bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rheology and Transport in Porous Media of New Water Shutoff/Conformance Control Microgels
Authors: Rousseau D. , Chauveteau G. , Renard M. , Tabary R. , Zaitoun A. , Mallo P. , Braun O. , Omari A. 
Published: December 2007

AbstractThe performances of new microgels specifically designed for water shutoff and conformance control were extensively investigated at laboratory scale. These microgels are preformed, stable, fully water soluble, size controlled with a narrow size distribution, and non-toxic. They reduce water permeability by forming adsorbed layers soft enough to be very easily collapsed by oil-water capillary pressure, so that oil permeability is not significantly affected. Since the manufacturing process of these new microgels make possible to vary chemical composition, size and crosslink density, they can be designed as desired to meet the requirements of a given field application. The laboratory results reported in this paper concerns mainly three microgel samples having significantly different crosslink densities. We describe the relevant laboratory methods used to determine main microgel characteristics. The microgels have remarkable mechanical, chemical and thermal stability. Their behavior in porous media have been investigated extensively, showing that: 1) their propagation distance is only limited by the volume injected, 2) their injectivity is facilitated by a shear-thinning behavior and 3) water permeability reduction can be achieved as desired by controlling the thickness of adsorbed layer. Thus, this new microgels, now available at industrial scale, look as very promising tools, not only for water shutoff but also for conformance control in heterogeneous reservoirs.
Solution Error Models: A New Approach for Coarse Grid History Matching
Authors: O'Sullivan A. E. , Christie M. A. 
Published: December 2007

Abstract
This paper presents a new technique - solution error models - and applies it to the problem of history matching using simple coarse grid models. The solution error model technique is based on building a statistical model that describes the errors introduced in the simplified solution. The difference between observations and the coarse grid solution is measured by the "goodness of fit" (or misfit) term. The results show that a standard least squares approach to quantifying the misfit function yields significantly biased estimates of parameters, if the underlying model is biased. The bias can be almost completely corrected through use of the solution error model. The solution error model also introduces the use of time dependent covariance, instead of the usual single valued variance. This improves confidence in estimates of reservoir parameters.
An Extensible Architecture for Next Generation Scalable Parallel Reservoir Simulation
Authors: DeBaun D. , Byer T. , Childs P. , Chen J. , Saaf F. , Wells M. , Liu J. , Cao H. , Pianelo L. , Tilakraj V. , Crumpton P. , Walsh D. , Yardumian H. , Zorzynski R. , Lim K.-T. , Schrader M. , Zapata V. , Nolen J. , Tchelepi H. 
Published: December 2007

Abstract
We discuss an object-oriented, component-based architecture for a parallel reservoir simulator. The architecture successfully balances the need for extensibility, maintainability, and reuse with the need for efficient computation. Parallelism is hidden from the application developer via a set of abstractions and a unifying framework that supports static and dynamic load balancing on unstructured and structured grids. We explain how the simulator architecture supports black oil and compositional models within a general formulation, and how it achieves parallel scalability for all the major components: property calculation, Jacobian construction, linear solver, well model, input/output etc. Some initial results are discussed for a selection of models ranging from standard benchmarks to large complex field cases.

Motivation
Current generation reservoir simulators typically have a lifespan of at least 10 years. As a result, many of the simulators in widespread use have their roots in petroleum engineering, software engineering and computing technologies that were originally targeted at structured grids and scalar architectures. Advances in software and hardware technologies, parallel computing, advanced gridding and modern software engineering techniques have created new opportunities. At the same time, evolving workflows involving complex geological models, large full-field simulations, near well studies, production and facilities optimization, and stochastic modeling have placed new demands on reservoir simulation technology.
Although object-oriented design has been the main staple of software development for quite some time, its application to scientific programming has been hindered somewhat by the perceived inefficiency of run-time polymorphism. However, in recent years the emergence of compilers that are in full compliance with the C++ standard has made use of generic programming techniques commercially practical. Generic programming offers the benefits of encapsulation and code reuse without the overhead of virtual function calls1,2. Object- oriented and generic programming techniques using C++ have been shown to be useful in the development of scientific and numerical applications3,4.
Large-scale object-oriented frameworks for scientific computing have been developed in many contexts5, and parallelism has been addressed for example in the POOMA project6. Object-oriented architectures for flow simulations have been developed in other industries7 and these techniques have been applied to reservoir simulators by several practitioners within academia8,9,10,11,12 and also in industry13.
Sibling Rivalry: Competitive Tendering vs. Direct Selection - A Debate of Suitable Procurement Method on the Achievement of Supply Chain Objective in the Oil and Gas Operator Industry
Authors: Komala M. , Modana I. G. K. , Le Hello Y. , Naibaho S. 
Published: December 2007

Abstract
Competitive Tendering (read: Call-for-Tender) and Direct Selection (abbrv. DS) are kinds of procurement method that should provide oil and gas operator with sound quality service and materials (read: goods), timely deliverance, competitive price, and high service quality for the exploration, production, and health-safety-environment. In fact, both rarely go hand-inhand in contributing such objectives. That makes the "Sibling Rivalry" term is represented in this paper.
In this paper, the author uses a deductive analysis using pilot project of these methods by a major operator, benchmarking, and survey of the distribution network will show data as the impact on the application of particular method. The scope's limitation set along with parameter of Center for Advance and Purchasing Studies, research only on the upstream level of the industry, and the exclusion of specific regulation of a particular country. The conclusion of whether certain method more suitable for a particular situation would finally be presented.
Initial Souring Monitoring and Souring-Mitigation Testing Using an Online Souring-Mitigation Cabinet (SMC) Prior to Live Produced Water Reinjection (PWRI) and Nitrate-Based Souring-Mitigation Treatment on Norske Shell's Draugen Platform
Authors: Dinning A. J. , Oliphant D. , Vik E. A. , Bruås L. 
Published: December 2007

Abstract
The risk of reservoir souring is understood as one of the most serious effects of produced water reinjection (PWRI). Costly well backflows are traditionally used to monitor these effects. On Draugen (produced water 60°C, lean in carbon), a PWRI pilot is currently implementing nitrate to mitigate souring. Well backflows were not possible and another monitoring method for souring parameters was required. A souring mitigation cabinet (SMC) (two 1.4m columns with a 12 cm diameter, using a reservoir simulated sandstone medium), was designed. A side-stream of produced water was routed through the SMC over 3 months to allow typical reservoir biofilm development. Varying doses of nitrate (100, 80 and 50 mg per L) and nitrite (100mg per L) were then tested over a period of 15 days.
Stoichiometric inhibition of SRB souring by nitrate (80 mg per L) and removal of background sulphide (100 mg per L) was exhibited. Nitrite (100 mg per L) exhibited short term stoichiometric mitigation. Control sulphide varied between 5 and 9 mg per L. 80 to 85% utilisation of nitrate and nitrite was shown. Dissolved organic carbon consumption was 28 and 29%, indicating no exacerbated carbon consumption in the test column. A two log10 difference in mesophilic SRB (30°C) and thermophilic SRB (60°C) was exhibited between the columns. NRB did not vary.
The application of nitrate and nitrite stoichiometrically mitigated souring in the Draugen system and reduced the SRB population in the test column.
This demonstrates the use of a SMC with a biofilm of the same properties as that developing in the near well area during PWRI. Such studies may reduce the requirement of backflows and give the opportunity to repeat trials of different mitigation strategies during operation and independent of PWRI. The SMC is being maintained on Draugen and is currently used to control mitigation effects on bulk produced water during PWRI.
Exploration Well Testing With a Venturi/Dual Energy Gamma Ray Multiphase Flow Meter — A Case Study From Oman
Authors: Al Araimi N. M. , Jha N. K. , Al Zakwani S. 
Published: December 2007

Abstract
Throughout recent years, in exploration well testing, multiphase flow metering technology has offered an attractive alternative to conventional well testing equipment. To assess the benefits and limitations of multiphase flow metering technology in exploration well testing, a multiphase flowmeter was used in combination with conventional well test equipment on an onshore exploration well in Oman.
In exploration well testing, conventional equipment has to handle solids, slugs flows, well construction fluids (N2, HC1,…) and well effluents. These particularly challenging conditions affect the capacity of measuring accurately the produced and completion fluids. With the use of the multiphase flow meter, a more complete flow history was obtained through accurate clean up monitoring. Quantifying recovered completion fluids assisted in a timely decision about end of clean up period thus saving time, while a good match with expected recovery volume increased the confidence in acquired data.
This exploration well test was performed in a remote desert location with unpaved access roads. The well testing set-up using the multiphase flow meter had a smaller volume of equipment and the reduced weights and footprints led to savings in terms of mobilization and set up time.
This paper presents the multiphase well test equipment used for this exploration well test highlighting the advantages over conventional well test equipment. The various steps taken to validate the multiphase flow meter measurement with particular focus on the water cut measurement have been reviewed.
Optimizing Streamline Coverage for Efficiency and Accuracy
Authors: Matringe S. F. , Gerritsen M. G. , Mallison B. T. 
Published: December 2007

Abstract
The efficiency of streamline simulation, and in particular compositional streamline simulation, can be improved greatly if the streamline density is allowed to be locally adapted.A dense coverage is generally needed near composition fronts while in other areas of the flow domain a coarse streamline coverage may suffice to give accurate saturation and compositions. In the traditional streamline method,streamlines are viewed as fluid carriers. The associated low order mapping of compositions from the streamlines to the background grid used to solve for flow requires each background grid cell to be crossed by at least one streamline. This constraint prohibits local streamline adaptation and often leads to an unnecessarily high density of streamlines in large parts of the reservoir. For compositional problems, for which most of the computation time is spent on flash calculations along the streamlines, this approach leads to high and unnecessary costs. In such applications, it is crucial to minimize the number of streamlines, while ensuring a minimum streamline density to achieve the desired solution accuracy.
We view streamlines as forming a flow-based unstructured grid for transport. This viewpoint, together with an improved accurate mapping from streamline grid to background grid proposed by Mallison, Gerritsen and Matringe (2004)1 allows us to locally increase or decrease the streamline coverage. The new framework also allows partial streamlines (that do not start and end at wells) to be used to dynamically increase the local streamline density where necessary. To determine what streamline density is needed in different regions of the flow domain we designed an indicator that a priori detects areas of potential high mapping errors. The indicator takes into account the local density of streamlines as well as the proximity of solution fronts. This new streamline coverage control algorithm, combined with Adaptive Mesh Refinement (AMR) along the streamlines, can be viewed as an AMR strategy for the streamline grid.
Residual Oil Characterization for a California Turbidite
Authors: O'Brien C. P. 
Published: December 2007

Abstract
California's oil fields are rapidly maturing. Enhanced oil recovery may sustain the life of these fields. Residual oil saturation is one factor in determining the success of enhanced oil recovery projects. Miocene turbidite data from the giant Elk Hills Oil Field, California, illustrate a process to characterize laboratory residual oil saturation tests and approximate values in gravity drainage and waterflooding processes. This characterization will aid in assessing the potential of enhanced oil recovery in California's mature oil fields.
A New Upscaling Approach for Highly Heterogeneous Reservoirs
Authors: Zhang P. , Pickup G. E. , Christie M. A. 
Published: December 2007

Abstract
Upscaling in highly heterogeneous reservoir models is a very challenging procedure, despite much research having been carried out over the past few decades.The fluid flow depends on the well locations, and crossflow may be significant. Traditional upscaling approaches such as the pressure solution method with locally applied boundary conditions, may be highly inaccurate. In two-phase systems,such as waterfloods, accurate reproduction of the flood front is also problematic.Two-phase upscaling is often impractical,but using only traditional single-phase upscaling may lead to large errors.
In this paper we demonstrate how conventional upscaling approaches may produce erroneous results and suggest a simple alternative.The new method uses boundary conditions based on the actual well pressures and solves the single-phase pressure equation over the global fine scale geological model.Inter-block transmissibilities and upscaled well connection factors are then computed. By using the appropriate boundary conditions,single-phase flow is accurately reproduced,and therefore the accuracy of two-phase flow at the coarse-scale is greatly increased.
We have verified that the new method may be applied to two-phase, highly heterogeneous reservoir models, including models with multiple relative permeability curves and significant gravity effects.We have also applied the method to the benchmark model of the SPE 10th Comparative Solution Project(1.1 million cells, unstable flood). The results show good agreement with the fine grid solution provided by Landmark using a parallel simulator.
As models of tens of millions of grid cells are now solvable on a PC in an hour, this method is a feasible approach for achieving highly accurate upscaled models. This method is particularly appropriate for later stages of field development, when models are large and accurate flow simulation is required.
Performance and Emissions Studies of a Car Engine Fueled with Gasoline and CNG
Authors: Aslam M. U. , Masjuki H. H. , Kalam M. A. 
Published: December 2007

Abstract
The emergent alarm about the fast depletion of petroleum-based fuels and the environmental pollution caused by their combustion has been a compelling incentive to all researchers to find out the ways to use environmentally friendly and renewable resources of energy and also by technologies to increase vehicle energy efficiency. CNG (compressed natural gas) is the most desirable alternative fuel option to the researchers today for facing the energy crisis and environmental pollution problems properly. This is because of its availability, low exhaust emissions, superior performance and longer engine service life. Malaysia also trying to diversify its automotive fuel options by introducing new mono fuelled CND/DI (direct injection compressed natural gas) engine for utilizing the substantial advantages of CNG fully as an automotive fuel. In the present study a bi-fuel proton car engine has been run with gasoline and CNG and the performance and exhaust emissions of the engine are analyzed & compared. This result will be used as a basis for examining the performance and emissions of Malaysian new CNG/DI engine in future. Present study also focuses on the Malaysian mono fuel CNG/DI engine. From the experimental results, it is found that CNG produced less power, consumed less fuel per kwh and emitted less CO, CO2, HC and more NOx compared to gasoline. It is suggested to build up lighter CNG storage tank and widespread networks of CNG supply stations through out the country for general acceptance of CNG as an automotive fuel.
Modeling of Pre-Gel Aggregate Growth During the Gelation of a Polyacrylamide-Chromium(III) Acetate Gel System Using the Theory of Branching Processes
Authors: Cheng M. , Wang C. , McCool C. S. , Green D. W. , Willhite G. P. 
Published: December 2007

Abstract
Models that describe the pre-gel aggregate growth during the gelation of a polyacrylamide-chromium(III) acetate gel system are presented. Using the theory of branching processes, two models were developed to estimate the bulk gel time of a gel system and the molecular weight averages and distributions of pre-gel aggregates as functions of reaction time and initial conditions. A multi-angle laser light scattering instrument was used to determine the weight-average molecular weights of the pre-gel aggregates as a function of reaction time. Good agreement between the experimental data and the model results was obtained.
Permeability Prediction Using Pore Throat and Rock Fabric: A Model From Indonesian Reservoirs
Authors: Jaya I. , Sudaryanto A. , Widarsono B. 
Published: December 2007

Abstract
There is no easy way to estimate permeability from well logs. Porosity alone does not serve as a good predictor of permeability. Various empirical approaches have been commonly used to estimate permeability. The more parameters used in the algorithm the more impractical the formula. In fact, there are no causative relationships among the calculated parameters. Recent developments are marked by the use of pore throat size distribution for relating porosity to permeability (Winland and Pittman equations). The equations are theoretically correct but they are actually established for estimating pore throat size distribution and are not intentionally developed for the purpose of permeability prediction for uncored wells. In this light, it is this study that emphasizes the use of Windland and Pittman equations for permeability prediction and is the first study using samples from Indonesian reservoirs.
This study was carried out to improve the accuracy of permeability prediction of the traditional permeability-porosity relationships in uncored wells with particular attention given to low permeability datasets. Correlations between radius pore-throat aperture radii and porosity-permeability, using 315 core-plugs taken from Indonesian reservoirs, have been established. Application of the correlations shows that accuracy of permeability prediction is significantly improved when pore throat radii were incorporated. The study also take into consideration rock fabrics of the core-plugs on the basis of mercury saturation percentiles. For practical consideration, the correlations are also expressed in form of nomographs so that it can be used easily by engineers and petrophycicists. In using the nomographs, the input variables (pore throat and rock fabric) can easily be derived only from drill cutting samples underlining the practicality of the approach resulted from the study.
Performance Analysis of Compositional and Modified Black-Oil Models for a Rich Gas Condensate Reservoir
Authors: Izgec B. , Barrufet M. A. 
Published: December 2007

Abstract
The modified black-oil model (MBO) was tested against the fully compositional model and performances of both models were compared using various production and injection scenarios for a rich gas condensate reservoir.
We evaluated the performance of MBO model by investigating: the effects of black-oil PVT table generation methods from a tuned equation-of-state, oil-gas ratio (OGR) and saturation pressure versus depth as initialization methods, uniform composition versus compositional gradient with depth, location of the completions, production and injection rates, kv/kh ratios, and vertical wells versus horizontal wells.
Contrary to the common belief that OGR versus depth initialization gives better representation of original fluids in place, initializations with saturation pressure versus depth gave closer original fluids in place considering the true initial fluids in place are given by the fully compositional model initialized with compositional gradient.
Unrealistic vaporization in the MBO model was encountered in both, production by natural depletion and gas cycling. The changes in oil-gas ratio of the recyled gas showed that, it is not possible to accurately represent the changing PVT properties of the recycled gas with a single PVT table. Unrealistic vaporization also led to different arrival times for the displacement fronts and different saturation profiles for the near wellbore area and for the entire reservoir for the two models even though the production performance of the models was in good agreement.
The MBO model representation of compositional phenomena for a gas condensate reservoir proved to be adequate for full pressure maintenance, reduced vertical communication, vertical well with upper completions, and for horizontal well producers.