bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reducing Risk: Priorities and Strategies for Environmental Protection
Authors: Loehr R. C. 
Published: December 2007

Abstract
In late 1990, the USEPA - Science Advisory Board (SAB) completed a major report for the EPA Administrator and the report recommendations have resulted in policy changes in EPA. A key component of the report is the identification of relative environmental risk and the need to focus on environmental problems of greatest risk. This paper discusses the background and rationale of the report, how the recommendations have been implemented within EPA, and the potential impact to the petroleum production and refining industry.
EPA Initiatives for Improving the Management of Crude Oil and Natural Gas Exploration and Production Wastes
Authors: Derkics D. L. , Robinson B. B. , Souders S. H. 
Published: December 2007

Abstract
Pollution prevention and waste minimization have become essential components of exploration and production (E&P) operations. Environmental accountability necessitates including pollution prevention and waste minimization in well planning and engineering, and waste management programs. Viable approaches should include waste minimization guidelines, employee training, and development of innovative technologies in addition to good housekeeping practices and product substitution.
This paper presents several initiatives instituted by the Office of Solid Waste (OSW) of the U.S. Environmental Protection Agency (EPA) for improving the management of E&P wastes. Through these initiatives OSW encourages a cooperative effort among industry, regulatory agencies, and other interested parties to develop creative solutions for improving E&P waste management practices.
Impacts of Environmental Initiatives on the Cost of Producing Crude Oil and Natural Gas Supplies
Authors: Godec M. L. , Smith G. E. , Kosowski Bundhrig 
Published: December 2007

Abstract
The environmental regulatory climate is dynamic, and the cost to comply with increasing environmental requirements can have a significant impact on oil and gas exploration and production operations. Identification of potential future requirements can allow operators to build environmental compliance into project designs, saving costly retrofit as new requirements are imposed. This paper describes many of the initiatives currently being considered under several major federal environmental statutes, discusses the potential cost of compliance, and examines the potential impacts of these initiatives on oil and gas supplies.
Land Treatment of Petroleum Hydrocarbon-Based Drill Cuttings: Pilot Scale Field Study
Authors: Barker G. W. , Armstrong K. W. , Adamson T. J. 
Published: December 2007

Abstract
A pilot scale feasibility study was initiated to evaluate the feasibility of landfarming diesel mud residues in southeastern Oklahoma. Results indicated that land application of diesel residues is an environmentally acceptable disposal method. In a plot with an initial oil and grease (O&G) loading rate of 7.6%, the O&G content decreased by 89.5% during the 209-day study interval. Addition of nutrients enhanced degradation rates and reduced O&G levels below the 1% phytotoxic threshold. An O&G loading rate of 5.8% resulted in no measurable hydrocarbon migration in the soil profile. BTEX levels in leachate samples did not exceed drinking water standards. Total metals measured in the zone of incorporation did not exceed guidelines for limiting constituents. Seed germination studies suggested that landfarming operations could be revegetated within 180 days.
Analysis of Gas-Rise Velocities From Full-Scale Kick Experiments
Authors: Hovland Frank , Rommetveit Rolv 
Published: December 2007

Abstract
Gas kick experiments in oil- and water-based mud have been studied in a full scale inclined research well. One of the main objectives from these experiments has been the study of gas rise velocities. In order to analyse the gas velocities, the parameters varying during a real drilling operation have been systemized and gathered in a data base. The work represents a significant extension to existing correlations for gas/liquid flows in a full scale inclined annulus with real drilling muds.
In high concentration gas kicks the gas rises faster than in low and medium concentration kicks, this is observed for both oil and water based mud. The rise velocity correlations obtained from these experiments is not significantly dependent on gas void fraction, mud density, inclination, mud rheology, and surface tension. The results are quite different from other previously reported correlations, and this has a major implication on kick simulations.
Use of a Unique Weighting Agent for Slimhole Drilling
Authors: Randolph S. B. , Walker S. H. , Young G. A. , Dorrough D. S. 
Published: December 2007

Abstract
Slimhole continuous coring and drilling is becoming an accepted method for oil and gas exploration. As the applications for slimhole drilling expand into frontier areas, weighted drilling fluids specifically tailored for slimholes are needed. In high speed (200 to 1000 rpm), slimhole, coring the use of conventional weighting material may result in its deposition on the inner wall of the drillstring making it difficult to wireline retrieve the core. To solve this problem a finer-grind weighting material, pigment-grade barite, was investigated. The overall results of this investigation are as follows: Weighted cationic brine muds, exceeding 14 lb/gal, may be formulated with acceptable viscosity using pigment-grade barite.A centrifuge rotating at reduced speed is capable of discarding much of the low gravity solids without discarding too much fine grind barite.The pigment-grade barite did not interfere with wireline core retrieval within reasonable operating ranges of drilling parameters.
Control of Water Influx in Heavy-Oil Horizontal Wells by Polymer Treatment
Authors: Zaitoun Alain , Kohler Norbert , Montemurro M. A. 
Published: December 2007

Abstract
Four horizontal wells producing a heavy oil from a sand formation were successfully treated with a new polymer process to reduce their water production. In this process, Polyacrylamide is injected with a swelling agent which induces a strong viscosity build-up in-situ before production release. The treatment was shown to reduce the relative permeability to water with little effect on the relative permeability to oil. Because of the high oil/water mobility ratio, the polymer was expected to invade the zones of highest water saturation preferentially and thus did not require zone isolation during injection. Polymer slug volume was optimized by numerical simulations. In the best case, the treatment induced a drop in the water cut from 85 to less than 50% and a strong increase in oil production. The treatments performed in 1989 are still efficient in 1992. In addition to its effect on the water cut, the treatment reduced sand production in three of the wells.
Electrical Impedance Variation With Frequency in Shales and Shaly Sands
Authors: Adisoemarta P. S. , Morriss S. L. 
Published: December 2007

Abstract
An experimental research program has been initiated to investigate the electrical properties of swelling shales across a wide frequency range, 10 Hz to 1.3 GHz. This range spans the spectrum of the commonly used downhole logging measurements, from the deep laterologs to the microwave dielectric tools. Three distinct measurement techniques have been utilized to span the range: multiple electrodes at low frequencies, two-electrode with balanced bridge for the middle frequencies, and open-ended coaxial probe with network analyzer at the high end. The probe technique is simple to use, potentially enabling field measurements of complex permittivity to be taken, although some accuracy is sacrificed. The effects of swelling are most pronounced at the lowest frequencies. The weight of a shale which has been exposed to a change in relative humidity reaches equilibrium long before the electrical properties do.
Styles of Deposition and Diagenesis in Leonardian Carbonate Reservoirs in West Texas: Implications for Improved Reservoir Characterization.
Authors: Ruppel S. C. 
Published: December 2007

ABSTRACT
Leonardian carbonate rocks in the Permian Basin constitute a thick succession of shallow-water platform deposits that display extreme degrees of reservoir heterogeneity and abnormally low recovery efficiencies. The complexity of these reservoirs is a function of the interrelated effects of (1) cyclic, multifrequency rise and fall of relative sea level, (2) paleotopography, and (3) diagenesis.
This paper presents a detailed geological characterization of Leonardian fades architecture based upon application of modern sequence stratigraphie concepts. It proposes a model that interrelates the distribution of depositional and diagenetic facies with development of porosity and permeability in this important hydrocarbon play.
Characterization of a Fluvial-Dominated Delta: Zone 1 of the Prudhoe Bay Field
Authors: Begg S. H. , Gustason E. R. , Deacon M. W. 
Published: December 2007

ABSTRACT
Core and log data indicate highly variable reservoir quality in the lower part of the Prudhoe Bay reservoir. Characteristic reservoir descriptions were developed in order to investigate the sensitivity of production performance to reservoir heterogeneity. Detailed core description and analysis showed that grain-size (lithotype) was the major control on poroperm. In turn, the spatial distribution of lithotypes is governed by the depositional environment, which is interpreted as a fluvial-dominated delta. This led us to develop new, quantitative, object-based models of the distribution of lithotypes within each of four major facies associations. These models were then converted to spatial distributions of poroperm on the core-plug scale, and these then re-scaled to give effective reservoir simulation grid properties. The quantitative lithotype models contain a number of variable parameters which enable sensitivities to uncertainties in the geological description to be studied.
Pressure Transient Behavior of Fractured Wells in Coalbed Reservoirs
Authors: Anbarci Kemal , Ertekin Turgay 
Published: December 2007

ABSTRACT
A solution package that describes the pressure transient behavior of coal reservoirs in the presence of a hydraulically fractured well is presented. In the development of the solutions uniform-flux vertical fracture model is employed. The proposed solutions are then extended to describe the pressure transient behavior of composite coalbed reservoirs with a vertical well which may have a vertical fracture. The proposed composite system solution has potential applications when "Tailored-pulse" fractures or damage exist around the degasification well.
In this study, dual porosity nature of coal seams is modeled by describing micropore structure by spherical matrix elements. The formulation employed includes single-phase laminar gas transport in the natural fracture network (cleat system). Flow within the micropores is described by Fick’s law of diffusion. Matrix to fissure flow mechanism is modeled by unsteady-state sorption/diffusion formulation. The equilibrium isotherm which defines the amount of desorbed gas is obtained through Langmuir’s theory. The solutions are obtained analytically in the Laplacian space and inverted to the real time domain via Stehfest algorithm.
The proposed solutions are tested against the subsets of the problem with known solutions and in each case excellent agreements are observed. Furthermore, the pressure transient data generated by a finite difference coal seam degasification model are used to check the validity of the solutions presented. Sensitivity of the solutions to a wide range of coal seam properties are also included.
The solutions presented in this paper equip me well test analysis engineer with a precise tool to analyze the pressure transient behavior of the hydraulically fractured degasification wells. The solution package encompasses infinite, constant pressure and no-flow outer boundary conditions together with constant flow rate specification at the wellbore.
Geologic Reservoir Characterization for Engineering Simulation, Hatter’s Pond Field, Mobile County, Alabama
Authors: Stoudt E. L. , Thomas A. R. , Ginger E. P. , Vinopal R. J. 
Published: December 2007

ABSTRACT
Geologic reservoir characterization of Hatter’s Pond Field, Mobile County, Alabama was conducted using a combination of lithologic and petrophysical data in order to determine appropriate reservoir layering and flow units for engineering simulation and reservoir management. 15,000 feet of core provided the foundation for the geologic study. Layer models were constructed via computer, and numerical grids were supplied directly to the simulator. Three dimensional computer modelling enhanced understanding of reservoir quality distribution.
Lithologic analyses indicate that productive Norphlet Formation lithologies are aeolian dune sandstones capped by a reworked transgressive marine sand sequence. Smackover Formation reservoir units consist of dolomitized transgressive marine carbonates shoaling upward into pellet/oolite bars and sealed by the intertidal and supratidal carbonates and evaporites of the overlying Buckner Formation. Significant variations in porosity and permeability occur both vertically and laterally within the producing formations.
Geologic controls on reservoir quality in the Smackover Formation at Hatter’s Pond are strongly diagenetic. Texturally destructive dolomitization has obliterated depositional fabrics, and created pore systems controlled by dolomite crystal size/shape and the presence of early fabric-selective leaching in grainstones overlain by exposed facies. Norphlet Formation reservoir character is related to the original depositional fabric, which has been modified by pressure solution and quartz cementation.
Without available core, the model would have been much less accurate, because logs alone do not reflect the diagenetic changes that control the reservoir. By combining core, log, and other petrophysical data, the layering and flow units provided to the simulator produced acceptable history matches in as few as 6 simulation runs.
A Simulated Annealing Approach to Constrained Nonlinear Optimization of Formation Parameters in Quantitative Log Evaluation
Authors: Cheng-Dang Zhou , Chu-Qiao Gao , Zhen-Wu Jin , Xi-Ling Wu 
Published: December 2007

Abstract
Quantitative log evaluation is essentially a model-based inversion of well logs, which is a constrained nonlinear global optimization problem when a prior information is sparse, where how to obtain global optimal solutions is the key problem. While many previous papers either avoid the nonlinearity by transformation methods, or simplify the nonlinearity in log analysis by linear approximation, or even use "steepest descent", or conjugate gradient techniques which are inapplicable for finding a global optimal solution in log analysis, based on an analogy between the model-algorithm system and a statistical mechanical system, this paper investigates the use of an efficient, global, stochastic optimization method, that of simulated annealing, for determining the optimal estimates of formation parameters in log analysis in such a case of constrained nonlinear optimization which is based on a well log interpretive model.
This paper presents the algorithm of simulated annealing global optimization of log analysis. The methods are given to determine the key parameters in such a simulated annealing. And finally both the advantages and limitations of this approach are pointed out.
A field example presented from China demonstrates the usefulness of this new approach and its comparison with the results processed by another log analysis software widely used in China indicates that this approach can efficiently overcome local minimum problem and provides more accurate estimates of formation parameters.
Identification of Clay-Supported and Framework-Supported Domains from Geochemical and Geophysical Well Log Data
Authors: Herron S. L. , Herron M. M. , Plumb R. A. 
Published: December 2007

ABSTRACT
Geochemical and geophysical well log data can be used to discriminate between clay-supported and framework- (or grain-) supported domains on the basis of observed clay and porosity relationships. The existence of these domains in unconsolidated materials has been inferred from experimental, bimodal mixtures of quartz and kaolinite but has not been demonstrated in consolidated rocks. The grain supported domain is characterized by decreasing porosity and increasing compressional velocity with increasing clay content. The transition to the clay-supported domain is marked by a reversal or flattening of these trends in porosity and velocity. In the clay-supported regime, increases in clay content correspond to increases in porosity and decreases in compressional velocity.
The existence of the two domains can be identified by modified v-shaped patterns in clay porosity crossplots or by inverted v-shaped patterns in clay velocity crossplots. Once the patterns have established for a given section of a well, they can be statistically analyzed, and then the clay volumes can be used to create synthetic logs of porosity and compressional velocity. Outside the range where the statistical fit is performed, deviations between the synthetic logs and the measured logs may be interpreted as geological discontinuities. These discontinuities are most likely due to the diagenetic history of the rocks, and in most cases probably represent time horizons.
A Comparison of Log Interpretation to Core Results Using a Full Element Model and a Reduced Element Model in the East Texas Cotton Valley Sandstone of GRI Well No. 3
Authors: Everett R. V. , Johnston D. J. , Quirein M. C. 
Published: December 2007

Abstract
The purpose of this project was to develop better methods for the evaluation of tight gas sands using logs and cores for enhanced hydrocarbon detection and enhanced stress profile determination. The results of this study showed that minerals greatly affect the interpretation of the hydrocarbon reserve potential derived from log measurements. Using the core measurements as a guide to determine which minerals were present in the formation, a mineral model that did not require core calibration was developed to convert elements to minerals. The first mineral model used the full range of elements available -Si, Ca, Fe, Al, K and Ti as well as correlations to the photoelectric effect (Pe) to derive Mg and the epithermal neutron-density logs to derive H2O+. The second model used a reduced set of elements, K and Th. Both models also used resistivity, electromagnetic, acoustic, epithermal neutron and density log measurements.
Areal 3D Seismic Methods for Reservoir Characterization Case History from the Niger Delta
Authors: Idowu A. O. 
Published: December 2007

Abstract
In the 1950s, early exploration period in the Niger Delta witnessed the use of 2D (two -dimensional) Seismic reflection method which is a adequate for imaging large subsurface geologic features including growth faulting and roll - over anticlines. This technique involves the Common Depth - Point Method (CDP) which acquires a plane of seismic information in distance along the surface and in time into the geological section, and is used to improve the signal - to - noise (S/N) ratio, to remove multiples and consequently give a representation of the subsurface particulrly if the data are collected up - or downdip.
By mid-1980s, the obvious geological structures have, in general been discovered and it became necessry to adopt a more sophisticated technique such as the 3D (three - dimensional) Seismic method to delineate more subtle reservoirs and resolve complex fault patterns in order to aid exploration as well as facilitate efficient field development. The case history discussed in this paper involves the use of areal 3D Seismic method for delineating the reservoir characterisation of the OK-field located in a shallow water area of the Western Niger Delta.
The areal 3D sismic technique is superior to the earlier CDP method in that a cube of seismic data can be collected in two dimensions in space and in one time by a variety of pattern adopted for gathering the 3D data for the OK-field’s reservoir which involves the shooting into lines of detectors which are at some angle to line of sources. The objective is to adequately sample the subsurface so that changes in vrious parameters such as the amplitude, phase or power in the seismic signal or velocity of propagation can be mapped areally and interpreted as an indication of changes in the physical properties of the rock matrix.
The 3D data for the field was acquired, processed through migration and it was possible to display what is essentially a cube of seismic data as a series of layers cut horizontally and vertically through the reservoir complex. This is done on a television screen for video presentation and reproduction, while the addition of on interactive computer system enables a three dimensional interpretation of the seismic data to be made. The net effect is that an efficient and cost-effective reservoir development was accomplished by proper timing and appropriate location of production wells for the drainage of this field.
Effect of Reservoir Stress Path on Compressibility and Permeability of Sandstones
Authors: Rhett D. W. , Teufel L. W. 
Published: December 2007

Abstract
Matrix permeability and pore volume compressibility are fundamentally important characteristics of hydrocarbon reservoirs because they provide measures of reservoir volume and reservoir producibility. In most laboratories these quantities are measured under hydrostatic (isotropic) loads that do not truly reflect the deviatoric stress state that exists in most reservoirs and do not adequately simulate the evolution of effective stresses in the reservoir as the reservoir is produced. Compression tests on reservoir sandstones show that both the compressibility and matrix permeability vary markedly with stress path (defined as the change in effective horizontal stress/change in effective overburden stress from initial reservoir conditions). Hence, changes in reservoir properties measured under hydrostatic loading conditions may be very misleading if applied to a reservoir that follows a non-hydrostatic stress path. Representative measurements of reservoir properties should be measured in the laboratory under loading paths that duplicate the stress path followed by the reservoir during production. Consequently, optimum reservoir management may require that the reservior stress path be determined by measuring in situ stresses early in the production history of a reservoir and periodically thereafter as the reservoir pore pressure is reduced.
NMR Imaging of Multiphase Flow in Porous Media
Authors: Chen Songhua , Qin Fangfang , Kim K-H. , Watson A. T. 
Published: December 2007

Abstract
The use of nuclear magnetic resonance (NMR) imaging techniques for determination of porosity and saturation distributions is investigated. Difficulties in quantitation which arise from the short transverse relaxation times exhibited by fluids in porous media are addressed. Procedures are presented whereby transverse relaxation during the signal acquisition process is modeled so that accurate estimates of intrinsic magnetization intensity, and thus porosity and saturation, can be obtained. Special consideration is given to saturation/position dependence and multi-exponential behavior of transverse relaxation. These procedures are validated with results for longitudinal profile images. The use of thin-slice cross sectional profile images are demonstrated by observing fluid displacement in a rock sample with structural heterogeneities.