bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Approaches to Safety on Alaska’s North Slope Successfully Reduce Accident Rates
Authors: Copoulos A. E. , Herndon Meyer , Manchester P. D. , Schmoyer Al , Welch J. L. , Stoehr Phil 
Published: December 2007

Abstract
New approaches to safety have been applied in the harsh operating conditions of Alaska’s North Slope. Dramatic reductions in accident rates have been achieved at higher activity levels and under busier, more difficult conditions by the service company that several of the authors represent (Fig. 1). Old approaches to safety no longer apply.
A number of actions were taken by both service and operating companies that contributed to the reduction in accident rates. In the service company, a series of management initiatives were implemented, including more direct management involvement, improved communications, more comprehensive safety training, direct organizational support, enhanced corporate support, investments in safety equipment and technology, and instilling the right attitude about safety in the employees. The operating company established a commitment to a long-term alliance, a monetary safety incentive program, and provided continued teamwork and assistance.
Although a number of factors contributed to the reduction in accident rates, the main reason, as determined through an informal survey of field personnel, is the new attitude toward safety, fostered through the strategic alliance formed between the two companies represented by the authors. Within the alliance, service company field personnel are under less pressure to rush jobs and are treated as partners. As a result, the field personnel feel comfortable taking extra time where needed in order to work safely, and they always make safety the top priority. Successful accident reduction depends mainly on field personnel and their willingness to have the right attitude about safety.
The resulting benefits, measured in terms of social, economic, and loss control, are substantial.
Field Validation of the Offshore Operators Committee (OOC) Produced Water Discharge Model
Authors: Smith J. P. , Mairs H. L. , Brandsma M. G. , Meek R. P. , Ayers R. C. 
Published: December 2007

Abstract
This paper describes a field study demonstrating the ability of the Offshore Operators Committee (OOC) Mud and Produced Water Discharge Model to predict the dilution of offshore produced water discharges. The test involved: adding a fluorescent tracer to the produced water discharged from an offshore Gulf of Mexico platform; making measurements of the current and hydrographic conditions near the outfall; collecting water column samples with diver-held sample bottles (0-25 m from source) and through an array of sampling hoses (3 - 103 m from source; 103 m = 628 discharge pipe diameters); and comparing measured tracer concentrations with model predictions. Model predictions were in excellent agreement (R2 = 84%) with concentrations of samples collected by divers up to 25 m from the discharge point. Concentrations of samples collected through sampling hoses were highly variable, but model predictions for distances 58-103 m from the source agreed with average field measurements within a factor of two. These results demonstrate that the OOC Model can predict the dilution of produced water discharges and provide a documented set of field data useful for checking the performance of other dispersion models. The observed produced water discharges were rapidly diluted: a 6000 bbl/d discharge was diluted by a factor of 100 within 10 m and by a factor of 1000 within 103 m. Rapid dilution limits the potential for adverse environmental effects in the water column. Comparisons with previously published values of the 7-day "No Observable Effect Concentration" (NOEC) for Gulf of Mexico produced waters showed that the discharges sampled in this study were diluted below the average 7-day NOEC within 10 m of the source and in less than 2 minutes after leaving the pipe.
In Situ Bioventing for Environmental Remediation of a Natural Gas Dehydrator Site: A Field Demonstration
Authors: Lawrence Alonzo Wm. , Miller Daniel L. , Miller Jeffrey A. , Weightman Robin L. , Raetz Richard M. , Hayes Thomas D. 
Published: December 2007

Abstract
The Gas Research Institute (GRI) is conducting a comprehensive research program in Natural Gas Industry Exploration and Production (E & P) Site Remediation and Residuals Management to assist the industry in achieving cost effective compliance with evolving environmental protection regulations. Biological processes are considered to be a key component of the remedial strategy since most of the chemicals of interest in soils and groundwater at E & P sites have been reported to be biodegradable. Bioventing/biosparging is an in situ biological process which may have significant potential for remediating subsurface contamination caused by compounds such as benzene and natural gas liquid alkanes. Bioventing/biosparging is defined as the engineered movement of air through the subsurface to effect the removal of volatile and semi-volatile organics by both physical transport and microbially mediated mineralization.
This paper describes a bioventing/biosparging field demonstration which has been conducted over a ten month period at a former glycol dehydrator site, located near Traverse City, Michigan. The goal of the demonstration was to determine the feasibility of using this technology to remediate dehydrator sites and to develop engineering guidelines for other such sites.
The project was conducted at a former stand-alone glycol dehydrator site. Dehydrator reboiler condensate handling practice common at the time resulted in contamination of the saturated zone of the subsurface. The constituents-of-interest at the site are aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene (BTEX); and alkanes (C1 thought C10), particularly the compounds C4 through C10 (Butane through Decane). Sampling has indicated that the unsaturated zone is relatively free of the constituents-of-interest, with the primary impacted locations being the capillary fringe and saturated zones. A pump and treat system has been used since 1991 to reduce the size of the groundwater plume. The bioventing/biosparging system was installed to treat the impacted soils and groundwater in the source area. Five air sparging wells were screened in the saturated zone for air and nutrient injection. An additional well was screened in the capillary fringe for soil gas sampling and for soil vapor extraction, if needed to control subsurface air flow. A shallow soil vapor extraction well was used to collect the injected air as a means of measuring offgas constituent discharge.
This paper describes the results of the remediation in terms of soil permeability; air flow patterns, and sparge and vapor extraction well radius of influences; constituent stripping rates; and, constituent biodegradation rates. The experimental results are discussed in the context of a mass balance engineering model of the subsurface which can be used to guide the design of future bioventing/biosparging dehydrator site remediation projects.
Geology, Geometry, and Effective Flow
Authors: Pickup G. E. , Ringrose P. S. , Corbett P. W. M. , Jensen J. L. , Sorbie K. S. 
Published: December 2007

Abstract
The effects of small-scale structure are frequently ignored in reservoir simulation, although they may have a significant effect on hydrocarbon recovery. Many sandstones exhibit lamination, and in such rock structures, permeability may vary by an order of magnitude over distances of a centimetre or less. Frequently, the laminae are inclined with respect to the pressure gradient, which gives rise to crossflow within the unit. In this case a tensor may be used to represent the effective permeability of the bed.
In this paper the effect of small-scale geological structure on single phase flow is investigated using a model of a crossbedded unit to determine which factors have the greatest effect on crossflow. In addition, a range of other types of bedding are considered, including models with stochastic variation. We have found that, in general, the geometry of the sedimentary structure has a significant effect on flow. The crossflow is greater (and therefore tensors are more likely to be necessary) when the angle of the laminae is large relative to the pressure gradient (up to 45°), when the permeability contrast between laminae is large, or when the structure is asymmetric.
Production Applications of Reservoir Geochemistry: A Current and Long-Term View
Authors: Larter S. R. , Aplin A. C. 
Published: December 2007

ABSTRACT
We describe two facets of reservoir geochemistry: (1) reservoir fluids (oil, water and gas) are often compositionally heterogeneous and can give insights into reservoir continuity early in field development; (2) interactions between non-hydrocarbons, water and rock minerals, suggesting the key role that non-hydrocarbons play in influencing wettability, plus the viscosity and PVT properties of reservoired petroleum.
Bayesian Sequential Indicator Simulation of Channel Sands From 3-D Seismic Data in The Oseberg Field, Norwegian North Sea
Authors: Doyen P. M. , Psaila D. E. , Strandenes S. 
Published: December 2007

Abstract
Subsurface models of lithology are often poorly constrained due to the lack of dense well control. Although limited in vertical resolution, high quality 3-D seismic data usually provide valuable information regarding the lateral variations of lithology. The Bayesian Sequential Indicator SIMulation (BSISIM) technique is a new stochastic method to generate seismically constrained models of lithology. Unlike cokriging-based simulation methods, BSISIM does not rely on a generalized linear regression model, which is inadequate when combining lithology indicator variables and continuous seismic attributes. Instead, BSISIM uses a Bayesian updating rule to construct a posterior probability distribution of lithoclasses at each location. The posterior distribution combines a local prior distribution obtained by indicator kriging with a function representing the seismic likelihood of the different lithofacies. The local posterior distributions are sampled sequentially at all points in space to generate realizations from the joint posterior distribution. The realizations define alternative, equiprobable lithologic models, representing a compromise between fidelity to the seismic data, as measured by the likelihood functions, and consistency with spatial continuity information, as expressed by the lithology indicator correlation functions. The simulation technique is applied to predict the lateral distribution of channel sands in the Ness Formation of the Oseberg Field. Channel sand maps are simulated using lithologic observations in fourteen wells, and seismic amplitude and channel orientation data extracted from a 3-D survey. Sand probability maps, generated by summarizing a large number of simulations, allow delineation of the probable lateral extent of the channel deposits. Comparison of seismically derived lithologic models to well-derived models demonstrates the improved definition of channel geometry achieved by integrating the geophysical information.
Integrated Reservoir Characterization: Beyond Tomography
Authors: Lines Larry , Tan Henry , Treitel Sven , Beck John , Chambers Rich , Eager John , Savage Charles , Queen John , Rizer William , Buller Paul , Cox Dale , Ballard James , Kokkoros George , Sinton John , Track Antoine , Guerendel Philippe , Harris Jerry , Lazaratos Spyros , Van Schaak Mark 
Published: December 2007

Abstract
In 1992, there was a collaborative effort in reservoir geophysics involving Amoco, Conoco, Schlumberger and Stanford University in an attempt to delineate variations in reservoir properties of the Grayburg unit in a West Texas Co2 pilot at North Cowden field. Our objective was to go beyond traveltime tomography in characterizing reservoir heterogeneity and flow anisotropy. This effort involved a comprehensive set of measurements to do traveltime tomography, reflector imaging, analysis of channel waves, shear wave splitting for borehole stress estimation, seismic anisotropy, combined with 3D surface seismic and sonic log interpretation. Results are to be validated with cores and engineering data by history matching of primary, water and CO2 injection performance. The implementation of these procedures should provide critical information on reservoir heterogeneities and preferential flow directions.
Transient Pressure Behaviour of Selectively Completed Horizontal Wells
Authors: Yildiz Turhan , Özkan Erdol 
Published: December 2007

ABSTRACT
This paper investigates the transient pressure behavior of selectively completed horizontal wells. A new solution in Laplace space is presented and asymptotic approximations are derived. Computational issues are also addressed. Flow characteristics of sectionally completed horizontal wells are discussed and the information that can be obtained from the analysis of pressure and derivative responses during various flow regimes are documented. It is shown that the solutions existing in the literature cannot completely describe the essential features of flow toward a sectionally completed horizontal well.
Static Modeling at Prudhoe Bay - Integrating Reservoir Characterization and Reservoir Performance
Authors: Wilson A. P. , Severson C. D. 
Published: December 2007

Abstract
Static modeling of the Sadierochit reservoir is proving to be an integral tool in depletion planning and reservoir management at Prudhoe Bay. A versatile engineering tool has been developed by integrating geological descriptions of the reservoir and field performance data. This paper details a novel methodology used to build 3-D models of field-wide fluid distributions within a relational software application.
Seismic and geological layering information is manipulated to form a 3-D cell lattice, or static model, of the reservoir. Petrophysical properties are calculated externally from well logs, averaged by zone, and interpolated into each cell within the geological layer. These properties plus volumetrics are stored by cell within the relational database framework of the application. Yearly fluid distributions at the well level are generated from a field- wide surveillance program. These well-level fluids are distributed within the Static Model layers and fluid phase volumes are calculated by cell. Examples of applying these models to reservoir management decisions are discussed. At Prudhoe Bay, static models assist in visualizing reservoir structure, rock properties and fluid distribution, calculating phase volumes, aquifer modeling, and history matching simulators.
Interpretation of Wireline Formation Tester Packer and Probe Pressures
Authors: Kuchuk F. J. , Ramakrishnan T. S. , Dave Yogesh 
Published: December 2007

Abstract
In this paper, we describe the basic features of the packer module and the observation probe tool combination of the multiprobe wireline formation tester. We present a model that captures the essential tool physics. A link between events within the tool and the formation pressures at the observation points is provided. Analytical solutions for both packer module and the observation probe are given.
A new interpretation method is presented for simultaneous interpretation of the packer interval and the observation probe pressure measurements. An optimization scheme that corrects the guessed rates calculated from the tool mechanical characteristics and simultaneously finds the formation parameters, such as reservoir pressure, and vertical and horizontal permeabilities is also presented.
Tandem Density Logging in Rugose, Tectonically Stressed Boreholes, Oman
Authors: Kimminau S. J. , Edwards John 
Published: December 2007

Abstract
Tectonic stress in Oman causes boreholes to breakout along the direction of least horizontal stress. Logging tools which apply a spring loaded pad to the borehole wall (such as density and microresistivity logs) tend to align with the breakout axis. Unfortunately the breakout axis is rugose, which severely affects tool readings, causing considerable uncertainty in porosity and net-to-gross calculations. The conventional technique of ‘short-axis’ logging has been tried, but with limited improvement. Various options were considered, with the most sucessful solution being to run two similar pad contact tools in tandem, but aligned at 90 degrees to each other, thus ensuring that one is in the smoother axis of the borehole. Examples of logs affected by rugosity and recorded with tandem pads are presented and discussed. This technique has contributed to a significant improvement in the evaluation of deep reservoirs in Oman, and should be of benefit in other tectonically stressed areas.
Geostatistical Modeling of Permeability with Annealing Cosimulation (ACS)
Authors: Deutsch C. V. , Cockerham P. W. 
Published: December 2007

Abstract
To provide accurate predictions of flow performance, the numerical model of permeability used by flow simulators must be consistent with all available geological and engineering data. The available data includes core permeability measurements, relevant permeability statistics (particularly, histograms, measures of spatial variability, and correlation with secondary variables such as porosity), and well test-derived permeability measurements. This paper documents an algorithm to generate 3-D permeability models that honor this variety of data. The algorithm, referred to as annealing cosimulation (ACS), generates stochastic permeability models using the numerical optimization algorithm known as simulated annealing. The application of simulated annealing to reservoir modeling is not new. The variety of information considered, however, and the practical example presented in this paper will be of interest to reservoir modelers.
Application of Simulated Annealing and Other Global Optimization Methods to Reservoir Description: Myths and Realities
Authors: Ouenes Ahmed , Bhagavan Srinivasa , Bunge P. H. , Travis B. J. 
Published: December 2007

ABSTRACT
This paper gives a general review of the application of global optimization methods to reservoir description problems. The important parameters that control the performance of these algorithms are described and illustrations of the effect on the convergence are provided. A detailed review of past applications is presented and used to illustrate the fact that current computer technology is sufficient. Several current applications of global optimization, other than stochastic modeling, are used to emphasize the benefits of these methods. With the development of routine codes designed for everyday use, the need for parallel/distributed systems becomes apparent. An inexpensive and affordable parallel/distributed optimization approach that uses workstations, and even PCs, is described and illustrated with geostatistical optimization.
Thermal Well Test Analysis Using an Analytical Multi-Region Composite Reservoir Model
Authors: Acosta L. G. , Ambastha A. K. 
Published: December 2007

Abstract
For thermal recovery processes, the use of well test analysis to determine the swept volume is an important concern. Well tests conducted on wells undergoing a thermal recovery process have been typically idealized using a two- or three- region composite reservoir model. However, simulated thermal falloff tests have shown that mobility and storativity may be continuously changing in the swept region. For these reservoirs, a two- or three- region composite model may not be appropriate, while a multi-region composite model is suitable. A multi-region, composite reservoir analytical model has been developed to study the effects of various trends of mobility and storativity variations, within the swept region, on well tests for reservoirs undergoing a thermal recovery process. Pressure transient responses from this multi-region composite reservoir model show that on a log-log graph, the intermediate-time semi-log pressure derivative data falling on a straight line, whose slope is less than unity, is due to continuously changing mobility or storativity. The preceding behavior has been observed on several simulated thermal well tests. However, no theoretical explanation for this phenomenon has been advanced prior to this study.
Improved Rxo Measurements Through Semi-Active Focusing
Authors: Eisenmann Pierre , Gounot M-T. , Juchereau Bernard , Trouiller J-C. , Whittaker S. J. 
Published: December 2007

ABSTRACT
A quantitative measurement of the flushed zone resistivity, Rxo, is one of the key parameters for complete log interpretation. When available at very high vertical resolution, evaluation of thin beds is rendered more accurate. To this end, a new device has been developed which not only provides good performance in thick mudcake/high resistivity contrast situations but has also proved reliable in the presence of thin mudcakes and/or low resistivity contrasts.
The pad-mounted device uses dual current focusing — vertically unmonitored and azimuthally monitored. This combination provides fine vertical resolution and strong immunity to mudcake or standoff effects. Three measurement buttons, optimally positioned within the main electrode, provide resistivities at three different depths of investigation. The central button reads the flushed zone resistivity, while two others, located towards the pad edges, are predominantly sensitive to mudcake properties.
Finite-element simulations were used for design optimization and for construction of the tool response data base. From this data base, the forward model of the tool was obtained by interpolation. The three parameters - Rxo, mudcake resistivity and mudcake thickness - are estimated in real time by a robust inversion algorithm based on the extended Kaiman filter method.
This new tool provides superior quantitative measurements of Rxo at a vertical resolution of less than one inch. Log examples show significant improvements in vertical resolution and accuracy in the determination of Rxo. Coherent quantitative estimations of mudcake thickness have been obtained allowing identification of permeable zones.
Applications of the Azimuthal Resistivity Imager Tool in Saudi Arabia
Authors: Al-Waheed H. H. , Audah T. M. , Cao Minh C. 
Published: December 2007

Abstract
The Azimuthal Resistivity Imager (ARI*) is a new laterolog-type resistivity tool introduced in Saudi Arabia in 1993. Along with the conventional Deep and Shallow laterolog (LLd and LLs), the tool gives 12 directional high-resolution deep resistivity curves that may be used in the following reservoir description applications.
1. The vertical resolution of the deep azimuthal resistivity is found to be better than one foot as compared with three feet for the conventional deep laterolog. Natural applications are the determination of Rt in thin beds and fractured reservoir characterization.
2. In "low" resistivity, we have observed interesting situations: where we normally expect the Groningen effect, there is none; where we don't, the effect shows up strongly. In each case, the ARI resistivity is found to agree well with a companion induction log.
3. The ARI resistivity image adds a new dimension to log analysis: the geological picture. Besides Rt, the image may be used effectively to estimate formation dips, study lateral heterogeneities, pinpoint fault planes as well as describing the reservoir rock texture.