bluuebunny/crossref_metadata_2025 huggingface dataset:
Application and Analysis of Tensor Permeability to Crossbedded Reservoirs
Authors: King M. J.
Published: December 2007

Tensor permeability may be used to describe fluid flow through layered and cross-bedded reservoirs, in which the natural directions of flow are not those of an imposed pressure drop. We present a discussion of tensor permeability, involving its nature and properties, method of computation, and an application to a naturally cross-bedded formation.
Analysis of Pressure and Pressure Derivative without Type-Curve Matching – III. Vertically Fractured Wells in Closed Systems
Authors: Tiab Djebbar
Published: December 2007

This paper is the third of a series of papers which discuss the application of the direct type curve synthesis technique for interpreting pressure transient tests in various reservoir systems. This new technique analyzes log-log plots of pressure and pressure derivatives without using type curve matching. This new approach is applied in this paper to the case of vertically fractured wells in closed systems. Both uniform flux fracture and infinite conductivity fracture cases have been investigated using log-log plots of pressure and pressure derivative functions.

For the uniform flux fracture case, pressure derivative plots for various xe/kf, ratios reveal three dominant flow regimes. During early times the flow of fluids is linear and can be identified by a straight line of slope 0.5. The linear flow line is used to calculate the half-fracture length. The infinite acting radial flow regime, which can be identified by a horizontal straight line, is dominant for xe/kf>8. This flow regime is used to calculate permeability and skin. The third straight line, which corresponds to the pseudosteady flow regime, has a unit slope. This line is used to calculate the drainage area and shape factor. Several simple equations have been derived using the time of intersection, and slopes of these three lines. These equations can be used for verification purposes or for calculating reservoir parameters if one of the flow regimes is missing such as in short tests.

For the infinite conductivity fracture case, pressure derivative plots reveal a fourth dominant flow regime, called here the bi-radial flow. This flow regime, which corresponds to the transition period between the early-time linear flow regime and the infinite acting radial flow regime, can be identified by a straight line of slope 0.36. The bi-radial flow regime can be used to calculate the half-fracture length, in the absence of the linear flow line. The permeability can also be obtained from this regime if the radial flow regime is not dominant, such as when xe/kf≤8. A step-by-step procedure is provided for calculating reservoir parameters of a vertically fractured well inside a closed system.
3-D Visualization in the Gravel Placement Process
Authors: Nguyen P. D. , Smith E. L. , Fanty S. D. , Woodbridge G. A. , Weaver J. D. , Restarick H. L.
Published: December 2007

A visualization software tool has been developed to aid in the analysis of the numerical output generated by a 3-D gravel pack simulator. The tool provides animated 3-D graphics showing the condition of moving fluids and the progress of gravel placement within the wellbore. The advantages, limitations, and pitfalls in implementing the 3D visualization for analysis of gravel pack simulation results are addressed.
A New Gravel-Sizing Computer Package for Effective Sand Control Design and Evaluation
Authors: Oyeneyin M. B. , Peden J. M. , Ren Guowu , Bigno Yann , Hosseini Ali
Published: December 2007

In this paper the details are presented of a software package which represents a new strategic approach to the selection of an optimum gravel size for effective sand control. The new approach not only considers the formation sand size distribution in the choice of the gravel to use, it goes further to evaluate the response of the probable gravels to operating conditions and the overall effect on the well production capacity

This software package which operates in a DOS ‘pseudo’ Window environment is developed on the premise that the best gravel size selection is a function of not only the formaton sand size distribution but also other characteristics such as sand sorting and shape, gravelpack structure which dictates the pack pore throat distribution, and operating conditions and the overall effect on the well production capacity.

The design and evaluation tool is made up of: A gravelpack structure simulator (Package 1) whose primary function is to carry out a 2-D/3-D simulation of the gravelpack structure from which the maximum pore throat distribution and corresponding poroperm data and pack structure coefficient are computed.The gravel sizing package(Package 2) which is the main subject of this paper is made up of three distinct but interrelated modules namely, the pack structure module, the bridging efficiency module and the well performance module. The possible gravels to use are selected with the pack structure module which permits history matching of the formation sand size distribution with the corresponding pore throat distribution of select gravels. The bridging efficiency module thereafter evaluates the bridging effectiveness of the selected gravels and the probable gravel is finally selected on the basis of the overall well performance evaluation.

Specific case studies have been considered to demonstrate the use of the package.
Object-Oriented Finite Element Analysis and Its Application in Basin Modelling Software
Authors: Ferguson J.C. , Iliffe J.E.
Published: December 2007

Object-oriented software design has provided many benefits to the development of scientific software by encapsulating the attributes and behaviour of models into separate entities or objects that can interact with other objects in the software project. Objects communicate via message passing not by external reading and writing of an object's attributes. This results in more maintainable code since variables can only be modified by the object's own methods. Furthermore, inheritance creates opportunities for extensibility. Finite Element Analysis is a powerful tool for modelling heat and fluid transfer in, and the deformation of, complex shapes. The method achieves generality by allowing element definition to proceed to some extent without regard to the geometry of the problem. It is only after the elements are 'embedded' into the problem space that their geometry is set. This separation of element definition and general methods for solution of the global matrices suggests that the Finite Element Method can benefit from an object oriented structure. A more complex element can be created by inheriting properties from a simpler element and adding any specific behaviour. Thus elements can be designed to match specific problem requirements more easily. Much of the element's complexity is hidden from the rest of the program making overall development simpler. We present a prototype object oriented library for applying the Finite Element Method and analyse its general structure and its benefits. Finally, we present an example of its application to 2-dimensional heat transfer within a basin.

Introduction

Basin modelling is a process whereby exploration geologists investigate the hydrocarbon potential of a geological basin area. Oil and gas are produced when organic material is subjected to an elevated temperature over a sustained period of time. Once produced, hydrocarbons may migrate due to pressure gradients in the source rock to a new location in the basin, the reservoir. Basin modelling is a four fold process:Reconstruction of the basin geometry back through to the age that the sediments were deposited, (this involves determination of the structure at present day, removal and decompaction of the sediments to obtain the time-depth history of the sediments, and restoration of any blocks that may have moved along faults).

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Geophysical Applications of Parallel Computing
Authors: Daube François , Highnam Peter , Ullo John
Published: December 2007

All current high performance computing platforms utilize parallel processing technology, with system sizes ranging from less than ten to a few thousand powerful processors. Geophysical computational tasks are now almost invariably 3D, from the processing of 3D seismic surveys to the modeling of wireline logging measurements. This paper reviews the computational challenges presented by 3D geophysics and describes the results that we have achieved using highly parallel systems. Because 3D structures are inherently more complex than 2D structures, realizing the full benefits of high performance systems requires ever more sophisticated visualization and model construction tools. We briefly review work on employing highly parallel systems in support of such tasks.
An Innovative Data Modeling Methodology Applied to Petroleum Engineering Problems
Authors: Chalon Philippe , Karcher Bruno , Allen C. N.
Published: December 2007

An innovative approach to modeling exploration and production data was derived from using an advanced, ISO standard, information description language, EXPRESS. In addition architectural principles have been developed to provide a strong structure to integrate data relevant to all the numerous disciplines of exploration and production. As a result this model is about one tenth as voluminous as in a classical structure, and provides more flexibility and extensibility.
Global Networking: Implications for Petroleum Engineers
Authors: Bailey J. A.
Published: December 2007

The current, rapid growth in the use of global networking promises to have an important impact on the way that all professionals, including petroleum engineers, do their work. Currently, this networking activity is embodied in a facility called the Internet. The Internet now consists of more than 1,000,000 computers (hosts), worldwide, connected by a variety of transmission media. Through this facility, professionals can communicate with colleagues by electronic mail, can have access to a massive collection of programs and data, can participate in special-interest discussion groups chosen from thousands available and may eventually receive many of their professional journals in an electronic form. It is the thesis of this paper that these resources will cause a qualitative change in the way petroleum engineers plan, organize and conduct their work. The Internet could even change the way petroleum companies structure their engineering organizations.

This paper examines the structure of the Internet, details the resources currently available through it and attempts to project the impact of global networking on the lives of working petroleum engineers.
An Improved Human Interface for Computer-Based Log Interpretation
Authors: Skolnakorn Jirapa , Morriss S. L.
Published: December 2007

Information from well logs is invaluable to the oil industry. However, only a limited number of people are able to fully utilize their logs by applying modern analysis techniques. Part of the limitation stems from the difficulty in learning to use log analysis software. There are a number of features that would serve to improve the human interface of this software, such as treating log curves as mouse-selectable objects which can be copied and moved to other displays or other tracks using familiar "cut and paste" methods common to graphical interfaces now found on personal computers. Observations of university students in an advanced logging class using two commercially available computer-based log interpretation programs helped identify performance obstacles encountered by users with limited experience. An experimental interface design which incorporates a number of new features has been developed using an advanced object-oriented development environment, thus allowing a great deal of flexibility in implementing changes and adding new features based on feedback from actual users.
Rod Pumping Expert System
Authors: Martinez E. R. , Moreno W. J. , Castillo V. J. , Moreno J. A.
Published: December 2007

This paper describes the development of a rod pumping expert system in which methods of emergent computation are extensively used. These methodologies include artificial neural networks (ANN) and genetic algorithms (GA). The system is implemented in order to provide assistance to the production engineer both in the problem diagnostic of operating units and the design of rod pumping facilities. The chosen computational methodologies prove to be very efficient in executing these tasks and require considerably less implementation time than other more common expert system methods.

The problem diagnostic method, implemented in the system, is based on the analysis of field dynamometer data by means of an ANN. These ANNs are computational tools, inspired on models of biological neural systems, with remarkable signal processing capabilities proven to be effective in areas such as pattern recognition and classification. The diagnostic task is achieved by using an ANN to analyze the down-hole pump cards and by means of its pattern recognition ability evaluate the condition of the pumping equipment. The ANN reacts to gross and subtle data features in the down-hole card and produces a response generalized from the "knowledge" stored in the network during a training process.

The facility design module of the expert system is implemented by means of a GA which executes an "intelligent" search in "pump configuration space" in order to produce automatically and fast several optimal design proposals compatible with the equipment restrictions and the "target" production entered by the user. Genetic algorithms (GA) are global search methods inspired in the principles of genetic evolution, which have been found to be very well suited for a multiparametric search in complex spaces. This outstanding search capability of GA is exploited in the configuration of rod pumping system designs based on the API RP 11L procedure. A run of the design procedure outputs several optimal configurations with the corresponding strokes per minute, plunger size, pumping speed, sucker rod type and operating characteristics.

Use of the expert system has proven to reduce the expertise required for problem diagnosis and design in rod pumping systems with considerable savings in the engineer man hours required by those tasks.
Document Management Systems: A Small Business Unit Implementation
Authors: Magstadt T. J. , Engler R. A.
Published: December 2007

An outline of the requirements developed to select and implement an electronic document management system for a small business unit is presented. Emphasis is placed on the system installed and how that system is being used to provide a wide variety of data access services to managers, supervisors and staff. Integration of the system into a multi-platform, LAN environment with other more traditional database resources is also discussed.

Questions that will be addressed include: What are some of the key components which should be considered when embarking on an investigation of document management systems and their potential use in the petroleum industry?How do we provide data in a timely manner to the people who need that information to make decisions?What are some of the key issues which arise when implementing a document management system?
PC-Based Cement Job Design System Improves Primary Cement Jobs
Authors: Kulakofsky D. S. , Henry S. R. , Porter David
Published: December 2007

Before the advent of graphical user interfaces (GUIs), cement job simulation programs were difficult to use, requiring large computer systems and occasionally yielding results that were difficult to understand. Often, the data input task was cumbersome enough to limit usage of these simulators. With the wide variety of today's Windows™*-based PC graphics packages, however, complicated results can be made understandable through visual displays. This paper describes a technically advanced, user-friendly, PC-based primary cement job design system that can use temperature-dependent rheology and Critical Reynolds Number when calculating frictional losses.
Flue Gas Generation Problems, Solutions and Cost - Block 31 Field
Authors: Caraway George E. , Lowery Leo L.
Published: December 2007

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

This paper outlines the physical equipment and flow of the Atlantic Richfield et al 54 MMCF/D Flue Gas Plant located in the Block 31 Field, Crane County, Texas. Conservation of resources; water, natural gas and energy was incorporated in the initial design.

Corrosion has been of primary concern to the operator. The results of a program evaluating ammonia and filming amines to control corrosion are reported.

Operating information is submitted on staffing, mechanical and fouling problem, factors governing the manufacture of flue gas as a ratio to input fuel gas and dehydration.

A method to be utilized in estimating cost of any size flue gas plant is suggested.

Introduction

The world's largest flue gas operation is being conducted in the Block 31 Field, Crane County, Texas. This multi-pay field was initially discovered by The Atlantic Refining Company, now Atlantic Richfield Company, in November, 1945. Early in the field's life, the industry's first miscible displacement program was started in the Devonian reservoir. At the time the 54 MMCF/D flue gas plant started operations on March 8, 1966, the miscible program had been conducted for approximately seventeen years. Prior to construction of the flue gas plant, a conventional gasoline plant and injection facilities were in operation. By taking a portion of the absorber residue gas and burning in a controlled atmosphere the volume can be increased nine to eleven times. The economic attractiveness of such a procedure was the discontinuation of purchasing 30 to 40 MMCF/D of natural gas, release for sale of 20 to 30 MMCF/D of produced gas and the assurance of a continuing source of displacement medium for the reservoir. In addition, the flue gas plant will increase oil recovery from the field through an extension of the economic life of the injection program.

PROCESS DISCUSSION

A diagram of the overall processing scheme of the Block 31 facilities is shown in Figure 1. Feed stock for the flue gas plant is absorber residue gas and air.

Incorporated in the flue gas plant is a treating system for the absorber residue gas prior to its combustion in the flue gas generators. The processing objective of the treating plant is to reduce sulfur content to a minimum.
An Improved Design Equation for Tubular Collapse
Authors: Issa J. A. , Crawford D. S.
Published: December 2007

This paper presents a new equation for predicting the collapse of tubulars under external pressure. The development of the equation is based on a large number of non-linear finite element simulations of tubulars with different geometrical tolerances and mechanical properties. The simulation results for the collapse pressure and post-collapse geometry of the tubulars were verified with full scale physical tests. A nonlinear regression analysis was then performed on the data obtained from the simulations to optimize the parameters of the collapse equation. The new equation accounts for variations in the tubular diameter, wall thickness, ovality, eccentricity, and material elastic-plastic behavior.

This new collapse equation provides significant advantages over existing formulas, mainly because it was developed based on non-linear mechanics solutions of the collapse problem as compared to equations derived from statistical analysis. In addition, the equation gives the true collapse pressure of the tubular, whether the tubular collapses elastically or after it has yielded. The new equation could be used to design tubulars based on manufacturing tolerances with respect to wall thickness, ovality, and eccentricity as well as material mechanical properties. This allows for design optimization which could account for significant cost savings, especially when designing expensive non-API tubulars such as corrosion resistant alloy tubulars. The new collapse equation presented in this paper provides accurate predictions of the collapse pressure of tubulars and accounts for tolerances in the tubular geometry and material elastic-plastic behavior. This new equation is simple and could be used in optimizing tubular design.
Critical Mud Weight and Risk Contour Plots for Designing Inclined Wells
Authors: Tan C. P. , Willoughby D. R.
Published: December 2007

An analytical method, used as part of a study to develop an understanding of stress-induced wellbore instability in the North West Shelf of Australia, has been prepared as a suite of spreadsheets with macros to carry out drained and undrained stability analyses of inclined wells under a generalised plane strain condition. The contour plots of critical mud weight and failure extent produced by the spreadsheets can be used together with the mud weight stability profiles to select optimum wellbore alignment and to assist with mud weight and casing design.
Development and Application of a Mineral-Oil-Based Mud and Tracer for Low-Invasion Coring at the Point McIntyre Field
Authors: Bloys J. B. , Rathmell J. J. , Kriel W. A. , Spence A. P. , Wylie G. S. , Ray C. R.
Published: December 2007

Coring operations were conducted with a mineral oil based mud to obtain low invasion cores from the Kuparuk sandstone in the Point Mclntyre field on Alaska’s North Slope. These cores were taken to provide oil saturation, porosity, and permeability data for calculation of oil reserve ownership for the three major oil companies participating in the field. This paper describes the development, testing and application of a very low invasion, low water content, mineral oil based coring fluid. This fluid, in combination with specially designed low invasion coring bits and high penetration rates, consistently produced 4-inch cores with filtrate invasions limited to the outer 0.25 to 0.50 inches of the cores in sandstone with permeabilities ranging from a few millidarcies to greater than 1.0 Darcy. A new oil soluble tracer was identified, which when present at 30 parts per million could reliably quantify mud filtrate invasion.
Core-Based Horizontal or Highly Inclined Well Stability Analysis for Unconsolidated Formations
Authors: Morita Nobuo , Ross C. K.
Published: December 2007

The prediction of a safe mud weight is important when drilling highly inclined or horizontal wells through permeable, poorly consolidated formations. If the mud weight used to drill these types of wells is too high, differential sticking of the drill string will occur. If the mud weight is too low, it is possible that the well bore will collapse. The standard linear elasticity borehole stability analysis methods used by many in industry predicts an unnecessarily high mud weight to prevent borehole collapse, while the safe mud weight is significantly lower. This paper describes a new core-based well stability analysis for horizontal or highly inclined wells in weak formations. New procedures to measure core strength and deformation and the numerical procedure to calculate the well stability for a highly non-linear formation are discussed. Field data and experiences are also included to validate the non-linear borehole stability analysis.
Slimhole Exploration Requires Proper Technical Preparation
Authors: Shanks F. E. , Williams K. R.
Published: December 2007

Any application of new technology requires proper preparation to ensure a safe and efficient field program. Slim hole technology requires different preparation and procedures than conventional rotary drilling techniques. Application of the mining industry’s coring techniques, small wellbore annuli, precise fluid flow measurement for kick detection, and specialized drilling fluids requires significant technical understanding and preparation. For Mobil in 1991, to prepare for a first application of Slim Hole Drilling Technology, the preparations included drilling a test well with Longyear Company’s Oil and Gas Division at Mobil’s Dallas Research Lab and using the information to prepare for two slim hole oil and gas exploration wells to be drilled in Bolivia, South America. The test well gave Mobil drilling personnel practical hands on experience with the technology and provided a slim hole test laboratory to perform extensive borehole hydraulics tests and practice well control techniques. The information gained from the test well was used to plan two exploration wells in the Madre De Dios Block in Northern Bolivia.

Industry has proven the economic advantages of utilizing this emerging new technology for Oil and Gas Exploration, especially in the remote frontier areas of the world. The planning, technical, and operational points of interest are highlighted in the paper. The advantages and disadvantages of the technology observed during the wells are illustrated. Methods available to allow the technology to adapt to Oil and Gas and API standards are discussed. Many technical aspects of the application of the technology are discussed which will give an insight to the minimum technical preparation a company needs to perform to be comfortable with a first application. Areas of technology are highlighted where additional development of the technology is needed.
Development of the Brookeland Field Austin Chalk Drilling Dual Lateral Horizontal Wells
Authors: McMann R. E. , Lipp C. R. , Pruski C. K. , Cooney M. F.
Published: December 2007

How can new technology be designed, or existing technology be used in a new way, to improve performance and reduce costs? This is a question every operator asks in an increasingly competitive market. With a successful horizontal development program in the Giddings Field in 1990 and 1991, Texaco’s Horizontal Drilling Team searched for answers to this question while expanding the program to the Brookeland Field in Newton Co., Texas.

The "Dual Lateral" concept was being used in other areas,1 but this was the first time Texaco would try this wellbore design - and in a wildcat area.

Planning aspects, the drilling operation and subsequent remedial operations will be reviewed. Production results and some conclusions as to the feasibility of drilling the dual laterals will also be presented.
Effective Safety Management Systems
Authors: Watson J. L.
Published: December 2007

For an oilfield service company to implement an effective safety program, the management of the company must be committed to the safety of its employees, itscustomers, and the environment through a common global safety philosophy. Management responsibility extends beyond reacting and correcting safety problems. For a safety program to reach the goal of "zero accidents," it must take a proactive approach, identifying and correcting known hazards before an accident occurs. There are numerous essential elements of the approach i.e., reporting, not only unsafe acts and conditions, but also near misses.

Successful safety programs require proactive processes or safety management systems which are more than a program but a philosophy - a method of management consisting of common concepts and attitudes, and a belief that "there must be a deliberate path to follow for continuous improvement." Safety management systems require a continual process of teaching, implementing, auditing, action, and management review. Such systems center around four major processes: eliminate, control, train, and require.

An effective safety management system also allows for the development of safety contingency plans to address any customer requirements or local safety regulations not covered by the established plan.

This paper presents the essential elements of an effective oilfield service company safety management system and discusses the value of establishing a proactive, globally audited safety program. Methods of implementation and continual improvement are presented.
An Ocean Data Gathering Program for the Gulf of Mexico
Authors: Patterson M.M.
Published: December 2007

With the increasing interest in deepwater oil and gas activities, it becomes evident that offshore operators need to understand in a fuller sense the ocean environment. Data on waves, winds, and currents are also needed for the development and calibration of environmental forecasting theories. To gather this data, Shell installed new, specially designed instruments on deepwater platforms in the Gulf of Mexico in 1967. platforms in the Gulf of Mexico in 1967. Details of the operation and installation of these pilot measuring stations are presented along with results of two years of data gathering.

Success of these pilot stations led Shell to seek the offshore oil industry's cooperation in developing a program that would gather data over a wide area in the Gulf. A set of specifications based on industry's experience was written by Shell with industry's help. Such a program called for measuring wind, waves, and barometric pressure on six platforms covering an area from South Pass on the platforms covering an area from South Pass on the east to East Cameron on the west. In addition a platform in the middle of this area was equipped to measure ocean currents. The stations are placed on platforms located in water as deep as possible. The program began in August 1968, and will gather data for 18 months. Its major task is to measure and record storm data. However, long term FM analog recorders will gather all data continuously. The program contractor, the Baylor Company, is required to furnish only limited analysis of the storm data consisting mainly of significant wave heights, wind speed and direction, current speed and direction and wave power spectra. They must also collect and store all other data and make it available at cost to the industry participants. participants. Portions of an analog tape from the program Portions of an analog tape from the program have been converted to digital form and analyzed to determine significant wave height, mean sea elevation and wave energy spectra. To date the entire system has recorded wave heights 60 percent of the time. Analysis performed on the raw data and calibration information from the contractor indicate that the entire system is operating satisfactorily.
A Monte Carlo Model To Assess Effects of Land-Disposed E&P Waste on Groundwater
Authors: Parker J. C. , Unlu Kahraman , Kemblowski M. W.
Published: December 2007

The objective of this study was to develop quantitative stochastic methods to assess effects of land-disposed E&P waste on groundwater quality. A computer model was developed to assess the probability of groundwater contamination from salts and oily waste constituents disposed by landspreading or in waste pits. The model considers leaching of chemicals from the waste zone over time until the constituent mass is depleted. It considers volatilization of organics for landspreading. Water flow is controlled by the net infiltration rate (rainfall minus evaporation and surface runoff), except for lined pits, in which flow may be limited by a low permeability layer. The program models one-dimensional convective-dispersive transport of dissolved constituents through the unsaturated zone and three-dimensional transport in groundwater zone. Organic constituents are subject to adsorption and biodecay. A Monte Carlo method is used to determine the probability distribution of maximum constituent concentration at receptor locations, given probability distributions of hydrogeologic and waste properties.

Deterministic simulations are presented for conditions representative of unlined E&P waste pits in the USA for receptors 500 ft (Receptor 1) and 1,500 ft (Receptor 2) directly downgradient of the source at the elevation of the water table. The results indicate peak groundwater concentrations are attenuated by a factor of more than 103 for TDS at Receptor 1 and by 104 at Receptor 2. For benzene, adsorption and biodecay combine to produce attenuation factors of more than 106 at Receptor 1 and 107 at Receptor 2. Monte Carlo simulations using national statistical distributions of soil and waste properties indicated TDS concentrations at the 85% cumulative probability level (15% probability of exceedance), of 15 mg/L at Receptor 1 and 4 mg/L at Receptor 2. For benzene at the same probability level, the concentration was 0.023 µg/L at Receptor 1 and 0.0019 µg/ L at Receptor 2.
The Fate of Underground Injection
Authors: Cooper K. J. , Lyle R. R.
Published: December 2007

Underground injection via Class II injection wells is a suitable technology for the continued safe and economically viable disposal of oil field brines in the United States. Currently, there is growing concern in industry regarding the regulatory fate of injection well technology. These concerns stem from the public’s perception of risk due to use of this technology and from an increasingly restrictive regulatory environment. As environmental regulations become more comprehensive and restrictive, brine handling and disposal costs are becoming a more significant constraint for both new and existing production operations. The potential for increased operator liability, additional financial burdens, and new logistical challenges are related to current and projected increases in operating costs. These factors are now becoming contributing factors for production being prematurely abandoned or never developed.

In this paper, a number of technical arguments that support the continued use of underground injection are summarized along with historical information regarding injection practices. Class I and Class II wells are compared along with a brief update regarding new and developing Class II regulations.
NORM: Projected Financial and Fiduciary Impacts on Exploration and Production Operations
Authors: MacDowell Peter , Gray P. R.
Published: December 2007

Regardless of the existence of regulatory constraints, fiduciary risk assessment, for any environmental liability is the art of defining the probability that contamination will occur in the first instance. Following its occurrence-assessment and quantification of the volume of contaminant present, discernment of the type and extent of pollutant, the cost of engineering controls, worker protection, remediation and the financial impact of any personal injury actions as a result of exposure and property damage litigation resulting from the mere presence of the contamination - are some of the management tasks to be addressed.

However in a regulatory void, simultaneously accompanied by the absence of prudent corporate environmental governance, an additional option exists. That is to simply ignore the presence of the pollution and do nothing.

The selection of either of these alternatives can be considered as the initial step in effecting the science of risk management - wherein the ultimate financial and fiduciary liability is directly proportional to the option selected.
Applying Financial Portfolio Theory to the Analysis of Producing Properties
Authors: Edwards R. A. , Hewett T. A.
Published: December 2007

Most owners of oil and gas producing properties realize that a significant amount of economic risk is inherent in their investments. Most also intuitively understand that if a number of producing assets are held, their total risk is reduced through the process of diversification. For an oil company that owns multiple producing oil and gas properties, two questions arise in analyzing risk. First, how to quantify the risk of the entire portfolio of producing properties including the affects of diversification; and second, how to manage the risk within a portfolio and strategically select specific investments or properties for acquisition or disposition to optimize the total portfolio risk-return relationship.

These two questions will be addressed in this paper. It is shown that if risk is one of the criteria used in decision analysis for an oil and gas investment, the economic analysis should consider the impact of that investment on the risk of the firm’s entire portfolio of investments, including the important effect of risk diversification. The results of such a portfolio-based risk analysis may be significantly different than for risk analysis performed within a single project framework.

It is proposed that a model based on financial portfolio theory can be used to quantify the risk and expected return of portfolios of oil and gas producing properties and identify new investments that can optimize the firm’s risk-return relationship. It is also shown that portfolio analysis provides an ideal technique for incorporating the results of geostatistical analysis and stochastic reservoir flow simulation into an economic framework that can be used for strategic decision making.
Composting Bioremediation for Exploration and Production Wastes
Authors: Martinson M. M. , Malter P. L. , McMillin T. G. , Fyock LeRoy , Wade Mark
Published: December 2007

Exploration and production (E&P) of oil resources typically result in the accumulation of process by-products from drilling, work over operations, field production facilities, and gas plants. These by-products currently are classified by Environmental Protection Agency (EPA) as exempt wastes. Increasingly, bioremediation options are being utilized to remediate the waste materials from these four E&P activities. Recent biological treatment applications using biological land treatment and composting technology have proven successful in meeting target reduction goals for organic and inorganic compounds found within the waste matrix.

Bioremediation using land treatment or soil composting technology provides engineered control of environmental conditions by stimulating either natural or augmented microbes, either in the landfarmed soil or within the compost mixture, to degrade organic carbon and immobilize inorganic constituents. This paper presents an overview of the three major composting processes for soil bioremediation applications and describes the critical environmental factors that control treatment success. Three soil composting bioremediation case histories from lab to pilot to field will be discussed. Costs and achievable treatment levels will be compared with traditional land treatment approaches.
Cost Trends in International Petroleum Activities
Authors: Kennedy J. R.
Published: December 2007

Explorationists, planners and engineers must be able to estimate quickly and consistently the costs for exploring and developing international oil and gas fields. This paper presents the major factors and relationships impacting these costs in various regions of the world, and the cost trends that have been established. PC-based software, which focuses on individual producing basins, allows the efficient generation of cost estimates using the relationships presented. The estimated costs presented are based upon accepted engineering design and operating practices for typical field developments, as well as a vast database of well and field data, terrain description and existing infrastructure.
Parallel Simulated Annealing for Stochastic Reservoir Modeling
Authors: Panda M. N. , Lake L. W.
Published: December 2007

Simulated annealing (SA) techniques have shown great potential to generate geologically realistic permeability fields by combining data from many sources, such as well logs, cores, and tracer tests. However, the application of SA in reservoir description and simulation is limited owing to its prohibitively large computational time requirement, even on modern supercomputers.

This paper introduces an implementation of a parallel SA algorithm for stochastic reservoir modeling on a Hypercube processor network (Intel iPSC 860). The corresponding sequential code, which incorporates univariate and bivariate statistics to generate the permeability field, is optimized to gain maximum advantage from the parallel application. In this particular parallel implementation, each processor runs the same source code asynchronously using the single-instruction-multiple-data (SIMD) approach, with synchronization linked to an optimality test. By porting the SA algorithm to a parallel computer we can generate permeability fields that represent non-Gaussian bivariate statistics and complex flow geometry at a finer scale than was previously feasible.
Reconciliation of Resistivity Log Readings in Vertical and Horizontal Boreholes
Authors: Bonnie J. H. M.
Published: December 2007

Two examples are discussed of a vertical pilot hole and a horizontal side-track, in which the resistivities recorded in the vertical hole are significantly different from those recorded in the horizontal hole. It is concluded that the differences may be caused by (1) variations in reservoir quality, (2) nearby layers, (3) resistivity anisotropy or (4) borehole and invasion effects. Resistivity tool modelling is found to be an essential tool in the analysis. However, the presently available computer codes are capable only of handling the effect of nearby, parallel layers. Full 3D modelling will be required to account for borehole and invasion effects and more complex layering. In addition, core data or data from "directional-resistivity" logging tools will be required to quantify the effect of resistivity anisotropy.

As long as it is impossible to fully quantify the above-mentioned effects, it is recommended to treat hydrocarbon saturations from horizontal well logging data with great care, especially when they are to be used in oil-in-place and/or reserves calculations. This applies in particular when no nearby vertical calibration well is available.
Enhanced Reservoir Description: Using Core and Log Data to Identify Hydraulic (Flow) Units and Predict Permeability in Uncored Intervals/Wells
Authors: Amaefule Jude O. , Altunbay Mehmet , Tiab Djebbar , Kersey David G. , Keelan Dare K.
Published: December 2007

Understanding complex variations in pore geometry within different lithofacies is the key to improved reservoir description and exploitation. Core data provide information on various depositional and diagenetic controls on pore geometry. Variations in pore geometrical attributes in turn, define the existence of distinct zones (hydraulic units) with similar fluid-flow characteristics. Classic discrimination of rock types has been based on subjective geological observations and on empirical relationships between the log of permeability versus porosity. However, for any porosity within a given rock type, permeability can vary by several orders of magnitude, which indicates the existence of several flow units.

In this paper, a new, practical and theoretically correct methodology is proposed for identification and characterization of hydraulic units within mappable geological units (facies). The technique is based on a modified Kozeny-Carmen equation and the concept of mean hydraulic radius. The equation indicates that for any hydraulic unit, a log-log plot of a "Reservoir Quality Index," (RQI), which is equal to 0.0314k/ϕ, versus a "Normalized Porosity Index" (ϕz) which is equal to ϕ/(1-ϕ) should yield a straight line with a unit slope. The intercept of the unit slope line with ϕz = 1, designated as the "Flow Zone Indicator" (FZI), is a unique parameter for each hydraulic unit. RQI, ϕz and FZI are based on stressed porosity and permeability data measured on core samples.

FZI is then correlated to certain combinations of logging tool responses to develop regression models for permeability predictions in cored and uncored intervals or wells. The proposed technique has been successfully tested in clastic rocks from East Texas, South America, West Africa, South East Asia and Far East Asia, as well as carbonate sequences from West Texas and Canada. This paper documents the theoretical development, validates and characterizes the hydraulic units, and presents predicted versus actual permeability data to demonstrate the efficacy of the proposed technique.
Control of Fractured Reservoir Permeability by Spatial and Temporal Variations in Stress Magnitude and Orientation
Authors: Teufel L. W. , Rhett D. W. , Farrell H. E. , Lorenz J. C.
Published: December 2007

A case study of the Ekofisk field, a naturally fractured chalk reservoir in the North Sea. demonstrates the strong influence of horizontal stress anisotropy on fracture conductivity and reservoir permeability. Directions and magnitudes of horizontal in situ stresses, as well as the distribution and orientations of natural fractures, vary locally across the structural dome that forms the Ekofisk reservoir. Fracture permeability is stress-sensitive and decreases as effective stresses in the reservoir increase due to pore pressure reduction resulting from production of oil and gas. Changes in fracture permeability also depend on the orientation of fractures relative to the evolving anisotropic stress field in the reservoir. Steeply dipping fractures aligned parallel to the local maximum horizontal stress direction show the smallest decline in permeability as the reservoir is depleted and can control permeability anisotropy in a naturally fractured reservoir containing multiple fracture sets.
Deep Gas Exploration in Middle Ordovician Prairie du Chien and St. Peter Formations in the Michigan Basin with Rose City Field as a Case Study
Authors: Harris J. W. , McRae C. D.
Published: December 2007

During the 1980’s, deep gas exploration in the Michigan basin targeted middle Ordovician sandstones in the Prairie du Chien (PdC) and St. Peter formations. Deeper-pool gas discoveries occur in simple closures associated with drape-fold anticlines, interpreted to overlie reactivated, oblique-slip basement faults. The PdC and St. Peter formations consist of up to 1300 feet of interbedded sandstones and shaly dolomites that pinch out along the southern margin of the basin. Tight, shaly, tidal-flat carbonates within the lower PdC, and transgressive marine carbonates and shales within the St. Peter provide good source rocks and top seals, producing multiple pay zones found in many fields. Clean, cross-bedded and skolithos-burrowed sandstones capping shelf sand bar or prograding shoreface sequences make the best reservoirs.

A multi-disciplinary study of the Rose City Field, a deeper-pool field discovered in 1985, served as an analogue for development and production of Shell’s other fields. The depositional environments of the sandstones were found to have significantly influenced their subsequent diagenesis and ultimately their present reservoir characteristics. The geologic model and calculated log values were combined with seismic structural interpretations to characterize the reservoir system and map the distribution of hydrocarbon-bearing pore volume (SgΦH). Volumetric and material balance estimates of OGIP agree within 10%, which is considered excellent. This approach was applied to other multi-well fields to help ensure equity and improve ultimate recovery.
Improved Method for Measuring Annular Water Flow in Injection Wells Using Continuous Oxygen Activation Logging
Authors: Trcka D. E. , Chace D. M.
Published: December 2007

A need exists for quality flow profile surveillance in waterflood programs. While oxygen activation has wide application in measuring behind casing water flow, the traditional methods of oxygen activation are limited for use in measuring injection flow profiles by the requirement that, for general applications, there can not be additional flow streams in the same direction as the flow in the casing-tubing annulus targeted for measurement, such as, injection flow in the injection tubing string.

A new oxygen activation technique has been developed which broadens the application of oxygen activation measurements in flow profiling by permitting the isolation of the annular flow signal from the tubing flow signal when the two flows are in the same direction. Potential advantages of this method include: a continuous log of volumetric injection flow rates with depth, greater vertical coverage of the well, and extension of the upper limit of the velocity measurement.

Laboratory data employing the measurement technique show excellent agreement between the measured annular velocity – in the presence of tubing flow in the same direction – and the true annular velocity.