bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying the Impact of Geological Uncertainty on Reservoir Performing Forecasts
Authors: Ballin P. R. , Aziz Khalid , Journel A. G. , Zuccolo Luca 
Published: December 2007

Abstract
This study addresses the problem of transferring uncertainty in the geological model through the flow simulation model (the comprehensive simulator – CS) up to the reservoir production forecasts. The uncertainty in the geological model is characterized by the differences between many equally probable reservoir descriptions that honor available data and that are generated by geostatistical stochastic simulation. The uncertainty in the production forecasts can be characterized by the variability or spread in the responses derived from the flow simulation, or more precisely by the probability distribution of response variables, such as cumulative oil production, oil recovery, breakthrough time, cumulative water-oil ratio, etc.
A new methodology to perform this transfer of uncertainty is summarized. Each reservoir description is first ranked using a fast simulator (FS) rather than the comprehensive flow simulator (CS). A few selected descriptions are then processed through the CS to generate an approximate probability distribution of the reservoir production response.
This new methodology is applied with a coarse grid as the FS model to a two-phase, three-dimensional field scale problem with five producing wells, 8×106 STm3 original oil in place, and a very large and active aquifer. The impact of uncertainty in absolute permeability and porosity on the field cumulative oil production is considered over 7.8 years of production. Good results are achieved with a 85% to 93% reduction in the computer time over the use of the CS alone. The favorable results achieved show that extension of the proposed approach to other types of problems is worthwhile.
Parallel Nested Factorization Algorithms
Authors: Maksimov M. M. , Galushko V. V. , Kutcherov A. B. , Surguchev L. M. , Bratvold R. B. 
Published: December 2007

Abstract
This paper presents a new technique for solving the linear equations arising in reservoir simulation using multiple processors in parallel. The parallel algorithms for the Nested Factorization method are developed and implemented on a network cluster of highperformance IBM RISC System/6000 workstations as well as on a network of transputers. It is demonstrated on different 3-D data sets varying from 10,000 to 750,000 grid cells that a very high efficiency is achieved on MIMD, local memory, parallel platforms.
Implementation of an Adaptive Implicit Method
Authors: Young L. C. , Russell T. F. 
Published: December 2007

ABSTRACT
This paper describes an Adaptive Implicit Method (AIM) for reservoir simulation. The method is based on an extension of the generalized compositional solution procedure. In addition to the creation of a robust method, we have tried to minimize the overhead associated with the method, so that our implementation is almost as fast as an IMPES (implicit-pressure-explicit-saturation) method when few implicit blocks are needed. Several test problems demonstrate important aspects of the switching logic and the tradeoffs between large highly implicit time steps and smaller time steps with less implicitness. We find that in most cases the greatest efficiency occurs when only a small number of blocks (less than 5 percent) are treated implicitly. In many cases the most efficient method is IMPES with time steps selected using the numerical stability calculations of AIM, Smaller time steps lead not only to higher efficiency, but also to solutions with less numerical dispersion. In general. AIM appears to benefit compositional problems more frequently than black oil problems.
The Productivity Index of an Inclined Well in Finite-Difference Reservoir Simulation
Authors: Lee S. H. , Milliken W. J. 
Published: December 2007

Abstract
In finite difference reservoir simulation, a well is generally treated as a point source or sink. As a result, a well productivity index must be specified to relate the difference between wellblock pressure and wellbore pressure to the production rate. However, analytical formulas for productivity indices are known only for a vertical or horizontal well in a homogeneous formation. In this paper, the method of reflections and slender body theory are shown to provide a means to obtain accurate measures of the productivity index in complex reservoir formations.
Using slender body theory, we have derived an asymptotic solution of single-phase flow around an inclined well that is applied here to the determination of the productivity index. The method of reflections can account for the presence of layer boundaries through the application of image solutions. In combination, these techniques permit the calculation of the productivity index in anisotropic formations with layer boundaries. A comparison of the results with numerical solutions verifies their accuracy. The previous formulas sire shown to be recovered as a special case.
Several examples are presented. The effect of layer boundaries on the productivity index is shown in both two and three dimensions. We consider both permeable and impermeable layers. We also investigate the productivity index of an inclined well in a layered anisotropic formation.
The Prediction of Waterflood Performance in Mixed-Wet Systems from Pore-Scale Modelling and Simulation
Authors: McDougall S. R. , Sorbie K. S. 
Published: December 2007

Abstract
The wettability characteristics of a porous medium play a major role in a diverse range of measurements including: capillary pressure data, relative ^rmeability curves, electrical conductivity, waterflred recovery efficiency and residual oil saturation. This study descritos the development and implementation of a pore-scale simulator capable of modelling multiphase flow in porous media of nonuniform wettability. By explicitly incorçxrating pore wettability effects into a steady-state mtoel, it has toen ^ssible to explain many experimental observations from a microscopic standpoint.
Results are presented which show how a (the fracrion of pores which are assigned oil-wet characteristics) affects resulting capillary pressure and relative Jtermeability curves. Simulated capillary pressure data demonstrate that some standard wettability tests (such as Amott-Harvey and free imbibirion) may give spurious results when the sample is fractionally-wet in nature. The corresponding relative pemeability curves have been used to calculate waterflood displacement efficiencies for a range of wettability conditions, and recovery, is shown to to maximum when the oil-wet pore fraction approaclies 0.5.
Furthermore, a novel test is promised which could to used to determine the wettability of both fractionally-wet and mixed-wet jxrrous media. To date, no such satisfactory test exists.
Fully Implicit Simulation on the Connection Machine
Authors: Dupuy Alain , Killough J. E. 
Published: December 2007

ABSTRACT
A fully-implicit, black-oil, reservoir simulator has been successfully ported to the Connection Machine massively parallel computer. Several problems with up to sixty-four thousand cells were simulated on a 4K processor Connection Machine 2 with performance similar to that of a large-scale, shared-memory, supercomputer. Scaled performance on a 64K processor CM-2 exceeded 1 GFLOP. Key to the parallelization of the model was the development of a fully-implicit linear equation solver based on the constrained pressure residual technique of Wallis1. Implementation of the solver involved the use of both multigrid-like and conjugate residual acceleration techniques. The effect of implicit well equations on the solver performance was investigated. Degradation of solver performance with problem and time step size was also investigated. Finally, the effect of communication overhead on model performance was evaluated for several cases.
A New High-Performance Linear Solution Method for Large-Scale Reservoir Simulation
Authors: Wallis J. R. 
Published: December 2007

Abstract
The solution of nonsymmetric linear systerns associated with a large three dimensional grid is frequently the most computationally expensive part of the reservoir simulation process. A new highly efficient iterative technique has been developed which significantly improves simulator performance particulary on vector computers such as the Cray Y-MP. The new preconditioning MVP combines power-ful approximation techniques used in preconditionings such as ILU(O)1, MILU(0)2, Nested Factorization3, INV4 and RS/ILU(0)5 with new ideas to develop a hybrid preconditioning very amenable to vectorization yet is very robust. The method has applicability to three dimensional grids using the conventional 7-point IMPES or implicit finite difference formulations and efficiently treats logically vertical faults and pinchouts. The method also reduces work and storage requirements by using a reduced system iteration.
Cost Control and Risk Mitigation of Major Projects
Authors: Caddy D. G. 
Published: December 2007

Abstract
In this paper and presentation, the four major types of estimates will be discussed, i.e., capacity factored, equipment factored, semi-detailed and detailed. Key relationships between particular portions of estimates will be discussed such as the relationship between direct field labor and indirect field costs.
Having set the basis for developing a project's cost through estimating, the paper will then list and discuss the fifteen key steps which must be followed to control the costs of a project.
Next, the subject of allowances and contingency will be discussed and defined and the differences between the two will be highlighted.
Having established exactly what contingency is, the subject of risk analysis through RANGE estimating will be discussed. The methods used to establish a precise contingency and probability of an over/under run will be discussed.
Finally, the paper will discuss the methods by which a project manager, owner or contractor can mitigate risks; that is to eliminate, transfer or minimize their effect.
Jerneh Gas Project Challenges and Implementation Performance
Authors: Perreau M. E. 
Published: December 2007

Abstract
The Jerneh gas project is part of Peninsular Malaysia's Gas Utililization Project, a mammoth undertaking to provide gas from the offshore fields off Malaysia's East Coast, to power stations and other industrial users throughout Peninsular Malaysia and Singapore. Prior to 1992, the only customers of the offshore Peninsular Malaysia gas were a local power station, and a steel mill in Terengganu, linked to the "Phase I" pipeline system shown in the map of Fig. 1. The Bekok platform is Esso Production Malaysia Ine (EPMI)'s gas collection platform for existing associated gas fields. The Duyong and Sotong platforms are gas production/compression platforms operated by PETRONAS (the Malaysian national oil company).
In late 1991, the onshore pipeline system was extended by PETRONAS to cover the west and south coasts of Peninsular Malaysia and Singapore depicted in the map (Fig. 1) as the "Phase II" system. With the completion of the Jerneh platform and offshore trunklines, Jerneh became the primary source of supply to an increased number of customers in the wider Phase II gas network. Jerneh is estimated to have three TCF of non-associated gas. Phase I customers were utilizing about 120 MSCFD and the demand is expected to initially step-up to 400 MSCFD in 1992 and progressively increase thereafter.
This paper provides an overview of the USS400M Jerneh project for which detailed design commenced in 1989 and was commissioned in 1992. The paper describes the technical challenges, project execution, safety record and actions to achieve the fast track schedule for this project.
Aluminum Chemistry Provides Increased Shale Stability With Environmental Acceptability
Authors: Clark D. E. , Benaissa Saddok 
Published: December 2007

Abstract
Previous laboratory and field evidence have proved that complexed aluminum compounds can be utilized in water-based drilling fluids to increase shale stability. This environmentally-sound chemistry has never been used to its utmost potential, primarily because the previous aluminum complex required pre-solubilization and pH neutralization. The low aluminum concentration resulted in high dilution volumes with associated increased drilling fluids cost, while taxing the surface mixing equipment on the drilling rig.
A newly invented approach simplifies the use of aluminum chemistry in drilling fluids. This new chemistry is the result of laboratory investigations that confirmed the inhibition characteristics on Wyoming bentonite. Further laboratory work proved the effectiveness of this chemistry on numerous shales of varying mineralogy. Field evidence in several areas of the world has reconfirmed that this aluminum chemistry can, cost effectively, be used to reduce the hydration rate of troublesome shales, stabilize well-bores, and reduce drilling problems. This chemistry has proved to have application when drilling troublesome shales with freshwater systems on land, seawater systems offshore, and high chloride systems in deepwater operations.
This approach for drilling fluid chemistry provides an environmentally sound replacement for current additives. It demonstrates increased shale stability without the addition of potassium or chloride ions. The resulting reduction in clay hydration eliminates the need for chrome lignosulfonate additions, especially in polymer-based drilling fluids.
A New Technique To Predict Multilayered Reservoir Characteristics Using Pulse Testing Data
Authors: Osman M. E. , Mohammed S. A. E. 
Published: December 2007

Abstract
In this study, a mathematical model was developed to present pulse and interference testing for multilayered reservoirs. It was found that apparaent storativity calculated from pulse testing data is always less than or equal to the actual storativity of the reservoir and that apparaent transmissibility is always greater than or equal to the actual transmissibility. For short cycle intervals, the fractional production rate from a particular layer is not proportional to it's tranmsissi-bility fraction. The effect of storativity variation on fractional production rate is negligible. Wellbore damage; affects both apparent transmissibility and storativity. Less accurate estimation of reservoir characteristics is obtained using pulse-test data as the contrast in reservoir properties increases and vice versa. A new approach is suggested to use data of single well test and pulse test to estimate properties of individual layers. The approach is demonstrated by a three-layer numerical example.
Reservoir Characterization: Efficient Random-Walk Methods for Upscaling and Image Selection
Authors: McCarthy J. F. 
Published: December 2007

Abstract
In recent years, with the increased availability of powerful computers, there has been much emphasis placed on improving the characterization of heterogeneities in reservoirs for simulation purposes. Software packages are becoming available which enable geologists and engineers to combine their field knowledge with the sophisticated techniques of geostatistics to generate stochastic simulations of the geological and petrophysical reservoir data. These simulations produce a (theoretically infinite) number of possible "realizations" of the reservoir, honouring the available data points and having the same histogram and spatial variability as the data. Fluid flow simulations appropriate to the recovery project being evaluated can be performed on an array of possible realizations to give a range of possible outcomes for important quantities such as the oil recovery factor. The object of the procedure is to facilitate a quantification of the uncertainties caused by the lack of detailed knowledge of the reservoir heterogeneity.
This paper addresses two difficulties associated with the above procedure — those of "image selection" and "upscaling". The stochastic simulations of the reservoir geology are usually performed on fine-scale grids to incorporate all the lithological data available from logs, cores and seismic. Before performing fluid flow simulations it is necessary to choose a few possible realizations representing the "best", "worst" and "average" cases. This is the problem of image selection. It is also necessary to use averaging procedures for the petrophysical parameters in order to scale the grid to a size accessible to reservoir simulations. This is the problem of upscaling. It is particularly difficult to devise efficient upscaling procedures for permeability because it is a transport parameter.
It will be shown how random walk methods provide an efficient and accurate alternative to costly fine-scale finite difference computations for upscaling and image selection in reservoir characterization. Simulations are performed on a variety of different realizations of the permeability distribution, generated by geostatistical, fractal and boolean methods, including the difficult case of sandstone/shale reservoirs. Both 2d and 3d examples are presented. Comparisons are made with finite difference simulations and with a variety of approximate methods suggested in the literature.
Development of New Modified Black Oil Correlations for Malaysian Crudes
Authors: Omar M. I. , Todd A. C. 
Published: December 2007

Abstract
In reservoir engineering calculations, reservoir fluid property data are one of the important input data sets. These data can be obtained either by conducting a laboratory study on reservoir fluids or estimated from empirical correlations. Although laboratory results give better accuracy where controlled reservoir conditions can be imposed, the results are heavily dependent on the validity of the reservoir fluid samples, especially when the reservoir has depleted below the bubble point pressure. In situation where the experimental data cannot be obtained or there is a need to cross check the laboratory results, empirically derived PVT correlations can be used to estimate the physical reservoir fluid properties. Since no black oil correlations have been developed for Malaysian crudes and none of the existing correlations give good estimates of fluid property for Malaysian crudes, this paper describes the development of suitable black oil correlations which give results more accurate than any correlations available in the literature.
A total of 93 PVT data taken from various Malaysian offshore oil-fields was used in the study. The PVT data consist of oil gravity range from 26.6 "API to 53.2 "API and bubble point pressures of 790 psig to 3851 psig. The crudes are essentially free of hydrogen sulphide with low nitrogen content (maximum of 1.15 per cent).
Using both non linear and linear regression analyses, new black oil correlations (of bubble point pressure and bubble point oil formation volume factor) were established for Malaysian crudes. These new correlations were developed based on Standing's existing equations. The most sensitive coefficient in the Standing correlations was determined and expressed as a linear function of other independent variable PVT parameters. The accuracy of the new correlations was determined by conducting statistical and graphical error analysis.
The results show that the new correlations give better accuracy in estimating reservoir fluid properties of Malaysian crudes than other known correlations available in the literature. The new correlations give low values of absolute average percent relative error, standard deviation with correlation coefficient values close to an ideal value of 1.0.
Development Planning in a Mature Oil Field
Authors: Pang S. S. M. , Faehrmann P. A. 
Published: December 2007

Abstract
The implementation of a plan for a 3-rig revisit campaign in a mature field, needs not only a sound multi-disciplinary field review as a basis, but also very detailed day-to-day actual well planning during the drilling phase. This is due to the need for constant evaluation of the impact of incoming well data on the yet to be drilled wells. Samarang Revisit Campaign II provides an Illustration on how a closely coordinated effort achieves the aim of maximising reserves in the most economic fashion. This effort is discussed in the context of a Joint Venture & Production Sharing Contract (PSC) environment.
Pressure Analysis of Gas Wells in Multilayered Reservoirs With Skin, Storage, and Non-Darcy Effects
Authors: Osman M. E. , Mohammed S. A. A. 
Published: December 2007

Abstract
This paper presents the first study of transient drawdown and buildup pseudopressure behaviour of a gas well located in multilayered infinite acting reservoirs wehre wellbore storage, skin and turbulence intensity effects were taken into account A mathematical model was developed to investigate the pseudopressure function and it's derivative for different situations of wellbore and reservoir characteristics. It was found that pseudopressure function ΨD, for all cases considered in this study, is characterized by a unit slope line (during early time) followed by a transition period and then a pseudoradial flow period during late time. The pseudopressure derivative function (Ψ’D*tPD) is characterized by a unit slope line, a curvature and then a constant value. The effect of the contrast in kh product on ΨD and Ψ’D*tPD was found to be significant compared to the effect of both skin factors and ϕh products. Type curves were developed for buildup and drawdown testing analysis. The drawdown type-curves can be used to analyze buildup test data as long as the duration of buildup test is less than the producing time before shuting-in the well. The fractional production rate from different layers can be evaluated using the mathematical model presented in this study. The results of a flow meter survey can be used to eva-luate the contrast in kh product of different layers.
Field Results of Applied Drilling Hydraulics in Deep Wells Using Nomographs
Authors: Mosby J.W. , Owens H.B. , Cheatham C. 
Published: December 2007

Abstract
One of the most important and critical factors in drilling a well is hydraulics. As wells go deeper, the drilling hydraulics calculations become more critical and lengthy. So that drilling personnel on the rigs can readily solve complicated hydraulics problems, a set of eight nomographs was developed. Mud volumes, velocities, type flows (laminar or turbulent) and pressure drops in drill pipe, across bits and in annulus are easily and rapidly found with the nomographs without solving equations. The equations derived for Bingham plastics were used in developing the pressure drop and flow nomographs. The pressure drop and flow nomographs. The nomographs have been found to be quite accurate and reliable.
Introduction
The drilling well hydraulic system is not unlike the circulatory system of the human body in its importance and functions. Good drilling hydraulics is probably the most important single factor in drilling deep, expensive wells. When drilling with water-base muds, the circulatory system of a drilling rig can be analyzed by employing the equations developed for Bingham plastics. Since solving the Bingham plastic fluid flow equations is both tedious and time consuming, nomographs were constructed. The prime reason for their development was to give the man on the rig a fast, simple, reliable means of solving his hydraulic problems. The field results have been excellent, and some of them are presented in this paper, along with the presented in this paper, along with the nomographs.
In planning development wells, parameters can usually be predicted with fair accuracy. In drilling rank wildcat wells, some parameters can be predicted, but others have to parameters can be predicted, but others have to be established while drilling. Although the nomographs presented in this paper are useful in drilling both type wells, it is in handling the unexpected problems, such as encountered while drilling wildcat wells, that they are of the most importance to the man on the rig.
BASIC REQUIREMENTS
There are many papers published in the literature which cover the different phases of planning and drilling deep or abnormally high planning and drilling deep or abnormally high pressured wells. pressured wells.