bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economics of Oil Shale Development in the United States
Authors: Biglarbigi Khosrow , Dammer Anton , Mohan Hitesh , Carolus Marshall 
Published: September 2008

Abstract
Oil Shale is one of the world's largest known fossil fuel resources. More than 1.8 trillion barrels of oil are trapped in shale in Federal lands in the western United States in the states of Colorado, Utah and Wyoming, of which 800 billion is considered recoverable. This amounts to three times the proven reserves of Saudi Arabia. During the past decade, a lot of attention has been given to the various extraction technologies to make oil shale economically feasible. Rising oil prices and improvements in technology have made the development of oil shale economically viable.
Detailed economic analysis has been conducted on the potential development of oil shale. This paper will describe the four representative production technologies being considered by companies for oil shale development. These include emerging in-situ processes as well as traditional mining with surface retorting technologies. The paper will provide details of various components of capital and operating costs for each of these technologies and the price at which each of these technologies will be economical. In addition to presenting an evaluation of the economic viability of an oil shale industry, this paper also describes the costs and benefits of such an industry to local, state, and Federal governments. Measures such as jobs created (for example: 2.5 million barrels of oil shale industry will require up to 300,000 direct and indirect jobs), GDP, and imports avoided will be described.
A Comprehensive Comparative Study on Analytical PI/IPR Correlations
Authors: Choi Suk Kyoon , Ouyang Liang-Biao , Huang Wann-Sheng (Bill) 
Published: September 2008

Abstract
Inflow performance is one of the significant components to quantify the reservoir's capability to produce hydrocarbon. There are two commonly-used quantities to represent reservoir inflow performance: productivity index (PI) and inflow performance relationship (IPR). Both relate fluid flow rate to pressure difference between bottomhole and reservoir. Much effort has been made on developing the PI or IPR solutions suitable for specific circumstances since Darcy proposed the simple and useful Darcy's law in 1856. As a consequence, various correlations for PI or IPR calculation have been proposed from simple analytical solutions to rigorous numerical formulations in the literature.
As horizontal or multilateral wells have been occupying an ever-increasing share of hydrocarbon production since the 1980s, more accurate PI or IPR estimation has been emerging as an important issue in the petroleum industry.11 The correlations become more and more complicated and rigorous in order to accurately describe inflow performance for complex well geometries. They can provide a better prediction or estimation of inflow performance, though they would be costly and computationally demanding. On the other side, researchers have been tried to simplify the complex solutions into analytical forms through extensive case studies. These provide a useful tool for the researchers and engineers to make quick estimations although they are confined to limited conditions.
In this paper, analytical correlations of PI and IPR from a comprehensive literature survey are reviewed. They have been categorized by well deviation, fluid phases and time dependence. The well deviation is divided into vertical (less than 15°), slanted (15 to 60°), highly-deviated/horizontal (60 to 90°), and multilateral wells; while fluid phases are categorized into single oil, single gas, and oil flow in two phases. For time dependence, steady state and pseudo-steady state have been considered, however the transient state has been excluded. In addition, case studies for the specific input parameters have been conducted to show the effective range, trends, and limitations of correlations as well as to provide the selection guideline for an appropriate estimation of inflow performance. All correlations of PI and IPR have been organized in the table for quick reference.
The Importance of Culture in Safe Work Environments
Authors: O'Connor J. , Woodrick T. , Schneeberger N. , Dettmann J. , Kuang J. 
Published: September 2008

Abstract
This study examined the joint influences of general organizational culture and process safety culture on employee perceptions of workplace safety. Statistical modeling was employed to analyze survey responses of employees at a Canadian energy provider. Results indicated that general organizational culture had both a direct and indirect effect on perceptions of workplace safety, and that process safety culture partially mediated the relationship between general organizational culture and perceptions of workplace safety. Findings also indicated that process safety culture is a more proximal predictor of perceptions of workplace safety than is general organizational culture. Lastly, management's action-oriented commitment to safety was found to be the strongest predictor of safety perceptions.
Prestack Seismic Inversion Tracks In Situ Combustion: 4D Seismic at the Balol Field, India
Authors: Sen Mrinal K. , Vedanti Nimisha 
Published: September 2008

Abstract
We present a case study of application of seismic inversion in monitoring the movement of thermal front in a heavy oil Field, Balol of Cambay basin, India using onshore time lapse seismic data. The land seismic data aquired over the Field was very noisy and the seimic difference sections were not informative. Thus the primary objective of this study was to make the time lapse 3D seismic data useful and comparable to the baseline data and to track the anomalies related to the combustion process. In this case direct amplitude differencing was not expected to work because of low repeatability of the monitor data sets with respect to the baseline data. The three sets of 3D data acquired during pre- (baseline) and post-combustion stages (monitor data) were different in frequency content, amplitude and spatial alignment; hence it was not possible to generate the difference sections. We therefore carried out pre-stack inversion of the 3D time lapse seismic data. The P-impedance volumes were obtained by simultaneous inversion of angle stacks generated from time migrated data sets corresponding to three production time steps. The inverted P-impedance volumes show spatial variations of some low impedance zones with production time, which can be related to fluid movements. The results from seismic inversion show great promise to monitor movement of thermal front if more well control is provided.
Matrix Acidizing of Carbonate Reservoirs Using Organic Acids and Mixture of HCl and Organic Acids
Authors: Chang F. F. , Nasr-El-Din H. A. , Lindvig T. , Qiu X. W. 
Published: September 2008

Abstract
Hydrochloric acid is the most commonly used acid for carbonate acidizing due to its low cost and high dissolving power. However, there are two major drawbacks associated with using concentrated HCl solutions in deep wells. The first is its high reaction rate with carbonate rocks, which limits acid penetration in the formation. The second is its corrosivity to well tubulars. Hence organic acids become viable material for matrix acidizing to alleviate these two problems. Though organic acids provide the benefit of retardation and low corrosivity, their low dissolving capacity may still limit the wormhole penetration leading to insufficient stimulation of the formation. Therefore, opportunity exists to mix HCl with an organic acid to achieve productivity enhancement by optimizing the wormhole penetration and profile.
Organic acids that are utilized in stimulating carbonate formations include formic, acetic, and more recently, citric and lactic. Selecting a suitable organic acid for a specific acidizing treatment is more difficult due to complex thermodynamic equilibrium and reaction kinetics. The reactions between organic acids and carbonate are less understood than those of HCl with carbonate rocks. Organic acid/carbonate systems are complicated because of the presence of CO2, organic ligands, and potential precipitation of the reaction products; the organic salts of calcium and magnesium. Therefore, more testing and modeling are needed to better understand these reactions.
This paper discusses the required information to properly design an organic acid or HCl plus organic acid treatment. In additional to reaction kinetics, data such as carbonate dissolving capacity at reservoir temperature and pressure, solubility of reaction products, and the effect of HCl to organic acid ratio are needed to better design field treatments. Recommendations are given on what and how laboratory evaluation should be carried out to obtain this information.
Profitability of Deepwater Petroleum Leases: Emipirical Evidence From the U.S. Gulf of Mexico Offshore Region
Authors: Iledare Omowumi O. 
Published: September 2008

Abstract
This paper describes and analyzes deepwater petroleum lease sales and development in the U.S. Gulf of Mexico region. Descriptive and Discounted Cash Flow (DCF) analysis of lease specific data suggest that the risk associated with deepwater lease development increases with water depth, and the return on investments rises significantly with water depth as well. Our empirical analysis shows that multiple bids tended to generate higher bonus per lease than single bids; independent firms paid more bonus per lease than integrated firms in the Gulf deep and less in the slope. Further, the difference in economic outcomes for leases won and developed by integrated firms and independent firms was more pronounced in the U.S. Gulf deep (water depths &gt; 900 meters) than in the Gulf slope (water depth of 200-900 meters). We found no evidence that solo venture leases out performed joint venture leases in a significant way in the deep, despite the fact that the high bonus per lease received for solo bidders was significantly lower than joint venture bidders, on average. In the aggregate, the economic outcomes for lease acquisition and development in the Gulf deep were significantly higher than in the Gulf slope.
Modeling the Economic Impact of Individual and Corporate Risk Attitude
Authors: Welsh M. B. , Begg S. H. 
Published: September 2008

Abstract
Walls' work [1, 2], based around Expected Utility Theory [3], has highlighted the relationship between corporate risk tolerance and value; and others have commented on the loss of value resulting from companies behaving in a non-risk-neutral manner (i.e. not using expected value (EV) to make decisions) [4].
Prospect Theory [5], however, extends Utility Theory [3] to describe decisions individuals actually make under uncertainty. Key features include: diminishing utility of returns, resulting in risk aversion for gains and risk seeking for losses; use of "decision weights" rather than probabilities; and asymmetry between losses and gains, with people weighting losses more heavily. All three effects impact on a person's risk tolerance (i.e., how risk averse or risk seeking they are).
We present four studies highlighting the impact of Prospect Theory on decision value and, particularly, changes in decision value resulting from differences between individual and company risk tolerances. Study one shows losses resulting from risk aversion due to diminishing returns, discussing and comparing individual and corporate risk tolerances; the second highlights the impact of using decision weights; and the third the effect of loss/gain asymmetry. The fourth study is not directly based on Prospect Theory but rather shows the effect of the chance of ruin [6] on risk tolerance.
Results indicate that the Prospect Theory effects cause changes in risk tolerance resulting in lost value compared to risk neutral decisions and that this is strongest when the probability of success is low. Any difference between individual and corporate risk tolerances also impacts on value. The results of the fourth study, conversely, show why it can benefit an individual or (less often) a company to be risk averse, as this is demonstrated to reduce the chance of ruin and thus can increase EV in the long run.
Finally, we discuss the implications of these findings for corporate and individual decision makers, arguing that the corporate risk tolerances observed by Walls [1, 2] are, in fact, aggregated individual risk tolerances which should be compared to ideal corporate risk tolerances calculated using the chance of ruin for a company with a particular portfolio of investments.
Optimization for Operational Decision Support: The Rig Fleet Management Case
Authors: Irgens Morten , Guzman Ricardo Prieto , Stamatopoulos Jacqueline , Jackson Ken 
Published: September 2008

Abstract
Exploration and Production (E&P) operations are becoming increasingly challenging to do well. Drilling operations are a good example. Planning, scheduling and operating the rig fleet are important functions. You do not need many rigs before minimizing rig movements and costs while maximizing utilization is practically unmanageable using a manual approach.
Recent advances in optimization and artificial intelligence technologies make it possible to support operational decision making and promote decisions that are aligned with key performance goals. These technologies address complex, dynamic situations, and show the tangible value of operational decision-making in real time.
Saudi Aramco in collaboration with Actenum Corporation has developed a software application where the rig schedule is optimized against multiple objectives, disruptions to the schedule are quickly managed, the impact of scheduling decisions on key performance indicators is immediately displayed, and schedule optimization is supported by a user interface enabling direct schedule manipulation in response to changing needs. The application brings near real-time automation to a previously manual process, applies optimization technology to dynamic, mission-critical operations, and strongly increases Net Present Value (NPV).
The results show reduced planning time, reduced response time, reduction in scheduling errors, improved "what-if" abilities and decision-making. The experiments reported in this paper show reduction in transportation cost and increased NPV, providing insight into the trade-offs between time-to market and operational cost.
Minimizing Sanding Risk by Optimizing Well and Perforation Trajectory Using an Integrated Geomechanical and Passive Sand-Control Approach
Authors: Rahman Khalil , Khaksar Abbas , Kayes Toby 
Published: September 2008

Abstract
The source of sand production is the presence of disintegrated sand grains due to rock failure at the wellbore and/or perforation walls. Decision for appropriate sand control strategy requires engineering analysis to evaluate timing and severity of sanding over the life of field conditions. Optimizing well parameters such as well trajectory, perforation orientation, and level of drawdown using geomechanical principles can minimize and delay sand production.
This paper presents a geomechanical modeling approach that integrates production history with information from drilling data, well logs and rock mechanics tests. A gas field in South Asia with 11 wells and several years of production experience is used to demonstrate this approach. Core-calibrated rock strength log profiles are estimated throughout the reservoir depth for all existing wells. A rock failure criterion at the sand face is developed as a function of in-situ stresses, rock strength, well trajectory, perforation orientation, reservoir depletion and drawdown. Sanding evaluation results are calibrated and verified with production data and evidence of sanding in existing wells. Sand-free operating envelopes and sand evaluation logs are then generated for all existing wells and planned infill wells for life of field conditions. Sand prone zones and timing of sanding are established as a function of depletion and drawdown for each well using production forecasts for the rest of field life. For new infill wells, optimum well trajectories, selective perforation intervals and optimum perforation orientations are proposed to minimize and delay sand production. Re-completion and utilizing passive sand control methods including selective and orientated perforations are recommended for a number of existing wells.
This paper is expected to provide well engineers with guidelines to understand the principles and overall workflow involved in sand production prediction and minimization of sand production risk by optimizing well trajectory, perforation orientation and selective perforation strategy.
A Case Study of Hydraulically Fractured Eddy County, New Mexico, Horizontal Wolfcamp Producers
Authors: Metcalf Arthur S. , Coronado Juan , Fisher Kelvin , Kvasnicka Dave E. , Castello Joel S. 
Published: September 2008

Abstract
In order to improve production and subsequent well economics in the Wolfcamp formation in Eddy County, New Mexico, horizontal drilling has been employed for the last seven years. Current stimulation practices in these horizontal wells involve hydraulically fracturing with proppant in multiple stages. The effectiveness of the various fracturing treatments on production responses is of interest, because any optimization or changes that can reduce stimulation costs improves profit. In addition, with the current shortages in all mesh sizes of sands, anything which reduces the quantities needed to effectively stimulate wells is a plus.
Production from a localized group of horizontal Wolfcamp wells was examined to establish the impact scenario that proppant choice made on performance. It was found that decline rates were the same or better on wells fracture treated using a significantly lower volume of an Ultra-Lightweight proppant compared to those wells treated with regular sand. This reduction in proppant used also resulted in a savings ranging from 4% to 33% of the stimulation costs.
New Grids for Robust Reservoir Modeling
Authors: Gringarten E. , Arpat B. , Haouesse A. , Dutranois A. , Deny L. , Jayr S. , Tertois A. L. , Mallet J. L. , Bernal A. , Nghiem L. 
Published: September 2008

Abstract
Geostatistical modeling of reservoir facies and petrophysical properties (e.g. porosity and permeability) must be performed in a pre-faulted, deposition space in order to reproduce the true spatial correlations of these properties. A transformation function is therefore required to bring the data from the current position of the reservoir into the modeling space where experimental variograms are computed; reservoir properties are then stochastically simulated in the deposition space and mapped back to the real space. Current reservoir modeling practice uses a stratigraphic grid to conform to the reservoirs structure (bounding horizons and faults). The (i, j, k)-indexing of the nodes of the cells is used as a discretization of a curvilinear coordinate system which acts as the transfer function to the deposition space. This leads to a very strong underlying assumption: the geological distances (in the deposition space) are a function of the (i, j, k)-indexing. In the presence of non-vertical faults, the cells of the stratigraphic grids are either stretched or squeezed, violating this assumption. Moreover, in the presence of complex structural geology, these grids simply cannot be constructed without tremendous simplifications. The new proposed approach uses a 3D parameterization of the subsurface yielding a grid that minimizes the distortions of distances imposed by geostatistical simulation algorithms. These new Geologic Grids allow the construction of robust reservoir models whatever the structural complexity of the reservoir. Additionally, they guarantee the accurate mapping and upscaling of reservoir properties into either structured or unstructured Flow Simulation Grids. They also enable the creation of structured Flow Simulation Grids in which faults are defined as stair-steps allowing representation of the complete reservoir structure and ensuring orthogonality of cells.
Accurate Single-Ended Distributed Temperature Sensing
Authors: Chen Yuehua , Ramos Rogerio T. , Hartog Arthur H. , Greenaway Robert , Powell Giles , Taylor David 
Published: September 2008

Abstract
Distributed temperature sensing (DTS) is a technique to obtain real-time temperature well logs which are used for several applications such as production allocation, heavy oil thermal recovery (e.g., steam-assisted gravity drainage, SAGD) steam-well management, and well-integrity monitoring. This system is based on measuring scattered light at more than one wavelength from an optical fiber placed along the well.
An issue arises when the attenuation of the optical fiber changes with time by different amounts at the different wavelengths used causing degradation in accuracy of the measurement. This differential loss can be compensated for by connecting both ends of the optical fiber to the DTS instrument in a double-ended (DE) configuration. However, it is not always possible to operate in DE configuration because of other constrains in the design such as lack of space or restricted number of penetrations in completion equipment. Single-ended (SE) operation configuration has been used in these cases, exposing the monitoring system to potential loss of accuracy.
An accurate single-ended (ASE) DTS system which provides differential loss measurement and compensation to single-ended installations is described. The instrument uses more than one light source to compensate for the optical-fiber differential losses at the relevant wavelengths. This compensation is applied continuously without the need of external recalibration. A system operating on this principle has been used for some time on single-mode fibers, and recent technical advances have enabled its application to multimode fibers.
Laboratory-test and field-test results are presented showing a dramatic improvement in accuracy in cases where differential losses have developed. Comparative data using DE, SE, and ASE DTS systems are presented showing cases in which optical fibers were subjected to extreme environments where the effect of differential loss is accentuated. Examples are shown in which errors of up to 100°C caused by differential loss were automatically corrected in real time by the ASE DTS instrument.