bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequential Measurement of Compressional and Shear Velocities of Rock Samples Under Triaxial Pressure
Authors: Desai K.P. , Helander D.P. 
Published: December 2007

Abstract
A laboratory measuring system was designed that can precisely and sequential measure both compressional and shear velocities of rock samples under identical conditions of stress distribution and stress history. This is required if accurate and realistic dynamic elastic properties of rocks are to be determined. The hysteresis effect on velocity pressure characteristics of rock was determined to pressure characteristics of rock was determined to illustrate this point. Lead titanate zirconate transducers were used for measuring compressional wave velocity, and AC-cut quartz transducers were used for measuring shear wave velocity. The system was tested using samples of standard material such as aluminum, steel, brass and lucite. Measurements obtained were accurate within 1 percent. percent. Compressional and shear velocities were measured sequentially on 10 samples of Berea sandstone and two samples of Bartlesville sandstone. It was found that 1. Both compressional and shear velocities increased with an increase in applied external pressure. pressure. 2. Compressional velocity depends upon both external (Pe) and internal (Pi) pressure. 3. Shear velocity depends only upon the differential pressure (Pne-Pe-Pi). 4. The nature of the fluid saturant had little effect on compressional velocity. 5. Shear velocity decreased with an increase in the density of the saturant. 6. The Berea sandstone indicated very little anisotropy. 7. The Bartlesville sandstone showed definite anisotropy.

Introduction
The various properties of an acoustic wave trainvelocity, amplitude, frequency, etc. may be modified, sometimes quite severely by the media through which the wave has traveled. This suggests the use of wave properties to determine, at least in part, the nature of the material through which the part, the nature of the material through which the wave has passed. To accomplish this successfully requires a reliable technique to for obtaining accurate values of all acoustic wave properties. One purpose of this paper is to describe a recently developed system that can precisely and sequentially record acoustic compressional and shear energies as functions both of time and of frequency. One example of the utility of this system is the accurate measurement of compressional and shear velocities through rock samples subjected to triaxial, i.e., simultaneous but independent vertical, circumferential and pore pressure. Since acoustic velocity and elasticity are closely interrelated, such a system would help to determine realistically the elastic properties of rock samples in the laboratory.
Integrated Well Performance and Analysis
Authors: Podio A. L. , McCoy J. N. , Becker Dieter 
Published: December 2007

SummaryComputer acquisition, processing, and analysis of acoustic, dynamometer, and related data at the wellsite offer new capabilities in analyzing a well's performance.A powerful lap-top computer is used in conjunction with a compact analog-to-digital (A/D) converter to acquire data from acoustic microphones, pressure transducers, load cells, accelerometers, motor current sensors, tachometers, and other transducers to analyze a pumping well's performance.The system is used in conjunction with a gas gun, microphone, and pressure transducer to measure the annular liquid-level depth in a well acoustically. This measurement is combined with the casing pressure and the casing-pressure buildup rate to determine the producing bottomhole pressure (BHP). This flowing BHP is analyzed in conjunction with the reservoir pressure and an inflow performance model to establish the producing rate efficiency of the well.The same equipment can be used with special software to acquire pressure-transient data. The computer is programmed to acquire data at a frequency specified by the operator. The computer automatically obtains the acoustic liquid-level depth measurement and the casing pressure. These data are processed to calculate the BHP as a function of test time. Conventional diagnostic plots [Horner, Miller-Dyes-Hutchinson (MDH), log-log, etc.] are presented at the wellsite to aid the operator in the analysis of the data and to determine appfopriate test completion time.In beam-pumped wells the system is also used to perform dynamometer analysis by the acquisition of polished rod load, polished rod acceleration, and motor-current data. Accelerometer data are integrated to calculate polished-rod velocity and position. Conventional surface and pump dynamometer calculations allow presentation of results for a complete dynamometer analysis in the field.All these data acquisition and analysis capabilities are available in one package. Software with operator prompts is used to aid in the proper acquisition and analysis of digital data. The acquired and processed digital field data are combined with a well database file and a pumping-unit library to assist the operator in obtaining a complete analysis of the well's performance.
Simulation of Paraffin Deposition in Reservoirs
Authors: Ring J. N. , Wattenbarger R. A. , Keating James F. , Peddlbhotla Sriram 
Published: December 2007

Summary
Certain reservoirs have a recurring wellbore damage problem caused by deposition of solid paraffin particles in the pore space. This paper describes the simulation of the reservoir processes of paraffin precipitation, convection, and deposition. The effect of reservoir heating treatments is included.
Modeling Vertical and Horizontal Wells With Voronoi Grid
Authors: Palagi C. L. , Aziz Khalid 
Published: December 2007

Summary
This paper discusses the treatment of wells in a flexible Voronoi grid. A new model problem is proposed to evaluate exact well indices for multiwell configurations and homogeneous reservoirs. A simplified model also is proposed and discussed. New exact and simplified well models for heterogeneous reservoirs are presented.
Role of Three-Hydrocarbon-Phase Flow in a Gas-Displacement Process
Authors: Mohanty K. K. , Masino W. H. , Ma T. D. , Nash L. J. 
Published: December 2007

Summary
The objective of this work is to identify the role of three-hydrocarbon-phase flow in the displacement of a reservoir oil by light-hydrocarbon-gas mixtures (methane through n-butane). Slim-tube displacements were conducted with several hydrocarbon-gas mixtures. A compositional simulator capable of handling three nonaqueous phases was used to simulate these 1D displacements. Slim-tube experiments show that as dilution with lean gas increases, the displacements go from first-contact miscible to multicontact miscible to three-phase, 3ϕ, immiscible to two-phase, 2ϕ, immiscible. Recovery is high (&gt; 85%) at high enrichment, but nonmonotonic with dilution. Simulation results mimic experimental slim-tube recovery and gas-breakthrough behavior qualitatively; especially the increase in oil recovery with increasing methane dilution of the solvent. High oil recoveries in the 3ϕ cases appear to be the result of condensation of solvent into the oil, resulting in (1) low oil viscosity and (2) effective displacement of oil by the second liquid phase that forms.
Predictive Theory for Viscous Fingering in Compositional Displacement
Authors: Blunt M. J. , Barker J. W. , Rubin Barry , Mansfield Mark , Culverwell I. D. , Christie M. A. 
Published: December 2007

Summary
A theory of compositional viscous fingering with no adjustable parameters that reduces to the Todd and Longstaff model for miscible floods is presented. The theory gives excellent predictive agreement with simulation results for a wide range of recovery processes. The high-resolution compositional simulations used to validate the theory are the first to resolve viscous fingering adequately in flow other than miscible flow.
Acreage Portfolio Management
Authors: Schneider Georges 
Published: December 2007

Summary
The need to manage U.K. North Sea acreage portfolios arises from fragmentation of holdings and complex partnerships. This management has generated friendly rationalization deals motivated by differences in perception of values and aimed at building up heartlands and balancing cash-flow forecasts. The business process includes identifying, evaluating, and negotiating deals. The economist plays a central role within the evaluation team and supports the negotiators.

Introduction
The U.K. North Sea has seen the emergence of acreage portfolio management in recent years. The resulting deals are made between companies that want to "rationalize" their acreage - i.e., to upgrade the value of their holdings through acquisitions and divestments while maintaining their overall position in the area. These companies often have well-established links within multiple joint-venture partnerships. The deals include conventional farm-ins and farm-outs and straightforward cash sales and purchases. They also include an increasing number of acreage swaps, which are a relatively new type of deal.
In the distribution of prospective acreage, most of the cards have been dealt and the many players now have to negotiate among themselves to improve their hands. These negotiations have to recognize the mutuality of interest between the parties to be successful. In this game, there can be many winners, with each player finding his niche eventually.
This article presents the situation in the U.K. North Sea and discusses how the deals are made and the role of the petroleum economist in the process. This article will have wider applications as other areas of the world reach maturity and look to the North Sea as a model.

Background: Setting the Scene
Acreage portfolio management has emerged from the distribution of license blocks among companies.
Overview: U.K. North Sea Acreage. In the U.K. continental shelf, licenses are awarded by the U.K. government, mainly on a discretionary basis, in license rounds held at regular intervals. These blocks are smaller than the Dutch or Norwegian blocks. Originally the area of a block was approximately 260 km2 in the far south and 200 km2 in the far north. After subdivision through partial relinquishments and subsequent reissues, however, the average block size is now around 120 km2. This decrease in size has increased the chance that discoveries will extend across block boundaries. At the end of 1990, 668 offshore blocks or subblocks resulting from relinquishments were under license in the North Sea part of the U.K. continental shelf. Another 70 blocks were awarded in the 12th round of licensing in May 1991.
3D Visualization for Improved Reservoir Characterization
Authors: Cairns Janet L. , Feldkamp Lynne D. 
Published: December 2007

Summary
This paper demonstrates visualization, modeling, and data integration in a 3D stratigraphic framework achieved with a computer workstation. Displaying petrophysical data in three dimensions on a graphics computer allows the interpretation of facies distributions and reservoir quality necessary for effective exploitation. Interactive computer modeling allows the flexibility in both visualizing and calculating data parameters for predicting flow patterns and hydrocarbon recovery. This viewing allows identification of numerous relationships among reservoir parameters derived from core, well log, and seismic information, as well as the integration of rock, pore, and fluid-flow data quantified at varying scales. Finally, a 3D computer model provides a common platform for all exploitation disciplines to enhance characterization of the reservoir and to prepare for numerical simulation.
User-Led Approach to Information System Investments
Authors: Pferd J. W. , Fuller A. G. 
Published: December 2007

Summary
Information-system (IS) expenditures for upstream E&P have come under strong review along with other overhead expenses. Increasing frustration with IS budgets and concern about their business value led Unocal Corp. to change the way it begins, manages, and implements IS projects. Successful IS investments are aligned with the goals and functions of work groups or business units and are balanced against other investments. The twin demands of business needs and sound technical design must be served together to achieve long-term success from IS investments. This paper describes project organizations and methods to achieve these two objectives.
Development, Distribution, and Utilization of Reservoir Engineering Workstation Software
Authors: Thomas L. K. , Evans C. E. , Sandoval R. K. , Reist R. D. 
Published: December 2007

Summary
This paper describes the development of the reservoir engineering workstation (REW) that includes software for reservoir simulation modeling and interpretation, well-performance modeling, and other petroleum engineering functions. The REW software package is installed on a company-wide network that consists of one or more high-performance color workstations in domestic and overseas offices. The workstations are networked internationally through use of Ethernet. This network also allows communication to the Cray Y-MP 232 and IBM 3090 computers at the company's major offices. REW features graphical-user-interface (GUI) interfaces, X terminal access, interactive input with on-line context-sensitive help, data checking, and units conversion.
Digital Images of Core Photographs
Authors: Hall J. D. , Howard W. E. 
Published: December 2007

Summary
Core photographs become more valuable when scanned and digitized into a database. The ability to zoom, enhance color contrasts, and compare directly with other log and well data allows details to be identified and interpreted that are barely visible on the original photographs. Examples of core images are shown that compare various photographic scales and scanning densities to illustrate effects on image quality. Core images are compared with microresistivity and acoustic images, demonstrating the interpretations available by combining various data sets. Thin-section and scanning electron microscope (SEM) images, which have been stored in the same database, are also displayed. Steps to create digital images of core photographs, including core preparation, photography, and data-set transfer, are discussed. High-quality digital images produce large blocks of data. Data-set sizes are compared for variations in scanning density, photographic scale, and color resolution. Some applications that use quantified image data, including thin-bed corrections, definition of pore geometry, and improved relative depth control, are discussed.
Computer Networks and Advanced Communications: Weighing the Pros and Cons
Authors: Koederitz W. L. , Macon B. S. 
Published: December 2007

Summary
One main method for optimizing computer usage is networking. However, for those who are contemplating a change from standalone computers to a network system, investigation of actual networks in use presents a paradox: network systems can be highly productive and beneficial, but they can create many complex, frustrating problems. The issue becomes a question of whether the benefits of networking are worth the extra effort and cost.
Here we review the implementation and management of an actual network in the Louisiana State U. (LSU) Petroleum Engineering Dept. The network, which has been in operation 4 years, is large and diverse (50 computers, 2 sites, PC's, UNIX RISC workstations, etc.). The benefits, costs, and method of operation of this network are described, and an effort is made to weigh these elements objectively from the viewpoint of the average computer user. Our intent is to provide those who may be considering the change to a network system with the benefit of experience gained in the actual operation of such a system.
Coiled-Tubing Drilling
Authors: Leising Larry J. , Newman Kenneth R. 
Published: December 2007

Summary
In the 1980's, a "coiled-tubing revolution" began when coiled-tubing services were expanded to include most workover services. In 1991, this revolution expanded to include openhole drilling with a coiled-tubing unit (CTU) in place of a drilling rig. This paper discusses the design process and the limits associated with the use of coiled tubing (CT) to drill new wells and horizontal re-entry wells.
Oil Recovery from Fracture Blocks by Cyclic Injection
Authors: Felsenthal M. , Ferrell H.H. 
Published: December 2007

Results obtained from a number of laboratory tests confirm the previously proposed idea that a cyclic pressuring/depressuring process in fractured pressuring/depressuring process in fractured reservoirs may have considerable merit over conventional waterflooding. A new idea brought out by our tests is that conservation of reservoir gas and supplementary gas injection appear to be necessary for the success of pressure pulsing in applicable reservoirs. We conducted laboratory experiments on 1- and 2-ft square X 2-in. thick limestone and sandstone "fracture matrix blocks," surrounded on all four sides by vertical fractures, and simulating portions of a naturally fractured reservoir. Results of the experiments were meant to apply as well to reservoirs dissected by networks of interconnected vugs, solution channels or stringers of large diameter pores. The sandstone was Berea outcrop (permeability to air, about 200 md; porosity, about 20 percent) and the limestone was Indiana limestone (permeability to air, about 10 md; porosity, about 18 percent). The blocks were first saturated with 50,000 ppm NaCl brine and oil-flooded to irreducible water saturation (Swi) by 80 pale oil. The 80 pale oil then was displaced by Soltrol-ethane mixture (bubble point, 300 psig; Bo, 1.3) at a displacement pressure point, 300 psig; Bo, 1.3) at a displacement pressure of 400 psig. The resulting average Swi equaled 29 percent of pore space. Pressure was lowered from 400 percent of pore space. Pressure was lowered from 400 psig to 100 psig in gradual steps to obtain primary psig to 100 psig in gradual steps to obtain primary oil production.
P. 141
A Note on the Theory of Temperature Logging
Authors: Romero-Juarez Antonio 
Published: December 2007

Interest in temperature logs has been renewed recently. One of the main problems of temperature logs in injection wells is that of determining the zones that are taking fluids. A great step toward solving this problem has been reported in a recent paper. paper. The purpose of this paper is to point out another aim of temperature logging namely, that of relating the flow rate in water injection wells to some characteristics of the temperature logs. It has been stated that a factor of 6:1 gives approximate values in converting into B/D. The factor F, which has been found empirically, may be explained from theoretical considerations and because of this, it may be estimated more accurately. It has been shown that, for flow of a liquid
,............................(1)
where
.......................(2)
a quantity that is different from zero. Eq. 1 can be written as
,..................................(3)
which shows that, as is defined in Ref. 2, is identical to A. For injection down casing, the over-all heat transfer coefficient, U, may be considered infinite. Therefore,
...................................(4)
Considering the wellbore as a linear point source,
....................(5)
or, if
........................................(6)
.......................(7)
It has been observed that surprisingly good results are obtained by using the values
k = 33.6 Btu/day-ft-F
and
a = 0.96 sq ft/day
for different locations. Taking the values
p = 350 lb/bbl, c = 1 Btu/lb-F,
one obtains:
........................(8)
It should be noted that the lower curve of Fig. 1 of Ref. 3 does not agree, for low values of t, with the solution
.........................(9)
corresponding to the constant heat flux line source and for this reason the graph should be used with caution. Eq. 8 has been plotted in Fig. 1 for three values of the external radius r'. It may be used to estimate the rate of water injection down casing from the shape of the injecting temperature log above the zone of entry of fluids.
P. 375
New, Simple Completion Methods for Horizontal Wells Improve Production Performance in High-Permeability Thin Oil Zones
Authors: Brekke Kristian , Lien S. C. 
Published: December 2007

Summary
Simple alterations to the completion can be used to enhance the performance of long horizontal wells producing from high-permeability formations. Production performance and operational feasibility of the investigated completion methods are compared. The methods should be considered for horizontal wells where frictional pressure losses along the perforated section restrict production performance.
An Experimental Study of Two-Phase Slug Flow in Hilly Terrain Pipelines
Authors: Zheng G. H. , Brill J. P. , Shoham Ovadia 
Published: December 2007

Summary
Experiments were conducted in a 76.2-mm diameter, 420-m long two-phase flow loop to study slug flow behavior in hilly terrain pipelines. Complex physical phenomena were observed, including generation of pseudoslugs at the horizontal/uphill elbow, variation of slug length along the pipeline, and persistent existence of slug flow in the downhill section.
Depth Constraint of Electric Submersible Pumps
Authors: Powers Maston L. 
Published: December 2007

Summary
This paper summarizes the various factors that limit electric submersible pump (ESP) operation at increasing depth. It explores in detail two parametrically related constraints, pump-shaft horsepower capacity and thrust-bearing load capacity. The former limits the product of head and rate; the latter limits head. Optimum shaft diameter for standard-configuration pumps is shown to be a compromise between these two factors. Head and rate limits resulting from these constraints are mathematically defined and graphically displayed, and means for expanding deep pumping capabilities are discussed. This paper also analyzes the effect of increased pumping depth on motor cooling. It shows that the temperature increase of fluid traversing a motor is proportional to head, independent of rate, and very sensitive to pump and motor efficiencies. This work also demonstrates the effect of elevated fluid temperatures associated with increasing depth on motor heat transfer coefficients.
The purpose of this paper is to help resolve a perceived dilemma. Pump manufacturers do not develop pumps with ultradeep capability because there is no market for them. Oil producers might abandon ultradeep discovery wells with low reservoir pressure because there is no way to pump them. This paper is intended to promote the interest of both groups in potential deep pumping capabilities.
Development of Analytical Design Equation for Gas Pipelines
Authors: Tian Shifeng , Adewumi Michael A. 
Published: December 2007

Summary
Based on mass and momentum balance, a rigorous analytical equation is derived for compressible fluid flow in pipelines. This equation gives a functional relationship between flow rate, inlet pressure, and outlet pressure. It is very useful in design calculations where any of these variables need to be estimated if the others are given. The equation can be used for any pipeline topology and configuration, including size and orientation. A number of problems of engineering importance are studied with this equation. They include bottomhole pressure (BHP) calculations in gas wells, gas injection calculations, and long-distance gas pipeline design calculations. The excellent agreement between predicted results and field data, with this equation for this wide variety of problems and conditions, demonstrate the efficacy of this equation for engineering applications. Simple computer programs, in both FORTRAN and BASIC, are developed to handle these applications. The BASIC program can be run on any programmable calculator with 3 kilobytes of memory.