bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Pressure Storage of Gas in Lined Shallow Rock Caverns — Results from Field Tests
Authors: Stille H. , Johansson J. , Sturk R. 
Published: December 2007

Abstract
At the Grängesberg Research Plant field tests have been performed regarding storage of gas at very high pressures in lined shallow rock caverns. The surrounding rock mass (granite) has proven to be very capable of withstanding loads at levels far above the initial rock stresses. No tendency of vertical uplift has been recorded. At an internal pressure of 52 MPa the maximum registered radial deformation in the rock was 5.65 mm, corresponding to a tangential strain of 2 per mille. The combined construction element liner-concrete-rock has fulfilled its main purpose, i.e. to confine the gas, throughout a tough load history. Leakage tests at high pressures have indicated that even a large failure in the liner can be controlled without any severe consequences.
The Micro Mechanical Description of Rocksalt Plasticity
Authors: Fokker P. A. , Kenter C. J. 
Published: December 2007

Abstract
The constitutive behaviour of rocksalt is explained from micro mechanical concepts. Rocksalt plasticity (or primary creep) can be well explained by a dislocation glide mechanism, where gliding becomes increasingly hindered by dislocations (in fact dislocation pairs or dipoles), disturbing the glide paths. Such dipoles are both the main source for hardening, as well as the main source for time dependent behaviour. From such a description a deformation model can be derived that relates strain rates to stresses, strains and the temperature. The resulting creep curve bears great similarity with the Lemaitre and the Menzel-Schreiner deformation law. However, different from these curve fitting laws, primary creep here is based on proper micro-mechanical considerations and moreover can cope with the transient effects as occurring when load or strain rate increments are suddenly changed.
Recent Results of Geomechanical Field Measurements in the TSDE Test at the Asse Salt Mine
Authors: Schneefuss J. , Droste J. , Heusermann S. , Sonnke J. 
Published: December 2007

Abstract
The German reference concept for the final disposal of spent fuel elements comprises their emplacement in Pollux casks in backfilled drifts of a repository in salt rock. Since 3,5 years the Asse salt mine is the location of a large scale trial to demonstrate this storage technology and is intended in particular to allow assessment of long term thermomechanical behaviour of backfill and rock mass. As a result of heating to a maximum 200°C a considerable increase was measured in rock mass deformation and drift closure. Substantial thermally induced stresses result in the rock mass. The backfill pressure shows a steady increase, which is however far below the initial stress state in the host rock.
Re-Injection of Produced Water – Field Experience and Current Understanding
Authors: Paige R. W. , Murray L. R. 
Published: December 2007

Abstract
This paper reviews field experience of produced water re-injection. Recent improvements in understanding the processes which control reinjection are described, demonstrating the key role of rock mechanics in enabling successful reinjection of large volumes of dirty water via waterflood induced fracturing. Methods for predicting injection well behaviour using models which couple reservoir simulation with rock mechanics, and tools for investigating fracture geometries are presented.
Safe Injection Pressures for Disposing of Liquid Wastes: A Case Study for Deep Well Injection
Authors: Abou-Sayed A. , Thompson T. W. , Keckler K. 
Published: December 2007

Abstract
The determination of maximum injection pressures is an important component of planning and permitting for deep well disposal of liquid wastes. In the United States, safe injection pressures are defined as those that do not initiate or propagate fractures. The maximum injection pressures are often based on the closure pressure at the wellbore; however, higher pressures can sometimes be demonstrated to be safe. This was the case during the recent preparation of a nomigration petition and permit applications for deep well injection at the BP Chemicals Inc. Lima, Ohio, facilities. In this case, a substantial database existed, which included core mechanical properties, in situ stress tests and transient pressure tests on a specially drilled Stratigraphie test well, as well as about 20 years of injection flow and pressure history. These data were used to provide the required assurances to the regulatory agencies that injection over the closure pressure could be adequately defined. This analysis was complicated by the stress dependance of the injection formation permeability and the pluggage of the near wellbore region due to fines in the injection stream. This paper describes the database used and the analyses conducted to demonstrate that injection above closure pressure at BP Chemicals' facilities at Lima, Ohio, does not initiate or propagate fractures in the injection zone and that the injected fluids will be contained in the injection zone for at least 10,000 years.
Finite Element Analysis of Compaction and Subsidence — Experience Gained from Several Chalk Fields
Authors: Plischke Bertold 
Published: December 2007

Abstract
For North Sea chalk fields, finite element models are used to evaluate the reservoir compaction and the associated seafloor subsidence. The present paper addresses aspects of the calibration of the stress strain laws to be used for the chalk and the overburden. Results of laboratory tests do not reflect the large scale deformation behaviour. The calibration is therefore mainly based on the back analysis of measured formation movements. Another topic is the coupling with reservoir simulation models, which provide the reservoir pressure. This coupling should be improved, if a local compaction cannot be derived from a simultaneous change in reservoir pressure at that location.
Recent Advances in Laboratory Automation Programming
Authors: Mahmood S. M. , Olsen D. K. 
Published: December 2007

ABSTRACT
Petroleum laboratories greatly benefit from automation because tests often involve rapid transient behavior, e.g., in determining unsteady-state relative permeability; and/or long slow processes such as capillary tests. Many smaller laboratories are not fully automated due to the high cost of developing custom-made software or modifying commercial software for their specific use.
This situation is rapidly changing with the emergence of a new generation of object-oriented computer languages. These new languages allow novice programmers to develop sophisticated systems with unprecedented ease and speed. This paper introduces the concepts behind this new generation of languages and their use for petroleum laboratory automation.
A public domain, general-purpose laboratory/pilot plant automation program, "LabWARDEN," developed at the National Institute for Petroleum and Energy Research (NIPER) for the U.S. Department of Energy is presented as a case-example. This menu-driven, user friendly program for data acquisition/control/analysis/presentation is a valuable tool for laboratories where test requirements change frequently. Its features include: run-time system setup reconfiguration; built-in constraints to eliminate operator errors; real-time graphic display of current and previous data with editing and smoothing; data export to other applications for report generation or animation such as automatic 3-D rotation; pictorial display of test status for quick trouble-shooting; error and out-of-range audio/video warnings to designated users on the network; automatic resetting of instrument(s) to rectify minor problems; and automatic shut-down in emergencies when the operator does not respond. Configuration of a high-temperature high-pressure steamflood oil displacement laboratory is described.
Seplant: An Expert System for Process Plant and Gas Lift Well
Authors: Patrício A. R. , da Rocha A. F. , Morooka C. K. 
Published: December 2007

ABSTRACT
Oil production is very sensitive to disturbances on process plant and/or well installation. Identification problem in gas-lift wells involves mainly symbolic reasoning, since gas surface card provides important information but not all data required for decision making. A variety of well problems can occur with this system. Neural nets were used to developed SEPLANT, an expert system whose purpose is to support the intelligent control of gas-lift and process operation by helping operators in making the correct decisions in contingency situations, in an effort to avoid problems and production losses.
Fuzzy Logic Controls Pressure in Fracturing Fluid Characterization Facility
Authors: Rivera Vincent P. , Farabee L. Mark 
Published: December 2007

Abstract
A fuzzy logic pressure control system has been designed and implemented to deal with the demanding requirements of the Fracturing Fluid Characterization Facility (FFCF), a test bed that simulates downhole conditions for investigating fluid behavior during fracturing stimulation. Pressure control in the fracture simulator was difficult because of the wide range of fluid types and pumping conditions used and by the compliant structure of the simulator, which uses servo-controlled actuators to maintain a constant gap width under varying pressure conditions. The FFCF pressure control system must handle fluids that vary from water to high-viscosity gel slurries at flow rates ranging from 1/2 to 3 bbl/min. Conventional control approaches were successful only under very limited conditions. To solve this problem, a fuzzy logic controller (FLC) was developed to be a user function in the FFCF supervisory control and data acquisition system. Using several fuzzy logic rules, the FLC generates a position set point for a slurry throttling valve. An electro-hydraulic directional control valve uses the set point supplied by the FLC to position the active control element of the slurry throttling valve.
3-D Visualization as an Investigative Tool for Understanding Recovery Mechanisms
Authors: Dria M. A. , Sharpe H. N. 
Published: December 2007

ABSTRACT
3D visualization can be an important investigative tool for understanding physical processes and recovery mechanisms in reservoir simulation. In this paper, we will demonstrate the utility of 3-D visualization in the context of compositional and thermal simulations, and how this new tool aids process understanding and facilitates project design.
The main uses of the reservoir simulator include history matching to understand past performance, gain credibility of the reservoir simulation model, and project design to optimize future recovery (in an economic sense) whether for continued primary recovery, waterflooding, or EOR. To achieve these goals, it is essential to understand the interaction of the fluid dynamical and physical and chemical mechanisms with the complex geology of the reservoir, and the operational parameters and constraints at the wells.
While the reservoir simulator is capable of answering these questions, one of the major problems in the past has been in the three dimensional representation of such key variables as oil, water, and gas saturations, pressure, temperature, and individual component concentrations. Maps of these quantities relative to local geology and wells are essential to understanding the complex interactions outlined above, before process optimization may be achieved. Even simple questions such as the location of bypassed pockets of oil, cannot be adequately addressed using these tools. With recent advances in complex reservoir characterization, it is even more essential to be able to visually understand the control that local geology exercises on the recovery mechanism.
Shifting From a Mainframe to a PC Environment
Authors: Benavides R. M. , Wilke J. G. 
Published: December 2007

Abstract
This case study of a PC-DOS®/Mainframe system highlights a unique method to reduce the dependence on the Mainframe Computer System by individuals preparing written engineering proposals for prospective customers. With the development and implementation of the Engineering Proposal System (EPS), data storage and remote communications are now the only two functions processed by the mainframe computer.
Two key areas for success were user involvement and proper training. While most of the individuals preparing the proposals had worked on the mainframe for some period of time, very few had worked on PC's. An EPS users' group was established to bring together the needs of the end user and the needs of the programmers. This group remains active in enhancing and troubleshooting the current system.
The problems involved with a totally dependent mainframe system, as well as communications problems experienced with remote locations, are discussed herein. Satellite and phone modem communications are also briefly discussed. Several hardware configurations were necessary to respond to various needs created by the engineers' location and working environment.
The existing PC system, its components and the method used to automatically combine all the components into a high quality end product are covered here. Since this is a case study, all aspects of the product experience are explored.
Document Imaging and Management: Implementation of a Geoscience Image Server With Corporate Scalability
Authors: Thrasher T. S. , Baughman S. A. , Grismore J. R. , Carnell D. A. 
Published: December 2007

ABSTRACT
This paper presents an overview of the process that resulted in the implementation of a document imaging and management system in the Research & Services Division of Phillips Petroleum. The purpose of this system is to capture the various documents maintained by the Reservoir, Geology, Geophysics and Production Technology branches into a master electronic fileroom. The system will facilitate sharing of data and information between groups and help reduce time required to search for and maintain project files. Many of the issues that were addressed are outlined in a format that serves as a case history example. These issues include system integration and alignment to existing Information Technology Architecture and Corporate Record specifications, adherence to Common Look/Feel and Client/Server guidelines, local and wide-area network compatibility, budget limitations, security and corporate scalability.
Systematic Steps to Operational Control: The Multi-Functional Potentials of Safe Job Analysis in Internal Control Regimes Reconsidered
Authors: Sunde Gunnar , Andersen L. B. 
Published: December 2007

Abstract
This paper presents a new system of integrated and multi-functional elements and strategies of Safe Job Analysis (SJA) developed by Rogaland Research for the Norwegian oil company Statoil. The scope of the system is integrated operational control of complex and risk exposed field operations in multi-team contexts. The new SJA system is especially designed to satisfy rules, regulations and documentation principles in internal control regimes like those of the North Sea countries. With small adjustments of the supplementary text, the system has also proved to be directly adaptable to onshore internal control regimes. Recent research as well as field experiences indicate that safety and quality aspects related to e.g. lost rigtime, stuck pipe, injury rates and equipment failures can be traced back to the actual level of operational control. Key words to lack of operational control are poor communication and information procedures due to insufficient pre-job repertoirs, generally causing poor experience transfer and a lack of mutual task understanding between individuals and team, and insufficient co-ordination during operations. New and promising multi-disciplinary approaches now indicate that such human error related aspects can be fruitfully attacked and controlled if systematically mapped and undertaken within a tailored internal control system in combination with the multifunctional potentiality of the proposed SJA model.
Management of a Declining Field
Authors: Fattahi B. , Okita P. J. 
Published: December 2007

Abstract
The growing cost to produce our maturing oil and gas reserve base has placed the U. S. domestic oil industry in an unfavorable position with worldwide competition. In striving to survive, we must direct our efforts at reducing the operating cost of our hydrocarbon production by optimally managing our reservoirs.
The operating cost structure of a large producing field can be complicated. So-called "fixed" and "variable" costs are often difficult to identify from historical cost data. In the case of declining production, the complication further amplifies due to the varying nature of the cost components. Shrinking revenues decrease per barrel profitability (and the remaining field economic life) if fixed costs are allowed to remain constant. Thus, there is a need to develop more rigorous operating cost models to better understand, monitor and control parameters which impact the bottom line profit. This approach will facilitate the use of proactive surveillance techniques and result in overall field optimization.
This paper examines key elements of the operating cost structure and proposes simple cost component models for consistent surveillance and economical production of declining fields. Application of such models to the Mt. Poso Field, California is discussed.
Mt. Poso, a thermally driven oil field, is one of the first large scale heavy oil producing operations that is declining towards its economic limit. An approach on understanding cost component behavior, modeling, devising a surveillance strategy, and finally the impact on maximizing the operating income are presented.
Reservoir Geology and Production Performance of Turbidite Sands at South Timbalier 295 Field: Some Encouraging Results
Authors: Mason E. P. , Scheibal J. R. , Purdy G. E. 
Published: December 2007

Abstract
Better than expected recoveries, generally strong pressure support and high production rates characterize the main pay sands ("K8", "K16" and "K40" sands) at South Timbalier 295 field. We interpret these sands to be turbidite mid-fan sheets ("K8" and "K40") and amalgamated channel sands ("K16") deposited within a closed basin.
All three intervals are geopressured, highly compressible, and subarkosic sandstones, with reservoir temperatures of about 210°F, and porosities and permeabilities of approximately 31% and 500 MD, respectively.
A New Interference Test Method for High-Precision Diffusivity Distribution Measurements
Authors: Najurieta H. L. 
Published: December 2007

Abstract
Classical interference testing techniques are based on the superposition of the line source solution. The use of this method is limited by the precision and time resolution that is normally obtained when measuring the production rate in active wells. In the new technique proposed, the pressure signal is measured at the active well and it is used to accurately calculate its diffusion in the reservoir. The higher precision in pressure calculation at the observing well gives more resolution to the analyst and provides more confidence when evaluating local reservoir heterogeneities.
The new method and related equations are presented and applied to a field example where a five-spot injection pattern is evaluated for a future CO2 injection pilot project. The diffusivity distribution estimated from the interference tests agrees with the description of the advance of the injected water obtained from radioactive tracer techniques.
Multilayer/Rate Testing in the Cusiana Field, Colombia
Authors: App J. F. 
Published: December 2007

Abstract
Multi-layer tests are performed to identify layer properties, such as permeability and skin, in commingled layer completions. This permits improved reservoir management and completion optimization. Multi-rate tests are required to evaluate rate sensitive skin. This paper presents the results of multi-layer/rate tests performed on the two active wells in the Cusiana Field, Colombia. The two wells were the Buenos Aires #1, an oil producer, and the Cusiana #2A-ST, a gas injector. The tests were performed by monitoring rate and pressure with a spinner and pressure gauge placed above the lower layer in a two layer system. These measurements were made at multiple rates to evaluate rate sensitive skin. Skin determined from these measurements was used to estimate the upper layer skin and permeability through simulations of the buildup and falloff responses. Knowledge of the permeability of the lower layers from previous pressure transient tests aided the analyses. All pressure transient analysis was performed with conventional well test analysis software.
High-Resolution Density Logging Using a Three Detector Device
Authors: Eyl K. A. , Chapellat Herve , Chevalier Philippe , Flaum Charles , Whittaker S. J. , Jammes Laurent , Becker A. J. , Groves Joel 
Published: December 2007

Abstract
Significant improvements in both the resolution and the precision of formation density logging tools are possible through the integration of a new "backscatter" gamma-ray detector into the traditional dual-spacing device. The spacing and the geometry of the new measurement permit intrinsic high resolution logging while much higher count rates provide increased precision.
Backscattering or single Compton Scattering in the formation complements standard attenuation logging by exhibiting a positive correlation between count rates and density. Statistical variations at higher densities are thus reduced. The reactions occur at short distances from the source dictating very short source-detector spacings and very high count rates. Such count rates have required adoption of a new crystal with attendant shielding and new count-rate electronics capable of digital treatment of the pulses. The backscatter detector is integrated into a skid that also carries more conventional short- and long-spacing detectors.
The energy spectra from the three detectors are binned into energy windows for data analysis. A nonlinear response model is established for each window count rate and the set of equations formed is solved for five unknowns—the formation density and photoelectric factor together with the mudcake density, thickness and photoelectric factor. This approach permits the optimal treatment of measurement errors and provides the best possible estimation of formation density and photoelectric factor available from the acquired measurements. The processing algorithms provide outputs at both standard and high resolution.
Field log examples show significant improvements in density precision and vertical resolution, and a dramatic improvement in the quality of the photoelectric factor (Pef) log.
Application and Interpretation of Continuous Oxygen Activation Logs for Measuring Complex Water Flow Profiles in Injection Wells
Authors: Chace D. M. , Trcka D. E. , Dawe B. A. 
Published: December 2007

Abstract
A continuous oxygen activation method of measuring water injection flow profiles in complex single and dual completion injection wells has been developed. The method allows deconvolution of superimposed activation signals originating from simultaneous, co-directional water flow in the tubing and tubing-casing annulus for a continuous log of annular water velocity. The theoretical basis of the measurement is reviewed and field examples are analyzed and interpreted. The examples of single and dual string completions demonstrate the measurement of continuous annular injection profiles in the presence of co-directional tubing flow and diagnosis of mechanical problems such as plug leaks and tubing-tubing communication.