Function in Oil and Gas Financing
Authors: Dodson Charles R. 
Published: December 2007

Introduction
Although petroleum engineering as a profession is relatively new timewise, it has matured rapidly and become a recognized and essential element in the financing of oil and gas operations. Most oil operators have become accustomed to working with the bank petroleum engineer and know that certain requirements must be met to obtain loans. It is worth noting that petroleum engineers have found bank work to be interesting, varied and rewarding. For the alert, competent and ambitious, there are ample opportunities for advancement and promotion to officer status.
The main objectives in this discussion are to comment on financing oil and gas operations by banks and to discuss in some detail the importance, content and usefulness of the engineering report in establishing the value of a property as collateral and in forecasting production for repayment of a loan. It may seem contradictory to the popular idea of conservative bank practice that a bank would accept as collateral for loans oil and gas still in the reservoir rock-commodities that are fluid, mobile, cannot be inspected or insured and must be produced from wells and sold in order to make payments on the loans. However, experience with loans based on properly engineered reserves has been most satisfactory and many oil-minded banks claim they have never had a bad oil loan.
Oil loans are not new to banks; they were started in the early thirties, increased noticeably after 1935 and especially since 1945. In the meantime, banks have made hundreds of oil loans and found them not only safe and profitable, but helpful in developing the growth of important relationships in regard to deposits and use of other bank services. The acceptability of the oil loan to commercial banks is due primarily tolegislation that regulates oil production to prevent waste,recognition of correlative rights,increased engineering ability to estimate with reasonable accuracy reserves and forecasts of production andadvanced production technology.
These factors have tended to stabilize prices and substantially improve reliance on reserve estimates and forecasts of revenue.
Results of Well Stimulation by Hydraulic Fracturing and High Rate Oil Backflush
Authors: Ghauri W.K. 
Published: December 2007

Abstract
Well stimulation by hydraulic fracturing and by associated techniques has been carried out in fields along the Whittier fault trend in the Los Angeles basin since 1953, with a total of 53 jobs performed to date. The hydraulic fracturing methods of hydrafrac and sandoil frac have been tried extensively along with the stimulation technique of the "high rate oil back flush", which consists simply of injecting large volumes of formation crude at high rates into the producing zone. Although several of the treatments individually have yielded no additional oil, well stimulation by these methods on an over-all basis has been highly successful and should find applicability to other California oil fields producing from similar low-permeability, shaly measures.

Introduction
The well stimulation treatments discussed in this paper were performed from 1953 to the present in the Brea-Olinda and Esperanza fields, which lie along the Whittier fault trend in the Los Angeles basin (Fig. 1). Since production stimulation by hydraulic fracturing is at present relatively unproved in California, the following geological and reservoir information regarding the producing measures where these treatments were performed is presented to aid in future applications to other California fields. The Brea-Olinda field, where most of the treatments discussed herein (80 per cent) were performed, extends for about six miles laterally along the Whittier fault trend and comprises a practically continuous, elongated belt of accumulation, about 1/2 to one-mile wide. Since the turn of the century, the field has undergone sporadic development as a result of the discoveries of deeper pools and the lateral extensions of existing pools. Cumulative production from the field is 260 million bbl of oil, with some 650 active wells currently producing 17,500 B/D. The Esperanza field, where the remainder of the treatments were performed, was discovered only recently (1956) and has yielded 250,000 bbl of oil, with seven active wells currently producing 400 B/D.
Surface Tension of Reservoir Crude-Oil/Gas Systems Recognizing the Asphalt in the Heavy Fraction
Authors: Firoozabadi Abbas , Katz Donald L. , Soroosh Hossein , Sajjadian Vali A. 
Published: December 2007

Summary
Improvements in predicting surface tensions for crude-oil/gas systems at reservoir conditions has been attributed to new parachors for distillation cuts of crude oil and the recognition that the last fraction or residue of distillation has a parachor not continuous with the distillation cuts.
For such reservoir gas/oil systems as condensates, which normally do not contain asphalt materials, the new parachors for the crude cuts would suffice for the surface-tension computation. For a reservoir fluid containing asphaltic substances, the calculation procedure should include a single measurement of the surface tension.
Field Consolidation of Fractured Core
Authors: Conley F.R. , Glover J.A. , Knutson C.F. 
Published: December 2007

Abstract
A recent investigation of fractured core from the Embar reservoir of the Gebo field, Hot Springs County, Wyo., utilized novel techniques that are believed to be worth reporting. The most successful procedure was to:
- cut the interval with a rubber sleeve core barrel;
- cut the core, encased in the rubber sleeve, into approximately 3-ft sections for ease of handling;
- plug the ends of the sleeve and displace the drilling mud, oil and water from around the core with a polyester resin;
- allow the resin to polymerize; and
- slab the core, which is cast in resin, and investigate the amount and type of fracturing exposed.

Discussion
An in-fill well to be drilled in the Gebo field, Hot Springs County, Wyo., provided an opportunity to do some additional coring in the fractured Embar formation. Since the recovery from this formation had been poor, the Gebo Unit No. 47 was scheduled to core the Embar using a rubber sleeve core barrel. The upper productive member of the Embar formation was cored in two 20-ft sections at an average rate of 15 min/ft, with a core recovery of 95 per cent. When the 20-ft sections of core encased in the rubber sleeve were removed from the core barrel, it was obvious from the limber nature of these sections and a number of narrow necks (or points of reduced diameter of the sleeve) that the core was broken into a number of pieces. In order to study the anticipated fracture system at leisure in the lab, alternate 3-ft sections of the core were cast into plastic briquets at the rig site. Several different plastic application techniques were tested, and the most successful method is described in this note. About 2 in. of core were removed from the end of each 3-ft section to be plastic treated. Rubber stoppers (with flared copper tubing running through them) were clamped in place, and the section was placed in a holder. This holder kept the rubber sleeve from expanding to more than 3 1/2 in. OD and kept fractures from being wedged open and increasing the length of the core. (See Fig. 1.) The section of core in the holder was then mounted vertically, and plastic was pumped into the bottom of the sleeve. (See Fig. 2.) Enough plastic was pumped into the bottom of the section of core to displace most of the oil, mud and water out the top of the core. After about 250 ml of clean plastic had been produced from the overflow at the top of the holder, the upper copper line was sealed off by bending and crimping; enough additional plastic was pumped into the bottom tubing to expand the sleeve against the holder.
Considerations for Optimum Fracture Geometry Design
Authors: Elbel J. L. 
Published: December 2007

Summary
This paper gives production forecasts for (1) various equal-proppant-volume fracture geometries with various formation permeabilities, (2) equal fracture lengths with different proppant volumes, and (3) equal fracture lengths and proppant volumes with various proppant distributions. It shows conditions when Prats' relationship for maximum productivity is true and when higher values of dimensionless fracture conductivity are beneficial. These should give the design engineer useful tools when optimizing fracture design.
Early Production: One Stage Further
Authors: Van Bilderbeek B. H. 
Published: December 2007

Summary
This paper discusses the design procedures followed during the development of a new mudline suspension system for use on jackup rigs in drilling or tieback applications. This has resulted in the design of an integrated system that combines mudline support hangers with the surface wellhead into a package that materially changes the method of operation on jackup rigs. The new system uses mandrel-type surface hangers that can be installed through the blowout preventer (BOP).
Analytical Chemistry of Portland Cement and Its Oilfield Admixtures
Authors: Simpson Benny E. 
Published: December 2007

Summary
The successful cementing of boreholes in earthen formations requires careful control of the properties of cementing slurries and of the final set product. Accurate, dependable, time-efficient chemical analyses are prerequisites in determining quality of cement, additives, field blends, slurries, and set cement. A review highlighting chemical, spectrochemical, microscopic, and thermal methods of analysis of portland cement and oilfield cementing systems is presented.
Four-Phase Flash Equilibrium Calculations Using the Peng-Robinson Equation of State and a Mixing Rule for Asymmetric Systems
Authors: Enick Robert M. , Holder Gerald D. , Mohamed Rahoma 
Published: December 2007

Summary
A technique for predicting one- to four-phase flash equilibrium is presented for multicomponent systems containing water, such as CO2/crude-oil/H2O mixtures that characterize the CO2 miscible flooding of petroleum reservoirs. The Peng-Robinson equation of state (PR-EOS) is used to describe the aqueous and hydrocarbon phases, and an accelerated and stabilized successive-substitution method is used to obtain convergence, even in the near-critical region.
In order to describe accurately multiphase equilibria involving water, a recently developed mixing rule for asymmetric systems is incorporated that permits the solubilities of both CO2 in H2O and H2O in CO2 to be modeled. The equation of state (EOS) is also modified to enable the aqueous-phase density to be predicted accurately. A comparison of predicted and experimental three- and four-phase behaviors is made for a CO2/Maljamar crude-oil/H2O mixture at 302.5°C [576.5°F].
Computer Determination of Calibration and Environmental Corrections for a Natural Spectral Gamma Ray Logging System
Authors: Koizumi Carl J. 
Published: December 2007

Summary
Pulse-height spectra recorded by a passive spectral gamma-ray logging system were simulated by radiation-transport calculations for several combinations of gamma ray sources and tool environments. Derived from the calculated log responses were (1) source- and energy-dependent environmental corrections and (2) calibration factors and an environmental correction method for three-window potassium/uranium/thorium analysis.