bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ranking and Upscaling of Geostatistical Reservoir Models Using Streamline Simulation: A Field Case Study
Authors: Ates Harun , Bahar Asnul , El-Abd Salem , Charfeddine Mohsen , Kelkar Mohan , Datta-Gupta Akhil 
Published: December 2007

AbstractIn this paper, we present a field example where a streamline simulator was used to rank multi-million cell geostatistical reservoir descriptions and to find the optimum level of vertical upscaling for finite-difference simulation. During geostatitstical reservoir characterization, it is a common practice to generate a large number of realizations of the reservoir model to assess the uncertainty in reservoir descriptions and performance predictions. However, only a small fraction of these models can be considered for comprehensive flow simulations because of the high computational costs. A viable alternative is to rank these multiple ‘plausible’ reservoir models based on an appropriate performance criterion that adequately reflects the interaction between heterogeneity and the reservoir flow mechanisms.In this study, we explore the use of ranking based on streamline time of flight connectivity derived from a streamline simulator. The time of flight reflects fluid front propagation at various times and its connectivity at a given time provides us with a direct measure of volumetric sweep efficiency for arbitrary heterogeneity and well configuration. The volumetric sweep efficiency is the simplest measure that reflects the interaction between heterogeneity and the flow field. It is a dynamic measure that can be easily updated to account for changing injection/production conditions. We show that the proposed connectivity criterion can also be used to evaluate the effects of vertical upscaling in the dynamic performance and to determine the optimal level of upscaling for numerical simulation purposes.Our field study involves a Middle Eastern carbonate reservoir under a moderate to strong aquifer influx. The reservoir is on primary depletion and has no injectors. Multiple geostatistical reservoir descriptions were generated using a hierarchical approach whereby the larger level of uncertainty is defined first followed by smaller levels. The aquifer is modeled with a constant pressure boundary and for each time update, the location of the boundary was modified to account for the water encroachment. Using the field-wide sweep efficiency as a performance measure, the realizations were ranked, and used for flow simulation to assess risks associated with various development strategies. Subsequently, three selected realizations were upscaled for the purpose of comprehensive history matching and performance prediction.
Improvements in Dynamic Modeling of Underbalanced Drilling
Authors: Fjelde Kjell K. , Rommetveit Rolv , Merlo Antonino , Lage Antonio C. V. M 
Published: December 2007

Abstract
The present work discusses some improvements that have been introduced in a dynamic model, which was developed for simulating the two-phase flow transient phenomena associated with underbalanced drilling operations. The model enhancements are basically obtained by implementing mechanistic closure relationships and more accurate numerical schemes. This process of improvement is validated through comparison to full-scale experimental data in transient scenarios, showing that the gains in terms of increasing the model accuracy are significant.
3D Modeling using Multiple Scenarios and Realizations for Pre – Reservoir Simulation Screening
Authors: Scheepens C. C. J. 
Published: December 2007

Abstract
Understanding and managing subsurface risk is becoming an increasingly important business driver for oil companies. The ability to generate, manage and rank multiple models of a reservoir will allow for better economic forecasting, particularly at early project stages.
3D geological modeling is becoming a standard work process in many oil companies. Properly utilizing multiple scenarios and realizations for risk analysis, however, is a technique that requires a more sophisticated work process. Two main themes are discussed. First: how to frame the problem to generate reasonable model trees that will contain multiple stochastic realizations. Second: how to perform model ranking and select a small number of models for further investigation and analysis.
This is an evolving workflow in many companies. In this presentation we provide some ideas and guidelines for streamlining and focusing the work to the desired goal.
Competitive Impact of New Canadian Reserve Guidelines
Authors: Etherington John R. , Chan Phillip 
Published: December 2007

Abstract
The Canadian Securities Administrators (CSA) has proposed new guidelines governing the annual reporting of oil and gas reserves for Canadian companies. The guidelines require disclosure of both Proved and Probable reserves and associated value; inclusion of Possible reserves information is optional.
Reserve disclosures are key criteria to establish relative company stock value. It is thus instructive to compare the CSA regulations to existing U.S. Securities and Exchange Commission (SEC) rules and further to guidelines endorsed by the Society of Petroleum Engineers (SPE).
The CSA mandates disclosure of Proved volumes and associated future net revenues using two economic criteria: a forecast cost and prices scenario ("forecast case") and a constant cost and prices sensitivity scenario ("flat case"). The SEC Proved reserve is comparable to the "flat case" Proved reserve quantities in most instances. The CSA guidelines for Probable and Possible reserves conform closely to the current SPE published criteria. While recognizing probabilistic reserve assessments, the CSA has adopted the SPE guidance that reserves should not be aggregated beyond the "field" level using probabilistic summations.
The CSA may allow so-called "cross-border issuers", those Canadian companies also listed on USA stock exchanges, the option to solely follow SEC constraints. SEC regulations specifically prohibit disclosure of Probable and Possible reserves in 10K filings but many U.S. companies refer to additional resource potential in "forward looking statements" in their annual reports. Canadian "cross-border issuers" may not have similar latitude.
Unique to the Canadian regulations are rules regarding establishment of an internal company reserves committee and use of a qualified independent evaluator to audit assessment procedures and assets.
Will the new CSA rules improve, or impair, the ability of Canadian companies to compete for investment dollars? Further, the Sarbanes-Oxley Act on CEO/CFO certification requirements may have some unique implications for Canadian oil and gas companies.
OPEC Oil Production Strategy and Its Implication on Global Oil Market Stability
Authors: Iledare Omowumi O. 
Published: December 2007

Abstract
This paper applies statistical analysis to data describing the trends in OPEC oil production ceiling allocations from 1982-2001 The empirical analysis presupposes that a corporate decision framework guides OPEC production ceiling allocations subject to individual member characteristics and objectives. On average, and with a highly significant confidence interval, the empirical results indicate that the responsiveness of production quota to capacity, crude oil prices, reserves and other determinants are relatively small but inelastic. The empirical results also show the contemporaneous nature of each of OPEC's allocation criteria. This suggests that if OPEC really wants to accomplish a stable oil market, then each member nation must accept some joint responsibility and bear some equitable production reduction based on these criteria as and when necessary. Such an agreeable mechanism governing production ceiling allocations on the basis of concrete factors/criteria can significantly reduce the apparent lack of production discipline among members that has hitherto plagued OPEC1.
Rotating Jetting Nozzle Adds Value in the Cleanup of Horizontally Gravel Packed Well-Case Histories from Sandstone Environment
Authors: Onwusiri Henry , Onwuzurike Chiji , Abiodun Afolabi , Uchendu Chike 
Published: December 2007

AbstractA 360-degree rotating jetting tool has been successfully deployed to cleanup about 1000 ft of 6.25" horizontal open-hole gravel packed (OHGP) well. The exercise was carried out using Nitrified 10% HCl placed from the toe to the heel at Coil Tubing average rate of 20 ft/min. Three passes were made at total fluids rate of 1.0 bpm. During the fluid placement, no losses were encountered. After the treatment and initial production testing, a baseline memory production log (MPLT) was acquired across the horizontal drain section to evaluate the completion/cleanup efficiency. The MPLT results indicated a better drain hole cleanup as seen in the inflow profile of the completed drain section. Higher contribution was also noticeable in the cleaner sand members. From the result obtained, the 360-degree rotating jetting tool can be efficiently applied to cleanup drain holes especially in horizontal wells equipped with gravel packs.
Improved Rheology Model and Hydraulics Analysis for Tomorrow&s Wellbore Fluid Applications
Authors: Becker T. E. , Morgan R. G. , Chin W. C. , Griffith J. E. 
Published: December 2007

Abstract
Wellbore fluid applications continue to expand in complexity, necessitating more versatile rheological and hydraulics models amenable to efficient real-time data analysis. Substantial recent advancements have been made by numerous workers, applying the Herschel-Bulkley model to drilling fluids, highlighting the underlying importance of fluid rheology. However, this classic model alone does not fully describe the complexity of oilfield fluids. Therefore, this paper presents a Generalized Herschel-Bulkley (GHB) rheological model and hydraulic analytical method that accommodate a broader spectrum of wellbore fluids, whether of simple character, or having the complex properties of multiphase fluids such as foamed cement and high-density cements in addition to drilling fluids.
The GHB model offers several advantages: (1) it readily reduces to several popular conventional models (Newtonian, power-law, Bingham-plastic, Casson, and Herschel-Bulkley), (2) it can provide additional flexibility for characterizing apparent viscosity functions of current and future multiphase fluid systems such as lightweight cements, foams, and high-density slurries, and (3) it can provide an effective generalized framework for developing friction prediction equations. A highly accurate numerical simulator for the comprehensive family of fluids modeled by the GHB model was developed for predicting laminar flow-friction loss in pipes and annuli. The computational method, based on several exact integrals of motion, could be made as accurate as desired by decreasing mesh size. While the simulator itself is not ideal for real-time application, the results of comprehensive calculations using it were incorporated into field-usable software by developing "generalized explicit functions" that encapsulated all the physics correctly. These practical functions are in turn used for accurately and rapidly predicting friction loss of the GHB family of fluids in pipes and annuli (concentric and eccentric) for laminar, transitional, and turbulent flow.
The Role of X-Ray Computed Tomography in Core Analysis
Authors: Withjack E. M. , Devier C. , Michael G. 
Published: December 2007

Abstract
Over the past several decades, x-ray computed tomography (CT) has gained acceptance as a routine core analysis tool. Its use for in-situ saturation determination, for example, has made it the method of choice for steady state relative permeability testing. The main objective of this paper is to provide a repository of information on CT scanning for core analysis, and to group the many earlier studies into reservoir engineering categories for convenient reference by others in the future. The review is prefaced with the introduction of a conceptual model (Cloud Model) for representing the influences of major factors on reservoir NPV, and a discussion of the value of CT for core analysis. The literature review is followed by an update of emerging CT technology (microscanning), and presentation of a new method for 3-phase saturation determination using combined CT and NMR.
Matrix Acidizing Case Studies for the Point Arguello Field
Authors: Patton Bartley J. , Pitts Farrell , Goeres Tom , Hertfelder Gary 
Published: December 2007

Abstract
Several techniques and acid systems have been used to increase the productivity of the Monterey Formation, Offshore California. Reservoir production data will be used to evaluate the effectiveness of different acidizing techniques and systems used to treat the Point Arguello field. Basic acidizing physics will be covered to help explain the decision making process used to develop acid systems for the Point Arguello field. Acid systems will be tied back to their delivery method; coiled tubing, bull heading, foam diversion and perf washing to determine overall effectiveness of the matrix treatment.
Prediction of Flow Units and Permeability Using Artificial Neural Networks
Authors: Aminian K. , Ameri S. , Oyerokun A. , Thomas B. 
Published: December 2007

Abstract
An accurate description of the reservoir is necessary for predicting the reservoir performance. The flow unit model is most practical approach for reservoir simulation purposes. The flow units are defined according to geological and petrophysical properties that influence the flow of fluids in the reservoir. Identification of flow units requires permeability data. Predicting permeability distribution is a difficult problem in heterogeneous reservoirs due to insufficient permeability measurements. The geophysical well logs are the most abundant source of data in a reservoir. Therefore, a well log-based methodology for predicting permeability can enhance prediction of the flow unit distribution.
In this study, in a complex reservoir was successfully characterized using flow unit modeling. Statistical techniques were employed to identify flow units based on limited data obtained from core analysis supplemented by mini-permeameter measurements and geological interpretations. Permeability was then predicted from geophysical well log and preliminary flow units using artificial neural network (ANN). An innovative approach for training and testing of the ANN was developed which provided consistent and reliable predictions. The neural network predictions were then verified for the wells with core data. Well log data, available on substantial number of wells in the reservoir, were then utilized to predict the distribution of flow units, permeability, and porosity in the reservoir. This approach led to development of a reliable reservoir model. The accuracy of model was verified by successful simulation of the production performance. The methodology presented in this paper can serve as a new guideline for the characterization of reservoirs with limited core data.
Development of Heather Field Satellites, Northern North Sea, UKCS
Authors: Scott G. G. , Morel E. H. , Salter T. M. 
Published: December 2007

Abstract
As the Heather oilfield celebrates 25 years production, and comes to the end of its own economic life, development of the West Heather and North Terrace satellites will revitalise production from the area, and prolong the use of Heather platform for another ten years.
The West Heather and North Terrace oil accumulations were discovered and appraised in the late 1970s, at a time when the then Heather partners were endeavouring to find additional oil to supplement the disappointing production from the Heather field. The results of this drilling were not sufficiently promising to warrant further investment, and after 1987 no further drilling by the original field owners was undertaken.
A change of Operatorship in 1997, and acquisition of new 3-D seismic data led to further exploration and appraisal drilling in the West Heather area, and significant oil volumes in better quality reservoir has been discovered. The new accumulation is being developed as a subsea satellite, tied back to the Heather platform via a 7 km flowline system. It is planned to bring on the neighbouring North Terrace oil accumulation via this subsea system as part of a phased development.
This paper describes the West Heather development and the main factors that have led to bringing it to the point of sanction. These have been the attraction of Upper Jurassic exploration plays, the recognition of upside Brent reservoir potential in the area, investment by new Partners with an innovative business model for managing technical and financial risk, and the incentive of deferring Heather decommissioning.
Description of a Highly complex Reservoir Using Single Sensor Seismic Acquisition
Authors: McHugo S. , Cooke A. , Pickering S. 
Published: December 2007

Abstract
Sandstone injectite reservoirs have been found in recent years to be a significant source of reserves in the North Sea. However, the fields in which these reservoirs exist were often found relatively late in the exploration history of the basin and all too often by serendipity in the search for deeper reservoir objectives. The reason for this lies in the difficulty in seismically imaging this type of reservoir. In this paper we describe how seismic data from point-receiver seismic acquisition and the resulting pre-stack inversion of the data, were used in an attempt to predict the lithology, and visualize the morphology of a complex sandstone injectite reservoir in a North Sea oil field.
Transient Pressure Behavior of Dual Lateral Wells
Authors: Fahem Abdelhafid , Tiab Djebbar , Jokhio Sarfraz , Owayed Jalal 
Published: December 2007

Abstract
This paper presents an analysis method of the transient pressure behavior of dual lateral wells. Conventionally lateral wells have been analyzed using horizontal well analysis techniques. As we will show in this paper, that if the phase angle between the two lateral sections differ from p, they can not be treated as horizontal well and such practices any result erroneous reservoir properties. An infinite conductivity solution for dual lateral wells was developed by coupling both; the infinite conductivity horizontal well model and the superposition concepts.
From the sensitivity analysis study, it was found that infinite conductivity solution for dual lateral wells is affected by the horizontal anisotropy, phasing of the lateral sections, dimensionless horizontal separation, mechanical skin, wellbore storage. It is less affected by the dimensionless vertical separation and the contrast between the dimensionless lateral lengths. Transient pressure behavior of dual lateral wells appears to be more pronounced in the cases: (a) for a phase angle decreasing, (b) for a horizontal separation decreasing, and (c) for a horizontal anisotropy increasing. The effect of the phase angle decreases while increasing the dimensionless lateral lengths and horizontal separation. The effect of the horizontal anisotropy on the pressure behavior is more pronounced for high phase angles. The wellbore storage dominated flow period tends to be more affected for small dimensionless lateral lengths, LD. The effect of unequal lateral lengths and vertical separation are pronounced only at early times. The intermediate time pseudoradial flow period displayed by dual lateral wells is more distinguishable from the wellbore responses in the cases of a large phase angle and a high value of the horizontal separation. It is worthwhile to note that the responses of dual lateral wells having a phase angle, β= π, may be viewed as an equivalent single horizontal well.
Also Tiab's Direct Synthesis (TDS) technique methodolgy for dual lateral wells has been developed, which adds to the analysis of such wells. Few examples are solved in a step-by-step manner, which demonstrate the use of the method developed.
Advanced Web Technologies Give Real-Time Capabilities To Enhance Production Operations and Reservoir Management
Authors: Richardson S. , Keron H. , Jatmiko W. , Booker J. , Osugo L. , Donachie J. 
Published: December 2007

Abstract
The traditional industry methods and processes used for managing production operations and optimising well performance highlight a significant gap in integrating daily production operations with reservoir management. The consequence can be a reactive production management process that results in deferred production or suboptimal asset performance. This case study illustrates how a real-time well surveillance service was successfully implemented in a mature North Sea oil field, resulting in a significant production performance improvement and increased flexibility and visibility in managing production from the asset.
Automated Reservoir Surveillance through Data Mining Software
Authors: de Jonge Gert , Stundner Michael , Zangl Georg 
Published: December 2007

Abstract
High frequency reservoir surveillance data become available in an increasing number of oil and gas fields.
Real-time data from both reservoir and surface facilities open the possibility to control and consequently optimize field production in real-time.
This real-time control would be a step forward to the industry's next goal - The Smart Field.
An integrated software and data approach is presented based on Data Mining methods&lt;sup&gt;1&lt;/sup&gt;. In this paper, the "Automation Task" concept is discussed which allows automation of data processing, event detection and user notification. An Expert System interface enables the surveillance engineer to program the software in order to run on a 24/7 basis.
Time savings in routine reservoir surveillance and accelerated production through faster and better reservoir management decision were identified as premium goals.
Technology Transfer into the Offshore Oil and Gas Industry
Authors: Tanner R. K. , Boyce G. , Quarini J. , Head P. , Dick J. 
Published: December 2007

Abstract
Technology transfer from other industries can offer major benefits to the offshore oil and gas industry but requires encouragement. The technology developers are often unaware of potential applications offshore, and oil and gas operators and contractors need to be convinced of the benefits. ITF's Pioneer Programme is a good mechanism for stimulating technology transfer as it offers feasibility study funding for higher risk but exciting technologies. Four examples of Pioneer projects are presented that describe technology transfer from the water, food, automobile and medical industries.
Optimising Well Service Resource - A Systematic Approach to Performance Improvement
Authors: Durham Craig , Fraser Ian , Morris Colin 
Published: December 2007

AbstractWell service activity in Shell's Northern Business Unit is outsourced to an integrated services contractor with targets set for HSE, quality, and cost management. Various key performance indicators are measured to provide the necessary focus for control and improvement. Historically this focus has been on operational time improvements and associated rig day-rate savings. However, approximately 25% of annual well services expenditure represents equipment rental charges and hence any efficiency improvement can have a major impact on budget performance. In 2001 a system was introduced to track and co-ordinate the movement of all rental equipment deployed offshore. By closely monitoring the status of all items from loadout to return, baseline efficiencies were established. Using Supply Chain Management techniques such as Just-in-Time shipping, opportunity scheduling and influencing sub-contractor pricing has lead to utilisation efficiency improving from 48% to 62% in 2002, equivalent to over £0.5 million of eliminated costs. As fields mature and well interventions represent a greater portion of operating expenditure, this type of saving could ultimately make the difference between extended field life and final abandonment.