bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rov Transportable Tool. Packages For Subsea Component Replacement
Authors: Chilton T. S , Pejaver D. R , White J. 
Published: December 2007

ABSTRACT
Esso Exploration and Production UK Limited is undertaking a multi-year design development and component prototype testing programme at a cost of €4 M to €5 M pounds sterling. The objective of the programme, known as the Esso Deepwater Integrated Production System (EDIPS) development programme is to ensure that Esso has the production technology available for commercial development of potential deepwater discoveries in the UK. The paper, after providing a brief overview of the total project, focuses on the description of innovative designs for the diverless maintenance of valves and control pods on subsea installations.
While diverless maintenance capability is a must in deep water, simple systems that can be deployed using remotely operated vehicles (ROVs) can be cost effective in all water depths ranging from a few hundred to several thousand feet. This paper describes such ROV transportable systems being developed by Furness Underwater Engineering Limited and Wharton Williams Limited under contract to Esso. The work is being done under the technical stewardship and coordination of Esso's research affiliate, Exxon Production Research Company, and draws on Esso's prior expertise on diverless maintenance system design.
The objective of the work described is to develop detailed designs for the tool packages and undertake in-water prototype testing, if required, to gain confidence in the technology for commercial application. Cost effectiveness of the system is improved by the use of commercially available ROV systems and by designing the valve and pod replacement tool packages to handle a range of valve and pod sizes, respectively.
Development and Use of a Drilling Applications Module for a Programmable Hand-Held Calculator
Authors: Brewton J. , Rau W. E. , Dearing H. L. 
Published: December 2007

ABSTRACT
The development of software for drilling applications has in recent years concentrated on mini and micro computer systems. While these systems have obvious uses in drilling departments, a low cost programmable calculator can perform many of the calculations needed in the office and at the rigsite with the development of an appropriate software system. This paper describes the development and use of a drilling applications module for the HP-41 calculator.
This applications module is novel in that it utilizes a 32k EPROM (Erasable, Programmable, Read Only Memory) and is designed with a standard program/user interface that is consistent throughout all programs. It's programming takes advantage of several advanced features of the HP-41 calculator in order to make the system "user friendly".
There has never been a greater need to increase productivity and reduce costs at the rigsite. The HP-41 software module described in this paper provides the "drilling man on location" with a powerful tool that can help him significantly impact well costs.
Field Comparison of 2-D and 3-D Methods for the Borehole Friction Evaluation in Directional Wells
Authors: Maidla E. E. , Wojtanowicz A. K. 
Published: December 2007

ABSTRACT
The two new general procedures for the borehole drag prediction, based on the borehole friction factor concept were compared. The procedures employed iteration over the directional survey stations, numerical integration between the stations and mathematical models of the axial loads within a moving pipe in the borehole. The models considered several new effects such as hydrodynamic viscous drag, contact surface, and the bearing angle component of dogleg severity.
The study addressed the extent and conditions under which the two-dimensional and the three-dimensional procedures diverged significantly. The method was based on the computer calculated values of the borehole friction factor from the measured hook loads. The field data used included four casing runs from the offshore locations in the Gulf Coast area. In addition, the systematic theoretical study was performed with over 100 computer-simulated directional wells.
The study revealed a good agrement between 2-D and 3-D procedures for most common drilling conditions. Two 2-D model's accuracy was mostly affected by the bearing angle component of shallow doglegs. In addition, the reliability of the borehole friction factor field assessment was mainly controlled by the inclination angle and the length of the slant hole section of a well.
Effect of Natural Repressurization of Thawed Permafrost on Strain of Surface Casing for Prudhoe Bay Infill Wells
Authors: Perkins T. K. , Weingarten J. S. , Bohon W. M. 
Published: December 2007

SUMMARY
When hot oil is produced through closely spaced wells that penetrate a permafrost zone, large thawed regions can be created. Thawing initially produces a sudden, large decrease in permafrost pore pressure; this results in compaction of the soil and strain in the casing. Induced pipe strains initially increase with time as the thaw front expands. Later, water flows into the thawed region from above and below the permafrost and repressures the pore space. Repressurization limits the induced casing strain, thus permitting the selection of adequate permafrost casing from a number of conventional casings.
Roller Bit Model With Rock Ductility and Cone Offset
Authors: Winters W. J. , Warren T. M. , Onyia E. C. 
Published: December 2007

ABSTRACT
This paper presents a model which relates roller bit penetration rates to the bit design, the operating conditions, and the rock mechanics. Rock ductility is identified as a major influence on bit performance. Cone offset is recognized as an important design feature for drilling ductile rock.
Each roller bit style is characterized via a laboratory drilling procedure. Mechanical behavior of the laboratory rocks is characterized via triaxial compression tests. The model relates these factors to predict the drilling response of each bit under reasonable combinations of operating conditions. Decomposition of the model provides a quantitative analysis of the bit mechanics.
The roller bit model provides two modes of field application. First, field data can be interpreted to generate a continuous rock strength log. These strengths correlate closely to the triaxial compressive strength of the rock at a confining pressure that is equal to the effective bottomhole differential pressure. The rock strength log can then be utilized to predict and interpret roller bit performance in offset wells.
Viscous Fingering Utilizing Probabilistic Simulation
Authors: King M. J. 
Published: December 2007

ABSTRACT
The local variations and fluctuations in fluid flow through porous media constantly excite the instabilities of a laboratory or reservoir flood. If the flooding process is dynamically stable, then the fluctuations will decay. Alternatively, the local fluctuations may grow to macroscopic size (viscous fingers). The method of probabilistic simulation (SPE #14366) includes fluctuations, and provides a computational framework for assessing fluid flow stability. Viscous fingers are produced by unstable floods. Stable floods exhibit smooth solutions, despite the ability of the method to naturally incorporate noise.
Solvent (miscible) flood is examined in detail. Scaling of breakthrough recovery, and its dependence on mobility ratio, M, is determined for .1 &lt; M &lt; 1000. Unstable floods self-stabilize on sufficiently fine grids; the cross-over to stable flow depends upon M.
The probabilistic algorithm of SPE #14366 is generalized to include the effects of physical dispersion, capillary pressure, and permeability heterogeneity. As expected, solvent flood is stabilized by the inclusion of sufficient amounts of physical dispersion.
Waterflood (immiscible flood) is examined including the effects of capillary pressure and spatial heterogeneity. The stabilizing effects of relative permeability and of capillary pressure are demonstrated. Correlated permeability variations lead to flow channelling. A low tension flood is demonstrated utilizing a simple modification of a waterflood.
The Nature of CO2-Induced Organic Deposition.
Authors: Monger T. G. , Fu J. C. 
Published: December 2007

ABSTRACT
This paper is an experimental investigation of reservoir parameters which influence CO2-induced organic deposition. A prototype high pressure/temperature apparatus is described which quantifies the onset and duration of heavy hydrocarbon flocculation, the extent of organic precipitation, and the alteration of wettability in porous media traps. CO2 is contrasted with pentane as a precipitating agent. Stainless steel filters were used to ascertain the role of miscibility, and to examine oil compositional effects. Native and treated Berea cores were utilized to probe the effects of initial rock wettability, brine, and clay activity.
The results show that CO2-induced organic deposition resembles asphaltene precipitation by n-paraffins. Significant distinctions include that deposition using CO2 can be more extensive, is less abrupt, and is associated with liquid-liquid phase equilibria rather than the bubblepoint. The extent of CO2-induced organic deposition correlates with pressure and temperature as they relate to the development of miscibility. Deposition caused by CO2 was somewhat inhibited by rich gas. Sufficient levels of CO2-induced organic deposition typically made Berea cores less water wet and more oil wet regardless of the initial core wettability. Native cores could be altered to a mixed-wettability condition, and artificially neutral cores became strongly oil wet. The presence of brine reduced but did not eliminate CO2-induced organic deposition in strongly water-wet cores. Clays appear to be important deposition sites.
Displacement Behavior of the Condensing/Vaporizing Gas Drive Process
Authors: Stalkup F. I. 
Published: December 2007

ABSTRACT
There is mounting evidence for some reservoir fluids that phase behavior in condensing-gas drives departs substantially from traditional concepts deduced for three-component fluids and that transition-zone compositions are established by a condensing/vaporizing mechanism rather than by condensation alone. To what extent does displacement behavior depart from traditional concepts as well and what is the significance of any departures? This paper addresses these questions through a series of compositional simulations for displacement in a one-dimensional slim-tube.
The simulations show that displacement behavior for a reservoir fluid does not depart substantially from traditional condensing-gas drive concepts for three-components even though the transition-zone building mechanism is one of condensation/vaporization. They show that when injection gas enrichment exceeds a critical value, displacement behavior of the reservoir fluid becomes miscible-like in the following important respects: 1) recovery is essentially 100% after one pore volume of injection in the limit of no dispersion, and 2) for a realistic level of dispersion, recovery at 1.2 pore volumes injected is insensitive to both relative permeability and relative permeability end-point saturation. Also, as with traditional concepts, the critical enrichment can be determined from slim-tube displacements by finding the point of breakover in a plot of oil recovery at 1.2 PV of injection vs. gas enrichment. However, with the reservoir oil, gases enriched above the critical value show a converging/diverging type of phase behavior on a pseudoternary diagram, and they leave a residual oil saturation, both of which are contrary to traditional concepts. The magnitude of the residual oil saturation depends primarily on mixing caused by diffusion/dispersion and should be relatively small, less than about 5% PV, in reservoir floods and even less in slim-tube displacements.
All the simulations were highly sensitive to the number of grid blocks used to model the slim-tube. This effect must be accounted for when simulated slim-tube behavior is compared with experiments, and it must be addressed in reservoir simulations. Simulations of 20% HCPV enriched-gas slugs driven by water show that a very high level of mixing shifts the point of optimum solvent enrichment to higher values. Numerical dispersion will cause this shift, even in simulations with as many as 100 grid blocks representing displacement length. Whether or not physical dispersion in the reservoir is great enough to cause it is an unanswered question.
Early Performance of a Large Hydrocarbon Miscible Flood at the Mitsue Field, Alberta
Authors: Omoregie Z. S. , Jackson G. R. 
Published: December 2007

ABSTRACT
The early performance of Stage 1 of a large three-stage hydrocarbon miscible flood project at the Mitsue field, Alberta, Canada, is presented. The project area was almost completely waterflooded before project initiation. Hence, this is largely a tertiary oil recovery project. The incremental recovery due to infill drilling is discussed. Project and individual well responses to solvent injection are presented and discussed. The performance of the observation well confirmed the ability of the injected solvent to mobilize tertiary oil. Other producing wells have since shown similar responses to solvent injection. Composition and production data are presented for the observation well. Asphaltene precipitation problems in producing wells and profile control measures taken to improve vertical sweep efficiency are documented. The project is already an economic success. Projections of future project performance are made in the light of performance to date.
Mechanism of Microgel Formation in Xanthan Biopolymer Solutions
Authors: Kolodziej E. J. 
Published: December 2007

ABSTRACT
A crucial concern in using Xanthan biopolymers for EOR applications is the susceptibility of the biopolymer to formation plugging. One particular plugging problem of interest is that of microgels. This microgel plugging problem has been studied in detail by others1,2,3,4, yet several key issues have remained unresolved. Two such issues include: an adequate description of what a microgel actually is, and a physical mechanism of how a microgel is formed. These issues are specifically addressed in this paper. Several interesting results are described in the paper, which indicate that the formation of microgels is dependent on two critical components – denatured proteins and salt. A mechanism is proposed to explain the role of these components in the formation of microgels.
Estimation of Absolute Permeability from Capillary Pressure Measurements
Authors: Thompson A. H. , Katz A. J. , Raschke R. A. 
Published: December 2007

ABSTRACT
We report extensions of our earlier work on permeability estimation from mercury injection to include carbonates with complex pore-size distributions. Excellent estimates of absolute permeability are obtained with no adjustable parameters in the estimate. We also discuss the effects of sample size and inhomogeneity and show that good estimates of permeability can be obtained in inhomogeneous samples when injection is performed on the same sample used for permeability measurements.
Stability of Flow of Viscoelastic Liquids
Authors: Fong C.F. Chan Man 
Published: December 2007

Abstract
The turbulent flow behaviors of viscoelastic liquids has aroused considerable interest in recent years. It has been observed that one of the characteristics of the turbulent flow of slightly viscoelastic fluids is a very pronounced suppression of turbulence accompanied by major reduction in drag coefficient.
No consistent theoretical interpretation of the turbulent flow behaviors has yet appeared in the literature. It is thought that a study of the stability of the flow of viscoelastic liquids would be a useful first step. In this paper the problem of the stability of parallel flow of viscoelastic fluids is studied. The analog of the Orr-Sommerfeld equation is solved by the method used by Michael.
It is found that the presence of elasticity destabilizes the flow and this is apparently contrary to recent experimental observations. Possible reasons for this discrepancy are discussed.
Introduction
In recent years there has been a growing interest in the study of the turbulent flow, behaviors of viscoelastic fluids. Several investigators have observed that the addition of very small amounts of certain polymeric solutes to a Newtonian fluid can greatly reduce the turbulent drag coefficient.
A consistent theoretical interpretation of the turbulent flow behaviors of viscoelastic fluids has not yet appeared in the literature. As the problem of turbulence is related to the stability problem, it is thought that a study of the stability of parallel flow of a viscoelastic liquid would be a useful first step. Furthermore, Seyer observed that the transition from laminar to turbulent flow is delayed by the addition of polymeric solutes. This observation suggests that the flow of viscoelastic liquids is more stable. Thus, a study of the stability of parallel flow of viscoelastic liquids would be of great practical importance.
STABILITY EQUATION
The linearized theory of stability of a viscoelastic liquid has been formulated by Walters. By considering a parallel flow with velocity components [U(y), 0, 0] referred to a Cartesian coordinate axis [x, y, z], with the x-axis along the direction of flow, and by superposing a small two-dimensional disturbance, the analog of the Orr-Sommerfeld equation for Liquids A and B has been shown to be:
........................................(1)
subject to one boundary conditions v = Dv = 0 at y = 1. It is worth noting that the analog of the Orr-Sommerfeld equation for a second-order fluid is identical with Eq. 1 above.
SOLUTION FOR PLANE POISEUILLE FLOW
The method used is similar to that employed by Michael and the reader is referred to that paper for the details.
Suppose (, RO) be a point on the neutral stability curve for a Newtonian fluid, with vo and co the corresponding wave function and wave velocity. We consider a perturbation about that point and write:
........................................(2)
Some Applications of Pressure Derivative Analysis Procedure
Authors: Ozkan E. , Vo D. T. , Raghavan R. 
Published: December 2007

ABSTRACT
The derivative analysis has been shown to be an important tool in identifying flow regimes and also to be of assistance for type curve matching pressure data. This paper extends procedures to analyze pressure data by suggesting new applications of the derivative method to determine formation parameters and initial reservoir pressure. It is shown that specific equalities exist between pressure changes and its derivative and that these relations can be used to analyze buildup data when the effect of producing time on buildup data is important including data following a slug test or an "impulse"test. It is also shown that the derivative method can provide a quantitative measure of the accuracy of the slope of the semilog straight line.
Petroleum Engineering Manpower Demand The 1987 SPE Manpower Survey – A Summary
Authors: Calhoun John C. 
Published: December 2007

Abstract
Responses to the survey were received from nine companies, but three of the replies were not complete, and one of the companies that reported complete date employed less than 10 engineers. Consequently, the heart of the analysis is based on data from five oil producing companies, each of whom employed more than 500 engineers at year end 1983. Seven of the companies (the group will be called set A) reported complete year end totals for engineers employed for the past five years and both high and low projections for the next five years. These companies report a past four year decline in the employed engineering staff from the end of 1982 to the end of 1986 of 12.4%. They roject a five year change, from year end 1986 to year end 1991, that ranges from an increase of 0.2% to a decline of 7.12. In short, they see little prospect for an increased engineering work force and a high probability that the engineering work force will continue to fall. The year-by-year tabulation is given in Table 1. Seven companies, which will be called set 8, reported not only the year end totals for engineering staff but also the year end totals for those who held degrees in petroleum engineering. (These are not the same seven companies that make up set A). The percentage of those holding petroleum engineering degrees varied by year from 39.3% to 43.7%. Over the four year period, from the end of 1982 to the end of 1986, the decline in year end petroleum engineers employed was 7.6% compared to the decline for all engineers of 16.4%. The year-by-year tabulation is given in Table 2.
Engineering Salary Trends in the Petroleum Industry
Authors: Brown D. C. 
Published: December 2007

Abstract
To understand the changes that occur cyclically in engineering manpower supply/demand trends in the petroleum industry, it is desirable to have an awareness of some of the major activities and factors affecting such trends; of starting Petroleum Engineering salaries relating to that background; of the on-going engineering salary status which developed from these activities; and of the large effect that high starting and on-going salaries do have in attracting and retaining engineers within the petroleum industry. It is important to realize that changes in industry trends can be brought about both by economic and political decisions, in both domestic and international activities.
There is no single entity or group, which by itself sets the climate for engineering manpower trends in all of the parts of the petroleum industry. Rather, it is set by the political and economic decisions of nations affecting the industry, and by the interactions of a very large number of companies and individuals, from the diverse and multiple parts of the industry, in creating demand for engineers of the various types and levels needed by their organizations.
Each organization must continually monitor and find ways to meet its needs for engineers for the present and foreseeable future, as to the various engineering subfunctions which must be filled in drilling, production, reservoir, process, mechanical, electrical, and other engineering activities.
Selection of a Discount Rate or Minimum Acceptable IRR
Authors: Sinha M. K. , Poole A. V. 
Published: December 2007

ABSTRACT
Most oil and gas companies use some form of discounted cashflow analysis (DCF) as a primary measure for investment decision. Internal Rate of Return (IRR) and Net Present Value (NPV) are the two most commonly used investment analysis methods in the industry. Selecting the appropriate discount rate to use with these investment analysis methods is important if stockholder wealth is to be increased. All opinions expressed herein are the authors' own and do not necessarily reflect those of Morgan Guaranty Trust Company.