bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Nonintrusive Ultrasonic Intelligent Sensors for Corrosion and Erosion Monitoring
Authors: Instanes G. , Lakshminarayan B. , Toppe M. , Nagy P. B. 
Published: December 2007

Abstract
Corrosion and erosion detection and monitoring are essential prognostic means of preserving material integrity and reducing the life-cycle cost of industrial infrastructure, ships, aircraft, ground vehicles, pipelines, oil installations, etc. Spatially dynamic pipeline monitoring systems have to necessarily face extremely hostile conditions of operation including surface roughness, fluid loading issues, temperature variations, and a host of other factors that make development of a robust wall thickness assessment tool a challenging task. This paper describes the working of ClampOn's Corrosion-Erosion Monitor (CEM) - an online, real-time path based thickness assessment tool that deploys a set of transducers over a given pipe area, and utilizes a combination of resonance and dispersion based principles to assess wall thickness loss. This instrument was developed keeping the needs of the oil, gas and petrochemical industry in mind, both upstream and downstream, but because it essentially monitors reductions in wall loss, it can find applications in many other industries. Experimental and analytical work in- house provide very promising results pertaining to the functionality of the CEM system, and some of these results have been discussed in this paper. The CEM is a permanent installation on the outer pipe wall to produce real-time pipe wall thickness information, not as a spot measurement, but as a unique average path wall thickness. This state-of-the-art technology is extremely versatile, and can serve as a particle and sand monitor as well.
Black Oil Delumping
Authors: Ghorayeb K. , Holmes J. 
Published: December 2007

Abstract
Black oil reservoir simulation still has wide application in the petroleum industry, because it is computationally far less demanding than compositional simulation. But a principal limitation of black oil reservoir simulation is that it does not provide detailed compositional information necessary for surface process modeling.
Black oil delumping overcomes this limitation by converting a black oil wellstream into a compositional wellstream, enabling the composition and component molar rates of a production well in a black oil reservoir simulation to be reconstituted.
We present a comprehensive black oil delumping method based primarily on the compositional information generated in the depletion process that is used initially to provide data for the black oil simulation in a typical workflow. Examples presented in this paper show the accuracy of this method in different depletion processes: natural depletion, water injection, and gas injection. The paper also presents a technique for accurately applying the black oil delumping method to wells encountering crossflow.
Successful Drilling of Basalt in a West of Shetland Deepwater Discovery
Authors: Close F. , Conroy D. , Greig A. , Morin A. , Flint G. , Seale R. 
Published: December 2007

Abstract
Drilling in deepwater is very expensive, with rig rates in the hundreds of thousands of dollars per day and high spread costs. When coupled with drilling exploration wells in areas with unknown and "difficult" formations, the risks escalate exponentially.
An example of this is the recent drilling on the ChevronTexaco Upstream Europe discovery well in the West of Shetland province of the UKCS. On this particular wildcat exploration well the potential of encountering a volcanic/basalt sequence had been highlighted at the planning phase. Only limited offset data was available, the closest offset well being some 15 miles (24km) from the proposed well location. A general overview of the well and its objectives is given. The paper focuses on the original drilling philosophy and why it changed during the drilling of the well and the reasons which ultimately led to the use of a turbine and diamond impregnated bit. Factors in the successful drilling of the above well including lessons learnt will be explained. The trade-offs with the various BHA configurations and the impact on data acquisition is also explained.
The paper also consolidates the offset information and some of the research and development of basalt drilling at high speeds using turbines. The paper therefore outlines the equipment run in the extensive volcanic/basalt section and the establishing of new benchmarks for the drilling of this extremely challenging formation in a deepwater and high cost environment.
Experimental Investigation of Wellbore Phase Redistribution Effects on Pressure-Transient Data
Authors: Ali A. M. , Falcone G. , Hewitt G. F. , Bozorgzadeh M. , Gringarten A. C. 
Published: December 2007

Abstract
Pressure transient analysis is a well established reservoir evaluation method. By analysing pressure and pressure derivative curves from build-up and drawdown tests, it is possible to identify reservoir characteristic parameters and heterogeneities. However, much of the pressure data recorded during a well test may be dominated by wellbore effects that can mask reservoir characteristics and lead to erroneous well test interpretations. This is particularly true when the well production rate is controlled at surface and more than one phase is flowing. These effects, which are transient in nature, include phase change, flow reversal, and re-entry of the denser phase into the producing zone.
This paper presents the results of experiments carried out at Imperial College to investigate the effects of phase redistribution and phase re-injection on pressure build-up data. Single-phase and two-phase flow tests were conducted with air and water. An experimental rig was designed to emulate a reservoir connected, via a resistance, to the base of a flowing well. The "reservoir" is recreated by a pressurised vessel, while the "well" is simulated by a vertical pipe. The "well" was flowed at controlled rates to mimic those encountered in gas condensate reservoirs. After steady-state conditions had been attained, the "well" was shut-in at the top of the rig (i.e. at surface) and the associated transient phenomena monitored via distributed measurements of pressure, temperature, liquid hold-up and wall shear stress. Pressure build-up data were interpreted using established well test analysis techniques.
The experiments provide a qualitative and quantitative understanding of the effects of gas rates, liquid rates and rising gas bubbles on wellbore phase redistribution and re-injection. The results yield an insight into the corresponding impact on well test transient pressure behaviour.
Injection Strategy and Best Practices for Managing Produced Water
Authors: Abou-Sayed A. , Zaki K. 
Published: December 2007

Proposal
Hydrocarbon production is associated with the generation of waste and by-products. The safe disposal of produced water, a common by-product, is of prime concern in oilfield operations. Long thought of as an economical and environmental liability, Produced Water Re-Injection (PWRI) provides an unrivaled option that is beneficial on both fronts. The paper identifies the operation's associated opportunities and risks. Emphasis is placed on procedures and best practices compiled during a 10-year, joint industry project (JIP). The overall theme of the paper is injector performance.
PWRI is used in water flooding for the purpose of pressure maintenance and the possibility of Improved Oil Recovery (IOR). The design process must meet production requirements, assure conformance and sweep and achieve desired pressure maintenance. Additional considerations include meeting waste management requirements for disposal volumes and reducing waste. These constraints translate into injector performance metrics and sustained delivery of the injection rate/injectivity. The paper examines the options available for balancing CAPEX (treatment facility, pumping equipment, and well drilling and construction) and OPEX (filtration, chemical, and biological treatment, stimulation and voidage replacement) to ensure long term injectivity maintenance.
Addressed are selection criteria for well completion, injection and thermal treatment. Issues such as vertical vs. horizontal wells, matrix vs. fractured or cool vs. hot water injection are tackled. Investigated are the damage mechanism and their effect on extended injection. Identification of the damage cause is paramount in guiding the design of an effective stimulation treatment or intervention. The optimal injection design provides the equilibrium between how to mitigate (selection of appropriate water quality) and when to remediate (plan effective stimulation) damage. Several field examples are included to support the conclusion and recommended best practices discussed in the paper.
Monitoring is an essential task during injection. The primary product of which is large amounts of raw data. The paper investigates the use of non-deterministic models and data mining techniques in ascertaining the physical correlations and observations from the data. A field case from the North Sea illustrates this application.
Permeability Estimation From Stoneley Amplitude, Corrected for Borehole Geometry and Rugosity
Authors: Canady W. , Spooner P. , Vasquez R. 
Published: December 2007

ABSTRACT
Theoretical research and field studies conducted over the past 20 years have demonstrated that the acoustic Stoneley-wave is strongly influenced by formation permeability. However, due to the many nonpermeability-related petrophysical parameters that affect Stoneley properties, the development of a practical Stoneley-to-permeability relationship has met with only limited success to date. Existing commercial techniques commonly compute useful, and often accurate, qualitative estimates of Stoneley permeability but are unable to make accurate quantitative measurements of formation permeability because of the complex acoustic nature of the mixture of pore fluids, the acoustic effects of drilling-induced damage to the sensed volume, and to other non-Biot mechanisms yet to be understood.
Current Stoneley-based permeability products use Stoneley amplitude, frequency, attenuation and phase attributes, by means of a comprehensive acoustic model or by forward modeling techniques, to identify and quantify the nonpermeability effects. However, the sophistication required by these methods, in terms of computing resources and expertise, makes them generally unavailable as workaday tools for the petrophysicst.
This paper presents an alternative approach designed for routine use by an analyst or petrophysicst. A simple empirical model of Stoneley-derived permeability is calibrated against a measured standard. To a limited degreee, this method also accounts for borehole rugosity (washouts), variations in borehole size, and for permeability estimation.
New Operational Technique Improves HSE in Offshore Acidising Operations
Authors: Sinanan B. , Rae P. 
Published: December 2007

Abstract
The world consumption of hydrocarbons is projected to increase by some fifty percent in the next twenty years. Yet, many of the countries supplying the world's insatiable demand will, themselves, become net oil and gas importers in the very near future. It becomes ever more important, therefore, to maximize the productivity of each and every well. While many new wells benefit from improved drilling and completion practices, there are a significant number of mature wells that are still capable of producing at economic rates, if properly stimulated. One of the simplest and most cost effective methods to do this is by matrix acidising.
Acidising has established itself as an indispensable technique for enhancing production from hydrocarbon reservoirs worldwide. Over the years, research scientists and engineers have developed and improved many chemicals and additives to enhance the efficiency of these acid systems, as well as reduce the health, safety and environmental impact they have on operations. Despite huge improvements in the last decade, many issues and concerns still exist today. Handling, mixing, storage, pumping and disposal of acid and acid additives remain critical concerns in the industry.
In response to these concerns, new operational methods using specialized equipment, improved mixing techniques and new acid systems have been developed. This paper discusses the current practice, reviews its shortcomings and introduces these improved methods for enhancing HSE practices and optimizing operational efficiency in offshore operations.
Finally, actual implementation of the technique in various offshore scenarios is discussed, describing the HSE and logistical advantages of the process, as well as the resulting synergies.
NMR and Capture Spectroscopy Help Resolve Producibility and Fluid Distribution in the North Alwyn Triassic
Authors: Longis C. , Vignau S. , White J. 
Published: December 2007

ABSTRACT
Hydrocarbon is found in both Jurassic and Triassic sandstones in the Total Alwyn North field, but the Triassic reservoir has historically attracted little attention as the production effort focused on the prolific Jurassic sands that lie above. As the larger reservoir is coming off plateau production, increasing attention is being paid to the Triassic where significant reserves remain.
Productivity of the complex Triassic formation is far less predictable than the Jurassic, and new techniques are being developed to better understand the production behavior. Part of this process is gathering data on the rock and fluid using new measurement technologies. On two recent wells (N46 and N47) the Triassic logging programs included a CMR Combined Magnetic Resonance log and ECS Elemental Capture Spectroscopy measurement. These two measurements are quite complimentary, as the CMR looks only at the fluid and the ECS looks purely at the lithology. Such focused measurements help simplify the interpretation in this complex formation.
The CMR was run primarily for porosity and permeability, which can be difficult to measure in the Triassic using standard density/neutron logs. In addition, some MRF (Magnetic Resonance Fluid characterization) T2-Diffusion stations were acquired, which were very effective in separating out the reservoir hydrocarbon from oil filtrate, water and any other fluids that may be present.
In N46 this was particularly useful as the alternative of formation sampling with a formation tester was not always an option. This is because much of the Triassic is too tight to get any samples with a formation tester within a reasonable time. Now a combination of MDT and MRF can effectively appraise the fluid type and distribution within these long reservoir intervals.
The ECS was run to address the lateral variations of reservoir quality that is a particular feature of the Triassic depositional environment, and understanding the reservoir quality ideally before setting casing would be a major objective of any operator. This sensor directly measures the elemental concentrations of Iron, Calcium and Silicon (among others) that indicate the volume of clays, carbonates and clastics present. Measurements of clay type and volume, along with any carbonate cement are useful indicators of reservoir quality, and could assist in the design of any stimulation job that was planned. Comparison of core XRD data with the ECS on N46 shows a good match, allowing the confident use of ECS on future uncored wells.
The contribution of CMR-MRF and ECS to the understanding of the North Alwyn field is reviewed in this paper. The applications discussed here should also be helpful in other fields, both new and old, with the potential of extending the life of many assets currently in the post-plateau stage of production.
Reservoir Management in a Deepwater Subsea Field – The Schiehallion Experience
Authors: Govan A. , Primmer T. , Douglas C. , Moodie N. , Davies M. , Nieuwland F. 
Published: December 2007

Abstract
The Schiehallion field has experienced many reservoir management challenges since first production in 1998. Dynamic data such as RFT's, pressure transient analysis, interference testing, tracer analysis and 4D seismic need to be interpreted with great care - Schiehallion has examples where the data has been invaluable, and others where the data is ambiguous or misleading. It is essential to integrate several data types in order to obtain reliable conclusions. The paper describes some of the highlights and pitfalls experienced in Schiehallion.
A Methodology To Quantify the Impact of Uncertainties in the History Matching Process and in the Production Forecast
Authors: Maschio C. , Schiozer D. J. , Moura Filho M. A. B. 
Published: December 2007

Proposal
Traditional history matching provides a unique deterministic reservoir model. However, it is well known that history matching is a complex inverse problem that can have multiple solutions. Therefore, a unique model is not sufficient to guarantee reliable production forecasting. This work presents a quantitative analysis of the uncertainties of the reservoir attributes integrated to the history matching process. Instead of use a set of deterministic attributes and changes them to adjust to the observed data, as in conventional way, a probabilistic analysis is incorporated. In this methodology, probability density functions are discretized in given number of levels. Comparing models response (simulation data) with observed data, there is a reduction of the probabilities of the scenarios that do not present a good match; some models can be discarded during the process. The major difficulty in this process is to determine how to redistribute the occurrence probability of the attributes of the remaining models. In this paper, a criterion to make the rearrangement of the probabilities is established. The main objective of the paper is to present a consistent methodology to integrate history matching and the impact of uncertainties in the production forecasting.
Firstly, the methodology is validated with synthetic cases derived from Tenth Comparative Solution Project (SPE 10, Model 2). Then, the proposed methodology is applied to a real case from an offshore field. In the two applications, the conventional history matching process is also applied in order to compare the results and evaluate the reliability of a unique model prediction against a set of most probable models predictions.
The main contribution of this work is to increase the reliability of prediction through reservoir simulation models and to show the necessity of incorporating uncertainties in the history matching.
A Laboratory Study With Field Data of Downhole Gas Separators
Authors: McCoy J. N. , Podio A. L. , Lisigurski O. , Patterson J. , Rowlan L. 
Published: December 2007

Abstract
Downhole gas separators are often the most inefficient part of a sucker rod pump system. This paper presents laboratory data on the performance of five different gas separator designs. Only continuous flow was studied. Field data is presented on two of the designs. The field data indicates that success or failure of the gas separator is dependent upon the fluids and wellbore pressures as well as the mechanical design of the gas separator. Successful and unsuccessful examples of gas separator performance in the field are shown along with field fluid data properties.
Profiling the Wall-Cake Characteristic of the Wellbore for Optimal Comparison of Logging-While-Drilling and Wireline-Bulk-Density Measurements
Authors: Terry B. , Lindsay G. , Elliot R. , Jebutu S. 
Published: December 2007

Abstract
The comparison of Logging-While-Drilling (LWD) and Wireline (WL) measurements is an ongoing challenge in Formation evaluation quarters. The differences are more often due to the dynamic changes that occur along the borehole wall and near wellbore formation environment, altering the measurement environment during the acquisition of both measurements. In conditions where these alterations are minimal, the LWD and Wireline usually have excellent agreement, while with increasing severity of the wellbore alterations, significant differences can occur between the LWD and Wireline.
This paper presents a methodology to profile the dynamic wallcake alterations by utilizing the variations in resistivity of the wallcake and near wellbore environment from time lapse logging-while-drilling and Wireline measurements. Traditionally such dynamic wellbore alterations are quantified with downhole mechanical calipers and ultrasonic acoustic caliper measurements, both of which measure variations in the physical dimensions of the wellbore diameter as a direct indication of wallcake and nearwellbore alterations.
Field examples are presented from wells drilled in the Columbus basin, Trinidad and Tobago. The near wellbore alterations are observed to show a strong correlation to the time-lapse resistivity ratios. Logging-while-drilling and Wireline-bulk-density measurements showed good agreement in the sections with minimal near wellbore alterations where the hole maintained near gauge conditions, while significant differences were observed in sections where severe alterations of the near wellbore has occurred and the hole had become under-gauged or over gauged. We also discuss some of the causal factors of the dynamic near wellbore alterations such as wall cake sleek along shale swells, filter cake buildup in permeable formations and hole washouts, and the implications for accurate petrophysical evaluation and reservoir description. The limitations of utilizing the time lapse resistivity method in profiling the near wellbore characteristics are also highlighted.
A new Integrated LWD platform delivers improved Drilling Efficiency, Well Placement, and Formation Evaluation services
Authors: Weller G. , El-Halawani T. , Tribe I. , Webb K. , Stoller C. , Galvin S. , Scot G. 
Published: December 2007

Abstract
Logging-while-drilling (LWD) services are today often provided by several separate tools that, when used in combination, result in some measurements being made far from the bit. Time to make up and break out LWD tools, memory dumping, as well as multiple tool reliability issues can significantly add to the well construction costs.
An innovative new LWD tool has been developed to simultaneously provide drilling-related measurements and an industry standard suite of formation evaluation measurements, equivalent to the classic "triple-combo" service, but co-located and closer to the bit, using only a single short collar. This means that less rathole is needed for logging, and fewer collar connections have to be made, resulting in a more efficient drilling operation. In addition, the co-location of the sensors reduces uncertainties in the interpretation of measurements that rely on multiple sensors.
A key focus during the development of the tool has been improvement in service delivery. This has been achieved through increased operational efficiency, higher rate of penetration (ROP) capability, significantly improved reliability throughout the system, and greater ease of maintenance. The use of a pulsed neutron source instead of a chemical source also dramatically reduces the environmental and operational risks normally encountered with the use of traditional LWD tools.
Pulsed neutron measurements delivered by this service include formation capture cross section (sigma) and elemental analysis from neutron capture spectroscopy. These new measurements are used to compute mineralogy while drilling. Azimuthal measurements are also available, allowing the formation and borehole to be imaged using a variety of properties. The result is a robust and complete interpretation with significantly reduced uncertainty, as well as a large choice of steering methods for effective well placement.
In this paper we describe the development of this new LWD service and show field-test examples of improved formation evaluation, increased drilling efficiency, and more effective well placement that the tool has provided.