bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subseismic Faults in Reservoir Description and Simulation
Authors: Munthe K. L , Omre Henning , Holden Lars , Damsleth Eivind , Heffer Kes , Olsen T. S. , Watterson Juan 
Published: December 2007

Abstract
A program system based on a stochastic model of the fault pattern and properties has been implemented. The faults are modelled as fault planes and displacement of adjacent rock. Realizations of the fault characteristics in a reservoir can be generated.
The generated set of faults is applied to a reservoir description (permeability field). The fault planes may act like barriers to fluid flow. The displacment of rock can disconnect a high permeable zone and thereby reduce the overall flow properties. On the other hand, it can also connect high-permeable rock and improve flow.
Although the reservoir geometry and properties are changed by the faults, well observations may still be honoured by taking faults into account when creating the description.
Real-Time Quality Control of Foamed Cement Jobs: A Case Study
Authors: Thayer R. D. , Ford D. G. , Holekamp Steve , Pferdehirt D. J. 
Published: December 2007

Abstract
Foam cement is a low density cement system prepared by mixing nitrogen gas and surfactants with API Portland cement. The lower density limit for conventionally extended slurries is between 11.0 and 12.0 lb/gal. Foaming permits cement slurry densities lower than water (8.33 lb/gal) while maintaining relatively high compressive strengths. These advantages and others have been well documented.
Actual field mixing procedures and additive rates are critical and must be monitored to assure a competent foam cement. Slight variations in base slurry density, base slurry rate, foamer and stabilizer rate, or nitrogen rate can significantly alter the final foam density. Formerly, foam density was measured by a radioactive densitometer. This allowed for significant error when densities were less than 8.33 lb/gal. There was no physical means to collect and weigh an actual foam cement sample.
This paper explains methods to improve the accuracy of the additive rates. It also defines a method for real-time measurement of foam cement density. The paper describes the use of a high pressure device downstream of the nitrogen addition that can weigh a pressurized foam cement sample during the job.
Fracture Initiation and Propagation from Deviated Wellbores.
Authors: Weng Xiaowei 
Published: December 2007

ABSTRACT
This paper presents the results of an analytical study of hydraulic fracture initiation and propagation from deviated wellbores. The interaction and link-up of the starter fractures initiated from perforations and the turning of the linked fracture are investigated. A criterion that correlates fracture link-up to stresses and wellbore parameters is established. The characters of the near-wellbore multiple fractures and their effects on fracture width reduction and friction loss are also studied. The model-predicted pressure response, which takes into account the near-wellbore friction loss, is compared to the measured bottom hole pressure data during a fracture treatment.
Thermodynamic Measurement and Prediction of Paraffin Precipitation in Crude Oil
Authors: Erickson D. D. , Niesen V. G. , Brown T. S. 
Published: December 2007

ABSTRACT
Economically and technically viable methods for controlling paraffin buildup in pipelines and wellbores are critical to the production of crude oil in deep water and cold environments. Conoco has identified laboratory test methods and developed a paraffin prediction program to better quantify the paraffin (wax) deposition potential of a crude oil and to evaluate or develop methods of preventing or controlling paraffin buildup. This paper will describe the thermodynamic paraffin model and the complementary laboratory test methods. A companion paper will describe the kinetic deposition model and the associated laboratory and field data.
The Use of Laser Doppler Velocimetry (LDV) for the Measurement of Fracturing Fluid Flow in the FFCF Simulator
Authors: Mears R. B. , Sluss J. J. , Fagan J. E. , Menon R. K. 
Published: December 2007

Abstract
Laser Doppler Velocimetry (LDV) is an optical point velocity measuring technique that has revolutionized velocity measurements in hostile flow environments. The high pressures and high temperatures encountered in hydraulic fracturing simulations at the Fracturing Fluid Characterization Facility (FFCF), coupled with the abrasive character of the proppant laden fracturing gels proposed for study, makes LDV the preferred technique for this application. This paper describes a unique nine probe LDV system that is applied to fluid flows in the FFCF simulator. The LDV system consists of nine specially designed laser probes, three power supplies, a unique signal processor/multiplexer, and a personal computer for system control and data display. In addition, three automated precision traversing stages are coupled to three of the laser probes for velocity profile studies. This system has been applied to both Newtonian and non-Newtonian fluids in the simulator at several crack widths and flow rates. Some point velocity data, along with extensive velocity profile data, is presented and discussed for several fluids. The fracturing fluid studies presented are for flows without proppant. The velocity profiles are compared to theoretical models that are applied with volumetric flow rates measured by an independent flowmeter. The results show that LDV is a valuable tool for gathering point velocity information from fracturing fluid flows in the FFCF simulator.
Gamma Ray Absorption Measurements, Laboratory Experiments in Bottomhole Conditions
Authors: Putz A. G. , Morineau Y. M. , Begani Rino 
Published: December 2007

Abstract
A gamma ray attenuation measurement apparatus performs saturation measurements during core flood experiments in bottomhole conditions. Pressure and temperature limits are 450 bar and 170°C. The core, with a maximum length of 1 meter, is mounted vertically. An americium 241 source and a detector can be translated and rotated very precisely along and around the core.
Two complex studies of primary depletion have been run, each lasted close to a year. The first experiment was a light oil depletion in a Berea core at 136°C and 220 bar, the other was a condensate gas depletion in a composite dolomite core at 406 bar and 135°C. The methodology of the saturation measurements is presented together with the saturation profiles. The accuracy of the results is determined in each case.
Matrix Permeability Measurement of Gas Productive Shales
Authors: Luffel D. L. , Hopkins C. W. , Schettler P. D. 
Published: December 2007

Abstract
Three laboratory methods were developed to measure matrix gas permeability (Km) of Devonian shale cores and drill cuttings at native water saturations. The first method uses pulse pressure testing of core plugs with helium. The second, new method uses pulse pressure testing of core chips or drill cuttings with helium. These methods gave comparable results on 23 companion shale samples from two wells, with Km = 0.2 to 19 × 10−8 md. The third, new method uses degassibility of core plugs with helium and methane, and yielded Km higher by a factor of 3 to 10. Most of the core plugs tested showed multiple microfractures that remain open at reservoir stress, and these dominate conventional flow tests. These microfractures are parallel to bedding, are coring induced, and are not present in the reservoir. Knowledge of Km is important in computer simulation modeling of long term Devonian shale gas production, and has been a key to understanding the nature of the natural fracture network present in the reservoir.
Tracking Injected Components in Fully Compositional Reservoir Simulations
Authors: Kim J. S. 
Published: December 2007

Abstract
A new method to track injected components has been successfully tested in fully compositional reservoir simulations. This method treats the injected components independently from the corresponding components indigenous to the original reservoir fluid in fluid characterization and reservoir simulation. This approach enables tracking both injected and resident reservoir components separately at the surface production stream and within the numerical model. Two test applications of this method, a gas cycling operation and a CO2 flood operation are discussed in detail along with the results.
Typical injectant components such as CO2, methane, ethane, or propane often exist in the initial reservoir hydrocarbon fluid. This makes it impossible to distinguish between injected and resident components in the conventional compositional reservoir simulations. In this work, at least one of the common components is represented as a pseudo-component with identical equation of state parameters: one initially present in the resident reservoir fluid, the other to be carried in the injection gas. Thus, both injected and resident components are traced separately in the surface production stream and within the reservoir fluid. This paper details how this method has been used to depict injected hydrocarbon gas or CO2 breakthrough, estimate make-up gas volume requirements and CO2 retention rate more rigorously, and track movements of injected components at different times during simulation studies.
This method gives the same results as the conventional techniques in equation-of-state characterization, oil production, GOR changes, and individual component concentrations in two simulation applications with only a 5–65% increase in computer time due to the added components. It is very useful in visualizing physical phenomenon such as mixing zone growth and injectant breakthrough. By tracking concentration changes and movements of injected components such as CO2, methane, ethane or propane within a numerical model and in the surface production streams, mass transfer effects can be clearly depicted during simulation studies.
An Economic Model for Assessing the Feasibility of Exploiting Naturally Fractured Reservoirs by Horizontal Well Technology
Authors: Guo Genliang , Evans R. D. 
Published: December 2007

ABSTRACT
An economic model for assessing the feasibility of exploiting naturally fractured reservoirs using horizontal well technology is presented. Detailed equations are derived for calculating the cost, return on investment and discounted net present value over the production life of a naturally fractured reservoir. An analytical production forecasting method is also developed for predicting the future production performance of horizontal wells in naturally fractured reservoirs. A computer program is developed which can be used to perform the production forecasting and economic evaluation of a naturally fractured reservoir for any given natural fracture characteristics, horizontal well configuration and reservoir fluid properties. A case study indicates that the proposed economic evaluation and production forecasting models provide a simple analytical tool for assessing the production process of complex naturally fractured reservoirs intersected by horizontal wellbores. They allow engineers to identify an optimum horizontal well drilling scheme from comparisons of the production and economic performance profiles for various alternatives.
An Evaluation of Recent "Mechanistic" Models of Multiphase Flow for Predicting Pressure Drops in Oil and Gas Wells
Authors: Pucknell J. K. , Mason J. N. E. , Vervest E. G. 
Published: December 2007

ABSTRACT
The reliable calculation of tubing pressure drops in oil and gas wells is important for the most cost effective design of well completions. None of the traditional multiphase flow correlations works well across the full range of conditions encountered in oil and gas fields. Consequently, two of the recently published "mechanistic" models, one by Ansari, the other by Hasan & Kabir, were evaluated. The performance of these methods was compared against traditional correlations in three ways:
The predicted against measured pressure drops were compared for stable flow conditions using 246 data sets collected from 8 producing fields, including a gas and gas-condensate field. None of these data were available to the developers of any of the multiphase flow models evaluated. Suitable methods should reliably predict the "lift curve minima". This determines when a well may need to be "kicked off', artificially lifted or recompleted. The multiphase flow model must not contain discontinuities or be subject to convergence problems.
No single traditional correlation method gives good results in both oil and gas wells. In fact, most of the traditional methods which work reasonably in oil wells give very poor predictions for gas wells.
Hasan & Kabir's mechanistic method was generally found to be no better than the traditional correlation methods. However, the Ansari mechanistic model gave consistently reasonable performance. Although it did not give the most accurate results in every field, it gave reasonable results across the complete range of fields studied. The Ansari method also gives a reliable prediction of the lift curve minima. Areas in which it needs improvement were identified.
By comparison the best of the traditional methods, the Hagedorn & Brown correlation, gave good results for stable flow conditions in oil wells, but it does not correctly predict the lift curve minima. A field example shows how this can lead to erroneous conclusions.
Strategic Exploration and Production Portfolio Management Using Marketing Planning Techniques
Authors: Harrison Robert , Jeffs Paul 
Published: December 2007

ABSTRACT
A method for managing the asset portfolio of an oil E&P company is proposed based on marketing planning techniques proven within the commercial sector. A multi-tiered approach is adopted to allow consideration of assets, both producing and prospective, within a regional, national or basinal context. The use of life-cycle concepts, gap analysis and directional policy matrices to evaluate and rank assets is illustrated through reference to a typical diversified North Sea portfolio. The implementation of these techniques within a company environment is also discussed. As well as allowing properties at different stages of maturity to be compared, appropriate strategies on how to manage the assets at each stage of development can be deduced from the categorisation introduced by the policy matrices. The method presented also allows the forecasting of potential shortfalls in production and facilitates strategic planning decisions to change the nature and size of the portfolio. The method is considered to be rigorous and rational and constitutes an improved, auditable technique for E&P portfolio management.
Beryl Alpha – Condeep GBS Analysis
Authors: Galbraith D. N. , Hodgson T. , Darby K. 
Published: December 2007

ABSTRACT
A significant upgrade to the topsides facilities of the Beryl Alpha platform has recently been undertaken by Mobil North Sea Limited (MNSL). Structural reassessment of the deck structure was performed to demonstrate its continued integrity under the resultant increase in topsides loads. Previous papers [1. 2] describe how this was achieved with only minor strengthening. The reanaiysis has now been extended to incorporate an assessment of the concrete gravity base substructure, which is of the Condeep design. VTNSL's purposes for undertaking this reanaivsis were to:
– reassess the structure taking into account the platform's operational history and the increased deck loads: – review the implications of extending the operational life: – investigate how the reinforced, prestressed concrete design performs against contemporary rules and codes: – provide a basis for future inspection: – provide a rapid reanalysis capability in the event of accidental damage or freak environmental loads.
Many aspects of the substructure design were evaluated, thus providing a unique opportunity to review the performance of a Condeep and its foundation after eighteen years of operation. The analysis included the development and validation of hydrodynamic and all other loads. A particular feature was the integrated use of both a simple skeletal simulation of the platform and a detailed finite element model. Extensive concrete code checking has been performed to a number of limit states using specialist software.
This paper presents the philosophy employed in, and discusses the preliminary results of, this analysis.
Planning and Start-Up of the Heidrun TLP Predrilling Program
Authors: Actis S. C. , Smith K. L. , Chenier D. E. 
Published: December 2007

ABSTRACT
Development drilling at the Heidrun field offshore mid-Norway is currently underway. The Heidrun field will be developed with a concrete hull Tension Leg Platform (TLP) in 345 meters (1132 feet) of water1,2. The pre-drilling program to be conducted from a semi-submersible includes drilling and partially completing nine wells, setting 30" conductor and 22" surface liners in the remaining 47 TLP-template well slots and drilling and completing 6 water injection wells in two remote subsea templates.
This paper will review the extensive planning as part of the overall Heidrun project and present a review of drilling operations to date. The state of the art drilling techniques being implemented to overcome unique drilling problems and complete the substantial scope of work will be described.
Piloting Safety Cases To Support Decisive Management of Change
Authors: Wong Norman 
Published: December 2007

Abstract
This paper discusses the piloting work done by Amoco (U.K.) Exploration Company, from 1988 to date, in developing safety cases for a total of 21 diverse installations in the United Kingdom sector of the North Sea.
The period is characterised by an unprecedented degree of change during which operators have sought to achieve a practical and consistent outcome in anticipation of new offshore safety regulations finally introduced in 1993 [1].
The paper describes Amoco's approach to the management of that change, the formation and the work of the Amoco Safety Case Team, and the value of the information and experience obtained during the process. It concludes by discussing the key elements in the project's success and the future challenges facing the industry in continuing to implement the new approach to safety.
Features of a Safety Case for a Complex of Platforms with NNM's
Authors: McIntosh A. M. 
Published: December 2007

Abstract
July 6th 1988 saw the worst disaster in the history of offshore operations. The total destruction of the Piper Alpha Platform claimed the lives of 165 of the 226 persons on board, and two of the crew of a fast rescue craft. The Public Inquiry into the Piper Alpha disaster led to the publication of the so called "Cullen Report&apos; in November 1990 containing Lord Cullen's 106 recommendations for improving or achieving optimum safety.
The report was welcomed and the recommendations were quickly accepted by the UK government. Many people envisaged the report as having a radical effect on the design and construction of offshore installations, and while this is true to a point, detailed examination of Lord Cullen's recommendations show that the greatest part of these related to Safety Management. Over half his recommendations refer to management and training issues, approximately a further 25% deal with safety engineering assessment and analysis and only about 25% relate purely to hardware issues.
Lord Cullen's first and overriding recommendation was that operators should be required by regulation to submit a Safety Case, similar to the CIMAH Safety Report, for each of its installations. He was firmly directing operators towards assessing and demonstrating a safe operation via the production of a Safety Case as is now required by the Offshore Installations (Safety Case) Regulations 1 992 and if the operator can make that demonstration then he will have met the intention of the vast majority, if not all of, Lord Cullen's recommendations.
A Joint Industry Research Project to Investigate Coiled-Tubing Buckling
Authors: Tailby R. J. , Cobb D. O. , Riva M. C. , Jones Colin , Rydland J. A. , Christensen O. S. 
Published: December 2007

Abstract
A joint industry project (JIP) has been conducted to investigate the behaviour and limitations of coiled tubing (CT) in a horizontal well environment. Full scale testing (FST) revealed limitations in traditionally accepted industry theories and changes have been implemented in field operating procedures. Residual bending in the CT, tip (end) load, and well profile are critical parameters with regards to maximising coiled tubing penetration into a well. Computer models have traditionally predicted significantly less penetration in these wells. However, recent testing and field experience has confirmed extensions to these predictions. This paper describes the JIP and presents the main results and conclusions, including some reference to recent field examples.
Continuous Semirigid Electric Line for Downhole Measurements in Highly Deviated Wells
Authors: Fay Jean-Baptiste , Huvey Michel , Grosjean Francois 
Published: December 2007

Abstract
The development of highly deviated to horizontal wells has raised the problem of using downhole measurement tools where such tools can no longer be run in under the simple effect of gravity. Transmission of a force from the surface, whether thrust or traction, to a logging tool at a depth of several thousand metres can be achieved by semirigid stems. Such stems made of composite materials — glass or carbon fibres embedded in a resin — may also include a way of transmitting data. As compared to steel, the combination of materials such as fibres and resin provides advantageous mechanical properties with regard to traction strength, flexibility and lightness. Moreover, the continuous manufacturing technique — pultrusion — is well suited both for producing long single-unit lengths and for inserting any line such as a monoconductor, multiconductor or coaxial electric conductor.
So far, several lengths of semirigid stems, including end fittings, have been produced, reaching more than 200 metres of single-unit length and showing that the extension to several thousand metres raises no technical problem. The principal parameters of the composite material such as the Young's modulus, the ultimates stress and strain have been measured during bending, tension and compression tests. Dynamic tests in tension and bending have also been performed.
The use of a semirigid stem may be considered by itself or inside a coiled tubing:
When used by itself to push or pull a tool in a highly deviated borehole, the integrated electric conductor ensures two-way data transmission; When used inside coiled tubing, it preserves all the inherent advantages of the coiled tubing (implementation, high-pressure hydraulic conduit). More hover, the semirigid stem is fully compatible with winding/unwinding cycles, and it protects the electric line from any damage.