bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Interactive Drilling Dynamics Simulator for Drilling Optimization and Training
Authors: Dubinsky V.S. , Baecker D.R. 
Published: December 2007

Abstract
The dynamic behavior of the drill bit is a critical factor in drilling efficiency. It affects ROP, hole conditions and the frequency of bit trips. Improved understanding of this behavior can result is significant improvements in all of these areas.
For this reason an interactive PC-based simulator has been developed. This system simulates the dynamic behavior of the drill bit for various drilling conditions. These conditions are defined by numerous downhole and surface factors, such as hook load, RPM, mud properties and flow rate, BHA configuration, drill bit design, borehole parameters, and formation properties. This system allows for accurate simulation of the major drilling dynamic dysfunctions, such as bit bounce, lateral vibrations, BHA / bit whirl, torque shocks, stick-slip and torsional oscillation.
The system was developed using field test results and both theoretical and practical knowledge about dynamic behavior of the drillstring, BHA and drill bit under certain drilling conditions. The so-called "System Identification" approach has been used as a basic tool for creating the simulator's internal model. The downhole dynamic and static measurements required for developing such a model were recorded at a high sampling rate during the field test of a prototype of an MWD downhole dynamics tool.
The simulator has certain self-learning capabilities and its "smartness" depends upon the amount of data used for developing and training the model. The simulator could be used as a key element in a closed loop drilling system which would allow the driller to be more reactive to any undesirable change in downhole dynamic conditions. By using the simulator "on-line", one could play different scenarios (i.e., drilling ahead based on the existing or anticipated drilling conditions). This could improve the selection of drilling parameters from the surface prior to event occurrence. Therefore, ROP could be optimized while reducing the severity of downhole dynamic dysfunctions. The simulator could also be efficiently used as a training tool for MWD operators and drilling personnel.
P. 639
Non-Darcy Flow Experiments in Anisotropic Porous Media
Authors: Cooper J. , Wang X. , Mohanty K.K. 
Published: December 2007

Abstract
The velocity-pressure drop relationship in the near-wellbore region of high capacity gas and condensate reservoirs often deviates from Darcy's law. Furthermore, many naturally occurring porous media are anisotropic and often layered. This study is directed at combining these facts in developing a mechanistic understanding of non-Darcy gas flow in anisotropic porous media. Non-Darcy flow coefficients, permeabilities, and electrical tortuosities are measured in cores with layers both in the parallel and perpendicular directions to flow and in non-layered, anisotropic cores. The presence of a connate water saturation decreases permeability in all cores but increases the non-Darcy coefficient significantly only in the perpendicular core. Both a macroscopic and a pore-scale network (microscopic) model of anisotropy are proposed. The product of permeability and non-Darcy coefficient is shown to be less anisotropic than either the permeability or the nonDarcy coefficient tensors in both experiments and simulations. In the microscopic model, the non-Darcy term has been found to be tensorial and proportional to the square of the superficial velocity at the macroscopic scale. As the pore-scale anisotropic parameter increases, non-Darcy coefficient and tortuosity increases, but permeability decreases. The models developed show order of magnitude agreement with experimental data.
P. 609
Discriminating Fracture Patterns in Fractured Reservoirs by Pressure Transient Tests
Authors: Wei Lingli , Hadwin Jerry , Chaput Eric , Rawnsley Keith , Swaby Peter 
Published: December 2007

Abstract
A new approach is described to characterise fractured reservoirs using a software code which can simulate transient well tests in a realistic 3D fracture/matrix model. By a process of iteration the geological and flow data can be reconciled to produce plausible models which could help to constrain reservoir simulation. The numerical results indicate that the simulated pressure derivatives generally show different characteristics with different fracture pattern configurations. The results also indicate that theoretical dual porosity behaviour is absent when a more realistic transient matrix to fracture flow solution is used. This approach has important implications in the use of well tests to determine parameters for input to a multiphase flow simulator, where the well positioning in relation to highly conductive fractures is critical. The advantage of the described approach, compared to conventional analytical analysis. is that the geological data are calibrated and preserved. Parameters can then be more accurately represented in a dynamic reservoir model.
P. 609
Estimation of Permeability Anisotropy and Stress Anisotropy From Interference Testing
Authors: Chen Her-Yuan , Hidayati Dewi Triarti , Teufel Lawrence W. 
Published: December 2007

Abstract
The purpose of this study is to relate current multi-well testing technology, which is limited to the estimation of fluid flow/storage properties, to the flow-induced stress changes of an anisotropic reservoir. Results suggest that the evolution of reservoir stress anisotropy will be influenced by the trend of permeability/flow anisotropy. A simple and reliable method is further developed to identify the trend of permeability/stress-change anisotropy using interference testing data. Examples based on published field data are given to show the main concept.
An Integrated Study of Reservoir Compartmentalization at Ewing Bank 873, Offshore Gulf of Mexico
Authors: Edman J.D. , Burk M.K. 
Published: December 2007

Abstract
Ewing Bank 873 is an offshore Gulf of Mexico field discovered in 1991 in 775 ft of water. The discovery well was drilled on a seismic amplitude anomaly on the flank of a salt withdrawal mini-basin. Field development began in 1994, and in mid 1998 daily production from the Bulminella 1 reservoir averaged 40,000 BOPD and 32 × 106 ft3/D of gas. The Bul 1 reservoir in this combination structural-stratigraphic trap consists of six stacked and overlapping Pliocene turbidite sand lobes. In turn, integration of seismic, well log, geochemical and pressure data indicates these six turbidite lobes comprise three compartments. All of the various data types give constraints on different aspects of compartmentalization, but at the stratigraphically complex Ewing Bank 873 field, geochemical analyses provided key information unavailable through any other means. These geochemical analyses were performed as individual wells in the field went on production and immediately provided information regarding fluid communication and reservoir connectivity that was missing from earlier interpretations based solely on seismic and log data. Early recognition of three reservoir compartments using geochemical data also helped constrain preliminary stratigraphic interpretations and provided initial input for flow units and reservoir simulation models. The geochemical information further provided advance notice of economically significant oil quality variations in the three compartments. These fluid variabilities were later substantiated by PVT analyses and include notable differences in oil gravity, weight percent sulfur, viscosity and solution gas. Integrating all available data shows there are three compartments at EW 873 and each compartment comprises different turbidite sand lobes and exhibits its own characteristic pressure regime and fluid properties. The early indications of both compartmentalization and variation in fluid properties by the geochemical analyses contributed significantly to improved field recovery and economics by allowing fewer and better placed wells to be drilled.
P. 653
Development Drilling of the Tawila Field, Yemen, Based on Three-Dimensional Reservoir Modeling and Simulation
Authors: Beattie C. I. , Mills B. R. , Mayo V. A. 
Published: December 2007

Abstract
Canadian Petroleum Ltd. and partners in the Yemen Masila Block have successfully used detailed three-dimensional reservoir modeling and reservoir simulation to optimize the development of the larger oilfields in the Masila area. The models were used to predict reservoir performance and plan additional development drilling which subsequently demonstrated that the models accurately predicted drilling results.
The main producing horizon in the Masila area is the Cretaceous Upper Qishn formation, a clastic-dominated transgressive depositional sequence with fluvial sediments at the base, tidal dominated estuarine sediments in the middle, and marine shoals at the top. This variable array of facies presents modeling challenges but the resulting heterogeneous models provide a realistic representation of actual reservoir characteristics. This paper describes the approach used to stochastically distribute both facies bodies and petrophysical parameters, and to upscale the model for reservoir simulation, while preserving the complex reservoir description.
The Tawila field was the first Masila field to have wells drilled on the basis of the modeling effort, with very encouraging results. For these new well locations, the model successfully predicted both reservoir development and oil-water contact movements resulting from production from existing wells. This paper presents key conclusions and predictions from the modeling and reservoir simulation, and compares them to the results from subsequent drilling. As a result of the successful development drilling, these models are now an integral part of reservoir management and development planning for all Masila fields.
A Quick Method of Identifying and History Matching A Gravity Dominated Reservoir with Localized Super-Permeabilities
Authors: Al-Dhamen A.A. , Pham T.R. , Al-Khatib M.A. 
Published: December 2007

Abstract:
This paper discusses a quick method of identifying and history matching gravity dominated reservoir area with localized Super-permeabilities (Super-K). The area of interest is part of a large elongated carbonate antic line Middle-East oil reservoir. Wells in the area of reservoir of interest are prolific producers with a high degree of Super-K occurrences. Layers with Super-K usually contribute more than half of the flow from few feet interval. Figure-l is a flowmeter which indicates a flow contribution of more than 50% from a dolomitic Super-K layer.
The lack of geological data and wide well spacing offers little help in identifying the areal extents of these Super- K layers. Therefore, correctly history matching the reservoir may be difficult due to the non-uniqueness nature of reservoir modeling that the match may be achieved with a wide variety of reservoir descriptions and permeability arrays. However, if the reservoir fluid mechanic could be identified, then the history match may be facilitated. The paper will discuss:a quick procedure of identifying whether the Super-K are localized or are a really widespread by using the simulation model in conjunction with flowmeters and production data.A quick procedure for pressure and saturation match.
These procedures are practical and help identify the reservoir fluid mechanics at the beginning phase of history matching.
In the case of the reservoir of interest, the model helps prove that most of the reservoir is gravity dominated even with a high degree of Super-K occurrences. The paper will outline how the well test permeability thickness data and the flowmeters are employed in constructing the model. It will discuss a quick, systematic procedure of pressure and saturation match. The overall match was achieved in a short time of a model with approximately 100 wells. The discussion will highlight the fact the knowledge of reservoir fluid mechanic and its behaviour is important before any attempt of history match is made.
P. 753
Oil Recovery from Bottom Beds of Kuwait Oil Lakes by Retorting
Authors: Elgibaly Ahmed A.M. 
Published: December 2007

Abstract
During the Gulf War in 1991, over six hundred oil wells were blazed in Kuwait. Oil gushed from these wells and resulted in the formation of more than 300 oil lakes covering an area of about 49 km2. According to recent studies the amount of the heavily contaminated bottom beds of these oil lakes has been estimated as 40 to 50 million tons. Oil extraction from these beds is necessary to reduce their environmental nuisance. Various methods were proposed for this purpose, but to date none has been accepted for application on large scale. This study investigates the potential of retorting as one of the most promising methods.
Experiments were performed on samples from different oil-lake sands heated to 500-600 C. The quantity and quality of oil produced and the reaction rate within the porous material have been studied. The effects of heating rate, operating pressure, water content, and specific surface area of the bed matrix were investigated. Four successive pyrolysis stages were observed during the retorting process: water volatilization, oil volatilization, vis breaking, and coking. A mathematical model was developed to describe the pyrolysis kinetics of the oil sand samples. The model was based on material balance, which involved kinetic expressions for reaction rates of the various mechanisms. Based on the experimental data, the developed model predictions agreed reasonably well as compared with the available models. The fluid holdup and coke, deposited within the porous medium, were also predicted during the retorting process. It was found that volatilization/distillation and vis breaking were the most dominant mechanisms that contributed considerably well in oil recovery. A simple model was also proposed to describe the kinetics of crude oil vis breaking within the oil- contaminated sand sample during retorting process. The model fitted well the experimental data.
P. 809
The Effect of Wettability on Three-Phase Relative Permeability
Authors: DiCarlo David A. , Sahni Akshay , Blunt Martin J. 
Published: December 2007

Abstract
We study three-phase flow in water-wet, oil-wet, and fractionally-wet sandpacks. We use CT scanning to measure directly the oil and water relative permeabilites for three-phase gravity drainage. In an analogue experiment, we measure pressure gradients in the gas phase to determine the gas relative permeability. Thus we find all three relative permeabilities as a function of saturation. We find that the gas relative permeability is approximately twice as high in a water-wet system than in an oil-wet system at the same gas saturation. The water relative permeability in the water-wet pack and the oil relative permeability in the oil-wet pack are similar. In the water-wet medium the oil relative permeability scales as kr0 S04 for So &gt;Sor~ where Sor is the waterflood residual oil saturation. With octane as the oil phase, kro So2 for So &lt; Sor~ while with decane as the oil phase, kro falls sharply for So &lt; Sor. The water relative permeability in the oil-wet medium resembles the oil relative permeability in the water-wet medium for a non-spreading oil such as decane. These observations can be explained in terms of wetting, spreading, and the pore scale configurations of fluid.
P. 869
Wettability Change Related to the Adsorption of Organic Acids on Calcite: Experimental and Ab Initio Computational Studies
Authors: Legens C. , Toulhoat H. , Cuiec L. , Villieras F. , Palermo T. 
Published: December 2007

Abstract
We have investigated the interactions between organic acids and a calcite powder by adsorption from an organic phase (benzoic acid and lauric acid in toluene) and from an aqueous phase (benzoic acid and lauric sodium salt.
In addition to the experimental study, ab initio quantum chemistry calculations were performed for cluster models, simulating the interactions of molecules with calcite surface sites.
At the toluene/calcite interface, acids chemisorb on surface calcium ions, replacing surface hydroxyls resulting from the previous surface hydration by water. This surface saponification phenomenon was predicted by ab initio calculations and confirmed by spectroscopic techniques. The adsorbed acids conferred a hydrophobic character to calcite, with the higher contact angles in water for the longest alkyl chains in the organic acid.
At the water/calcite interface, organic acids do not displace water.
As electrostatic forces determine the stability of thin water films between calcite and crude oils at reservoir conditions, from our calculations, we deduce that when crude oil fills the biggest pores of the reservoir rock, oil/calcite interfaces appear where the adsorption of organic acids can change the wettability to oil-wet. By contrast, the mineral should remain water-wet at places where the capillary pressure has not been able to thin the aqueous phase beyond a critical value at which the film would collapse. This can occur even if the aqueous phase contains dissolved organic acids transferred from crude oil. Mixed wettability patterns might therefore be related to the spatial distribution of pore sizes.
Our results support the latter conclusion in the specific case of organic acids with calcite.
P. 889
Integrated Study of a Faulted and Fractured Reservoir
Authors: Lyon T. A. , Fuller J. , Granier B. , Hozayen M. , Al Riyami A. , Khalaf A. , Thiebot B. 
Published: December 2007

ABSTRACT
This paper presents a case study drawn from an integrated reservoir study on a faulted and fractured carbonate reservoir offshore Abu Dhabi. Particular emphasis is put on demonstrating how the results of 3D seismic interpretation impacted the structural understanding. The paper also explains how the seismic interpretation, well-bore observations and production data were integrated to provide an improved reservoir model.
Development of a Bottom-hole Energy Source for Active-SWD
Authors: Yokota Toshiyuki , Mizohata Shigeharu , Kozawa Takeshi , Shimada Nobusuke , Tsuru Tetsuro , Taniguchi Ryosuke 
Published: December 2007

Abstract
"Active-SWD (Seismic While Drilling)" is a newly proposed data acquisition method which utilizes an artificial source in addition to the seismic wave generated by the rotating drill-bit. With this improvement, Active-SWD can acquire higher quality data when drilling soft formations with a PDC bit than conventional SWD data acquisition which uses only the drill-bit as a seismic source.
Based on the Active-SWD concept, this paper describes our first and second generation bottom-hole sources which employ an electric magnetostrictive hammer (EMH) developed by Japan National Oil Corporation (JNOC) and Mitsubishi electric corporation.
The objective of the first generation bottom-hole source was to increase its output energy by implementing the resonance of a spring-weight system. The principal shortcoming of this source was that, its source-signature frequency spectrum was highly monochromatic and required sophisticated software to recognize the first break times. A pattern recognition technique was designed for first break picking which gave good results for synthetic data situations. However, further development was needed for application to field data circumstances.
The second generation, bottom-hole source has a broader source frequency spectrum and an increase in total energy output. This increase results from combining the emitted signals from the drill-bit and the artificial source. Conventional SWD processing techniques can be used for processing data generated by this new source.
A Guideline for Research in Affluent Developing Countries
Authors: Sevgur S. B. , Islam M. R. 
Published: December 2007

Abstract
Research is considered to be something elite and is often related to predominantly graduate schools. Recently, there is a push in the United States toward putting the burden of research on individual faculty members, arguing that university should exist with the sole purpose of teaching and any research should be done at the professor's own time. It is even suggested that any extra incentive of doing research during the academic year be eliminated and professor focus on nothing but teaching during the academic year (Bess, J. Higher Education: 69(1), 1998). This short-sighted view can be attractive for many who are interested in making a university professor's life more miserable than it already is, but in-depth look will reveal that this policy is guaranteed to make a university less than third-class in ranking. If one understands the meaning of research and higher education, one can clearly see that research is not luxury, it is rather a necessity for even the most modest of undergraduate institutions. Particularly in engineering education, the need of research is often misunderstood while the need of fancy equipment is glorified. An engineering educator should instead focus on productivity, collaborative research and its inherent relationship with creative thinking and innovation. Most universities in developing affluent countries are indeed predominantly undergraduate institutions and can fall in the trap of non-research, based on the fallacy that research belongs to graduate institutions. Administrators, who often do not rationalize from the perspective of faculty members, have crucial role to play. It is a matter of deciding to make the university strong both in research and teaching or let the university slide into a pitfall of a merely mediocre government institution. Both are possibilities, and the probability of one of them being the option is not trivial.
This paper details the need of research and provides one with a guideline suitable for a seemingly prosperous yet developing country, such as the United Arab Emirates. In this context the recent developments in the western countries are discussed and compared vis a vis efforts in the developing countries.
High Rate Gas Well Design: Issues and Solutions - Goodwyn Gas Condensate, NWS, Australia
Authors: Teng D. , Nettleship G. , Hicking S. , Hindmarsh K. 
Published: December 2007

Abstract
Goodwyn platform wells produce up to 220MMscf/d of raw gas yielding up to 20,000 bpd of stabilised condensate. The high productivity of the wells has reduced the number of development wells needed to satisfy platform capacity with significant cost savings. This high well capacity was achieved through the early recognition of the reservoir inflow potential in the completion design and addressing the critical issues of erosional velocity, lifecycle sand production, sub-surface and surface equipment integrity in a high flow, high stress environment. To maximise the well potential the erosional limit was extended based upon actual experience. The risk of sand production was managed through a philosophy covering sand prediction and its control during operation. Well hardware was tightly specified and qualified within the defined operating envelope. These solutions were applied to both the initial conventional wells and for the later extended reach horizontal wells. Results from Goodwyn wells demonstrate that actual performance match the targeted ideal and that the issues have been manageed.
This paper presents a systems approach to well design where technical and external issues are taken into consideration. It is a retrospective look at the issues addressed for Goodwyn well design, with updates to include current techniques.
P. 281