bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revival of the van der Waals Classical Theory via Silberberg Constant
Authors: Lawal A. S. 
Published: December 2007

ABSTRACT
Starting from the state equation reported by Hirn in 1863 and the experimental studies of Andrews (1863), plus over a century and twenty years of efforts on the van der Waals classical theory, the search for a predictive equation of state led to reexamination of the work of eight Nobel Laureates and revised value of van der Waals’ gas constant for the Silberberg constant. The use of the Silberberg constant provides a better basis in theory for the development of the predictive equation of state than the purely empirical definitions used by earlier investigators. The perceived confusion of the van der Waals gas constant, which hitherto has been assumed to be synonymous to the constant of the gas laws, has also been resolved with the Silberberg constant.
The question of why van der Waals theory of the cubic equation of state was in error is an intriguing one, and its answer provides dramatic proof of the human side of science. This paper uncovers the source of the error and pin-points the Nobel speech of van der Waals as the fruitful source of resolving the two oversights of his earlier works. A reformed van der Waals equation of state is used to demonstrate the solution for two important and often puzzling areas of active research: improvement of the predictive power of the equation of state for complex hydrocarbon molecules and the prediction of critical points of disparate molecules from their constituent components.
A Study of Fractured Wells in Bounded Reservoirs
Authors: Chen Chih-Cheng , Ozkan E. , Raghavan R. 
Published: December 2007

ABSTRACT
This work is a rigorous evaluation of vertically fractured well responses producing fractured reservoirs. Detailed evaluation of plausible responses to be expected from short-term tests are provided. New diagnostic rules, analytical procedures, and working curves are presented. The effect of fracture length on flow patterns in the reservoir is documented. Practical issues that the analyst must be cognizant of are documented.
Two-Phase Flow Interporosity Effects on Pressure Transient Test Response in Naturally Fractured Reservoirs
Authors: Al-Bemani A. S. , Ershaghi I. 
Published: December 2007

ABSTRACT
Complexities related to multi-phase flow in naturally fractured reservoirs have been somewhat addressed in numerical models used for performance prediction purposes. This paper examines the concept of the two-phase (oil and water) flow in analytical modeling of pressure transient response in naturally fractured reservoirs.
Under the condition of the two phase flow in both the matrix rock and the fractures, the capillary pressure and the relative permeability characteristic associated with prevailing saturation conditions are integrated into the pressure transient models.
Characteristic shape of the transition portion of pressure response curve, for naturally fractured reservoirs, is influenced by the specific assumptions made about the nature of matrix-to-fracture flow. The analytical solution presented here describes the effect of two-phase interporosity on the transition portion of the pressure response. The interporosity parameter is modified to incorporate the contribution of the relative permeability and capillary pressure effects associated with countercurrent flow.
Our studies show that without proper consideration of two-phase flow, and the saturation conditions, the estimated values for interporosity coefficient, estimation of the shape factor and block sizes are subject to errors.
With independent measurements from cores and well logs, to ascertain the wettability and fluid saturation conditions in both fractures and matrix rock, the proposed model allows improved estimation of the interporosity flow parameter, shape factor and block sizes for history matching purposes.
Using a Multiarray Induction Tool to Achieve High-Resolution Logs with Minimum Environmental Effects
Authors: Barber T. D. , Rosthal R. A. 
Published: December 2007

Abstract
Over 30 years ago Poupon proposed using several simple induction arrays, each measured separately, and combining them to produce an induction log with improved characteristics. The response of each simple array becomes a "basis function" that can be combined with the others without introducing unwanted interactions. This approach has been used in the Array Induction Imager Tool (AIT*). The AIT tool consists of eight three-coil arrays, six of which are operated simultaneously at two frequencies.
By treating the response of each measurement as a basis function, an optimization technique has been developed to combine all the raw measurements into logs with vertical, radial, and two-dimensional (2-D) response properties that are not achievable with conventional fixed-focus induction arrays. Using this approach, a set of logs has been developed with a 90% vertical resolution width of 1 ft and a reasonable rejection of borehole rugosity effects. Additional log sets are available that have different resolution-cave effect tradeoffs. A log set with a vertical resolution of 2 ft has less cave effect than conventional induction logs with 8-ft resolution, and a 4-ft resolution set has virtually no cave effect. The effectiveness of this response shaping technique has been demonstrated in case studies with both computed and field logs over a wide range of environmental conditions.
Practical Solutions for Interactive Horizontal Well Test Analysis
Authors: Ohaeri C. U. , Vo D. T. 
Published: December 2007

ABSTRACT
This study presents new approaches to solve problems of flow to horizontal wells. It documents a procedure to obtain solutions to problems of single phase liquid flow to horizontal wells. This procedure, which couples the source function approach with a real space Laplace inversion algorithm, gives very accurate results for a wide variety of wellbore and reservoir conditions including constant wellbore pressure, wellbore storage, skin and fluid phase redistribution. This approach is valid during both transient and boundary-dominated flow periods. Furthermore, the solution technique is very fast and is ideal for interactive well test analysis and design. This paper presents a complete analysis of well test data using an interactive type curve matching procedure and the solutions derived in this study.
Interdependence Between Geology and Well Test Interpretation
Authors: Massonnat G. J. , Bandiziol D. 
Published: December 2007

ABSTRACT
This paper shows the leading role of geology in the choice of a well test interpretation model and in the selection of the best solution; at the same time the results coming from well test interpretation contribute to improve the geological model. Three field cases are discussed: The first case evidences the need of a good sedimentological analysis, in order to choose among the different reservoir models that match properly the derivative plot: Radial Composite, Homogeneous with two parallel or three boundaries. Geology indicates that the reservoir was deposited in the median part of a deep-sea fan, and that the perforated interval belongs to a channel layer. The model retained is therefore the homogeneous reservoir with two parallel boundaries, which gives a channel width of about 400 meters, in accordance with sedimentology.The second case deals with a shaly formation with few sandbodies. Regional geological knowledge allows to divide this formation into two main units with different sandstone sedimentological origin: fluvial or lacustrin. Interpretation of the well tests performed in the different sandbodies emphasizes the differences between the two sedimentological units, and allows to locate their limitIn the case of the fractured reservoir some input parameters were affected by a high degree of incertitude, and interpretation led to a too big range of possible values for the output parameters (permeability, vertical permeability anisotropy). Geological studies allow to decrease the incertitudes.
A multidisciplinary approach with repeated information exchanges between geologist and reservoir engineer seems to be the best way to deal with well test interpretation problems.
Collection, Analysis, and Integration of Discrete Fracture Data From the Monterey Formation for Fractured Reservoir Simulations
Authors: Gale J. E. , Schaefer R. A. , Carpenter A. B. , Herbert A. 
Published: December 2007

ABSTRACT
Fracture orientation, trace length, termination mode, spacing and other surface and shape data have been collected, using scanline and areal mapping techniques, on approximately 1600 fractures from surface outcrops of the Monterey Formation in western Santa Barbara county. Trace lengths for each cluster or set of fractures appear to follow a log-normal distribution with mean values that vary by up to a factor of five between clusters in the same area and rock type. Spacing values also appeared to follow a log-normal distribution. However, mean spacing values differ only by a factor of up to two between clusters in the same rock mass. Correcting the raw data for censoring and truncation produced a significant change in the distribution statistics.
These fracture statistics have been used to create both 2-D and 3-D stochastic fracture network models that have been analyzed using discrete fracture flow codes to determine the effects of fracture geometry on reservoir permeability. Comparison is made to other work in which fracture geometry and hydraulic data have been integrated, using 3-D discrete codes, in order to provide 3-D reservoir properties that have compatible flow and transport properties.
Geomechanical Evidence for Shear Failure of Chalk During Production of the Ekofisk Field
Authors: Teufel L. W. , Rhett D. W. 
Published: December 2007

Abstract
The Ekofisk Field is a naturally-fractured chalk reservoir in the Norwegian Sector of the North Sea that has been producing hydrocarbons for over 20 years. In situ stresses in the field have been constantly changing because of the decline in pore pressure that has occurred in the reservoir as a result of production. The effect of production and pore pressure drawdown on the minimum horizontal in situ stress in the Ekofisk Field has been determined from shut-in pressure data from 37 hydraulic fractures conducted during the past 15 years. The effective stresses in the reservoir increase linearly with pore pressure drawdown, but at different rates. The reservoir stress path, defined as the ratio of the change in effective minimum horizontal stress to the change in effective overburden stress, is approximately 0.20. Laboratory experiments, which simulate the stress path followed by reservoir rock during the production history of the field, show that shear failure has occurred during compaction of high porosity chalk as the shear stress increased with pore pressure drawdown. Shear failure during depletion will increase fracture density and reduce matrix block dimensions in the fractured reservoir, thereby maintaining reservoir permeability as the apertures of older natural fractures are closed with increasing deformation. It is suggested that the shear failure process may account for the continued good producibility of the Ekofisk Field, in spite of compaction.
Marine Pipe Laying Methods
Authors: Dwyer Jolly 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
A number of marine pipelaying techniques have developed over the years, but their potential for installing large diameter pipe in deep water is severely limited. A survey of present day technology is desirable to evaluate its limitations for the needs at hand, and to determine where new techniques are required.
All present day techniques have many elements in common. These can be combined in a variety of ways, and some of the combinations offer possible solutions to the problems of laying pipe in deep water. pipe in deep water. This paper describes the most common components of marine pipelaying systems, and discusses the present day combinations. The components include: barges, stingers, launchways, reels, winches, tensioners, pontoons, caissons, chambers and submersible vehicles. The combinations include: lay barges, tie-in barges, lowering barges, reel barges, and pull barges.
The paper then goes on to describe the potential applications of other systems to the problems of laying pipe in deep water. It suggests that economical solutions to those problems are within the capability of present day technology, without excessive developmental effort.

Introduction
When petroleum discoveries stepped from dry land into the marshes, and eventually into the sea, the associated pipelines had to go into the water as pipelines had to go into the water as well. Short lines in shallow water could readily be made up on shore and pushed or pulled into position. However, pushed or pulled into position. However, long pipelines, even through marsh lands, required a different solution, and the pipelaying spread took to the water pipelaying spread took to the water on a lay barge. From these beginnings various marine pipelaying methods have evolved and are in use today.
As the: need grows to lay pipelines of larger diameter in deeper water, even present day techniques are becoming present day techniques are becoming restrictive.
Designing and Selecting Wax Crystal Modifier for Optimum Field Performance Based on Crude Oil Composition
Authors: Singhai H. K. , Sahai G. C. , Pundeer G. S. , Chandra K. 
Published: December 2007

ABSTRACT
The present paper deals with the studies of crude oil composition, physicochemical characterisation of pour point depressants (PPD's) and waxes to know the specific & selective performance of PPD on crude for designing wax crystal modifier according to requirement.
The study reveals that the performance of PPD is closely governed by composition of crude in respect of nuclei present mainly asphaltene, type & amount of waxes and the amount of distillates. The study indicates that PPD can be made more effective by compounding waxy crudes with light distillate fractions and vice versa by the change in PPD composition, degree and extent of polymerization and creating environment suitable for co-crystallization.
The chain length of the alkyl ester chain should corresponds with the carbon number ranging C20-C24. It has been observed that polymers having Mow molecular weights do not affect the rheology. The melting point of PPD should match with the melting point of the waxes for limiting the growth of the crystals. C22 to C29 normal paraffins are predominant in GS-16-4 & Bombay High crude oil. The studies may be helpful for selection of PPD’s for high wax content crudes.
Offshore Pipeline Risers and Their Adaptability To Deep Water
Authors: Faust Richard C. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
Through the years as the offshore petroleum industry has developed and petroleum industry has developed and water depth increased, there has been an evolvement of pipeline riser type. This water depth now has reached the proportions such that pipeline riser proportions such that pipeline riser technique must now be looked at from a practical standpoint in order to economically produce through pipelines.
During the 20 years of pipelining offshore, various types of risers have been utilized by different companies, depending on their own needs.
It is the purpose of this paper to review the progress of the development of pipeline risers through the years with the intention of singling out those which the author feels are the most practical from a standpoint of deep water pipelining techniques.
The first wells offshore were sufficiently close to land that the production could be carried by production could be carried by pipe-lines across trestle-like pipe-lines across trestle-like structures from the offshore well to the mainland, however, this obviously was just an extension of the typical methods used in marshes and dry-land areas. Later as the wells advanced further offshore, still in relatively shallow water depths, pipelines were laid on bottom of the gulf and the extension of these lines up to the production decks of the structures were treated just as though it were a change in elevation within a plant site; that is, the line was brought up to the structure, a short radius elbow was attached to the end of the pipeline and a vertical run extended up the side of the structure to the production deck. This is the most commonly used riser in the Gulf of Mexico, even in deep water locations.
However, this is but one type riser - presently there are five basic types being used. The conventional riser (Figure 1) is attached to the structure by clamping after it has been welded to the horizontal run of pipe. pipe.
Optimizing the Completion Procedure To Minimize Sand Production Risk
Authors: Santarelli F. J. , Ouadfel H. , Zundel J. P. 
Published: December 2007

Abstract
A 3D Finite Element Code is used to model the near well bore region of a perforated well. The stress concentration around perforations is computed and related to the possibility of reservoir rock failure and hence to sand production risk. Results of a complete parametric study are used to show the influence of various controllable geometric features, such as perforation length and diameter, shot density, phasing, cementation quality, etc, on sand production risk. An optimization of the completion procedure is presented which maximizes IP expectations by lowering sand production risks, thus avoiding the use of sand control means when not strictly necessary from the production requirements.
Perforating Skin as a Function of Rock Permeability and Underbalance
Authors: Hsia T- Y. , Behrmann L. A. 
Published: December 2007

Abstract
Experimental tests were performed under simulated downhole conditions to determine the minimum underbalance necessary to obtain zero-perforation damage skin in two sandstones of different permeabilities. The objective of this paper is to study the transient cleanup resulting from the dynamic surge of fluid through the perforation immediately after perforating, prior to any postshot flow.
Single-shot perforation flow tests were conducted in nominally 100-md Gold and 200-md Berea sandstone cores under various underbalances. Prior to shooting, the virgin whole core diametral and axial permeabilities were measured. Perforation damage skin was determined using analytical and finite element models.
For each of the two basic rock permeabilities, (1) the minimum underbalance required to obtain zero-perforating skin without postshot flow was determined, and (2) a relationship of skin to perforating underbalance was obtained.
The experimental results were used to establish a Reynold’s number criterion for zero-perforation damage skin. Using the Reynold’s number criterion, a simple equation can be employed to predict, as a function of formation and fluid properties, the minimum underbalance to achieve zero-perforating skin prior to any postshot flow.
The Effects of Weather on Offshore Pipeline Construction in the Gulf of Mexico
Authors: McCarron J.K. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
The effect of weather on the construction of offshore pipelines has been analyzed by use of a computer simulation program. Results are given for hypothetical projects in terms of the average construction time to be expected for different seasons of the year and for the probability that any given construction time probability that any given construction time will be exceeded. The analysis includes variations in the capabilities of the construction equipment to evaluate the effect of equipment performance on construction time. performance on construction time. The accuracy of the simulation is dependent upon adequate weather statistics for the particular location, including both the frequency particular location, including both the frequency distribution and persistence of the weather. Graphs are presented showing both of these parameters for wave heights in the Gulf of parameters for wave heights in the Gulf of Mexico.

Introduction
In any type of construction work, weather plays an important part. This is especially plays an important part. This is especially true in offshore construction, where lost time as a result of bad weather can be quite costly. A contractor's expenses for laying an offshore pipeline are approximately proportional to the pipeline are approximately proportional to the total time on the job, including the time required for mobilization, traveling to and from the job location, and installation of risers, and the time required for actually laying pipe. The time expended on each of these operations, and hence the total cost for a project, is highly dependent upon the weather. project, is highly dependent upon the weather. If it were possible to predict the weather accurately on a long-range basis, it would be relatively easy to estimate total required time and the total cost for any given offshore job. Unfortunately, the art of weather forecasting Ins not yet developed to the point where this can be done. As a result, there is a certain weather risk associated with each estimate of an offshore project. Since most offshore pipeline contracts are let on a turnkey basis, pipeline contracts are let on a turnkey basis, the contractor is forced to assume this risk. In the long run, of course, the pipeline companies pay for the effects of weather, as the contractor pay for the effects of weather, as the contractor adds to his bid an allowance for bad weather. At present, with relatively few years of construction of offshore pipelines, there is insufficient experience from which to assess the real effects of weather. One of the purposes of this study is to develop a means to quantitatively determine the risk of bad weather for any given job.
Kinetic Model of Pour-Point Phenomena
Authors: Becker H. L. 
Published: December 2007

ABSTRACT
Selection of crystal modifier chemicals to reduce the pour point of paraffinic crude oils and to provide paraffin deposition inhibition has, in the past, been accomplished by laboratory physical testing. This paper presents a method for selection of these chemicals based on a technique of modeling the cooling rate behavior of paraffinic crude oils. Using this method to model the cooling rate characteristics of various crystal modifier compounds and comparing them to the modeled characteristics of crude oils provides selection criteria for matching the best crystal modifier to a particular crude oil.