bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality User Support Supporting Quality Users
Authors: Woolley T. C. 
Published: December 2007

Summary
This paper describes how Oryx Energy Co. addressed problems and opportunities created by the explosive growth in computing power and needs coupled with industry contraction. A successful user-support strategy is described. Characteristics of the program include (1) client-driven support, (2) empowerment of highly skilled professionals to fill the support role, (3) routine and ongoing modification of the support plan, (4) use of the support assignment to create highly trained advocates on the line, and (5) integration of the support role to the reservoir management team. Results of the plan include a highly trained work force, stakeholder teams that include support personnel, and global support from a centralized support organization.
Modeling Decisions in Emergency Situations
Authors: Doheny J. G. , Fraser J. L. 
Published: December 2007

Summary
In this paper, we describe a methodology and supporting software tool that we developed for helping to model the decisions that people make in emergency situations offshore. We believe that this is the first time that people's decision-making has been incorporated into egress and evacuation models. Our work, therefore, is an important first step in the introduction of improved approaches to the evaluation of platform layout, facilities, and emergency procedures.
We worked with our collaborators to integrate our model of people's decisions with their model of people's movement. Our result indicates that people's movements are modified by factors such as their reactions to alarms, their reactions to hazards, their familiarity with the installation, their training, and their roles. Our program has a generic architecture for modeling decisions. We used "scripts" to define typical actions or procedures associated with particular conditions: people in the computer simulation adopt particular scripts according to the situations in which they find themselves.
In future developments, we would like to improve the decision model by incorporating communication between individuals as a scenario proceeds. This would be particularly useful in (1) scenarios that go beyond muster to evacuation, (2) scenarios where there is significant structural damage, (3) scenarios where there are casualties, and (4) scenarios that cannot be simulated realistically in exercises.
The software runs on a 486 PC under Windows 3.1. Safety analysts can build floor plans and set up scenarios with different facilities, populations, or hazards to determine their various effects.
Multivariate Optimization of Networked Production Systems
Authors: Fujii Hikari , Horne Roland 
Published: December 2007

SummaryToday, many oil and gas production systems have flowline networks with many wells and surface pipelines. In the design of such production systems, the determination of parameters like separator pressure, the diameters of tubing, pipeline, or surface choke, and the length of pipeline is important to the achievement of an optimum production rate.The optimization of such problems, however, has been difficult because of the nonlinearity of the solution caused by the interaction between these parameters. In this work, multiple production parameters were optimized simultaneously in well networks in terms of a profit-based objective function, such as total production rate, net income from the oil product, or present value discounted by interest rates. The techniques applied in this work were Newton-type methods (derivative based), the polytope method (function-value based), and a new technique that uses a genetic algorithm (GA). On the basis of several test calculations on various types of optimization problems, the polytope method turned out to be the most efficient and consistent for low dimension problems with small numbers of wells, while the GA performed well in large systems with many variables to be optimized.The optimization of a pipeline network system was achieved successfully without any limitation on the selection of objective functions and decision variables to be optimized. The optimization technique can be used in the design stage of newly developed fields or in the planning of workovers in existing fields. The combination of this technique with reservoir simulation would be a powerful tool in a project implementation design process.
Laboratory Investigation of Combination of Alkali/Surfactant/Polymer Technology for Daqing EOR
Authors: Shutang Gao , Huabin Li , Hongfu Li 
Published: December 2007

Summary
Alkali/surfactant/polymer (ASP) formulas were developed for the Daqing oil field, Peoples Republic of China, with two surfactants from the U.S. (Petrostep B-100 and a blend of TRS-18 and TRS-40) and one Chinese surfactant (PS-D2). Each ASP solution gave interfacial tension (IFT) values in the range of 1 × 10−3 mN/m. Rheologic studies with polyacrylamide polymers indicate that solution viscosity decreases with alkali addition, as does the pseudoplasticity of the solution. Addition of surfactant to the alkali/polymer solution increases the solution viscosity with no slope change in the viscosity-vs.-shear-rate plot. Incremental oil recovery was higher than that with waterflood; 20% original oil in place (OOIP) for 0.2-PV ASP injection and 33% OOIP for 0.3-PV ASP injection in Daqing core. Surfactant and alkali retention were both &lt; 1 mg/g sand. The positive results of this laboratory study provided a fluid formula for a pilot ASP flood in the Daqing oil field.
The Release of Solution Gas from Waterflood Residual Oil
Authors: Hawes Robert I. , Dawe Richard A. , Evans Richard N. 
Published: December 2007

Abstract
A series of experiments have been undertaken to visually observe the formation and growth of bubbles formed when solution gas is released from waterflood residual oil. The experiments were performed using an etched glass micromodel which represented a two-dimensional section of a sandstone core. This micromodel was mounted vertically within a temperature controlled water bath, and the flow of fluids within the micromodel was observed through a microscope and recorded on video. Experiments were performed under water-wet conditions, using a mixture of low boiling point hydrocarbons, which had a positive spreading coefficient for the oil phase in contact with water and its own vapour. In these experiments the gaseous phase was produced by raising the temperature of the micromodel until it reached the bubble point of the oil, at atmospheric pressure.
The following features were observed:
In keeping with the spreading oil, all gas that was generated as bubbles within the oil ganglia from which it was produced. Bubbles did not form in all ganglia, nor did they all form at the same time. As more gas was released from solution, the bubbles expanded, pushing the gas/oil and oil/water interfaces outwards. Buoyancy forces had little initial influence on the expansion, which occurred in all directions. The bubbles themselves were unable to migrate, and the gas remained immobile until the volume of individual bubbles had increased to the extent that adjacent bubbles became connected. The oil phase was transformed from being immobile droplets or ganglia, into films surrounding the gas bubbles, in which the oil was mobile.
A mathematical model for the growth of a single bubble has been developed, which includes the effect of gravity as well as capillary forces in controlling the development of the bubble. Calculations using this model show that the initial growth pattern is dominated by capillary forces, but as the bubble becomes larger buoyancy forces start to play an important part in the way that the bubbles grows.
CO2 Foam: Results From Four Developmental Field Trials
Authors: Hoefner M. L. , Evans E. M. 
Published: December 2007

SummaryFour pattern-scale CO2-foam field trials were conducted to determine the effectiveness of foam in reducing CO2 channeling, to evaluate the economic potential of the process, and to develop application criteria and procedures. The trials were conducted under various process and geologic conditions so that the resulting technology would be applicable in a number of different CO2 floods. Two different surfactants, Rhodapex (formerly Alipal) CD-128 and Chaser CD-1045, and two injection methods, alternating vs. coinjection of CO2 and surfactant, were tested in San Andres (west Texas) and platform carbonate (southeast Utah) reservoirs. In all, 161,000 Ibm of active surfactant was injected in the four field trials, with one well undergoing foam treatment for as long as 18 months. The treatments resulted in a significant reduction in gas production and indications of increased oil production. The total cost of the four treatments (excluding labor and overhead) was $700,000.
Case History and Appraisal of the Medicine Pole Hills Unit Air-Injection Project
Authors: Kumar V. K. , Fassihi M. R. , Yannimaras D. V. 
Published: December 2007

Summary
The Medicine Pole Hills Unit (MPHU) EOR project is the deepest air-injection/in-situ-combustion project in the Williston basin. A unit comprising 9,600 acres with 13 producing wells was formed in July 1985, and air-injection operations began in Oct. 1987. Laboratory combustion tests and detailed feasibility studies were completed before starting the full scale project. The combination of light oil (39°API), carbonate formation, hot reservoir (230°F), and low permeability (1 to 30 md) makes this a unique air-injection project. Cumulative air injection as of Dec. 1993 was 12 Bscf. This paper reviews production performance of the MPHU to date. Oil production from the unit has shown a significant increase over its historical decline, and a processing plant has been installed to recover the liquids stripped from the oil by the produced flue gas. Although well workovers, acid fracturing, and pump changes in some producers complicate the determination of the oil response to air injection, production decline-curve analysis was used to estimate the incremental oil recovery due to air injection. The current air/oil ratio (AOR) is 8 Mscf/STB. Also discussed are the changes in air utilization over time, the benefits of the liquids recovery from the produced-gas stream in such a light-oil project, and an estimate of the field burned volume.
Simulating Flow in Heterogeneous Systems Using Streamtubes and Streamlines
Authors: Thiele M. R. , Batycky R. P. , Blunt M. J. , Orr F. M. 
Published: December 2007

Summary
We present a fast technique for modeling convective displacements that are dominated by large-scale reservoir heterogeneities. The novel feature of our method is the integration of any 1D solution with periodically updated streamtubes or streamlines to simulate displacements in two and three dimensions. We use streamtubes in two dimensions and streamlines in three dimensions. We construct approximate solutions using two to five orders of magnitude less computation time than by conventional simulation. Our approach allows us to decouple the physics describing the displacement from the size of the grid used to model the reservoir geology. In addition, because 1D solutions are often analytical, or can be obtained numerically using higher-order methods, the resulting 2D and 3D solutions are free of numerical diffusion.
We present examples in two and three dimensions for a variety of displacement mechanisms and compare our results with conventional finite-difference solutions showing excellent agreement. Because of its speed, our method becomes particularly effective for estimating the uncertainty in forecasting reservoir performance resulting from the uncertainty in the description of the reservoir geology.
Modeling Early-Time Gas Migration Through Cement Slurries
Authors: Prohaska Michael , Fruhwirth Rudolf , Economides M. J. 
Published: December 2007

Summary
This work identifies a mechanism that could be responsible for substantial gas invasion into a cemented column after placement. A model is developed to predict the risk for gas invasion and to aid in the design of a cement job suggesting a "tail" and a delayed "lead" slurry. The model provides the absolute theoretical migration height when cement properties and formation parameters are known. The work accounts for the calculation of the hydrostatic pressure drop, for the estimation of the inflow rates resulting from shrinkage and filtration, and for the description of the bubble-rise process. A sensitivity study on important design and well parameters is included.
Air Foam Improves Efficiency of Completion and Workover Operations in Low-Pressure Gas Wells
Authors: Scott S. L. , Wu Yulin , Bridges T. J. 
Published: December 2007

Summary
Air foam has developed into a cost-effective alternative to nitrogen foam for completion and workover operations in low-pressure gas wells. In most cases, air foam represents less than one-third the cost of nitrogen and is being used with increasing frequency in the Texas/ Oklahoma Panhandle region of the U.S. This paper addresses the three traditional concerns associated with the use of air foam: (1) lower available pressures and rates, (2) flammability, and (3) corrosion. The paper also details the use of these portable air-foam units in circulating operations, including coiled tubing. Newer applications are discussed where air foam can reduce costs compared with swabbing. Experimental results demonstrate that air foam can be used at circulating temperatures up to 120°F with commercially available corrosion inhibitors. We show that extension of air foam to deep wells with temperatures up to 350°F is possible with a newly developed inhibitor.
An Integrated Approach to Gas Well Deliverability Analysis, Hugoton Field
Authors: Sweeney M. J. , Sites O. A. 
Published: December 2007

Summary
This paper describes an integrated approach for analyzing gas well deliverability for a large complex well system by using electronic gas measurement (EGM) data, inflow/outflow performance (IOP) prediction, material balance, and pipeline modeling. The primary benefit is a more accurate production forecast for project analysis.
In the past, determining gas well deliverability for a large multiwell system (MWS) was difficult because an efficient method was not available to analyze fully rate and pressure information, completion configuration, proration regulations, state test information, gathering system response, and reservoir material balance.
Recent developments in technical software and hardware and the widespread use of EGM have led to more efficient and accurate determinations of wellhead deliverability.
Representation of Reservoir Geometry for Numerical Simulation
Authors: Hirasaki G.J. , O'Dell P.M. 
Published: December 2007

Abstract
For most reservoirs the reservoir thickness and dip vary with position. For such reservoirs, the use of a Cartesian coordinate system is awkward as the coordinate surfaces are planes and the finite-difference grid elements are rectangular parallepipeds. However, these reservoirs may be efficiently parallepipeds. However, these reservoirs may be efficiently modeled with a curvilinear coordinate system that has coordinate surfaces that coincide with the reservoir surfaces. A procedure is presented that may be used to determine a curvilinear coordinate system that will conform with the geometry of the reservoir. The reservoir geometry is described by the depth of the top of the reservoir and the thickness. The mass conservation equations are presented in curvilinear coordinates. The finite-difference equations differ from the usual Cartesian coordinate formulation by a factor multiplying the pore volume and transmissibilities. A numerical example is presented to illustrate the magnitude of the error that may occur in the computed oil recovery if the Cartesian coordinate system is simply modified to yield the correct depth and pore volumes.

Introduction
Many reservoirs have a shape that is inconvenient and possibly inaccurate to model with Cartesian coordinates. The use of a curvilinear coordinate system that follows the shape of the reservoir can be advantageous for such reservoirs. The formulation discussed here will have the greatest advantage in modeling thin reservoirs but will have little advantage in modeling a reservoir whose thickness is greater than its radius of curvature, such as a pinnacle reef. pinnacle reef. In this paper the reader is introduced to various grid systems used to model reservoirs. A brief discussion of some concepts of differential geometry contrasts differences between Cartesian coordinates and curvilinear coordinates. A curvilinear coordinate system for modeling reservoir geometry is presented. Formulation of the conservation equations in curvilinear coordinates and the necessary modifications to pore volume and transmissibility are discussed. A numerical example illustrates the magnitude of the error that may result from some coordinate systems.
Evolution of Analyzing Reservoir Simulation Data
Authors: Phelps R. E. , Huang A. Y. 
Published: December 2007

Summary
Petroleum-producing companies world-wide routinely use numerical reservoir simulation as an engineering tool to manage their hydrocarbon reservoirs efficiently. The task of building models with a large number of gridblocks is not easy, and analyzing the voluminous results produced by such models is even more difficult. This paper discusses the historical evolution of techniques used to analyze reservoir simulation data over the past decade. It outlines how the advancement of workstation technology and the introduction of an X-Window system opened up an entirely new way of using mainframe computing power and workstation graphical display capabilities simultaneously. The paper also discusses Saudi Aramco's experience in the development of sophisticated reservoir simulation postprocessing packages. We emphasize the need for direct communication between the programmer and end users to facilitate a userfriendly package.
We present a practical example illustrating the benefit of these postprocessing packages in the construction and history matching of a large model with approximately 52,000 cells. We estimate savings in manpower and computer resources using current technology.
Scanned Well-Log Image and Digital Data Management
Authors: Zainalabedin K. A. , Derr M. E. , Fenn C. J. 
Published: December 2007

Summary
As part of a comprehensive, multidisciplinary data-management project, libraries of computer-archived well logs that provide access to both scanned-image and digitized-curve data are under development. A comprehensive set of retrieval and management tools facilitates log-image and digitized-curve access and use.
Images are accessible for viewing on Unix workstation and mainframe terminals at all office locations and also may be plotted as hard-copy paper prints. Network connectivity and file sharing also facilitate transfer to workstation analytical software.
By using the central mainframe as a library and catalog manager, mass storage and database-intensive management tasks are handled outside of the Unix networks. Independence from the rapidly developing workstation network environment reduces database maintenance and permits longer-term data management planning than would otherwise be practical.
Image libraries are a developmental step in a trend toward an imagebased work environment in which well-log and other geotechnical image data are expected to become primary analytical resources.
An Integrated Deterministic/Probabilistic Approach to Reserve Estimations(includes associated papers 31056 and 35248 )
Authors: Patricelli J.A. , McMichael C.L. 
Published: December 2007

Abstract
Mobil Oil Exploration and Producing Corporation utilizes a unique methodology for reserve and resource evaluation. The approach integrates both deterministic and probabilistic methods to evaluate externally reported reserves and establish the full hydrocarbon potential of our projects. There are three basic classifications for hydrocarbons in our reserve/resource system; Reserves (appropriated projects that are economic at today's prices), Contingent Resources (projects being appraised or not viable with today's prices and technology), and Speculative Potential (yet to be drilled). In addition, the Reserves and Contingent Resources classifications each have three categories: Proved, Probable, and Possible. Proved and Probable are calculated deterministically utilizing in house definitions which conform to SEC and SPE guidelines.
Monte-Carlo simulation is then run to establish the cumulative probability distribution for recoverable hydrocarbons. This distribution and the deterministic results are used to define the possible category and to establish the project expected value. Average risk factors are calculated for each of the categories to ensure they meet Mobil guidelines. These average risk factors (truly confidence factors) are reported in association with their category value. The ultimate or EV is then used for economic assessment of the field and equals the projected ultimate recovered amount.
Screening of Geostatistical Reservoir Models With Pressure Transients
Authors: Herweijer J.C. , Dubrule O.R.F. 
Published: December 2007

Summary
A geostatistical reservoir study provides an ensemble of possible reservoir models, with a variability reflecting the uncertainty of the geology and fluid-flow properties. A production test links the static geostatistical model with dynamic fluid-flow data and thus provides possible means of validation and selection. We used a highly efficient 3D single-phase simulator to simulate pressure transients without compromising the fine-grid resolution typical for geostatistical models. This simulator was applied to Boolean and Gaussian geostatistical models that represent reservoirs consisting of heterogeneous fluviodeltaic deposits. Simulated buildup and interference tests were analyzed and related to 3D permeability and connectivity patterns. Effective well-test permeability was compared with 3D averages obtained from different volumes within the geostatistical model. The cases studied show that combining geostatistical models and well tests can reduce uncertainty with respect to geometric connections and the permeability distribution. However, the study also confirms that well tests have a limited capability to assess lateral continuity precisely and uniquely. Simulation of an interference test has the potential to screen the geostatistical model for high-permeability connections between wells. This pragmatic integration of pressure transients and detailed heterogeneous reservoir models through forward simulation provides a simple means to evaluate these models. It allows testing a model based on small-scale (core-plug) permeabilities and qualitative geologic information vs. routine field measurements representing large-scale hydraulic behavior of a reservoir.

Introduction
During the early stage of field development, production tests are the only data providing information about fluid flow in oil reservoirs and about permeability in the wider volume surrounding a well. At the same stage, construction of a geostatistical reservoir model is now a viable option. The main purpose of this model is to assess the uncertainty of reservoir performance resulting from incomplete knowledge of the heterogeneous reservoir. Geologic data and core measurements are honored at the wells, and models are created between wells that are statistically similar to those inferred from geologic analogs. These are static data, and subjecting the geostatistical model to verification on the basis of dynamic fluid-flow data (i.e., pressure-transient production tests) is a logical step. The pressure transient reaches faraway boundaries in a relatively short time.