bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operational Advances from Field Application of Short-Radius Horizontal Drilling in the Yates Field Unit
Authors: Odorisio V. G. , Curtis S. C. 
Published: December 2007

ABSTRACT
Operational advances in short radius horizontal drilling have been achieved in conjunction with the placement of 23 drainholes in the Yates Field Unit, Pecos County, Texas. These advances include improvements in drilling of the curve section, application of gel squeezing technology to isolate the curve section, and drilling of the lateral section which are discussed for horizontal recompletions from existing vertical wellbores with 7 inch and 5-1/2 inch casing. In addition, the cost savings and performance enhancements realized from these operational advances are reviewed.
The most significant improvements have been realized through implementation of a short radius articulated mud motor system to replace rotary tool assemblies. The motor system has been optimized through refinement of motor and steering assembly specifications, and bit selection. The refined system has provided as much as a five-fold increase in penetration rates, a three-fold increase in lateral length, and a substantial improvement in directional control. The enhancements have also resulted in a reduction of over 60% in the cost per foot of drainhole length drilled.
Guidance for Designing Offshore Modules Evolving from Gas Explosion Research
Authors: Bakke J. R. , van Wingerden Kees 
Published: December 2007

Abstract
Recent accidents in the North Sea1,2 have confirmed that gas explosions constitute a major hazard for gas and oil production on offshore facilities.
Research on gas explosions at CMI has for more than 10 years focused on experimental research into flame propagation in complex geometries as well as the development of a gasdynamic code (FLACS) capable of predicting gas explosion propagation in industrial environments.
The FLACS code calculates the turbulence generated by the interaction of the gas explosion with confinement and equipment and the positive feedback of this turbulence into the gas explosion. The code predicts pressure and drag forces due to gas explosions for specified module layouts and for different fuels and ignition locations.
The paper gives a brief introduction to the nature of gas explosions and an overview of previous research at CM, followed by a presentation of results from the present research on the subject. As an example the effect of water deluge on explosion propagation will be discussed.
Finally an overview is given of lessons that have been learned by using the FLACS code, which is used by operators to design offshore modules. The effect of vent area location, types of vent area covers, module shape, equipment location and platform layout is discussed.
Cyclic Steam Injection with Additives: Laboratory and Field Test Results of Steam/Foam and Steam/Solvent Processes
Authors: Mendez Zuleyka , Alvarez J. M. , Escobar Elena , Colonomos Peter , Campos Enrique 
Published: December 2007

Abstract
Cyclic steam injection is the most commonly used method to produce the heavy oil reservoirs in the Bolívar Coast in Western Venezuela. The efficiency of this method in this field, as measured by the oil to steam ratio, is remarkably high, mainly due to compaction drive. Nevertheless, later cycles show a natural decline in the efficiency of the process.
In order to improve the efficiency, and to extend the application of cyclic steam injection in the field, different types of additives are being tested. Laboratory study, and field tests were conducted in order to study the possible merits of the addition of small amounts of solvent as part of the injection process. On the other hand, due to the massive sand bodies, and shale intercalations that exist in the heavy oil reservoirs of the Bolívar Coast, foam was used in order to improve the vertical sweep efficiency of steam injection during huff’n puff.
After the conduction of laboratory experiments with steam/foam, a set of 16 wells were selected in order to test the injection of two commercial foaming agents (LTS and BBS). In this work, the field results of these pilot test of foam injection are analyzed, and correlated with several variables.
Four wells were stimulated with steam injection with solvent. The solvent used was an industrial diesel. As in the previous case, field results were analyzed. The merits of the process are obtained by comparing the response of the wells, with neighboring wells with similar characteristics. Prior to the field tests, laboratory experiments were carried out, in order to obtain the operating conditions.
Optimum Water Alternate Gas Injection Schemes for Stratified Reservoirs
Authors: Surguchev L. M. , Korbfll Ragnhild , Krakstad O. S. 
Published: December 2007

Abstract
Water alternate gas (WAG) injection technology is a method which may improve oil recovery efficiency by combining effects from two traditional technologies - water and gas flooding. Both microscopic oil displacement and sweep efficiency can be improved by WAG implementation. This paper describes a method of designing an effective water/gas flooding in stratified reservoirs.
The analytical approach taking into account effects of three phase flow, gravity and viscous forces in anisotropic media, allows the determination of optimum parameters of water/gas injection. A three-phase extended black oil simulator with relative permeability and capillary pressure hysteresis, was used to validate the optimum WAG injection parameters obtained by the analytical method. In this work, the efficiency of different injection schemes was compared. Simulation results which demonstrate the influence of WAG injection parameters, as water-gas ratio, injection rates and cycle periods, on the recovery process, are discussed.
A Case Study of Reservoir Characterization From DST and Seismic Data
Authors: Klimentos Theodoras , Steyn Andries , Stallbom Kevin 
Published: December 2007

ABSTRACT
Resevoir heterogeneity can be created by complex sedimentary and diagenetic processess and modified by a sequence of tectonic changes. Integrated information from geophysical, petrophysical, geological and reservoir engineering studies could enhance reservoir characterization even at the discovery-appraisal stage which is vital for oil company sound development and economic planning.
This paper presents a dynamic characterization of a gas-condensate reservoir from well-test interpretation in conjunction with the static description obtained from reflection seismics, well-logging, core and other studies.
Interpretation of a Heavy Mineralogy Formation, North Slope of Alaska, Using Logging-While-Drilling 2 MHz Resistivity: Laboratory Measurements, Modeling, and Wireline Comparisons
Authors: Murphy W. F. , Auzerais F. M. , Lüling M. G. , Anderson B. I. , Tomanic J. , Bonner S. D. , Sakura Shinichi , Wolcott D. S. 
Published: December 2007

Abstract
In order to understand better the effects of lithology, an anomalous log from a 2-MHz Logging While Drilling propagation resistivity tool is compared to a log from a wireline dual induction – SFL* Spherically Focussed Tool. The C-sand in the Kuparuk River Field contains the minerals siderite and glauconite which exhibit atypical dielectric properties. For several wells in the Kuparuk River Field where both the 2-MHz and wireline logs were obtained, the agreement is good after dielectric processing. However in this well, the 2-MHz tool reads differently from the wireline induction tool. In this well, the 2-MHz tool had been run during a washdown trip rather than while drilling. A combination of laboratory core characterization and forward modeling is used to reconcile the differences between the two logs. The 2-MHz and induction tool responses were modeled based on the laboratory results. The remaining differences between the 2-MHz and induction resistivity were caused by invasion effects in the washdown mode.
Transient Pressure Response of a Well With Partial Completion in a Two-Layer Crossflowing Reservoir
Authors: Shah P. C. , Thambynayagam R. K. M. 
Published: December 2007

ABSTRACT
Although the technical literature contains several transient pressure response models for reservoirs producing multiple crossflowing layers, none of these models is adequate for the applications where they are most needed. None of these models accounts for partial completion. Further, all but one of these models approximate the crossflow through a steady-state assumption and ignore the variation of the pressure within each layer in the vertical direction. Layered models with crossflow are often used to interpret tests in thick carbonate reservoirs or in wells with bot-tomwater drive or gas caps. Partial completion, often in the extreme form, is invariably employed in such systems. Ignoring it in test interpretation may lead to incorrect estimation of some key parameters and unidentifiability of others.
An analytic model is presented for the transient pressure response of such systems. This model rigorously accounts for both partial completion and the dynamics of vertical flow. The Laplace domain solution includes a different skin factor in each layer and can account for the effects of wellbore storage and dual porosities. The solution is obtained by applying the finite Hankel transforms and employing the pressure averaging technique. Computer-based symbolic manipulation was necessary to render the solution into a form suitable for practical evaluation.
The new model enables improved interpretation of well tests in several types of reservoirs to yield parameters that cannot be estimated with the existing models (e.g., the vertical permeabilities in two communicating layers, and. the horizontal mobility in the gas cap or in the water zone communicating with an oil reservoir). This model can also be used for interpretation of the single well vertical interference test.
Models for Meandering and Braided Fluvial Reservoirs With Examples From the Travis Peak Formation, East Texas.
Authors: Davies D. K. , Williams B. P. J. , Vessell R. K. 
Published: December 2007

Abstract
Meandering and braided rivers produce reservoir sand bodies of different size and heterogeneity. The heterogeneity and size of channel reservoirs can be predicted at an early stage in field development. Reservoir models derived through geological analysis of meandering and braided channel sands in the Travis Peak Formation are similar to those developed independently by reservoir simulation studies.
Pressure Transient Behavior of a Finite-Conductivity Fractured Well with Spatially Varying Fracture Properties
Authors: Poe B. D. , Shah P. C. , Elbel J. L. 
Published: December 2007

Abstract
The pressure transient behavior of a finite-conductivity vertically fractured weil is important in reservoir engineering because it provides valuable information concerning the well completion, and provides estimates of the in-situ reservoir properties and the propped fracture dimensions and conductivity. The pressure transient behavior of finite-conductivity fractured wells has typically been analyzed using mathematical models that assume relatively simple fracture properties. Most of these models assume uniform fracture height, width, and proppant permeability distributions with respect to space, and many of these models also assume that fracture storage effects are negligible.
This paper presents the pressure transient solution of a well intersected by a finite-conductivity vertical fracture with a lengthwise variation in the fracture geometric and material properties. The general solution of the fracture fluid-flow problem, and an approximate solution of the problem in which the effect of fracture storage has been assumed to be negligible, are presented. Comparisons of the pressure transient behavior predicted with the two finite-conductivity fracture solutions are given. The effects of spatially varying fracture height, width, and material properties are investigated with these pressure transient solutions. The new solutions provide more realistic pressure transient analysis models which may be used to better design, implement, and evaluate hydraulic fracture treatments. They will also provide better agreement between the prediction of the fracture geometry and its post-treatment evaluation.
Integration of Seismic Monitoring and Reservoir Simulation Results for a Steamflood at South Casper Creek Oil Field, Wyoming
Authors: Johnston P. F. , Andersen G. R. , Wachi Noboru , Lee D. S. , Martens F. G. , Han D. H. 
Published: December 2007

Abstract
Repeat 3-D and cross-well seismic surveys were acquired to monitor inter-well temperature distribution during a steamflood at South Casper Creek Oil Field, Wyoming. Baseline surveys were acquired before steam injection started in an inverted pilot 5-spot pattern. Monitor surveys were acquired after 7 and 12 months of steam injection. Laboratory ultrasonic velocity measurements were made on 1" plug samples of reservoir rock, over a range of temperatures, to quantify a velocity-temperature relationship. A numerical reservoir simulation predicted reservoir temperature and saturation distributions vs. time for the 5-spot being studied. The velocity-temperature relationship and these simulation distribution predictions were used to compute expected seismic velocity changes and seismic travel-time changes after 7 and 12 months of steam injection. Simulation derived velocity and travel-time changes were compared to measured travel-time changes, and the agreement was found to be good.
Use of Flowmetering Technique for Improved Drillstem Test Interpretation
Authors: Brown P. A. , Ehlig-Economides C. A. 
Published: December 2007

Abstract
Fluid flow rate and density at the sandface measured during drawdown in a drillstem test (DST) are key measurements that are normally unavailable using conventional techniques. Production logging flowmeters cannot be used in most cases, and the presence of wireline in the test string when the well is flowing is sometimes an undesirable complication. Furthermore, intrusive devices such as spinners have proven especially vunerable to damage by cuttings and produced sand.
This paper presents field data recorded using a prototype downhole multiphase flowmeter sensor that is particularly well-adapted to DST. This fullbore tool can be positioned below the test valve and provides continuous mass flow rate, density, pressure and temperature measurements.
Drawdown data were interpreted to yield permeability, skin and reservoir limits which were comparable to the values determined from a conventional buildup interpretation. In addition, it was possible to monitor any changes in skin while flowing the well during the cleanup period.
Interpretation of Gas Condensate Well Tests With Field Examples
Authors: Saleh A. M. , Stewart George 
Published: December 2007

Abstract
The total apparent skin factor in a gas condensate system contains contributions from mechanical damage and perforation, liquid drop-out and non-Darcy flow. A comprehensive theory of the skin factor in two-phase flow based on pseudo-pressure is developed. Field data from three gas condensate reservoirs have been analysed using the pseudo-pressure function. The effect of compressibility variation was accounted for by the use of pseudotime extended to two-phase conditions. The method requires knowledge of relative permeability relations and a review of these for gas condensate system is given. The determination of relative permeability from well tests is shown to be nearly impossible in practice. Conditions where the reservoir pressure is above or below the dew-point are examined. In the former case the test can be analysed in a dry gas with a composite skin. In the latter a two-phase pseudo-pressure must be used. Permeability relation are utilised in the interpretation of gas condensate well tests.
Transient Test Analysis: Solution-Gas-Drive Reservoir Examples
Authors: Chu Wei-Chun , Little T. M. , Robinson J. C. 
Published: December 2007

ABSTRACT
Considerable research has been devoted to the analysis of pressure-transient data obtained from solution-gas-drive reservoirs. Several techniques from the literature are demonstrated on data acquired from two wells in the Sand Dunes Field. Comparison and discussion of the resulting analyses are provided to aid the practicing engineer in selecting the appropriate evaluation method. Techniques evaluated for determination of flow capacity include pseudopressure, pressure-squared, modified MDH, direct calculation from derivative data, and type-curve analysis. Recent developments that enhance the quality of pressure-transient analysis, including the integral pressure, normalized integral pressure and changing wellbore-storage model, are also applied. Additionally, determination of drainage area from pressure-derivative data is demonstrated.
The Use of Computers in Pressure Transient Analysis
Authors: Buhidma I. M. , Chu W. C. , Singh P. K. 
Published: December 2007

Abstract
The use of computers for pressure transient analysis is now a routine practice in the petroleum industry. Several pressure analysis techniques have been developed over the last few years that not only lend themselves to easy implementation on computers but necessitate the use of computers. The combination of the ability to acquire highly sensitive and accurate pressure data and the easy access of these analysis techniques allows the engineer to employ sophisticated methods to analyze the data. This paper presents state-of-the-art computer applications of pressure transient analysis using techniques available in today’s software. Field examples of applications that a typical user would not attempt without a computer are presented. The advantages of these methods over conventional analysis methods are also demonstrated. Applications include pressure derivative, pressure integral, rate superposition, and the use of pseudo functions.
This paper also presents a list of recommended features and attributes of what constitute, in our opinion, a good pressure transient analysis program. It is hoped that the list will provide a standard and serve as a guide to developers of pressure transient analysis packages.
Robust Procedures for Parameter Estimation by Automated Type-Curve Matching
Authors: Carvalho R. S. , Redner R. A. , Thompson L. G. , Reynolds A. C. 
Published: December 2007

Abstract
Type curve analysis of pressure transient data influenced by wellbore storage effects can yield non-unique answers due to similarity in the shapes of the curves. In order to alleviate this problem, several researchers have proposed methods for unbiased parameter estimation using nonlinear regression analysis techniques. Typically, these methods are sensitive to initial guesses for the parameter values; thus, with poor initial estimates, it is possible that the schemes may diverge or converge to wrong answers. The probability of convergence to correct parameter values is further decreased if the data contains outliers; i.e., measured data whose behavior is significantly different from the "average" behavior of the data set.
In this work, we focus on practical methods of applying the nonlinear regression to the analysis of pressure transient data. Our aim is to provide procedures that enhance the probability of obtaining a unique match, and which detect and properly account for the presence of outliers. A new two-step procedure which utilizes the pressure-pressure derivative ratio in the first step, is demonstrated to increase the chances of obtaining a unique fit. Also, we present a new method of applying "robust" parameter estimation (which accounts for data outliers) that uses commonly available algorithms based on least squares (LS) regression. We demonstrate applicability of the proposed methods by analyzing several sets of field data.
Reservoir Characterization, Haygood Limestone (Ferry Lake Anhydrite), Caddo-Pine Island Field, Louisiana
Authors: O’Hearn T. C. , Funk J. J. , Callender C. A. , Pepin G. P. 
Published: December 2007

Abstract
Reservoir characterization of the Haygood Limestone (Ferry Lake Anhydrite, Early Cretaceous) at Caddo-Pine Island field in Caddo Parish, Louisiana, has enhanced the design of a proposed waterflood recovery program. Analyses to evaluate reservoir geology, formation injectivity, porosity types and pore size distributions include conventional core description, thin section petrography, X-ray diffraction, X-ray computed tomography (CT), and petrographic and scanning electron image analysis (PIA and SEM-IA).
The Haygood Limestone is a thin, very fine calcarenite to fine calcirudite (intraclast bioclast packstone to grainstone) which is overlain and underlain by bedded anhydrite. The reservoir interval has an average porosity of 17.0%, an average permeability of 10.89 md and is characterized by a homogeneous pore network with a narrow pore size distribution. The base and the top of the Haygood are characterized by thin nonreservoir zones which effectively enhance the in situ stratigraphic trap. These zones possess decreased porosity and permeability and heterogeneous pore networks with broad pore size distributions.
Porosity types include interparticle, moldic, intraparticle and microporosity. Interparticle and moldic pores are the dominant pore types, and are variably reduced by bladed to equant calcite and blocky anhydrite cements. Microporosity is locally significant, establishing a bimodal pore system and increasing bound (irreducible) water content.
Simulation of Subseismic Faults Using Fractal and Multifractal Geometry
Authors: Belfield W. C. 
Published: December 2007

Abstract
An important problem of reservoir description is the prediction of faults that are not detected by seismic techniques. Such faults can disrupt flow unit continuity or may be potential targets for horizontal drilling. One approach to describing their distribution is stochastic modeling. This paper describes a technique to simulate the number, length, orientation, and spatial distribution of subseismic faults using fractal and multifractal concepts.
The approach exploits the fractal nature of faults to determine their true length distribution. Faults are characterized by a multifractal spectrum rather than just a single fractal dimension. The multifractal distribution of mapped seismic faults forms the basis for the areal allocation of stochastic faults. One use of the stochastic fault simulations is to predict the probability of intersecting a fault as a function of well length.