bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Method for Measuring Annular Water Flow in Injection Wells Using Continuous Oxygen Activation Logging
Authors: Trcka D. E. , Chace D. M. 
Published: December 2007

Abstract
A need exists for quality flow profile surveillance in waterflood programs. While oxygen activation has wide application in measuring behind casing water flow, the traditional methods of oxygen activation are limited for use in measuring injection flow profiles by the requirement that, for general applications, there can not be additional flow streams in the same direction as the flow in the casing-tubing annulus targeted for measurement, such as, injection flow in the injection tubing string.
A new oxygen activation technique has been developed which broadens the application of oxygen activation measurements in flow profiling by permitting the isolation of the annular flow signal from the tubing flow signal when the two flows are in the same direction. Potential advantages of this method include: a continuous log of volumetric injection flow rates with depth, greater vertical coverage of the well, and extension of the upper limit of the velocity measurement.
Laboratory data employing the measurement technique show excellent agreement between the measured annular velocity – in the presence of tubing flow in the same direction – and the true annular velocity.
Reservoir Boundary Identification from Seismic Imaging for Well Test Analysis
Authors: Guérillot D. R. , Beydoun W. B. 
Published: December 2007

Abstract
Given a well test, the aim of this paper is to demonstrate that the range of possible reservoir boundaries derived from a seismic image is a valid constraint in the reservoir response.
A lens model was considered. Synthetic seismic and well test data were generated. The focus was to verify that the single phase well test response is sensitive to modifications of the reservoir boundaries derived from a poststack seismic depth image, all the other variables being fixed.
A specific prototype software was developed to implement the proposed methodology.
Analytical Expressions for Pseudoskin for Partially Penetrating Wells Under Various Reservoir Conditions
Authors: Gomes Edmond , Ambastha A. K. 
Published: December 2007

Abstract
Many times, oil reservoirs are accompanied by bottom-water zones and/or gas caps, and these reservoirs are produced using partially-penetrating wells. An extra pressure drop occurs around such wells during production because of partial penetration. Several correlations have been presented in the literature to estimate pseudoskin for a partially-penetrating well located in either a homogeneous or a layered reservoir with closed top and bottom boundaries. This study aims to develop new analytical expressions for pseudoskin for partially-penetrating wells in multi-layered reservoirs with both closed top and bottom boundaries, and with bottom-water zones and/or gas caps. A pseudosteady-state interlayer crossflow has been assumed in this study.
These new analytical expressions are simple and easy to use. Evaluaion of pseudoskin using these expressions requires a knowledge of two parameters when the top and the bottom boundaries are closed, and three parameters in the presence of a bottom-water zone or a gas cap, regardless of the number of layers. The estimated pseudoskin is very close to the actual pseudoskin obtained from the complete analytical solution. These new analytical expressions are also applicable to the corresponding homogeneous and single-layered cases. The estimated pseudoskin values have been compared with those estimated by other researchers. Effects of the open interval location, the presence of bottom-water zone and/or gas cap, and the layer refinement on pseudoskin have also been studied.
Integration of a Geological-Engineering Model With Production Performance: A Case Study at Patrick Draw Field, Wyoming
Authors: Chang M. M. , Szpakiewicz M. , Schatzinger R. , Jackson S. , Sharma Bijon , Tham M. , Lim F. H. 
Published: December 2007

Abstract
Analysis of production performance data from the Almond Formation in Patrick Draw Field, WY, a mesotidal shoreline barrier reservoir, was integrated with geological, geophysical, hydrogeochemical, and engineering information to generate an integrated reservoir model.
Reservoir compartments and flow barriers were indicated by high Hall plot slopes and discontinuities in saturations and properties of formation fluids. The flow barriers identified corresponded to areas of thin reservoir-quality sand and faults mapped from log and seismic information. In the northeastern portion of Patrick Draw Field, imbricated coquina beds and carbonate cemented zones degrade the reservoir quality, hinder lateral communication and result in poor sweep efficiency and low waterflood oil recovery. Formation water analysis data are relatively inexpensive and extremely useful in identifying reservoir compartments and are required for accurate calculation of oil saturations from resistivity logs. The wide variations of water salinity found in Patrick Draw Field indicated reservoir compartmentalization and demonstrated the degree of error in oil saturation calculations that may result if a uniform resistivity value is assumed.
Analysis of changes in producing gas-oil ratio, oil bank period, water breakthrough time, recovery efficiency, and rock-fluid properties indicated the location and nature of reservoir heterogeneities. Oil recovery near the gas cap was improved through pressure maintenance. Dykstra-Parsons coefficients wer not a good indicator of waterflood production performance in Patrick Draw Field. However, waterflood recovery efficiency increased with the average well permeability.
A New Modular Approach to Comprehensive Simulation of Horizontal Wells
Authors: Brekke Kristian , Johansen T. E. , Olufsen Rudi 
Published: December 2007

Abstract
The development in drilling and completion technology for horizontal wells has created new demands for enhanced comprehensive simulation methods. Wellbores with complex flow geometries are not easily implemented in commercially available simulation tools. A modular, comprehensive modelling of well and reservoir is proposed in this paper. The model consists of a detailed horizontal well flow simulator coupled to a reservoir simulator. The wellbore simulator is based on a network model which is capable of solving a broad range of possible flow configurations in the horizontal part of the well. The modular approach is facilitated by a coupling technique that reduces the requirement for iteration between the modules. The simulator is applied to high flowrate horizontal wells in thin oil zones with high permeability. Due to the flexibility in wellbore configuration, the simulator may be used to optimize well location, well path and completion approach. The coupling provides a detached wellbore simulation module which is reservoir simulator independent. The new simulation approach should be considered for horizontal wells where frictional pressure loss or geological inhomogeneities along the well are of importance to a well's production performance. The simulator will be used to evaluate completions with a complex flow configuration, potential cross-flow and for optimization of production and injection performance of wells in heterogeneous reservoirs.
Effect of Accelerational Pressure Drop in a Horizontal Wellbore
Authors: Ihara Masaru , Shimizu Nobutoshi 
Published: December 2007

ABSTRACT
It is desirable that a horizontal well is properly designed with regard to the production performance, as well as the well completion. A rigorous analysis of flow hydrodynamics in a horizontal well was performed by including the accelerational pressure drop in the wellbore. This has been recognized as one of the unsolved, yet most important problems in the production engineering.
Pertinent experimental data were acquired with a large scale test facility, which was suitable for acquiring data on the relationship between the pressure drop along the wellbore and the fluid influx from the reservoir.
An initial mechanistic model was improved by including the accelerational pressure drop in the wellbore. As evident from the comparison of the experimental data with the model, the improved model described more rigorously the flow behavior m a horizontal well configuration. The model would be applied for field applications, by combining with the Inflow Performance Relationship (IPR) approach and the black oil model.
A Simplified Pseudo 3D Model to Evaluate Sand Production Risk in Deviated Cased Holes
Authors: Kessler Nicolas , Wang Yarlong , Santarelli F. J. 
Published: December 2007

Abstract
When comparing various wells on a given field in terms of sand production, it often happens that they display quite different behaviours: for example, deviated wells will produce sand whilst vertical ones won’t.
A major reason behind such an apparent paradox is the orientation of the well and its perforations in the in-situ stress field. Such a problem is usually studied by using complex non linear 3D Finite Element Models. In an attempt to make such an approach more flexible, this paper presents a simplified, semi quantitative analytical model able to evaluate sand production risks in cased holes with various deviations.
This pseudo 3D model, based on linear elasticity, confirms that sand production risk for a given perforation strongly depends on well deviation and on the orientation of the perforation in the plane orthogonal to the wellbore. A field case illustrates how the model can hence provide an understanding for observations which could have otherwise remained unexplained.
Finally, by introducing special failure criteria calibrated on hollow cylinder and cavity failure tests, an extension of the model is compared favourably to some 3D non linear numerical simulations in the case of a second field case. Because of its analytical nature, such an extension can easily be used in conjunction with logs in order to give a rather precise idea of the sand production risk on a newly drilled well.
Graduate Programs in Petroleum Engineering at Stanford University
Authors: Marsden Sullivan S. , Ramey Henry J. , Miller Frank G. 
Published: December 2007

Abstract
The described graduate degree programs in Petroleum Engineering at Stanford have been Petroleum Engineering at Stanford have been developed to meet the diverse needs of engineers and researchers involved with petroleum production. The M.S. program is essentially a production. The M.S. program is essentially a professional curriculum with only minor emphasis professional curriculum with only minor emphasis on research. The Ph.D. program emphasizes research and requires courses in engineering, science and mathematics. The Engineer's degree program, intermediate in goals and requirements, program, intermediate in goals and requirements, has one option which emphasizes professional engineering and another (the Management Option) which combines engineering and business courses and requires a thesis based on a combined engineering-economic study.
Introduction
Graduates of today's petroleum engineering departments may be expected to carry out a variety of tasks. While their undergraduate training can provide fundamental training for these, there is usually not enough time in a baccalaureate program to give much more than an introduction to production and reservoir engineering methods. Specialized training in these fields as well as in research must be left for the graduate level. Because the goals of graduate study are multipurpose and generally different from those of undergraduate study, we have found that several distinct graduate programs are necessary. We would like to describe programs are necessary. We would like to describe those which have been devised in our petroleum engineering department with the hope that this description may be of interest and help to others.
A dozen years ago most of our graduate students were M.S. candidates who had received their B.S. from our Department the previous year and so the undergraduate and graduate programs were closely related. Now most of our programs were closely related. Now most of our graduate students are Ph.D. candidates who have either taken their M.S. degree here or more usually, obtained it elsewhere. Thus our undergraduate courses are often taken by graduate students as electives to make up deficiencies. These courses are also taken by our own undergraduates as well as by students from other departments.
In addition to the M.S. and Ph.D. degree programs which require graduate residency of programs which require graduate residency of one and three years, respectively, we also have two programs leading to professional Petroleum Engineer degrees, and each requires two years of graduate residency.
Fracturing of High-Permeability Formations: Mechanical Properties Correlations
Authors: Morales R. H. , Marcinew R. P. 
Published: December 2007

ABSTRACT
Geological and mechanical laboratory experiments were conducted on several core samples in order to characterize the material behavior and generate data for the design of hydraulic fracturing treatments for high-permeability formations. Photomicrographs of thin sections were used to classify the specimens according to their granular constitution and pétrographie components.
The results of evaluations of fracture toughness, permeability, porosity, static and dynamic Young’s modulus and Poisson’s ratio are presented. Based on linear regression analysis, correlations relating static to dynamic Young’s modulus were derived. The error between the predicted and measured values was minimized by dividing the samples into three porosity groups.
Unconventional Acid Design Used to Stimulate Sandstone Reservoirs in the Gulf of Mexico
Authors: Ewing J. W. , Clements Todd , Ali Syed , Dunlap D. D. 
Published: December 2007

Abstract
Formation damage from the migration of fines has historically been the cause of rapid production decline at the Eugene Island 361 field in the Gulf of Mexico. Conventional acid systems have been used with limited success to stimulate these oil reservoirs. An acid system was needed to address complexities that are seen in this field and in many other Gulf of Mexico sandstones. These complexities include high feldspar and clay content, a high percentage of silt-sized particles, and low bottomhole temperatures.
Current acidizing techniques in the Gulf of Mexico generally employ the use of either 12:3% HCl:HF or 7.5%:1.5% HCl:HF acids. However, the abundance of clays and feldspars occurring in this area hinder the long term success of these conventional treatments. The conventional systems only partially remove near wellbore fines causing these wells to realize only temporary stimulation benefits. An unconventional system employing various combinations of HCl:HF acids has proved to provide the best production response and economic success. This paper details the laboratory and field evidence of this unconventional treatment’s success.
The Optimum Injection Rate for Matrix Acidizing of Carbonate Formations
Authors: Wang Y. , Hill A. D. , Schechter R. S. 
Published: December 2007

Abstract
Our main result is the discovery of an optimum acid injection rate to obtain acid breakthrough in linear corefloods of carbonates using a minimum total acid volume. Low rates result in acid spending at the core surface while high rates result in the formation of multiple, highly ramified wormholes. At the optimum intermediate rate, a single, small wormhole penetrates the core.
The optimum acid rate is found to be a function of the rock composition and reaction temperature as well as the pore size distribution of the virgin formation rock. All of these factors are included in the theory developed here. This theory provides a quantitative prediction of the optimum rate. The practical ramifications of the results are also considered.
API Tank Vapors Project
Authors: Choi M. S. 
Published: December 2007

Abstract
The E&P industry has tens of thousands of field storage tanks in produced oil service. Most of the tanks do not have vapor recovery and the evolved gases are vented to the atmosphere. With the implementation of the 1990 Clean Air Act Amendments (CAAA), the industry is faced with the need to quantify its emissions. These emissions inventories must be broken down by components due to the distinction placed upon the category of Hazardous Air Pollutant (HAP).
In addition to HAPs, Volatile Organic Compound (VOC) emissions also need to be quantified for purposes of regulatory reporting and as design basis for vapor recovery units (VRU). Many operators have attempted to measure emissions directly. However high cost and erratic results that can be directly attributed to the nature of the tank system have discouraged the use of field measurement as a viable option for estimating emissions.
In June of 1993, an American Petroleum Institute (API) project was initiated to develop an estimation method for HAP and VOC emissions from oil field storage tanks. The method is based on the use of computer process simulation techniques, predicated on minimal and easy-to-acquire field data and laboratory analyses. This paper describes the methodology that will be used and the deliverables that are expected from the joint industry effort.
Fracture Height Containment with Continuum Damage Mechanics
Authors: Valkó Peter , Economides M. J. , Leoben Mining U. 
Published: December 2007

Abstract
A recently introduced fracture propagation model, incorporating continuum damage mechanics (CDM) has been found as an adequate and consistent vehicle to predict both the level and trend of the net pressure. In this paper the CDM concept is applied to a pseudo-3D propagation model to describe height growth. In contrast to equilibrium theory, both the vertical stress profile and the (possible different) CDM coefficients are responsible for the final fracture morphology. This model is not burdened by the frequent capricious behavior of linear elastic fracture mechanics (LEFM) based models. The paper presents the model development and discusses the computational results. A comparison is made to the results of other fracture simulators published in a recent comparative study. A procedure is suggested to obtain the necessary CDM parameters from minifrac tests.
Prediction of the Oil Rate Increment With Water Profile Control by Polymer Injection
Authors: Giudicelli C. B. , Truchetet R. A. 
Published: December 2007

ABSTRACT
The efficiency of a water profile control treatment by polymer injection is usually predicted by laboratory measurements.
An analytical model is described which allows calculations of the incremental oil rate The model is based on a two-layer system and integrates both laboratory results and reservoir characteristics. It shows that the basic principle of water profile control by polymers is the reduction of productivity of the water-flooded zones.
This model handles as well uncertainty on the various parameters involved through a probabilistic approach which provides uncertainty brackets on the results.
A field data analysis is completely performed before application of the model and results are presented.
Linking Universal Kriging and Reservoir History Matching
Authors: Watkins A. J. 
Published: December 2007

ABSTRACT
This paper describes how the framework developed for universal kriging can accommodate a general formulation of the reservoir history matching problem. We illustrate this framework with simple examples, and then show that the specification of the required covariances and correlations provides an opportunity to introduce explicitly some pertinent reservoir engineering knowledge into history matching. We then briefly consider the elicitation of this information in the form of parameter values in functional forms for covariances, and discuss how the specification of weights can influence calculations, and hence convergence to an optimal history match. We conclude with a review of some of the available diagnostics and a summary on practical applications of the framework.
Visualization of Rock Samples in Their Natural State Using Environmental Scanning Electron Microscope
Authors: Gauchet Renaud , Cheneviere Pascal , Tricart J- P. 
Published: December 2007

Abstract
Among the new tools which have been developped recently in the area of rock characterization at the microscale level, Environmental Scanning Electron Microscope (ESEM) is particularly relevant in petroleum technology. This technique allows visualization of rock samples in their natural state in presence of fluid distribution, and during microdynamic experiments in presence of both brine and oil. In addition to this dynamical process recording, imaging and elementary analysis are also available.
This new technique has been used in our laboratories to perform various experiments on gas/liquid and liquid/liquid systems, on core samples coming from different reservoirs known for their wettability behavior.
First, a set of condensation-imbibition tests on shaly samples were carried out to investigate the anticipated preferential affinity for water of illite versus kaolinite. This direct visualization of contact angles and imbibition effectiveness in an air/brine system showed a clear affinity of clays for brine and an imbibition process mainly controlled by shape factors.
Secondly, a step by step visualization of fluids distribution in an oil/brine system during initial water saturation or residual oil saturation installation has been performed. This allowed to visualize oil and brine distribution in the case of three reservoir core samples, one water wet, one intermediate wet and one oil wet. A series of images illustrates some of the oil/brine displacement mechanisms at the microscale.
Reservoir Management in Tertiary CO2 Floods
Authors: Merchant D. H. , Thakur S. C. 
Published: December 2007

Abstract
Since 1984, Amoco has operated four major enhanced oil recovery projects using CO2 in West Texas. Due to the high cost of CO2 injectant, the economic success of these floods depends on the ability to properly monitor and manage CO2 utilization. This paper describes a new approach to the surveillance and management of the Slaughter Estate Unit CO2 flood. The method described here involves real-time monitoring on a well-by-well, pattern-by-pattern basis by displaying raw as well as processed data using the "Montage" concept. Using this concept, injection, production, and other data from a well or a group of wells can be viewed simultaneously by zooming into any area of the field. Inter-well communication and gas cycling can be recognized quickly and changes in operating variables can be made. As a result, the economic performance of a CO2 flood can be optimized by making prompt adjustments to gas-water ratio, CO2 and water half-cycle slug sizes, and injection and production well pressures.
Is Parallel Computing Ready for Reservoir Simulation? A Critical Analysis of the State of the Art
Authors: Killough J. E. 
Published: December 2007

Abstract
Recently the lure of scalable distributed memory parallel computing with hundreds or even thousands of inexpensive, but powerful, RISC-based processors has resulted in a significant effort in the development of software for petroleum engineering and seismic applications. Unfortunately, few if any applications have found their way into a production environment from the reservoir engineering perspective. Several hurdles remain to be overcome if parallel computing is to become commonplace as a tool for applications. This article addresses three areas of concern for a reservoir simulation: load balancing, data structures, and linear equation solutions. Examples from real reservoir simulations and possible solutions for several situations are discussed.