bluuebunny/crossref_metadata_2025_split huggingface dataset:
Choosing the Right Synthetic-Based Drilling Fluids: Drilling Performance Versus
Authors: Patel Arvind D. 
Published: December 2007

Abstract
Environmental issues have created ever-moving targets for drilling fluids, or muds. Environmental regulations are diverse, complex, and have a tremendous impact on drilling operations, economically as well as logistically. In order to successfslly meet these regulatory constraints, synthetic-based muds are beconiing increasingly popular as substitutes for conventional oil- based muds. Continual evolution of synthetic-based muds (SBM's) and the increasing diversity of synthetic base fluids (SBF's) have made the selection of environmentally acceptable synthetic fluids increasingly complex requiring knowledge of chemical composition and structure effects on toxicity, biodegradability, and performance.
Examination of the SBF's, the synthetic base fluids, provides insight into the environmental and performance issues that affect the selection and drilling performance of the SBM's, the mud. The toxicity, biodegradability, and bioaccumulation of SBM's depend on the molecular composition and structure of the base fluid. In general, the degree of branching affects the biodegradability and the molecular weight affects the toxicity of synthetics derived from similar chemistry. The thermal stability and performance characteristics of the SBM's depend on the chemical composition of the base fluid and emulsifiers used in the SBM's. The final choice of the SBF (and thereby the SBM) depends on the application and environmental requirements for a particular area; however, synthetic hydrocarbon-based fluids have shown to be overall best in cost vs performance.
P. 95
Multilaterals: An Overview and Issues Involved in Adopting This Technology
Authors: Vij S.K. , Narasaiah S.L. , Walia Anup , Singh Gyan 
Published: December 2007

Abstract
Multilaterals, an upcoming technology, offers the potential for substantial improvement in well economics. Integrated efforts of service companies and operators have made this upcoming technology a viable completion technique. The issues like maturing reservoirs, many of the existing wells with uneconomical- to-recover results in place and increasingly expensive offshore structure and drilling operations, are addressed in a very positive way by recent advances in the ML Technology. This technology allows to have same magnitude of reservoir exposure with lesser number of wells on surface platform. Also, there is a potential for reducing water-gas Coning and improved recovery of oil.
Overview of multilateral technology, its applications and limitations have been covered in the paper. Being comparatively a new technology, higher costs and risks involved during drilling/ completion/servicing would need to be kept in view while deciding to go in for multilaterals.
Modelling of multilaterals may be complex for particular configurations, because of likely interplay between reservoir performance and friction losses and pressure continuity in the well bore. Special simulation packages (coupling fluid flow in the reservoir and laterals) may be required for the purpose. Studies so far undertaken in the industry on this issue have been discussed.
Multilateral system offered by various service companies, from existing and new wells, have been discussed, covering issues like isolation between laterals, flow control, re-entry access/interventions, dual string completions. Worldwide experience on economics of multilaterals has also been covered.
Reservoir screening criteria provided in the paper may be used as guidelines for selecting reservoirs for possible applications of multilateral technology. Multi-disciplinary approach would be required for effective implementation of this technology.
P. 109
Use, Quantification and Learnings From a Vertical Pulse Test Conducted for Barrier
Authors: Kikani Jitendra , Jasek D.E. , Mathis L.S. 
Published: December 2007

Abstract
A vertical pulse test was conducted in a water injector in the Goldsmith San Andres Unit (GSAU) in West Texas for determining the integrity of a low permeability barrier separating two carbonate facies. This test was conducted as part of a CO2 pilot project. The effective vertical sweep efficiency is controlled by the barrier and is important to quantify.
The pulse test design was tempered by tailing it with a standard interference sequence to mitigate unforeseen situations. This proved useful as the reservoir pressure was lower than anticipated and the well went on vacuum. The data was interpreted using conventional techniques and numerical modeling. The numerical model was tuned to provide transient quality results by comparing against standard analytical solutions before using it to interpret the pulse test.
This paper presents the conduct, analysis and interpretation of the vertical pulse test and discusses some of the learnings. Sensitivity analysis was performed on slab, layercake and geostatistical models for the flooding pattern, to understand the influence of small scale heterogeneity on short tests. The results indicate that one can distinguish between a casing leak and reservoir vertical communication from a pulse test. The vertical permeability governs the peak arrival and magnitude of the pulses whereas the horizontal permeability controls the magnitude and shape of the fall off portions of the test.
P. 155
A Comprehensive Reservoir/Wellbore Model for Horizontal Wells
Authors: Penmatcha V.R. , Aziz K. 
Published: December 2007

Abstract
Comprehensive, three-dimensional, anisotropic and transient, reservoir/wellbore coupling models are developed for infinite-conductivity and infinite-conductivity wellbores to calculate the productivity of a horizontal well placed in a box-shaped drainage volume. The finite-conductivity well model considers frictional and accelerational pressure drops in the wellbore. It also takes into account the effects of fluid inflow into the well. These models are semianalytical in nature and can be used under transient or pseudosteady state flow conditions. The infinite-conductivity well model is compared with the uniform flux model to show the differences in well productivity calculations. The effects of wellbore pressure drop on well productivity are shown using the finite-conductivity well model. These models can provide reference solutions to calculate well indices or to check the accuracy of a numerical simulator. Because of their analytical nature they are easier and faster to use than numerical simulators. Using superposition in space and time, these models can be run under a variety of constraints. We believe that our finite-conductivity well model is more general than any published previously.
P. 191
Interval Pressure Transient Testing with MDT Packer-Probe Module in Horizontal
Authors: Kuchuk Fikri J. 
Published: December 2007

Abstract
In this paper, the use of various pressure measurements is investigated for determining formation pressure as well as permeability distribution by using the Multiprobe Formation Tester Packer and Probe Modules in horizontal wells. It is shown that reservoir pressure measurements along the wellbore give local as well as reservoir scale information about how the reservoir is being depleted and how cleanup takes place. The estimation of horizontal and vertical permeabilities. skin, and reservoir pressure along the wellbore is also presented by using interval (local) pressure transient tests. For the Multiprobe Formation Packer and Probe Modules in horizontal wells, an interpretation methodology is presented for determining the reservoir parameters. A few interval pressure transient test examples are presented for both formation pressure and permeability distribution.
P. 205
A Study of Pressure Behavior of Dual-porosity Composite Reservoir with Non-uniform
Authors: Xiang Kaili , Guo Jianchun , Kun Wang 
Published: December 2007

Abstract
The theories and models of well testing analysis of dual porosity reservoirs with uniform thickness have been discussed in detail in the literature. In order to completely describe the situations of real reservoirs, this paper first studies the pressure behavior of dual-porosity composite reservoirs with non-uniform thickness and lateral heterogeneity. In this paper, the dual-porosity composite reservoir with non-uniform thickness and lateral heterogeneity is defined as the dual-porosity reservoir that consists of many zones with non-uniform thickness, different fluid and formation properties. A new effective radius mathematical model of this composite reservoir in the presence. of skin, wellbore storage and phase redistribution is presented. Laplace-space solutions for this mathematical model with outer constant pressure boundary or outer impermeable boundary are obtained by Laplace transformation and the typical curves for the modern welltesting analysis are given by numerically inverting method. The mathematical model has improved the welltesting analysis theories and the pressure behavior of this reservoir is discussed. The model and solution can be used in the fractured reservoir with variable formation properties or containing water injection wells, gas injection wells, polymer injection wells or finite damaged zone.
P. 235
Inter-relationships between Polymer/Crosslinker Chemistry and Performance in
Authors: Moorhouse Ralph , Harry David N. , Matthews Les , Merchant Uday 
Published: December 2007

Abstract
Fracturing fluid systems based on the natural polymer guar, or its derivatives, crosslinked with boron or certain transition metals, such as zirconium, have become the staples of the pumping services industry worldwide. It has been estimated that in North America alone, one billion gallons of fracturing fluid were pumped in 1997. These fluid systems have been designed to operate over a wide pH range and at temperatures to 400F (about 200C) by the appropriate choice of polymer crosslinker, stabilizer and buffer. Not only has it become apparent that the same fracturing fluid composition is not suitable over such a wide range of applications, but it is also becoming increasingly apparent that seemingly identical fluid compositions yield different results.
This paper is the result of a systematic effort to demonstrate some of the reasons why seemingly identical fracturing fluid compositions may produce considerably different results, and the steps that may be taken to minimize the odds of making an undesirable choice.
P. 253
Amenability of Eocene Crude to Thermal Conditioning and Chemical Treatment for
Authors: Nihalani M.C. , Sinha S. , Dubey H. , Kulkarni T.G. 
Published: December 2007

Abstract
Laboratory studies have been carried out to assess the comparative effectiveness of chemical treatment and thermal conditioning on the crude oil being produced from Eocene formations by Oil India Limited (OIL) in the upper Assam region of India. The studies have indicated that the present Eocene crude is amenable to both thermal conditioning and chemical treatment, and combination thereof. The study has shown that he thermal conditioning of crude has distinct advantage over chemical treatment in terms of improvement in rheological parameters, reduction in pour point and remarkable reduction in depositional characteristics. However, the thermally conditioned Eocene crude has shown some ageing effect, and has poor thermal stability.
P. 271
Combating Hazardous Sludge Disposal Problem at Lakwa (India) Oil Field Effluent
Authors: Sengupta P. , Dutta D.K. , Goswamee R.L. , Saikia P.C. , Borthakur P.C. 
Published: December 2007

Abstract
The effluent treatment plant (ETP) at Lakwa oil field (India), generate huge amount of sludge containing about 7–10 % hydrocarbon. Disposal of the sludge with the high hydrocarbon content is of environmental concern. The possibility of combating the problem through total utilization of the sludge in making building brick and light weight aggregate has been investigated. This communication highlights the result of preliminary investigation. Common masonry brick and light weight aggregate with acceptable physical and chemical properties could be prepared using about 34 % as received sludge.
P. 279
Removal of Downhole Strontium Sulphate Scales By Chemical Dispersion Technique
Authors: Maithani A.P. , Sah A.K. , Rai Ramashish , Singh Gyan 
Published: December 2007

Abstract
Scaling is a major problem in any oil field. Calcite or Calcium Carbonate (CaCO3) and Celesite or Strontium Sulphate (SrSO4) are the common type of scales encountered in oil field operations. various fluids (e.g. Brine, liquid and gaseous hydrocarbons and other gases) mix in the reservoir and/or wellbore under varying thermodynamic, kinetic and hydrodynamic conditions resulting into scale formation. While CaCO3 scales are possible to be removed by the use of common acids, Strontium and Barium Sulphate require special formulations to remove.
Laboratory investigations for characterization of scales recovered from a well of Bombay High and their removal from down hole equipment and wellbore by chemical treatment have been carried out.
Produced water and injected water has been analyzed for ionic composition to monitor scale formation tendencies. The possibility of formation of Strontium Sulphate (SrSO4) scales in wellbore and tubing is well established from these analysis. Further, the well production decline in some of the wells were analyzed and corroborated with formation of scale which were later confirmed during workover.
The dissolution of Strontium Sulphate scales with special chemicals / formulations have been upto 75% under laboratory conditions, whereas other conventional solvents/chemicals were not effective for dissolution.
Accordingly squeeze treatment with chemicals for scale removal from formation face, perforations and down hole equipment's was recommended. These treatments has been carried out in some wells and results have been very rewarding.
This paper presents the results of these evaluations and field applications of scale treatment.
P. 285
Pipeline Transportation of Heavy/Viscous Crude Oil as Water Continuous Emulsion in
Authors: Sharma Kuldip , Saxena V. K. , Kumar Avinish , Ghildiyal H.C. , Anuradha A. , Sharma N.D. , Sharma B.K. , Dinesh R.S. 
Published: December 2007

Abstract
The heavy oil belt of North Cambay Basin comprising of Santhal, Lanwa and Balol oil fields poses great problems in floatation of these heavy oils due to high viscosity (10,000–16,000 cps) of the emulsion. Oil-in-water emulsions provide a cost effective alternative to the heated pipelines or diluents for their transportation. Emulsions in different phase ratios and application doses of 2000–5000 ppm of non-ionic surfactants have been found to be effective in phase reversal of emulsions with drastic reduction in viscosities which are in 100–400 cps range at pipeline operating conditions. Non-ionic surfactants have the advantage of relative insensitivity to the salt content of the aqeous phase. The non-ionic family of surfactants has been used successfully for the formation of stable emulsions that resist inversion to a wide operating temperature range. Resulting reverse emulsions are heat sensitive and resolve themselves at elevated temperatures without addition of dehydration chemicals. Suggested surfactant treatment has the potential to successfully transport heavy/viscous emulsions of Lanwa oilfield resulting in tremendous savings in transportation costs.
P. 301
A Model to Quantify Residual Saturation Distribution in Heterogeneous Reservoirs
Authors: Virnovsky G.A. , Skjaeveland S.M. , Skauge A. , Helset H.M. 
Published: December 2007

Abstract
To study capillary trapping phenomena in 2 and 3D a mathematical model is developed facilitating rapid fine grid computation of the saturation fields in heterogeneous reservoirs. The reduction in Computation time is achieved due to the fact that the model is much simpler than a conventional black oil simulator. Influence of wettability type, magnitude of capillary pressure, rate, and gravity forces are studied in 2D and 3D analytically (qualitatively) and by way of computations (quantitatively). It is shown that at infinite time in the strongly water wet reservoirs all the mobile oil is recovered, while in the oil-wet and mixed reservoirs a certain amount of capillary trapped oil exists. The capillary trapped oil saturation has a tendency to increase in the direction from injection to production wells, though it reveals a non-monotonous behavior locally.
The developed model is useful in calculation of recoverable reserves, and in optimization of waterflooding strategy to minimize remaining oil in heterogeneous reservoirs including the fractured ones.
P. 307
Perforation-Specific Inflow Fluid Characterization with Downhole Video
Authors: Maddox Steve 
Published: December 2007

Abstract
It is useful to confidently know what type of fluid is coming into the wellbore from each specific perforation and to accurately establish the depth associated with that fluid entry. The more confidence you are able to assign to your knowledge of the fluid type entering a specific perforation, the more valuable that information is to the engineer trying to maximize oil or gas production and trying to minimize water production. Knowing if the fluid entering a specific perforation is gas, oil, or water and establishing the exact depth of that perforation relative to other downhole equipment is possible using downhole video technology.
After a brief overview of the development and current state of the art of downhole video technology, this paper presents some examples of perforation-specific fluid characterization. These examples include analysis of flow patterns at specific perforations actually observed and the factors that contribute to those patterns. Examples include videos of oil, gas, and water entry at various depths, pressures, temperatures, watercut percentages, inclination angles, and tubular sizes.
Fresh Sonic Interpretation in Limestone Through Modulus Decomposition
Authors: Saxena Vimal 
Published: December 2007

Abstract
The conventional acoustic interpretation in porous formations often utilizes Pickett's plots for lithology calibration, variations in sonic velocities for porosity estimates and relative shifts in V,/Vs ratios for hydrocarbon evaluation. In practice, it alone does not provide satisfactory answers as true formations are composite media. In limestone, additional heterogeneities are observed in porosity type and its distribution created as diagenetic imprints on the formation. A variable degree of dolomatization is also found in carbonates. The advent of recent success in modulus decomposition of sonic velocities or hydrocarbon evaluation in silici-clastic composite porous rocks influences to implement decomposition technique in carbonates by addressing the problem as multi-constituent media. It provides a new resistivity independent exciting approach for petrophysical understanding in limestone formations, which should be reviewed in comparison with conventional results.
Modulus decomposition combines both the sonic velocities in a multi-constituent model to account for dolomite and fluid influences and provides the evaluation of an effective' dry frame bulk modulus, under known fluid conditions and vice-versa. The study of evaluated bulk and shear dry properties show the presence of an excellent inter-relationship. Extending it to unknown fluid conditions, provides a resistivity independent indication of hydrocarbon in carbonates. It also allows to compute the effective fluid modulus ill pores to estimate hydrocarbon saturation through a mixing law. The study observes the presence of a strong Semi- logarithmic relationship between shear modulus and formation porosity. The relationship is found to be limited by a terminal' porosity. The general relationship holds good in all the studied limestone.
P. 339
An Experimental Study for Oil Identification in Very Fresh Water (Salinity&lt;10000PPM)
Authors: Sun Deming , Li Lijun 
Published: December 2007

Abstract
The oil identification of pay zone in very fresh waterbearing reservoir in China is hard problem to be solved by logging analyst. This is because the difference of resisitivity between oil and water zone in this kind of reservoir is relatively small. For this, logging analysts have been trying to find non-electric logging methods to solve the problem. Many methods have been found. The dynamic Poisson's ratio obtained from acoustic log is one of those. However, as we have known, the dynamic Poisson's ratio is useful for oil identification in high salinity- bearing sand. But, the mechanism of oil identification in very low salinity water- bearing sand is uncertain because interval transit time of the rock has a relation to the formation water salinity. In order to solve the above problem, an experimental study has been carried out with natural cores in Lab. under the reservoir conditions. The results of the experiment show that the Ave. values of dynamic Poisson's ratio are about 0.3 and 0.25 respectively for the cores saturated with fresh water and natural oil. Those also show that it is possible to identify the oil using dynamic Poisson's ratio even in very low salinity water- bearing sand.
P. 379
A Novel Streamtube Model For Tracer Flow In An Areally Heterogeneous Reservoir
Authors: Marathe R.V. 
Published: December 2007

Abstract
A new method is proposed to obtain streamline distribution in an irregularly shaped reservoir with an arbitrary placement of injection and production wells and randomly oriented sealing faults, Using streamline distribution thus obtained, it is possible to predict tracer breakthrough times.
The proposed method models flow around a permeability barrier by a distribution of vortices around the barrier plane obeying the appropriate boundary conditions of vanishing normal velocity component along the barrier plane and the overall boundary condition of no flow or uniform potential along the reservoir boundaries. In addition, the requirement that net circulation around the permeability barrier be zero is also satisfied. Flow around a vortex is modeled by the arc-tan solution to the Laplace equation, while flow towards vertical well is modeled by conventional infinite line source (log r) solution. In thin reservoirs, flow towards horizontal producers/injectors is modeled by Infinite Conductivity Vertical Fracture (ICVF) solution to the Laplace equation. Specific advantages of the model based on steady state potential flow theory over full fledged numerical simulation model are:it is free from numerical dispersion and grid orientation effectsflow geometry near wells and permeability barrier is taken care of naturally in the model andit is easy to use.
P. 423
Investigation of Hydrocarbon Miscible Gas Injection by Experimental and Modelling
Authors: Javadpour F.G. , Jamialahmadi M. , Shadizadeh S.R. 
Published: December 2007

Abstract
The present investigation reports the results of extensive experimental and theoretical work to determine the minimum miscibility pressure of a mixture of hydrocarbon gas and eight Iranian crude oils. The measured minimum miscibility pressure values were modeled with a fully compositional simulator. The results show that the available gases alone or with some enrichment can develop miscibility process with crude oils at reservoir condition. At the end a new empirical correlation presented which can predict the minimum miscibility pressure (MMP)with acceptable error.
P. 447
Optimization of Cyclic Steam Stimulation Using an Analytical Model
Authors: Tamim Mohammad , Ali S.M. Farouq 
Published: December 2007

Abstract
A comprehensive cyclic steam stimulation simulation study for a typical Canadian heavy oil reservoir using an analytical model which considers fracturing at the wellbore has been conducted. It is concluded that several factors are involved for successful oil recovery. The results are based on a single well operation and the process becomes more complex as well interference becomes more pronounced.
p. 457