bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical Flow Properties of Steam
Authors: Chien Sze-Foo 
Published: December 2007

ABSTRACT
Understanding the thermodynamic properties of steam at critical flow conditions is important to the design, operation and management of steam distribution network and hence the cost of production in steam-enhanced recovery projects. Using the homogeneous equilibrium model, the properties of steam at critical flow conditions are presented. These properties include critical velocity, critical pressure, critical temperature, critical steam quality, critical specific volume, critical steam flux and Napier's parameter. The critical velocity, Napier's parameter and the dimensionless form of other properties are shown to be functions of the stagnation steam quality. The steam pressure is shown to have a slight effect on some of the properties. Empirical correlations for these properties are established for selected operating ranges and experimental results are presented to verify the model's predictions.
A Nine-Point Differencing Scheme Based on High-Order Stream Tube Modelling
Authors: Sammon Peter H. 
Published: December 2007

Summary
Grid orientation artifacts and smeared fluid fronts can often be seen in the predictions generated by numerical simulations of EOR processes, or even in the simulations of adverse mobility waterfloods. Nine-point techniques exist that can attack these problems but various complications result when these methods are extended to non-square blocks and reservoirs with permeability contrasts.
A new method that avoids these complications is presented and discussed in this paper. The method calculates interblock fluid flows on a staggered grid using an interpolation between pressures taken at the usual finite difference nodes. The computation takes strong reservoir permeability contrasts into account, including those induced by differing fluid saturations at a sharp front. A stream tube decomposition is used to track the actual fluid movements in the reservoir.
Also, a new higher order modification for the calculation of (Darcy) velocities is described. This technique calculates the average effect on mobility of the saturation distribution created during the invasion of a shock into a grid cell and adjusts the velocity accordingly.
The combination of stream tubes and careful convective differencing provides the strong geometric component and accuracy required for accurate modelling.
Three-Dimensional Stochastic Flow and Displacement in a Five-Spot Pattern
Authors: Schafer-Perini A. L. , Wilson J. L. 
Published: December 2007

ABSTRACT
Flow and miscible displacement through a three-dimensional, single five-spot well field is numerically simulated for heterogeneous reservoirs where the permeability is treated as a spatial stochastic process. Permeability fields are generated geostatistically using a Fast Fourier Transform method and are described in terms of the log of permeability by a mean, variance and covariance. The flow fields are simulated by finite differences, and displacement is simulated using a new front tracking technique.
Results of the simulations for the stochastic reservoir show that flow fields, displacement fronts, and breakthrough curves are highly non-uniform. Heterogeneity has a significant effect on reservoir behavior even for small spatial correlation and variance of the log permeability. As permeability correlation length decreases and variance increases recovery curves at pumping wells typically breakthrough earlier and take longer times to reach ultimate recovery. The fronts demonstrate significant three-dimensional fingering, even in the absence of any instabilities. Vertically distributed breakthrough curves and well flow rates provide a good indicator of vertical correlation length and vertical flow behavior. Vertically integrated breakthrough curves and flow rates, the type of information typically available, disguise this behavior. This disguise is related both to parameter sensitivity and the non-linearity of the equations in terms of the parameters.
Practical Aspects of Horizontal Well Technology: A Perspective
Authors: Ahmed U. , Jacobsen S. 
Published: December 2007

ABSTRACT
Horizontal well completions to enhance hydrocarbon recovery have increased considerably in the past several years. The success of horizontal wells appears to be related to the development and application of special technology. Documentation of new technology exists in the literature; application to date has been limited and has not always met with measurable success. A critical evaluation of the technology and its associated applications allows one to choose the most practical options and methods.
This paper discusses seven specific categories of horizontal well technology: reservoir and well location selection, well planning, drilling, formation evaluation, completion and testing, stimulation and production and reservoir monitoring. In each category the practical options and techniques are presented in conjunction with specific applications. The associated discussions will allow the reader to use the information as a reference. Generic tool and technique names have been used; however, when discussing specific applications of the technology, references to Schlumberger services have been made.
Development of Composite Reservoir Model for Heterogeneous Reservoir Studies
Authors: Yu J. P. , Yang Jian-ru 
Published: December 2007

Abstract
Oil and gas production across a producing reservoir may vary in a complex manner that is unrelated to any one physical property. Such variations relate to properties which together can be called reservoir heterogeneity. Some forms of heterogeneity can sometimes be resolved by classical geologic and engineering methods, but often the variability is not resolvable because of incomplete data, poor reservoir pressure analysis, or simply because the reservoir heterogeneity is beyond resolution as dictated by well spacing or well distribution. Thus, a new composite reservoir well testing model is a necessary tool to obtain more pertinent data for future studies. This composite reservoir model has the variation of fluid viscosities in two different zones. Hence, the fluids distribution information can be obtained with the pressure testing analysis. The composite reservoir can model reservoirs with a fluid bank, reservoirs with a water flooding front, and reservoirs with steam or a miscible flooding front.
When the reservoir heterogeneity of different formations can be more accurately defined, then fracture stimulation and well specing can be planned in a more manageable fashion. The production manager and engineer will be able to optimize production and infill drilling. The above objectives will definitely help West Virginia's current and future energy challenges.
Estimating Gas Desorption Parameters from Devonian Shale Well Test Data
Authors: Lane H. S. , Lancaster D. E. , Watson A. T. 
Published: December 2007

ABSTRACT
The feasibility of detecting and accurately estimating gas desorption parameters from a history match of Devonian shale well-test pressure data is examined. Both drawdown and buildup tests are analyzed, and based on the results of these analyses a desorption-specific well-test design is proposed. The results from a simulated desorption-specific test suggest that it is possible to characterize gas desorption from a well test with reasonable accuracy, even when the effects of desorption are partially masked by wellbore storage and skin effects.
Using Measured Flow Rate and Bottomhole Pressure Data to Analyze a Fracture Treatment in a Devonian Shale Well
Authors: Murtha J. A. , Lancaster D. E. 
Published: December 2007

ABSTRACT
Extensive data were gathered during the pumping and flowback of a nitrogen foam stimulation treatment on a Devonian Shale gas well in eastern Kentucky. Subsequent analysis of these data revealed that 1) duplicate monitorinc equipment, properly calibrated, yielded nearly identical data, 2) the job execution, largely because of extensive quality control, closely followed job design. 3) friction loss in the pumping annulus could be calculated at all stages of the treatment, and 4) both perforation friction loss and the number of holes open could be estimated throughout the job.
As part of the Comprehensive Study Well program sponsored by the Gas Research Institute (GRI). this fracture treatment design, planning, execution, and analysis involved cooperation.among several GRI contractors, the service company, and the operator. On-site monitoring equipment included densiometers. pressure gauges and transducers, and various types of flowmeters. Two control vans monitored real-time data and permitted adjustment to one of three tentative pumpinc schedules based on downhole treating pressures during the prepad stage. Direct measurements led to real-time calculations of foam quality, foam rate, and downhole proppant concentration.
When the data were analyzed, the wealth of data coupled with the redundancy allowed various calculations to be made with confidence. Direct comparisons between the two sets of monitoring equipment showed near-perfect agreement. Similarly, the actual data matched the desien estimates. Recently published results dealing with discharge coefficient change and hole enlargement formed the basis of our analysis of perforation friction.
This analysis has been performed on one other set of data from an offset well and led to similar conclusions. Comparable data is being acquired from other wells and may eventually provide a valuable database for fracture design in the Devonian Shales.
Analysis of Air Drilling Hydraulics
Authors: Adewumi M. A. , Tian Shifeng 
Published: December 2007

Abstract
Analysis of wellbore hydraulics is motivated by the need for improved understanding of this system so as to enhance air drilling operation. A viable wellbore hydraulics model is utilized as the basis for this study. Several important parameters that influence air drilling operations are analyzed, such as drill cutting size and size distribution, hole size changes, attrition, and particle shape. This work defines several areas that need special investigation and sheds light on several previously unanswered questions. The most salient findings are that hole size changes, cuttings size and size distribution and particle shape affect the wellbore hydraulics very significantly. The analysis led to the evolution of a clear explanation for choking in air drilling.
Experimental Observations of Hydraulic Fracture Propagation through Coal Blocks
Authors: Abass H. H. , van Domelen M. L. , El Rabaa W. M. 
Published: December 2007

ABSTRACT
Hydraulic fracturing experiments were conducted on coal blocks in the laboratory to investigate the effect of stress variation on hydraulic fracture propagation through a coal formation.
The first part of this study presents the measurements of mechanical properties of coal samples, which include Young's modulus, Poisson's ratio, tensile strength, compressive strength, shear strength, and fracture toughness. Mohr envelopes were determined to obtain the failure characteristics for the coal used in this study. A relationship between Young's modulus and confining pressure was derived. The physical explanation of this relationship is given.
The second part of this study presents the experimental results of hydraulic fracture propagation through coal blocks. Two groups of experiments are presented; unconfined and confined tests. This paper discusses observations and results which ranged from multiple parallel fracture systems when the blocks were unconfined, to single fractures created when a confining stress was applied. Laboratory conditions were designed to investigate the creation of T-shaped fractures in the coal, and to study the treating pressure response during the creation of these unconventional fracture shapes.
Treatment pressure response during these tests was significantly different from those observed when fracturing sandstone blocks in the laboratory. The factors which govern this different type of pressure response (roughness, fracture tortuosity, cleat system, spalling, etc.) will be described in detail. Also, a comparison is drawn which relates the observations made during this laboratory testing to actual field reports made during mineback experiments.
New fracture width, height, and initiation criteria related to coal seam fracturing, are presented in this paper. These criteria are based on close examination of the rock properties of coal under different stress-loading conditions.
Depth Control for Openhole Frac Procedure
Authors: Knowlton L. W. 
Published: December 2007

ABSTRACT
This paper describes a method of measurement to be used in completing an open-hole frac procedure. Unlike cased hole work, a gamma ray – CCL log is used in correlation with a steel line measurement (SLM) to supply the completion rig crew with correct depths for placement of completion activities. This assures that the dollars spent for stimulation of the reservoir rock will be used to achieve the greatest results.
North Sea Application of Seismic Correlative and Seismic Velocity (ITT) Techniques to Predict Pore Pressure
Authors: Haas Michael A. 
Published: December 2007

Abstract
It has become extremely important in recent years to do a better job in well planning to ensure that well cost estimates and drilling programs are as complete and accurate as possible. Comprehensive well programs and realistic estimates are necessary to determine which drilling prospects are most attractive considering current upstream economics.
Pore pressure analysis is the initial, and in most cases, the most important step in developing an accurate, complete well program. Casing setting depths, hole sizes, number of casing strings, mud programs, and hydraulics are examples of items in a well program which are influenced by the pore pressure profile determined for a well. Pore pressure analysis is especially critical for exploratory and delineation wells but until recently our predictive techniques were somewhat inadequate.
This paper will present the application of seismic correlative and seismic velocity (ITT) techniques to predict pore pressures on a North Sea exploratory well prior to drilling. Actual mud weights used on the prospect are compared to the predicted pressures.
The steps used to predict pore pressures will be discussed including sonic log pore pressure analysis correlated to the prospect, development of a regional pore pressure overlay for interval transit times, and analysis of ITT information developed from seismic shot points at the prospect and an offset well. Results from this interpretation of seismic information will be compared to the actual pressures determined after drilling the well to emphasize the effectiveness in using these techniques for pore pressure prediction.
Steam Separating Solves Phase Splitting Problems in Wet Steam Distribution Systems
Authors: Rector Bradley P. 
Published: December 2007

Abstract
Texaco operates several large steamflood projects in the Southern San Joaquin Valley in which individual wellhead mass flow rates and steam quality measurements are difficult to obtain. Uneven and unpredictable phase splitting at lateral and dead end tees is the problem (Hong, 1978.) In one instance, Texaco has solved this problem by utilizing a horizontal separator to separate 10,500 BPD of 70% quality cogeneration steam.
The separator is able to deliver saturated water and 96.5% quality steam. These two single phase flows can be divided into any number of flow streams and then measured using simple orifice plate, differential pressure, technology.
The steam flood distribution piping consists of two single phase trunk lines running the length of the field to serve small headers located near the steam injectors. The purpose of these headers is to measure and control water and steam for each well, using orifice meters and adjustable chokes. Because each injector is controlled separately, the injector mass flow rates and steam qualities are independent of one another. Not only does this solve the phase splitting problem, this flexibility allows some injectors to receive higher or lower qualities than others. For instance, lower qualities may be warranted for patterns experiencing steam breakthrough, or for areas of the field in which the flood is more mature.
One of the problems associated with this type of operation is the chemical treatment of the dry steam line. A neutralizing amine needs to be added to combat the high pH caused by the formation of carbonic acid. The goal is to hold corrosion to 6.25 mpy (1/8 " over 20 years.)
This paper addresses the system design, flow measurement, and automatic control apparatus, as well as the details, results, and sampling techniques of the chemical program.
Long Term Performance of Small Cogeneration Units in Oil Field and Gas Plant Operation
Authors: Livesay Joseph D. 
Published: December 2007

Abstract
Amoco Production Company installed two of its first onshore cogeneration units during late 1983 and mid-1984 in west-central Wyoming, USA. These 2.4 megawatt cogeneration units were placed in an oil field that uses steam and hot water injection in the recovery of a viscous crude oil and in the operation of a natural gas sweetening plant that uses steam for its heat-medium requirements. This paper examines the operating performance of both units over the past six years, improvements made in these systems to achieve high online operating factors and the economic justification for their installation.
Completion and Workover Well Control Needs Are Different
Authors: Rike Jim L. , Whitman David L. , Rike Erik R. , Hardin Lynn R. 
Published: December 2007

Abstract
Applying blowout prevention concepts that have been developed for drilling operations to a completion/workover situation is improper in many cases. In fact, application of all rules required by drilling well control courses and manuals will result in dangerous situations on many workovers. Furthermore, the majority of class time in a typical well control school is devoted to minimizing surface casing pressure during a kick, a principle that has almost no application in a completion/workover situation.
There are at least sixteen key differences between workover wells and drilling wells that demand a different set of requirements for safe well control. These important differences continue to be revealed in the form of surprises as workover crews struggle to comply with a multitude of very strict rules, all of which have evolved from situations encountered while drilling. This paper will emphasize these key differences and will introduce an idea for replacing current Completion and Workover Blowout Prevention Specifications with just a few easily understood specifications based on the Barrier Concept.
Combination of Selected Solvents and Mutual Solvents Successful in Removing Hydrocarbon Based Formation Damage
Authors: Hamberlin C. W. , Thomas D. C. , Trbovich M. G. 
Published: December 2007

ABSTRACT
Solvents and mutual solvents have been used for numerous years as stimulation treatments or as components of stimulation treatment packages. This paper presents the results of field case histories of stimulation treatments using a unique combination of selected solvents and mutual solvents to remove hydrocarbon based formation damage. Treatment with this chemical has been effective in removal of multi-constituent hydrocarbon and hydrocarbon/water caused damage. The removal of this damage in producing wells provides increased production at rates and lifetimes exceeding those obtained by conventional solvent or solvent/acid treatments, and hot oiling treatments.
Dual Injection with Steam and Hot Water in the Kern River Field - A Case History
Authors: Messner G. L. , Stelling D. R. 
Published: December 2007

ABSTRACT
In 1984, Texaco initiated a field test of multizone thermal recovery with dually-completed injection wells. With a single tubing string and packer, a concentric injection arrangement was implemented. Hot water was injected down the tubing into a previously-steamflooded sand, while high-quality steam was injected down the tubing-casing annulus into an overlying active steamflood zone. While both floods have demonstrated favorable production behavior, the heat transfer between the tubing and annulus has had a major impact on the planned injection strategy, with indications that the "hot waterflood" has actually been a low to mid-quality steamflood for most of its project life. Furthermore, regional gravity drainage has unexpectedly been a dominant recovery mechanism in the lower zone, creating regions of distinct production characteristics within the project area.
This paper analyzes the field results from the first 2-1/2 years of the dual injection project and discusses the identified recovery mechanisms in addition to the heat transfer consequences of dual steam/hot water injection.
Computer Simulation Improves Cement Squeeze Jobs
Authors: Bour Daniel L. , Creel P. , Kulakofsky D. S. 
Published: December 2007

ABSTRACT
Squeeze cementing has been a common oil field operation for decades. During this time, technical improvements in squeeze job performance have been achieved through (1) a better understanding of hydraulic fracturing principles, and (2) utilization of fluid loss additives. In spite of these improvements, however, the common practice of interpreting downhole performance from surface pressure indications has remained arbitrary and imprecise. Typically, attainment of some specified final surface pressure is regarded as an indication that the well has been squeezed, with little or no regard for fracture gradient, frictional pressure, or hydrostatic pressure---all of which contribute to the actual downhole squeeze pressure.
Computerized simulation of squeeze cementing operations, which allows operators to take into account various well parameters, has recently been developed. Based on fluid densities and rheologies, fracture gradients, and well configuration, a prediction of nonsqueeze surface pressure is provided for the entire job. This allows operators to obtain an accurate determination of when they are actually getting a squeeze--without excessively exceeding the fracture gradient--by noting when actual surface pressure rises significantly above the predicted pressure.
The simulator has proven particularly useful in squeeze job applications utilizing foam cement. A description of operation of the simulator is provided, including case histories comparing actual and predicted wellhead pressures.
Segmented Bond Tool - A New Generation Cement Bond Logging Device
Authors: Tyndall J. H. 
Published: December 2007

ABSTRACT
A new cement integrity tool has been developed, the Segmented Bond Tool (SBT), which affords a complete cement bond analysis in one logging pass. An array of transmitter-receivers, mounted on six pads, are utilized to extract quantitative measurements of the cement bond in six 60 degrees segments around the borehole. In addition, by effectively mounting the transmitters and receivers in contact with the casing wall through the use of pads, many of the problems common to the standard mandrel-type tools are effectively eliminated. Experimental laboratory tests indicate that angular resolution of the tool is 60 degrees as expected and that channels as small as 15 degrees can be detected.
From conception of this new generation CBL to final product, several rigid parameters were demanded. Briefly these are: Ease of interpretation.Eliminate ambiguity of conventional bond logs by quantitatively depicting the bond condition around the casing (i.e. channelling).Complete data acquisition in one logging pass in all casing sizes 4-1/2" to 13-5/8" in both vertical and deviated wellbores.Be unaffected by gasified wellbore fluids, fast formation and slight tool decentralization.
The purpose of this paper is to determine the success of the SBT in fulfilling these goals. Presented here are four Canadian examples from widely varied areas having casing strings cemented with various slurries.