bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Transient Analysis in Gas Condensate Reservoirs Producing Under Three Phase Flow Conditions
Authors: Jokhio S. A. , Tiab D. , Baladi S. , Tunio A. H. 
Published: December 2007

Abstract
This paper shows how to establish correlation between effective permeability as a function of pressure using well test analysis techniques in three-phase gas-condensate systems. Rigorous mathematical treatment led to correlations to estimate pseudopressure for gas condensate fluids that also use surface production data. The main purpose of developing correlation from well test analysis techniques is to use it in well performance analysis in such systems. Thus pressure transient techniques are helping to establish the flow behavior of gas condensate systems in their later life. Reservoir properties can also be estimated, however, to estimate absolute permeability, knowledge of relative permeability is required.
Three-phase gas condensate systems include water producing gas condensate reservoirs. Such wells are often equipped with artificial lift to unload the produced water. To model such a three-phase flow, relative permeability curves are needed. Getting relative permeability curves becomes further demanding when reservoir conditions of pressure and temperature coincide with near critical conditions. Analysis of pressure data in such multi-phase systems requires the exact knowledge of the individual phase surface rate, which itself is a demanding task and requires the separator and stock tank properties of gas and liquid phase. In this paper we have eliminated the knowledge of individual phase surface rate. Instead, we have developed models that use the surface measured rate of these phases.
Finally, an example is solved to show the use of the new technique developed.
3D Generalised Inversion (AVO, AI) as Direct Input to the Reservoir Model. Deepwater Exploration Offshore North West Borneo, Malaysia – A Case Study.
Authors: Reymond S. B. , Johnson T. E. , Lucas N. , Davies H. , Voon J. W. K. 
Published: December 2007

Abstract
The need to rapidly produce a notional field development plan, to reduce costs and cycle-time has driven a fast-track reservoir characterization and reservoir model-building project for one of many fields offshore North West Borneo, Malaysia. The objectives of the study have been defined based on the deliverables stated by the reservoir engineers. Considering the list of data and limited time available, an efficient generalised inversion workflow was designed to process a large volume of deepwater 3D seismic data with a single exploration well to: Locate and map all sands (3D geobody identification) versus non-reservoir rocks.Sub-divide reservoir sands into 4 lithofacies (well log neural net based calibration).Propagate 4 lithofacies to entire reservoir volume (within two fluid types).Integrate the fault framework with the sand and fluid distribution to build a first pass reservoir model.Include multiple realizations to manage uncertainty.Check sand connectivity and compute volumes of reserves in place.
An innovative combination of 3D geostatistical and neural network techniques was used both for the well log data and for 3D seismic attributes (AVO, Acoustic impedance and dipazimuth combinations) to map the spatial distribution of the sand and their lithofacies.
The results of the calibrated and quantitative generalised inversion were used in four different modes to assess the best way to build a first pass reservoir model and compute independent reserves within a short time-frame.
This case study illustrates how a purposefully designed 3D/3D reservoir characterisation workflow can reduce the time required to build a first pass static reservoir model and how a similar process can be applied to other complex deepwater hydrocarbon accumulations. It focuses specifically on the different ways a static reservoir model can be built from 3D seismically derived volumes (3D/3D, Hybrid and grid-based).
New Insights into Water Control - A Review of the State of the Art
Authors: Di Lullo Gino , Rae Phil 
Published: December 2007

Abstract
It could be argued today that oil companies would be better described as water companies. Total worldwide oil production averages some 75 million barrels per day (BOPD) and, while estimates vary, this is associated with the production of 300-400 million barrels of water per day (BWPD). These values of approximately 5-6 barrels of water for every barrel of oil are quite conservative. In the United States, where many fields are depleted, the ratio of water-to-oil production is closer to 9-to-1. In some areas around the world, fields remain on production when the ratio is as high as 50-to-1.
Water production is always a harbinger of problems in an oil well. It can cause scaling problems in susceptible wells, induce fines migration or sandface failure, increase corrosion of tubulars, and kill wells by hydrostatic loading, amongst other things. Thus, while water production is an inevitable consequence of oil production, it is usually desirable to defer its onset, or its rise, for as long as possible.
Numerous strategies, both mechanical and chemical, have been employed over the years in attempts to achieve this. Simple shut-off techniques, using cement, mechanical plugs and cross-linked gels have been widely used. More exotic concepts, like relative permeability modification (RPM), have also been applied with varying degrees of success.
This paper reviews the traditional techniques and proposes some new methodologies and technologies that can be used in the design of RPM treatments, in particular. New insights offered in this paper have been gained from the design and analysis of various experimental treatments around the world.
The paper includes several of these, as case histories, to support the concepts and conclusions.
Minimizing Coring-Induced Damage in Consolidated Rock
Authors: Hettema M. H. H. , Hanssen T. H. , Jones B. L. 
Published: December 2007

Abstract
During a successful coring operation some 720 meter of continuous core hasbeen taken with full recovery. The main purpose of the core is to obtainmaterial for rock mechanical testing. To minimize coring-induced damage, asystematic and detailed planning is made for all stages of the coringoperation. New models are developed to avoid core damage due to core bendingduring retrieval through a curved wellbore and to determine the maximumtripping velocity for core retrieval without harmful over-pressurization.Preliminary laboratory test results indicate a high core quality.
Deformation Analysis in Reservoir Space (DARS): A Simple Formalism for Prediction of Reservoir Deformation With Depletion
Authors: Chan A. W. , Zoback M. D. 
Published: December 2007

Abstract
We introduce a formalism, Deformation Analysis in Reservoir Space (DARS), to quantitatively predict the degree of compaction and potential for induced faulting in a depleting reservoir. Compaction occurs when the stress state exceeds the end cap (or critical state) of a formation at any given porosity. For reservoirs in which the vertical stress is larger than the two horizontal stresses, there is also a potential to induce normal faulting in a depleting reservoir when the change of minimum horizontal stress, ΔSh, exceeds a critical fraction of ΔPp (the change in formation pressure due to depletion). The stress path defines the change in horizontal stress with depletion (A=ΔSh/ΔPp). Utilizing relatively simple laboratory experiments, we transform the end caps from laboratory space into reservoir space (DARS) such that production data can be evaluated directly to study the evolution of the deforming reservoir due to production. Field X in the Gulf of Mexico is examined in the context of the DARS analysis. The analysis shows that the initial state of the reservoir was such that normal faults present in the field were active. However, production-induced normal faulting is not likely to occur. Deformation is dominated by compaction. Our analysis estimates that porosity of the formation was reduced from about 23% to 21%, while the permeability was reduced from about 230md to 50-140md.
A New Age in Well Perforating History - Evolving from Roman to Gothic?
Authors: Guinot Frédéric , Papanastasiou Panos , Grove Brenden , Dzialoszynski Arnaud 
Published: December 2007

AbstractThis article presents numerical calculations that show that shooting elliptical perforations can prevent or delay sand production by modifying the state of stress around the perforation tunnel. Elliptical perforations will allow for greater drawdown values and larger depletion before sanding. In formations with anisotropic permeabilities, elliptical perforations could also significantly improve well deliverability. Explosive and charge design technology has been investigated and show the feasibility of properly creating and orienting elliptical perforations to shoot these new elliptical tunnels.The switch from cylindrical to elliptical perforation tunnels implies a change in mentality similar to when Abbot Suger, getting away from the Roman arch, introduced Gothic architecture to Western Europe. This article uses the analogy of XII to XVth century architectural developments to present and justify attractive and feasible new ideas on well perforation.
Model Identification with Fuzzy-Optimisation Techniques in Geological Data Mining
Authors: Finol Jose , Buitrago Saul 
Published: December 2007

AbstractZadeh's proposal of modelling the mechanism of human thinking with linguistic values rather than ordinary (crisp) numbers led to the introduction of fuzziness into statistical and dynamical modelling and to the development of a new class of systems called fuzzy models. In fuzzy modelling, one of the most important problems is the identification of a predictive model from a set of measurements. In a similar way, Data Mining is aimed at sieving data from large databases, data repositories or data warehouses in order to discover interesting knowledge such as pattern associations, trends, and significant structures. Therefore, many similarities can be found between data mining and fuzzy model identification, specially when one has to deal with imprecision and noise in very large data sets. Two of these similarities correspond with the inverse problem of variable selection and parameter identification in order to select the most appropriate predictive model that fits a set of observed (training) data.In this paper we introduce a data mining procedure which uses global optimisation methods, that seeks for useful features, pattern relations, and functional representations in order to derive fuzzy models from large data sets, that characterise the unknown functions as precise as possible. The effectiveness of the proposed data mining method is proved using petrophysical data (core plug measurements) from two oil wells in the Maracaibo Basin.
Application of Coiled Tubing Technology to control water production in the Greater Burgan Field of Kuwait
Authors: Al-Ali Abeer Khalid , Vegesna Raju , Redlich Lyle 
Published: December 2007

Abstract
Rig workover is the most commonly utilized technique in water shut-off applications for water drive reservoirs. Implementation of a rig workover consumes considerable amount of time with significant cost. Furthermore, it will have an adverse effect on well availability and production.
Alternatively cost effective coiled tubing technology for water shutoff was prformed in the Greater Burgan Field successfully. This paper explains the implementation of the same through case histories with diagnosis before and after each job.
Improving Borehole Quality and Drilling Efficiency with a New Suite of Drilling Tools
Authors: Russell Richard 
Published: December 2007

Abstract
In an ideal world, a borehole would be a perfect cylinder with a smooth, frictionless interior and would retain the original diameter of the drill bit. However, in the real world, a perfectly cylindrical borehole can never be achieved. A number of factors contribute toward this less-than-perfect borehole, such as formation instability and interactions between the drilling and formation fluids. Another major contributor is the actual mechanics of the drilling process and the resulting effect most types of drilling have on the borehole geometry.
This less-than-perfect borehole manifests itself in a number of ways, all adversely affecting the efficiency of the drilling process and all increasing costs. These problems include reduced drift, increased torque and drag, poor hole cleaning, slower drilling rates, and increased downhole tool failures.
The phenomenon of borehole spiralling is being increasingly recognised to be a result of the inefficiencies of conventional drilling assemblies. Short-pitch micro-tortuosity and the mechanisms that cause it are responsible for many of the problems described above. It has been found that borehole spiralling can largely be eliminated with a new suite of drilling tools. This suite of tools has adopted a new drilling assembly design utilising a long gauge bit and the ‘point-the-bit’ concept of directional control.
The application of this suite of tools can have a significant effect on drilling operations, especially in the field of horizontal and extended-reach drilling where the improvement in hole quality can impact well design and economics.
Integration of 3D Seismic with a Reservoir Model for Reservoir Characterisation
Authors: Melville Peter D. , Guruswamy Srikanth 
Published: December 2007

Abstract
This paper presents a methodology and results of the integration of 3D seismic data with well log data and simulation model of a giant carbonate reservoir. The work highlights the vertical scale differences between seismic and reservoir models and brings forward a method to match the scale and resolution. Seismic reservoir characterisation of a field with a large number of wells with different vintage and quality data requires statistical methods to discriminate valid data to build AI-Porosity transforms. The method adopted for integration has allowed a better understanding of the complex wrench faulting, and improved the porosity description of the reservoir. 4D fluid effects have also been observed as a result of combining well and seismic with simulation data.
Fast and Robust Computation of Effective Permeabilities
Authors: Nomura M. 
Published: December 2007

Abstract
The current requirement of geologic detail to be built into reservoir descriptions has been exceeding the computational capabilities of reservoir simulation due to a need of huge number of simulation grids. This has motivated the development of a variety of upscaling techniques for flow simulation.
This paper presents an efficient upscaling method effective for an oil-wet heterogeneous reservoir, which offers a means of simulating multiple geostatistical realizations. A new effective permeability correlation is developed through application of one of the non-parametric regression techniques to the results of intensive numerical experiments. The developed empirical correlation enables us to compute effective permeabilities fast and accurately for a wide variety of heterogeneous permeability fields from layered to random system and can be easily extended for averaging two-phase flow properties under viscous limit or capillary limit.
The paper describes the developed technique in detail and demonstrates how the overall upscaling procedure can be speeded up with the desired accuracy.
Integrated Development Approach For A Mature Oil Field
Authors: Murty Challa R. K. , Al-Haddad Abdulla 
Published: December 2007

Abstract
Bahrain field, discovered in 1932, is a highly faulted asymmetrical anticline trending in North - South direction (Fig.1). There are as many as seventeen oil producing and three gas producing reservoirs within Jurassic to upper Cretaceous formations apart from the Khuff gas zones below in Permian limestone formations (Fig-2). These reservoirs occur with divergent lithology, rock and fluid properties. Some of them are saturated while some are highly under saturated. Some of them are oil wet and some water wet. They operate under various drive mechanisms and pressure maintenance schemes. Gas injection in Mauddud, which is one of the major oil producing zones in Bahrain field, has been in operation for the last 65 years. Gas injection in Arab-D is in progress from 1986. Pilot peripheral water injection is in progress in wara sands in NE area of the field since 1995. Additionally, different production mechanisms like gas lift, pumping and stop cocking for GOR control is applied. The field being mature and structurally complicated naturally demands an integrated approach for effective reservoir management to ensure maximum recovery. Due to application of diverse reservoir management techniques, reservoir characterization, Geo statistical application for anisotropy and increased accuracy for simulation, the field has been producing with minimum annual decline (Fig-3). By integrating the Geological, Seismic and reservoir / production data the productive limits of various reservoirs have been extended adding substantial reserves. This paper briefly discusses the approach adopted in the effective reservoir management of this giant mature oil field.
Sequence Stratigraphy of the Khuff Formation Comparing Subsurface and Outcrop Data (Arabian Plate, U.A.E.)
Authors: Strohmenger Christian J. , Alway Robert H. S. , Broomhall Robert W. , Hulstrand Richard F. , Al-Mansoori Abdulla , Abdalla Azhari A. , Al-Aidarous Abdullah 
Published: December 2007

Abstract
The Khuff Formation can be described as a second-order transgressive-regressive sequence. The transgressive sequence set comprises Khuff third-order composite sequences KS7 through KS5 and the third-order lowstand/transgressive systems tract of KS4. The regressive (highstand) sequence set comprises the highstand systems tract of KS4 as well as Khuff third-order composite sequences KS3 through KS1. Major Khuff gas reservoirs are associated with the second-order highstand sequence set.
Khuff analogues have been studied in the Musandam Peninsula at Wadi Bih and Wadi Hagil (Ras Al-Khaimah, U.A.E.) and are compared to well data from Abu Dhabi (U.A.E.). The outcropping carbonates of the Permian Bih and overlying Hagil formations as well as the lower part of the Triassic Ghail Formation are interpreted to be time equivalent to hydrocarbon bearing carbonates and siliciclastics of the subsurface Khuff of the Arabian Platform.
Khuff Sequence KS1 corresponds to the lower part of the Ghail Formation. The Hagil Formation comprises Khuff sequences KS2 and KS3. Khuff sequences KS4 through KS7 are interpreted to correspond to the Bih Formation. At Wadi Bih the Permian-Triassic Khuff sequence boundary SB1 at the base of the uppermost Khuff Sequence KS1 is well exposed.
It is marked by a karst breccia overlain by oncoid packstones of the Ghail Formation. In Wadi Bih as well as in Wadi Hagil, Khuff sequence boundary SB3 is interpreted to correspond to an exposure surface showing mud-cracks and possible raindrop imprints. This sequence boundary also marks the boundary between the underlying Bih and the overlying Hagil Formation.
Characterization of Tar From a Carbonate Reservoir in Saudi Arabia: Physical Aspects
Authors: Harouaka A.S. , Mtawaa B. , Nofal W.A. 
Published: December 2007

Abstract
A detailed physical characterization of tar from a carbonate reservoir in Saudi Arabia was made to evaluate its mobility and ways of establishing contact between the lighter oil and its aquifer. Density and viscosity measurements were carried out on several tar samples, under simulated reservoir conditions of pressure and temperature. Other physical parameters such as simulated distillation, pour point and penetration index were also experimentally determined.
Tar physical properties were found to vary with depth and area within the same field. The obtained experimental results showed a gradual increase in density and viscosity from the tar/oil contact towards the tar/water contact. This increase was much more pronounced in the neighborhood of the tar/water contact. Density and viscosity of tar diluted with toluene were in excellent agreement with those of pure tar.
The density of non preserved tar varied between 0.956 g/cc at 200°F and 1.008 g/cc at 76°F while that of preserved tar varied between 0.944 g/cc at 200°F and 0. 991 g/cc at 76°F. The tar samples analyzed appear to behave as Newtonian fluids.

Introduction
The present paper discusses detailed physical characterization of several extracted and RFT bottom hole tar samples obtained from a carbonate reservoir in Saudi Arabia. The chemical aspect has already been presented elsewhere [1]. Tar is defined as extra heavy oil with a gravity ranging between 29 and 9°API albeit the distinction between heavy oil and tar is rather shady.
Tar mat is present in abundance in the Middle East, Africa and elsewhere. In recent publications Kaufman et al. [2] mentionned the presence of a tar zone at the water/oil contact in Burgan field. This has been known for a long time. However, to ascertain lateral and vertical delineation of the tar zones appear to be still unresolved. Thick tar zones identified through visual observation and Latroscan analyses of weathered core samples were reported in the Raudhatain field [3].
A tar mat is generally a thick column laying between an aquifer underneath and a much lighter oil reservoir above. This peculiar location poses a host of challenging problems for an efficient management of the lighter oil and ultimately for a proper management of the tar zone itself [4].
In this study, density of tar was measured with a digital Anton Parr densiometer having a maximum temperature range of 300°F and a pressure limit of 6000 psi. Based on these measurements, specific gravity and API gravity were determined.
A rolling ball viscometer was used to measure tars viscosity at elevated pressures and various temperatures. The effect of visbreaking or permanent viscosity reduction due to thermal alteration has also been examined.
Is Bioremediation A Solution for the Treatment of Oily Waste?
Authors: Chaîneau Claude-Henri , Setier Jean-Claude , Morillon Anne 
Published: December 2007

Abstract
As a general trend in the Oil and Gas industry, the treatment and disposal of waste is a serious environmental issue. During Exploration and Production activities, drilling operations may generate oily waste as drill cuttings. Hydrocarbons may also enter the soil ecosystem in the case of accidental oil pollution. These wastes are usually disposed of in a variety of methods including thermal and physico-chemical treatments. Over the last ten years, bioremediation has been considered as a possible alternative to « classical » treatments since it has been well established that hydrocarbons are prone to be biodegraded. This paper presents the scientific principles of bioremediation and on-site applications illustrated with cases of studies: landfarming of drill cuttings, biocomposting of hydrocarbons-polluted soils and oily cuttings, natural attenuation hydrocarbons-polluted soil, development of biodegradable oil-based mud and phytoremediation processes. This publication aims at demonstrating that oily waste can be depolluted by biological treatments; however, in-situ biodegradation must not be over-estimated. Our experience demonstrates that in certain local conditions the biological activity is not efficient, and the treatment duration becomes a critical issue. Systematically, a detailed waste management study, including feasibility, cost, logistics and regulations has to be completed to verify that bioremediation is the key solution for the oily waste treatment and disposal.