bluuebunny/crossref_metadata_2025_split huggingface dataset:
Service Companies' Perspective of Strategie Alliancing in Alaska
Authors: Barnette J. C. , Spearman J. W. 
Published: December 2007

ABSTRACT
The well servicing alliances between BP Exploration (Alaska) and several nonaligned service companies are now in place and thriving from both the operator's and the service companies' perspectives.
Although these successful alliances were formed for the same reason as with most working alliances (e.g., maximum value), the development of these working relationships was radically different. Independent alliances were implemented rather than a single alliance with numerous aligned service companies. This paper will detail the procedures taken to form and maintain these alliances.
Some items of interest to be discussed include:
Past operations — previously driven by bidding; however, under these alliances, maximum value and quality are the driving forces. Conflicting goals — realigned from the traditional relationship to a partnership where both operating and service companies work out issues together. Traditional "sales" — refocused to concentrate on service, job planning, and communication, which allows the service company to provide input in all stages of the operation. Accounting practices — streamlined and simplified with invoicing being changed from daily, or per job, to monthly. Pricing structures — redesigned to provide the operating company with the flexibility to use the best service needed for the job rather than using the least expensive technique. Incentives — put in place so that safety and environmental protection are top priority. Performance incentives — put in place to ensure continuous improvement and to maintain required standards.
Cost-Effective Solutions to Well Plugging and Abandonment
Authors: Smith M. V. , Pitura J. M. 
Published: December 2007

ABSTRACT
Plugging and abandoning wells and squeeze cementing zones in wells have become increasingly more expensive and labor intensive. Recently, however, two cost effective methods have been developed for "one-trip" setting of both bridge plugs and cement retainers, eliminating the need for extra contractors and equipment, and reducing job time considerably. In some instances, the contract service rig can also be eliminated.
Coiled-Tubing Drilling in Kern County, California: A Case Study
Authors: Love C. L. , Eagle T. M. , Adamson Sam 
Published: December 2007

ABSTRACT
Two shallow wells were successfully drilled with coiled tubing (CT) in the McKittrick Field, Kern County, California in April, 1993. These wells were the first "grass roots" wells drilled with coiled tubing in the United States and the first known wells worldwide to be drilled with medium diameter bits (6.25") which would permit completion with 5" casing1. The operator's objective of providing low cost evaluation of undeveloped stepout areas and the contractor's objective of adapting a conventional coiled tubing unit (CTU) for economic drilling or redrilling were effectively achieved. This local adaptation of coiled tubing drilling (CTD) opens the door for a series of niche applications within the general area of well drilling/completion.
This paper summarizes the case history experience of application of this new technology to the specific two well situation and defines some potential applications of the technology.
The Effective Use of Pulse Neutron Logging for Fluid Surveillance in a Low-Salinity Environment, Endicott, Alaska
Authors: Cunningham A. B. , Schnorr D. R. 
Published: December 2007

ABSTRACT
The Pulse Neutron Log (PNL) is often an ineffective tool for water influx and water breakthrough surveillance when formation and injected water salinities are low. This is the case in most of the North Slope fields in Alaska. However, at Endicott, which has uniform low capture cross-section sands, the precision of the sigma measurement is sufficiently accurate to identify, and quantify, water movements behind casing. Aquifer influx as well as seasonal salinity variations of injected seawater are detectable using time lapse logging techniques. Because of tailpipe and sub-sea safety valve restrictions, the PNL was also chosen for the Endicott key well gas monitoring program. Gas cap movement and gas under running are effectively monitored using detector count-rate ratios, porosity, and Sigma measurements.
Associated PNL measurements such as Sigma borehole and inelastic count rates have been effectively used to identify casing leaks, and flowing perforations not detected with standard production logging suites. Water production and water channeling are also readily identified by logging the PNLs with the pulse neutron generator off in order to identify sources of oxygen activation. Water Flow logging, WFL*, has also provided additional ability to identify water production and channeling.
The PNL has been used effectively to monitor fluid movements within the Kekiktuk Formation. However, as the field matures, various factors lessen the utility of the PNL for fluid surveillance. Wells which were initially logged flowing must increasingly be logged shut-in due to steadily rising gas production and associated diffusion problems from gas in the wellbore.
Also, the increasing presence of barium sulfate scale, with associated high background radiation, eventually reduces the ability to make accurate measurements and interpretations across these affected portions of the wellbore.
Applied Hydraulic Fracture Modeling Improves Results, Cleveland Sand, Ochiltree County, Texas
Authors: Aud W. W. , Brady C. L. , Rainbolt M. F. , Perry K. F. 
Published: December 2007

ABSTRACT
This discussion shows the positive results obtained from using state-of-the-art technologies to interpret, diagnose, and predict hydraulically fractured well characteristics and responses. Extensive reservoir and geological data were collected and integrated into both reservoir simulation of production and pressure transient responses and advanced hydraulic fracture modeling to characterize the Cleveland formation in the Ellis Ranch Field area. The results showed that vertical proppant placement was a critical issue and that by making the necessary adjustments to improve the proppant placement the fracture treatment costs could be reduced and the production results improved.
Multiphase Science and Technology for Oil/Gas Production and Transport
Authors: Oliemans R. V. A. 
Published: December 2007

Abstract
During the past twenty years multiphase flow technology has become increasingly important for the economic transportation of well streams from reservoir to process. In particular, production offshore, where the trend is to develop numerous small fields by transporting untreated fluids Via existing infrastructures, imposes high demands on the multiphase science and technology required to ensure economic and safe operation. This paper addresses the state of the art in the development of multiphase production systems and highlights future trends. It subsequently scrutinizes the reliability of models and techniques currently available and identifies issues in the area of multiphase flow technology that need to be addressed. Typical aspects that will be covered are steady and transient two-phase pipe flow modelling, the effect of water on oil/gas flow, multiphase metering and multiphase boosting, and the use of trunkline management systems in multiplatform production schemes.
Influence of Small-Scale Rock Laminations on Core Plug Oil/Water Relative Permeability and Capillary Pressure
Authors: Honarpour M. M. , Cullick A. S. , Saad Naji 
Published: December 2007

Abstract
Relative permeability is a critical parameter in reservoir engineering calculations and performance predictions using numerical simulation. Little has been published on the effect of core-scale heterogeneities on relative permeability. Small-scale rock heterogeneity can lead to directional-, length-scale dependent relative permeabilities, and distinct hysteresis characteristics.
This report presents relative permeability and capillary pressure data on a core that is characterized by millimeter-scale parallel laminated bedding. The core was characterized using petrographic analysis, CT scanning, and minipermeametry. Anisotropy of relative permeability is demonstrated by comparing relative permeability measurements on a plug drilled parallel to the laminations with those of a plug drilled normal to the laminations. Steady-state and unsteady-state oil-water relative permeability data were collected using X-ray Scanning for insitu fluid saturation measurement. Measured secondary drainage curves show distinctive characteristics when the principal flow is parallel to laminations as compared to flow normal to the laminations. Porous plate and centrifuge capillary pressure measurements illustrate differential drainage and imbibition among laminations.
These results demonstrate relative permeability anisotropy attributed to capillary pressure contrast among small-scale laminations. The directional variability is not apparent from single-phase directional permeability measurements. Core plugs with more isoptropic permeability distribution show reduced impact of small-scale heterogeneity.
Mixed Reservoir Characterization Methods
Authors: Damsleth Eivind , Holden Lars 
Published: December 2007

Abstract
The main objective of reservoir characterization is to describe the features which influence the amount, position, accessibility, and flow of fluids through a reservoir. These features will be: The structural aspects (depth to the reservoir boundaries and inter-reservoir surfaces), faults (both seismically identifiable and sub-seismic faults), flow-units or facies bodies (position, orientation and size), and the spatial distribution of the relevant petrophysical parameters (permeability, porosity, saturations, …) within each flow-unit. Although some "hard" data from seismic and wells will be available, there is a definite stochastic element in all these features. Stochastic techniques are thus required to model them properly.
The paper reviews a number of techniques available for stochastic modeling of the above features: (marked point processes, Markov fields, truncated Gaussian fields and indicator kriging for modeling discrete events (flow-units, faults, barriers); Gaussian fields and indicator kriging for modeling property values (depths, fault transmissibility, petrophysical variables)). The different techniques can be mixed or combined to give a complete stochastic model of every relevant aspect of the reservoir. Several examples from the North Sea will be presented.
Selection of Optimum Intermittent Lift Scheme for Gas Lift Wells
Authors: Chacín J. E. 
Published: December 2007

Abstract
Maracaibo Lake wells are currently producing approximately 800 mstbd of crude oil from some 7000 wells. 90% of these well are in gas lift and approximately 760 wells are being lifted intermittently. Natural reservoir decline will increase the number of wells that will require intermittent lift at an estimated rate of 150 wells per year.
Continuous research and modeling efforts have been performed over the last thirty years to understand the dominant physical characteristics and develop mechanistic computational tools for the design of the various existing intermittent lift schemes (conventional, plunger assisted, chamber lift). The present paper will review relevent published work regarding intermittent lift and describe key modeling considerations for each scheme.
Furthermore, we will focus on proper selection of intermittent lift scheme as a function productivity index, reservoir pressure, wellbore equipment and completion and other inportant well parameters.
Compositional Gradients in Petroleum Reservoirs
Authors: Whitson Curtis H. , Belery Paul 
Published: December 2007

Abstract
This paper describes methods for calculating the one-dimensional, vertical variation in composition with depth caused by gravity and thermal gradients. The Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) cubic equations of state (EOS) are used as thermodynamic models. Examples of calculated compositional gradients are given for reservoir fluid systems ranging from black oils to near-critical oils.
A solution algorithm is suggested for solving the isothermal gravity/chemical equilibrium (GCE) problem. The algorithm is simply an adaptation of a method proposed by Michelsen1 for calculating saturation pressure. The problem of false (unstable) solutions is discussed, and the subsequent need for applying phase stability analysis to identify such false solutions. Finally, an algorithm is given for determining the location of a gas-oil contact (GOC).
A model for treating both gravity and thermal gradient has been used to quantify the potential effect of thermal diffusion on compositional grading. The model used was proposed by Belery and da Silva2. Unfortunately, the physics and thermodynamics of thermal diffusion are not well understood. This model is only one of several approaches which have been suggested for treating thermal diffusion. Examples given in our paper show that thermal diffusion can have a marked effect on compositional grading, with the possibility of enhancing, reducing, or completely eliminating gradients caused by gravity alone.
We illustrate the potential danger of using gradient calculations for defining original hydrocarbon distributions (oil and gas in place) when limited fluid samples and PVT data are available. Furthermore, guidelines are given for when to use gradient calculations, and how to develop an EOS fluid characterization for reservoirs exhibiting compositional variation.
Predicting the effects of pore pressure penetration on the extent of wellbore instability: Application of a versatile poro-elastoplastic model
Authors: McLellan P. J. , Wang Y. 
Published: December 2007

Abstract
A poro-elastoplastic wellbore stability model, which accounts for the presence of an internal filter cake in a plastic yielded zone, and capillary threshold pressures has been developed for a Mohr-Coulomb, strain-weakening material. The extent of the plastic yielded zone may be predicted for steady state fluid inflow (underbalanced) or outflow (overbalanced) conditions. The model predicts that for overbalanced drilling conditions the filter cake efficiency, or its ability to reduce pore pressure penetration, can significantly affect the extent of the plastic yielded zone which can develop in a permeable formation. Example applications of the model to drilling and completing horizontal wells in a unconsolidated, bitumen-saturated sand and a weak, cemented sandstone are described.
Rock-bit wear in ultra-hot holes
Authors: Macini Paolo , Mesini Ezio 
Published: December 2007

Abstract
The paper presents a new model of rock-bit wear, and refers to bits utilized in ultra-hot wells drilled in the geothermal area of Larderello, Tuscany, Italy. In particular, the model, conceived from field data, indicates that the correct evaluation of rock-bit wear, considered in the light of the knowledge of drilling parameters and downhole conditions, can improve the overall drilling performances through a better interpretation of the relationships among rock-bit, formation properties and bottomhole temperature. This paper investigates the detrimental effects, not yet very well understood, of high bottom hole temperature on sealing and reservoir systems of friction bearing rock-bits. A particular bearing wear model for friction bearing rock-bits utilized in ultra-hot holes has been considered and further verified via laboratory inspections on dull bits. A novel interpretation of flat worn cutting structure has been derived from the above wear model and viable recommendations for improving the cost of drilled interval are suggested. Also, rock-bit field data from several Italian geothermal wells are reported and analized as an example of field application.
Exploiting Poroelastic Effects and Permeability Contrasts to Control Fracture Orientation
Authors: Boone Thomas J. , Wawrzynek Paul A. 
Published: December 2007

Abstract
This paper demonstrates how poroelastic effects, acting in combination with anisotropic permeabilities (i.e. a vertical permeability that is less than the horizontal permeability), will typically favour reorientation of a propagating fracture from vertical to horizontal. The paper includes examples of fracture reorientation using a specially adapted finite element code that can model curved fracture propagation.
Contribution of Poroelasticity to Reservoir Engineering: Lab Experiments, Application to Core Decompression and Implication in HP-HT Reservoirs Depletion
Authors: Boutéca M. J. , Bary D. , Piau J. M. , Kessler N. , Boisson M. , Fourmaintraux D. 
Published: December 2007

Abstract
The linear mechanics of porous rocks is summarized : basic equations – i.e. constitutive law and fluid mass balance – and most useful relationships are given. For reservoir engineering applications, the hydrostatic loading case is dealt with in detail. The conventional diffusivity equation -i.e. uncoupled pressure equation-is then derived. Experimental procedures are suggested and results obtained on outcrop and reservoir sandstones are given. The data indicate that the sandstones have a nonlinear behavior and that volumetric coefficients are functions of the difference between the confining pressure and the pore pressure. A model is then proposed based on Biot's semilinear theory. The reservoir rock behavior is shown to be in agreement with this model for the experiments performed. As an application effective stress is computed. Finally the role of pore pressure in damaging cores during the pulling out phase is investigated.
Application of Simulation Techniques to Low Permeability Reservoirs
Authors: Ancell K.L. , Young K.L. 
Published: December 2007

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

Abstract
This paper represents an effort to apply simulation techniques to low permeability gas reservoirs. Problems encountered are illustrated by an actual field example. Techniques normally employed for gas reservoirs are not easily extended to the low permeability case. The results show that it is permeability case. The results show that it is possible to rigorously calculate the possible to rigorously calculate the performance of such reservoirs, but to do performance of such reservoirs, but to do so requires data that make application to large fields impractical. However, certain adjustments can be made that approximate performance of such reservoirs, making large performance of such reservoirs, making large applications possible under some restricted conditions.

Introduction
Natural gas transmission companies must invest millions of dollars in surface pipeline systems and compression facilities in pipeline systems and compression facilities in order to produce natural gas and transport it thousands of miles to the market area. These surface systems are designed to fit the specific reservoirs with which they are connected.
In the mid-continent gas supply area, and specifically the Anadarko Basin, many gas reservoirs are characterized by low permeability. Reasonable gas rates that permeability. Reasonable gas rates that satisfy both the transmission company's market requirements and the producer's economics result in large pressure transients existing over extended periods of time. While the pipeline company is basically interested in stabilized well performance, the individual well rates are often determined by short term transient well tests. This makes it necessary to calculate both highly transient and stabilized flow. Numerical simulation techniques would appear to offer the best solution to such a problem. This paper deals with experience gained from simulating a low permeability reservoir and is illustrated with an actual field example.

THE PROBLEM AND DATA AVAILABLE
The simulation of gas reservoirs in the Anadarko Basin requires consideration of low permeability. The extension of techniques permeability. The extension of techniques used for high permeability fields has proved to be not entirely adequate. This study represents an effort to calculate the complete performance of a reservoir that is characterized performance of a reservoir that is characterized by low permeability, then to develop a technique to evaluate such reservoirs in a routine manner.
Geoengineering Confidence Building for the Design and Construction of Salt Caverns
Authors: Langer M. 
Published: December 2007

Abstract
Rock salt is particular impermeable to gases and liquids. The solution-mining method provides the means for the creation of large storage capacities at economic costs. The geotechnical behaviour of rock salt is well-known with sufficient details for dimensioning purposes. Due to its favourable geomechanical properties, halite remains stable over long periods of time without support.
However safety analysis has to be carried out in each case based on specific data. Such an analysis comprises engineering geological study of the site, laboratory and in-situ measurements. Model calculations are essential.
The study of uncertainties is fundamental part of the confidence building. The uncertainty of parameters (geometry, material behaviour, initial conditions, loading) given in a validated model can be expressed by a probability density function, but the model uncertainty is not a stochastic resp. probabilistic attribute. It can be described as a lack of dependability of a model to predict structural response assuming precisely defined parameters, Therefore the objective of model validation exercise must be the demonstration that a model is sufficiently accurate to predict structural response or migration of toxic particles by knowing the logic of idealization or justification of simplification (conservatism).
In-situ Stress Orientation and the Effects of Local Structure – Scott Field, North Sea
Authors: Yale David P. , Rodriguez J. M. , Mercer Thomas B. , Blaisdell David W. 
Published: December 2007

AbstractIn-situ stress orientation was measured in 17 wells throughout the Scott field in order to predict the orientation of waterflood induced fractures. The Scott field is heavily faulted and significant variations in in-situ stress orientation were found between different fault blocks. The in-situ stress orientations appear to be strongly controlled by the orientation of the local faults and tectonics. The direction of maximum horizontal stress appears rotated 30° to 50° on either side of the NNW-SSE regional compression trend generally found in the North Sea. In most cases, the maximum horizontal stress is parallel to the orientation of nearby normal and wrench faults, as would be predicted by a tectonic model of such faulting. However, the tectonics of the region suggest that the rotation of the regional stress field from fault block to fault block is due to the presence of the faults rather than active faulting.The orientation of the in-situ stress was determined from shear acoustic anisotropy measurements on cores from 5 wells and from wellbore elongation measurements in 13 wells. The two methods show very similar orientations within the same fault block. No statistical variability in stress orientation was noted between different formations or with depth.Shear acoustic anisotropy utilizes the polarization of shear acoustic waves propagating through oriented core samples and has proven to be very reliable in determining stress orientation. The observed wellbore elongations in the field do not appear due to breakouts. The character, magnitude, placement, and orientation of the wellbore elongations strongly support the premise that the measured elongations were due to drilling or coring induced wellbore fractures. Previous experience by the authors and other recently published observations support this conclusion and the reliability of these elongations for the determination of stress orientation.