bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precipitation of Asphaltic Sludge During Acid Stimulation Treatment: Cause, Effect, and Prevention
Authors: Suzuki Fumiko 
Published: December 2007

Abstract
This paper discusses the detrimental effects of sludge formation during acid stimulation treatments, and our experience in preventing the problem. Acid sludging in some oils in the US, particularly in California and the Rocky Mountain Region, has been reported in the literature in the mid 60’s1. In the early 1980’s, when incidents were reported independently in the company’s three different fields in central Alberta, we began to investigate the extent of the problem.
Our tests show that crude oil from all the company’s fields, scattered across western Canada, has strong tendencies to form sludges when the crude is in contact with a strong acid such as 15% HCl, and the conventional anti-sludge additives are ineffective in controlling it. Sludging is especially severe when Fe is present in the acid. The major source of Fe is corrosion and mill scales in the tubing.
Both field and laboratory observations indicate that sludging can cause serious plugging in the formation, leading to ineffective acidizing. Effective sludge control was difficult in the early days, as the technology was new to the industry. However, with close co-operation with the service industry, notable progress has been made, and currently, sludging can be controlled economically in the presence of up to 40,000 ppm Fe in HCl up to 28%.
Produced Water Chemistry Points to Damage Mechanisms Associated With Seawater Injection
Authors: Braden J. C. , McLelland W. G. 
Published: December 2007

ABSTRACT
Producing well water samples from the Prudhoe Bay Eastern Operating Area were evaluated with respect to the fraction of seawater in the sample. The evaluation demonstrated that the previous method of using magnesium or sulfate to determine percent seawater was in error. Because the water contains acetic acid, which was titrated as bicarbonate, scaling calculations overpredicted calcium carbonate scale formation.
The data show that there are at least two different waters in Prudhoe Bay. Additionally, potential reservoir mechanisms driving chemical reactions were identified as cation exchange (fines migration), scale precipitation (calcium carbonate, barium sulfate), formation dissolution and metabolic conversion of sulfate (leading to iron sulfide precipitation).
Pressure Buildup Techniques Applied to Identify Decreasing Fracture Stimulation Performance
Authors: Frailey S. M. , Crawford G. E. , Pierce A. E. 
Published: December 2007

ABSTRACT
Fracture stimulation characteristics were measured and studied for changing behavior over a 6 month period using pressure buildup tests conducted on a Prudhoe Bay well. The suite of pressure tests included a pre-frac buildup, and two post-frac buildups at six month intervals following the fracture stimulation treatment. Pre-frac analysis exhibited radial composite characteristics consistent with other Prudhoe Bay well test analysis. Post-frac analysis showed the fracture length and conductivity to decrease over a six month period. Corroborating the well test results, production from this well decreased more rapidly than expected. Numerical simulation confirmed the results. Data acquisition pertinent to a successful well test analysis is discussed.
Permeability Evaluation in Heterogeneous Formations Using Geophysical Well Logs and Geological Interpretations
Authors: Ameri S. , Molnar D. , Mohaghegh S. 
Published: December 2007

ABSTRACT
Permeability is the key parameter for reservoir characterization. The permeability of the formation is usually evaluated from the cores and/or well tests. It should be noted that cores and well test data are often only available from few wells in a reservoir while the well logs are available from the majority of the wells. Therefore, the evaluation of permeability from well log data represents a significant technical as well as economic advantage.
The evaluation of permeability in heterogenous formation from well log data however represents a difficult and complex problem. Generally, a simple correlation between permeability and porosity cannot be developed in heterogenous formation. The goal of this study has been to develop a generalized methodology to determine the permeability of a heterogeneous formation utilizing geophysical well logs as well as other geological information.
Granny Creek Field in West Virginia has been selected as the study area in this paper. This field has produced oil from Big Injun Formation since early 1900's. The waterflooding operation was initiated in 1970's and currently is in progress. Well log data are available on substantial number of wells. Core samples are also available from a few wells. Core samples and the well logs were analyzed to determine permeability, porosity and water saturation. The results of core and log analysis were complemented by geological interpretations to develop a correlation between permeability and well log responses. The results presented in this paper could serve as a guideline for correlating permeability with well logs responses in heterogeneous formations. A systematic and synergetic approach which integrating data from various well logs as well as depositional, lithological and sedimentological interpretations has been developed to evaluate the permeability.
Improved Oxygen Activation Logging for Waterflood Surveillance Measurements
Authors: Schnorr D. R. , Targac G. W. , Guillory R. J. , Pearson C. M. , Eck M. E. 
Published: December 2007

Abstract
This paper reports the results of using an improved impulse oxygen activation logging tool for water flood surveillance in the Kuparuk River Field, Alaska. The modified logging tool now enables the monitoring of water injection profiles in the "selective single" well completions over a wider range of injection rates with better vertical resolution when compared with an earlier impulse oxygen activation tool configuration.
The resolution and dynamic range of this service have been improved with a modification to the pulsed neutron tool. The modification increased the vertical resolution at high injection rates from 15-ft to 6-ft. Using a series of station measurements, it is possible to measure water velocities from less than 2 ft/min (0.01 m/s) to 300 ft/min (1.5 m/s). Knowing the cross sectional area of the casing/tubing annulus, water flow rates from 10 to 9500 BWPD are directly calculated.
These measurements have provided injection profiles to determine vertical conformance and the need for profile modification. Three case histories are discussed. 1.) The results of the pre- and post-logging programs are presented as well as the results of the successful profile modification. 2.) Detection of thin high permeability thief zones. 3.) Multiple water velocities measured in the same direction at same time to determine the injection profiles inside and outside of the tubing. This has all been possible with the successful modification of the WFL* tool to increase its vertical resolution. Impulse oxygen activation logging has become crucial to the continued surveillance of the secondary recovery project of the prolific C Sand in the Kuparuk River Field. Additionally, the information could be used to make an assessment of ultimate recovery, the need for infill drilling and enhanced recovery processes.
New Electronic Measurement System Enhances Slickline Service Capabilities
Authors: Larimore D. R. , Kerr W. L. , Hulme P. L. 
Published: December 2007

ABSTRACT
This paper will describe a new electronic measurement system that maximizes the efficiency of slickline operations by providing greater depth-measurement accuracy than previously possible. Conventional systems employ mechanical measurement devices that cannot make measurement adjustments for environmental or physical stress factors; for this reason, depth measurements do not provide absolute accuracy. Through use of a recently-developed electronic counter, this new measurement system has the capability to make the needed adjustments to address this problem.
The continuous need for cost efficiency in today's oil and gas industry has made depth measurement accuracy more critical for service operations. Through continuous high-speed depth adjustment and data transmission capabilities, this system fulfills today's accuracy needs and extends use of slickline beyond the limitations of simple mechanical measurement systems.
Through the results obtained from testing and case histories, the paper will address the practical benefits and features for improved depth measurements. These include: Depth-measurement accuracy for all commonly used slicklines and braided lines.Measurement corrections for stretch resulting from line tension and temperature effects on counter wheel.High-speed microprocessing compatible with slickline speeds.Retrieval of depth and time information for use with downhole memory production surveys.Use of the system for downhole memory tool surveys as a cost-effective alternative to electric-line logging.
High speed resolution and data retrieval make this system more sophisticated than any other offered for slickline well servicing. Additional testing indicates that planned electronic development will further increase the scope of slickline for well servicing by providing even greater efficiency and versatility.
The Petrophysical and Geological Impact of Borehole Images
Authors: Bigelow E. L. 
Published: December 2007

ABSTRACT
Formation images from wireline measurements have reached maturity. Corroborated by numerous comparisons to core, the images are considered to be an acceptable substitute for core in the absence of core data. Since 1985, the geological impact of these services is self-evident, but attributes of imaging logs can also lead to more efficient petrophysical analysis.
Modeling the Effect of Imbibition Capillary Pressure in Heterogeneous Porous Media: Waterflood Recoveries of the Romeo Interval, Prudhoe Bay Field
Authors: Angert P. P. , Begg S. H. , Sallak N. H. 
Published: December 2007

ABSTRACT
Advances in the development of geostatistics and object modeling, have allowed the construction of numeric representations of the Zone 1 interval, Ivishak Formation, Prudhoe Bay Field, that retain the character of the porosity / permeability seen in conventional core data. Modeling of the distribution of imbibition capillary pressure forces associated with these heterogeneous distributions was accomplished via the conventional Leverett J-Function.1 Subsequent water / oil fluid flow simulation, has revealed the effect of capillary forces on recoveries to waterflood.
The Application of Gas-Lift Injection Pressure-Operated Spring Valves in the Western Operated Area of the Prudhoe Bay Field: A Case Study
Authors: Vigil G. R. , Nordlander G. S. , Valencia R. L. , Watkins J. O. 
Published: December 2007

Abstract
Recent advances in injection pressure operated gas lift spring valve technology have proven to be beneficial in the Western Operated Area (WOA) of the Prudhoe Bay Oil Field. The temperature independent nature of the spring valves combined with their ability to operate at injection pressures as high as 2400 psig at valve depth make them the proven choice over conventional bellows charged gas lift valves. This cost effective technology has simplified both gas lift design and operation in the WOA. Two case wells which exemplify the benefits derived from the utilization of spring valve technology are described in this paper.
Quality Assurance: Bellows-Operated Gas-Lift Valves
Authors: Lagerief D. L. 
Published: December 2007

Abstract
A gas lift valve quality assurance program has been in place for the Eastern Operating Area (EOA) of Prudhoe Bay, Alaska since 1981. The program has involved data gathering, analysis and direct involvement by the field operator in the set-up of live gas lift valves.
The quality assurance program results have prompted a change in gas lift design methodology. Future gas lift designs will incorporate higher pressure drops between unloading valve surface closing pressures to avoid valve interference. Gas lift valve vendors have been given important feedback on minor problems that appear to be supplier specific. The design modifications, vendor equipment modifications, and valve set-up changes resulting from the quality assurance program have improved the reliability of Prudhoe EOA gas lift designs.
Experimental Study of an Environmental Remediation of Gulf Coast Crude-Oil-Contaminated Soil Using Low-Temperature Thermal Treatment
Authors: Alcocer C. F. , Chowdhury H. R. 
Published: December 2007

Abstract
Laboratory research was conducted to study the remediation of crude-oil-contaminated soil under the "Low-Temperature" burner system. Low temperature burner systems are those which operate below or up to 650°F whereas, those above 650°F are called "High-Temperature" systems. In this study, the effectiveness of remediation processes at three different levels of operating temperatures of 300°F, 650°F, and 2,000°F and three different levels of retention times of 2, 15, and 30 minutes in the burner were investigated. Twenty-nine experimental tests were performed using four different types of oils. The result of the initial soil test showed less than 100 ppm Total Petroleum Hydrocarbon levels. Before Weatherization of four different crude-oil-contaminated soils, the results of Total Petroleum Hydrocarbon (TPH) levels for sample numbers 5318, 5331, 5332, and 5351 were measured 45,000 mg/kg, 26,000 mg/kg, 27,000 mg/kg, and 29,000 mg/kg respectively. After Weathering the samples for two weeks, (average high and low temperatures were recorded at 77.6°F and 67.1°F respectively); the results of TPH levels for sample numbers 5318, 5331, 5332, and 5351 were measured 32,000 mg/kg, 19,000 mg/kg, 15,000 mg/kg, and 28,000 mg/kg respectively. Then After Ashing by combustion, the experimental results of TPH levels for sample numbers 5318, 5331, 5332, and 5351 at 650°F and 30-minutes retention time were measured 980 mg/kg, 3,400 mg/kg, 2,700 mg/kg, and 2,900 mg/kg respectively. Tests conducted in this study include sonication to agitate sample for disrupting cells, bacteria, or tissues; infrared detection to measure TPH levels; and combustion to burn all hydrocarbons. Based on the results of this tests, the study suggested that the cleanup or remediation of hydrocarbon/or non-hydrocarbon compounds by "Low-Temperature" burner system are possible but only at high retention time. The retention time required to achieve this remediation process range from 49, 52, 53, and 52 minutes respectively (figures 1.1-1.4). For the "High-Temperature" burner system, the result of this study showed that at two-minutes retention time, the total remediation of oil-contaminated soil required the burner temperatures of 3,100°F, 2,900°F, 2,600°F, and 3,100°F for sample numbers 5318, 5331, 5332, and 5351 respectively (figures 1.5-1.8). The remediation of petroleum-contaminated soil under low temperature system is technically feasible but may not be economically practical because of the long retention time required to achieve the goal.
Windowing Systems Enhance Computer Simulation
Authors: Fife L. D. , Henry S. R. 
Published: December 2007

ABSTRACT
Historically, simulation has been performed on mainframe computers, obtaining input through a text file. Creation of the input data file was error prone, and use of the simulator was often difficult. Debugging an input file containing erroneous information was difficult and time consuming. When error checking occurred, it was often within the simulator and fatal errors would result in wasted execution. These computer systems were often remote and expensive to use.
The increased speed and capacity of computers allows simulations to be performed on increasingly complicated problems. Application research allows processes to be represented more precisely. As simulators and computers become more complex, creation and debugging of input data files becomes more difficult. The difficulty of required simulations, coupled with the enhanced speed and capacity of available machines, increases the difficulties associated with interfacing the engineer with the simulation and data file creation processes.
In particular, the availability and capacity of desktop computers eliminates the need of mainframe computers for many simulators. This solves many of the cost problems associated with remote mainframe computers. However, the human-machine interface provided under desktop computer operating systems is not a significant improvement on the mainframe environment.
Using a graphical user interface (GUI) can improve the environment encountered by the engineer, provide sophisticated data checking, and provide other enhancements to the simulation process. The GUI can offer solutions for many of the input file and data error difficulties.
PC-Based Cement Job Simulator Improves Primary Job Design
Authors: Kulakofsky David , Henry S. R. , Porter David 
Published: December 2007

ABSTRACT
Until recently, cement simulation programs have been difficult to use, required large computer systems, and occasionally yielded results that were difficult to understand. Often the data input task was cumbersome enough to limit usage of these simulators. With the advent of Graphical User Interfaces (GUIs), even the most sophisticated simulator can be easy to use. With the wide variety of today's PC Graphics packages, complicated results can be made comprehensible through visual displays. This paper describes a technically advanced PC-based primary cement job simulator illustrating how a simulator can be sophisticated and easy to use at the same time. The simulator description includes recent enhancements, such as the capability to utilize temperature-dependent rheology and Critical Reynolds Number when calculating frictional losses.
Benefits of 3D Visualization to Reservoir Simulation
Authors: Austin A. Z. 
Published: December 2007

ABSTRACT
This poster session will present the benefits of 3D visualization as applied directly to reservoir simulation pre-processing and post-processing. Scientific or 3D visualization has been traditionally used for architectural engineering, finite-element analysis and computational fluid dynamics running on CRAY super computers. With the recent improvements in computer performance, 3D visualization systems can now be operate practically on graphic workstations such as the HP/Apollo, IBM RS/6000s and Silicon Graphics.
It can be difficult to visualize three-dimensional flow through porous media based upon a two-dimensional representation of the actual three-dimensional flow. Add a highly faulted structure upon the porous media and the three-dimensional flow becomes even more difficult to assimilate. Furthermore, reservoir engineers are constantly asked to review more production scenarios or alternatives in shorter periods of time thereby necessitating their need for more effective ways to interpret their simulation results. The need to transform the vast amounts of simulation results into easily understood images is crucial to improving our effectiveness.
Highlights of achieved benefits as well as current problems with 3D visualization approaches to understanding reservoir simulation results will be shown.
Overview of Key Remaining Issues in Reservoir Fluid Properties and Phase Behavior for Successful Reservoir Development Applications
Authors: Pande P. K. , Meyer B. J. , Banthia B. S. , Lawal A. S. 
Published: December 2007

Abstract
The properties of reservoir fluids axe critical for the successful exploitation of petroleum oil and gas reservoirs. Integrated PVT sampling and testing programs are key to successful reservoir development applications. Recently developed laboratory measurements and advanced computational tools have enhanced knowledge of phase behavior and physical properties of reservoir fluids. However, many aspects of phase behavior remain unresolved.
This poster session highlights the integrative aspects of PVT programs and provides insights and solutions for unresolved problems. Issues covered include the following:
RESERVOIR FLUIDS SAMPLING COMPLEXITIES Sampling Under Dynamic Reservoir Conditions: Petroleum reservoirs are continually in a dynamic state. Thus, obtaining representative samples during any stage of depletion or development presents its own unique challenges. Case histories are provided of the pros and cons of bottomhole vs. surface sampling.Sour Crude Oil System Sampling: Sampling and laboratory testing of systems which contain hydrogen sulfide (H2S) deserve special consideration as absorption of H2S on the surface of sampling vessels can occur. This is of particular importance in studies of minimum miscibility pressure (MMP) since H2S is beneficial in lowering MMP for miscible hydrocarbon gas displacements.Condensate Fluids Sampling: Well conditioning for sampling of condensate fluids are critical in ensuring that representative fluids are obtained. The difficulty in obtaining representative samples results from liquid dropout of the condensate in the near wellbore region.Compositional Variation Within a Reservoir, Oil Fingerprinting: Utilization of oil fingerprinting, a chromatographic technique, represents a significant stride for reservoir surveillance and reservoir management of fields which contain multiple crude oils. The technique can be used as a production allocation tool for reservoir surveillance and is much more accurate and cost effective over conventional production logging techniques.
Prudhoe Bay Miscible Gas Distribution
Authors: Cockin A. P. 
Published: December 2007

Abstract
This poster covers the new methodology for miscible gas distribution described in SPE 241591 which was adopted by the Prudhoe Bay Unit in 1991 and has led to a 50% increase in the volume of oil being mobilized by miscible gas at Prudhoe Bay, The poster additionally covers the post expansion philosophy and the current status of the Prudhoe Bay Miscible Gas Project (PBMGP).
The PBMGP started in 1987 following a pilot in 1982. In its fully expanded form it has reserves in the range 410-480 million stb. The project is shown on Figure 1.
Miscible Injectant (Ml) rates of up to 450 mmscf/d have been achieved to date, after 1995 this should increase to a peak of 650 mmscf/d.
Application and Analysis of Tensor Permeability to Crossbedded Reservoirs
Authors: King M. J. 
Published: December 2007

ABSTRACT
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.