bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Rotating Deoiling Cyclone: Recent Development and Operating Experience
Authors: Triponey G. , Woillez J. , Bezard C. 
Published: December 2007

ABSTRACT
Since its presentation in 1987 (Ref 1), the rotating de-oiling cyclone has been proven as a technical competitor to existing de-oiling equipment.
Extensive trials in 1989-1990 by an independent testing laboratory using a size 2 (2500 BWPD) rotating cyclone in parallel with a static cyclone and a flotation unit (Ref 2), and a field test with a size 2 and two static cyclones (Ref 3) have demonstrated the superior separation capability of this equipment.
However, in order to answer to the criticism concerning the mechanical reliability of this equipment due to the fact that it is a rotating machine, a one year extended mechanical test has been carried out with a size 2 unit on a petroleum field near Paris, with good results.
At the same time, the need for a larger capacity cyclone led to the construction of a size 4 (10 000 BWPD) rotating cyclone. This cyclone has been hydraulically tested with satisfactory results. The mechanical design is different from the size 2 and uses hydrostatic bearings in order to improve the reliability. This unit will be installed on a North Sea platform by the end of 1992, for full capacity field testing and performance evaluation.
The rotating cyclone has been mathematically modelled and the results compared with the laboratory and test loop data. The model will be used to explore the behaviour of the cyclone in specific ranges of operation (oil concentration and flowrates) and to optimize the inlet/outlet geometry.
Application of rotating cyclone is not limited to produced water de-oiling; it can be applied also to dehydration of crude oil. The results of laboratory trials carried out on the pilot unit are also presented.
The History of Horizontal Wells in the V Fields
Authors: Robertson C. J. , Rapach J. M. , Grant N. T. , Smith M. H. 
Published: December 2007

ABSTRACT
Six horizontal wells have been drilled in the V Fields reservoirs with a further two wells planned to be drilled in 1992. Several objectives pursued by these wells include,
Increasing the probability of penetrating a high permeability sand body in a heterogeneous formation. Increasing deliverability by extending the length of contact of the well with the formation. Draining low relief, flank areas of the field. Accessing multiple, potentially isolated fault compartments.
The degree of success has been mixed. Some wells surpassed their objectives while others have been disappointing. Regardless of the commercial results, every well has provided a major insight into the reservoir dynamics and description of these complex fields.
The results show that,
Accurate reservoir description is important to a successful well. Horizontal wells appear to improve the chances of attaining commercial gas production rates from heterogeneous formations. Deliverability can be enhanced by extended formation contact in both good quality sands and individual high permeability features. Compartmentalisation may affect V Fields reservoir performance but faulting is less important than sedimentary heterogeneity.
Feasibility Study for a Horizontal Well in a High-Pressure and Temperature Environment
Authors: Santarelli F. J. , Dardeau Claude , Zurdo Christian 
Published: December 2007

Abstract
When planning the development of a new field, the potential of horizontal wells is systematically investigated from a reservoir engineering point of view. Yet, from a drilling point of view, the feasability of such wells must be questionned. When reservoir temperature and pressure are high, the margin of admissible mud weight which will avoid kicks and yet not lead to mud losses becomes very narrow and may even prohibit the drilling of such wells. This paper describes such a study and shows how log and core data from vertical appraisal wells can be interpreted and used in various models to determine such a margin.
After estimating precisely, in situ stresses and rock mechanical and thermal properties, a first margin of admissible mud weight is calculated.
This first result is then modified to account for the effects of mud temperature and circulation which are also modelled. The model results are calibrated against an FMS log on a vertical well showing drilling induced hydrofractures which corresponded to mud losses in certain formations. The paper concludes at the feasability of the well provided certain tripping practices and mud monitoring techniques are used.
Process Optimization for an Oil Field Under Gas Injection
Authors: Bu Tor , Berge Lillian , Solsvik Olav , Overaa Sverre 
Published: December 2007

Abstract
The Oseberg oil field is produced by immiscible gas injection. Produced gas is reinjected, and the pressure is kept almost constant by additional injection of gas imported from the nearby giant Troll gas field. The so called TOGI scheme is described in another paper presented at this conference [1]. Fig. l gives a schematic representation of the field development.
By installing a Dew Point Control module (DPC) there is a potential for increased condensate production, which again leads to injection of a leaner processed gas (higher methane content). The question is if this early gain in liquid production could be offset by a reduction at a later stage.
As the lean injected gas mixes with the gas cap gas the liquid content of the gas decreases. When the injected gas contacts the oil component exchanges between the oil and the gas phase take place. In addition, compositional variation will occur during periods of pressure depletion. Such effects are demonstrated in a series of PVT experiments, reported in a previous paper [2].
Another important issue is the quantification of the total condensate (oil from gas) production, which in this case will add significant reserves to the previously estimated oil production.
In this work we explain how a multidisciplinary approach, combing process simulation, Equation of state PVT simulation, compositional and black oil reservoir simulation; leads to quantitative estimates of compositional effects.
The emphasis is on method rather than on quantitative results. We discuss the simulation tools that have been applied, how the required input data are generated, and how the component exchanges in the reservoir and various simulation artifacts may affect the results.
Effect of Low Interfacial Tensions on Relative Permeabilities in Some Gas Condensate Systems
Authors: Ronde Hidde 
Published: December 2007

Abstract
This paper shows that a C1-C3 near-critical fluid system goes through a Cahn transition(at an IFTC1-C3 = 03m N/m), the latter value being based on pendant drop-measurements on a 2,6-lutidine-water model system and the application of critical scaling principles.
A Cahn transition into a perfect wetting regime is not just a transition from very good wetting to perfect wetting in the capillary sense. This is a consequence of the fact that for near-critical fluids in thermodynamic equilibrium the solid(channel) wall is an essential part of the system that is in thermodynamic equilibrium, leading to a redistribution of phases in the hydraulic channels, whereas the spreading coefficient becomes essentially zero for such a system. When viscous forces are dominant this leads on its turn inside the Pressure-Composion Cl-C3-(Berea) phase envelope to a core-annular ("film-flow") regime for the bigger channels. The smaller ones go upon pressure depletion through a noticeable transition region outside this envelope, causing capillary condensation, that might start in the millidarcy-range. At the Cahn transition inside the envelope relative permeability curves of the Cl-C3(Berea) system straighten. In the filmflow-regime an Einstein emulsion contribution to relative permeability is clearly identifiable at the saturation extremes leading to asymetric straightening of the relative permeability curves.
Improved Formation Evaluation and Borehole Stability of Ovalized Wellbores
Authors: Berger Pierre , Williams Leon 
Published: December 2007

Abstract
A large percentage of boreholes drilled in the Mahakam delta area in East Kalimantan are adversely affected by tectonic stress. Stress imbalance in the borehole results in enlarged and elongated holes and borehole breakouts in the shales. Pad type logging devices are seriously affected by such borehole conditions.
The use of a short axis logging kit enables good logging data to be acquired in such boreholes. The stress imbalance can be minimized, by optimizing mud weights used in drilling, through estimations of in-situ stress and mechanical properties obtained from shear sonic logging data.
Simulator for Predicting the Mobara-Type Production Performance
Authors: Tazaki Yoshiyuki , Yamazaki Toyohiko 
Published: December 2007

Abstract
Mobara gas fields are dissolved-in-water natural gas fields which exist in Minami-Kanto. The wells of Mobara gas fields have particular production performance curves called "Mobara type". The GWR (Gas Water Ratio) curves of Mobara type production perfor-mance are initially low, and then increase to be so high as to blow up a large amount of water.
The deposits are restricted to Kazusa group consisting of alternate thin layers of sandstones and silty mudstones. The gas is indigenous to Kazusa group. Most of the gas generated in silty mudstones is dissolved in the formation water. A little of the gas is distributed as discontinuous globules due to pore throats in silty mudstones.
The bubbles begin to move toward sandstones when the formation pressure has been reduced. The authors elucidated the flow mechanism and constructed the sand/silt system. In the mechanism silty mud-stone properties are very important, especially relative permeabilities and capillary pressures.
The reservoirs of Mobara gas fields are a dual porosity type. The authors developed a production estimation simulator which is combined with a gas-lift calculation program. It is useful in simulating Mobara type production performance.
Optimal Oilfield Development of Fields With a Small Gas Cap and Strong Aquifer
Authors: Behrenbruch Peter , Mason L. T. 
Published: December 2007

Abstract
Production practices for oil fields with gas caps usually centre around Conservation of the gas cap (energy) to maximise oil recovery. A less conventional but effective reservoir management approach involves an early gas cap blowdown phase in situations where the gas cap is small and a strong aquifer is present.
This paper describes the critical parameters and the benefits from a less orthodox depletion plan. After discussing this subject from a general point of view, the reservoir management plan for the Skua Field, located in the Timor Sea, is cited as a successful application.
Neural Network-Based Formation Parameters Estimation From Well Logs in Quantitative Log Analysis: A Comparative Study
Authors: Zhou Cheng-Dang , Wu Xi-Ling 
Published: December 2007

Abstract
Accurate estimation of formation Parameters from well logs is essential to quantitative log analysis. The conventional log analysis techniques are largely dependent on the initial assumptions about log analysis Parameters. However, without any assumptions and mathematical raodels, neural network(NN) based formation parameter estimation approaches can quickly estimate formation Parameters directly from well logs after successful training.
In this paper, a four-layer feedforward neural network, and a neural model of principai component analysis and linear regression are used to estimate porosity from well logs. And a model-based Inversion of well logs and a principai component regression algorithm are used for comparison with the above two neural approaches.
Severai examples from a Chinese oilfield demonstrate the NNs-based approaches' advantages over the conventional methods in estimating formation Parameters from well logs. Even though the results show that the estimates of formation Parameters from the four-layer NN approach are in the best agreement with the core data, when applying to different wells with complex geological structures, this four-layer NN approach often fails to give satisfactory and consistent results. In consideration of such limitation of a single net, the paper presents an integrated approach to solve this problem.
An Enhanced Recompletion Design Methodology for Vertical, Inclined, and Horizontal Wells
Authors: Ahmed Usman 
Published: December 2007

ABSTRACT
Upon initial completion, a good number of wells (vertical or horizontal nor inclined) typically do not produce at expected flowrates. To remedy the situation, an effective re-completion design is needed that can address the various components of wellbore total skin associated with faulty and/or inadequate completion. Important components of total skin include mechanical skin (wellbore damage), partial completion and ineffective perforation or gravel pack. Reduced well production due to partial completion will not be remedied by an effective acid job. Also, by increasing the perforation interval, one may not be able to remedy problems associated with wellbore damage.
In this paper we present a technique that can allow one to differentiate between the various components of wellbore total skin and thus provide the opportunity to design an effective and optimized re-completion design. The technique involves integration of petrophysical log and well test derived permeability with either production or injection profile data. The paper concludes with a field case study to illustrate the application of the technique.
Transient Wellbore Pressure and Flow Rates in a Commingled System With Different Layer Pressures
Authors: Shah P. C. , Spath J. B. 
Published: December 2007

ABSTRACT
This work addresses the problems of design and interpretation of layered reservoir tests (LRT) in commingled wells when the layer potentials are different; the difference may be in the conditions either at the initial time or at the outer layer boundaries. The multilayer models for commingled wells are constructed from existing single-layer analytic solutions to account for different layer properties and boundary conditions. A general situation is considered in which some layers have a constant pressure condition and others have a no-flow condition at the outer boundary. The algorithms developed here will allow the reservoir engineers, for the first time, to rigorously design and interpret the multi-transient LRTs using the extensive catalog of existing single-layer analytic models, rather than relying on numerical simulation. This development will not only save a great deal of computer time, but will also enable interpretation of tests in reservoirs whose geometries and parameters place them beyond the capability of existing simulators.
An LRT design consists of calculating the transient wellbore potential and the individual layer rates for a given variation of the total flow rate. Two alternative scenarios are considered for the initial state of the reservoir: Either the reservoir is in equilibrium and the well is put on production at t=0, or the well is initially producing in a steady state. Algorithmic procedures are derived from the first principles and validated by comparison with the results of finite difference numerical simulation for three different reservoir systems. A fourth example, which is beyond the capability of simple reservoir simulators, is presented to demonstrate the power of the new procedure.
The LRT interpretation requires the calculation of the total and individual layer flow rates during a multitransient test, given the measured wellbore potential over the test period and the production history of the well. The scheme presented for this problem relies on a synthesis of the new test design calculation procedures with the existing algorithms for flow rate calculation.
Formation Permeability Determination Using Impulse-Fracture Injection
Authors: Gu Hongren , Elbel J. L. , Nolte K. G. , Cheng A. H-D. , Abousleiman Younane 
Published: December 2007

ABSTRACT
"Impulse fracture" is an injection test used to determine formation permeability and reservoir pressure. The test consists of a small-volume water injection to create a short fracture and a shut-in period afterwards to record pressure falloff. The pressure falloff after fracture closure is used to deduce permeability and reservoir pressure. The fracture can pass the near-wellbore damaged area and have the true formation exposed to flow transients. Also, fracturing may sometimes be difficult to avoid for injections in low-permeability formations.
The theory and analysis of impulse fracture are based on an instantaneous-source solution to the diffusivity equation. Numerical simulation examples and field case studies are used to support the validity of the analysis. The applicability of impulse fracture in gas reservoirs is demonstrated by numerical simulation results from a multi-fluid-bank simulator and by field cases. The impulse-fracture injection test is an economical and simple means to determine formation permeability. The test can be conducted in conjunction with mini-fracture or micro-fracture stress-test injections.
Laboratory Measurement of Critical Rate: A Novel Approach for Quantifying Fines Migration Problems
Authors: Miranda R. M. , Underdown D. R. 
Published: December 2007

ABSTRACT
Formation Damage resulting from the migration of small, mobile mineral particles within hydrocarbon producing formations has been, and continues to be a major concern of drilling and production engineers. The flow rate at which these small, usually colloidal, particles begin to dislodge and move within a formation is referred to as the critical flow rate.
Many factors can influence the migration of fines within a producing formation: mineral composition, size and shape; pore throat size and distribution; relative fluid saturations; particle wettability; viscosity of the mobile fluid phase; fluid interfacial tension; production rate; and chemical alteration by drilling and completion fluids can affect the mobility of mineral species responsible for formation damage from in situ fines migration. A novel approach for the analysis and quantification of formation damage resulting from fines migration is described in this paper. The analysis is routinely performed on core plugs from whole core, rotary sidewall cores, and percussion sidewall cores. The technique described employs industry accepted practices for the measurement of single and multiphase permeability of core samples at reservoir conditions, as well as a novel experimental methodology and data processing technique for critical rate determination. A baseline permeability is established at a very low production rate. The rate is subsequently increased in a step wise fashion, returning to the established base rate after every consecutive rate increase. Experimentally derived flow rate and permeability data are converted to bottom hole and wellhead production rates using completion data and well geometry.
The technique described in this paper is used successfully to augment production efforts in several producing formations by integrating the data obtained from flow studies with X-ray diffraction, scanning electron microscopy, and petrographic analysis.
By imparting the ability to vary drilling and completion procedures while under simulated reservoir conditions in the laboratory, this analytical technique can reduce the risk of formation damage at all stages of well operations.
Annular Pressure Predictions Throughout Foam Cement Operations
Authors: Garcia H. , Maidla E. E. , Onan D. L. 
Published: December 2007

Abstract
A joint effort was undertaken by an oil company, aresearch institute, and a service company to carry out field operations using foam cement This was achieved by understanding the fundamentals and technology involved, as they stand today.
The problem is presented and solved, considering both technical and managerial strategies. Learning was a key issue, together with the problem definition, the strategy involved, the management requirements, the technical procedures, the planning of the field operations, and the analysis of the final results.
The theory on pressure behavior during foam cement operations is covered and the complete formulation is presented in a way to allow the development of a numerical simulator. Concepts on the design of foam cement operations are covered, and field and foam cement requirements are addressed.
The type curve matching technique is presented for postanalysis and a complete field case study is covered that shows how to apply the method. The resulting uncertainties are addressed through statements of hypothesis that are then supported by the simulator results, other calculations, and field observations during the actual foam cementing job.
The results showed that the planning strategies were successful, as was the field case study diagnosis.
A New Model for Laminar, Transitional, and Turbulent Flow of Drilling Muds
Authors: Reed T. D. , Pilehvari A. A. 
Published: December 2007

Abstract
The concept of an "Effective" diameter is introduced for the flow of drilling muds through annuli. This new diameter accounts for both annular geometry and the effects of a non-Newtonian fluid. It provides the link between Newtonian pipe flow and non-Newtonian flow through concentric annuli. The method is valid in any flow regime and can be used to determine whether a non-Newtonian flow is laminar, transitional, or turbulent. An analytical procedure is developed for computing frictional pressure gradients in all three flow regimes. The analysis also quantifies how flow transition is delayed by increasing the yield stress of a fluid. In addition, it is shown that transition in an annulus is delayed to higher pump rates as the ratio of inner to outer diameter increases. Furthermore, the method accounts for wall roughness and its affects on transitional and turbulent pressure gradients for non-Newtonian flow through pipes and concentric annuli. Finally, the method runs on a 386 PC in only a few seconds.
High-Temperature, Borate-Crosslinked Fracturing Fluids: A Comparison of Delay Methodology
Authors: Ainley B. R. , Nimerick K. H. , Card R. J. 
Published: December 2007

ABSTRACT
Borate crosslinked guar fracturing fluids have recently been re-engineered to allow use at higher temperatures in both fresh water and seawater. A key part of this work involves control of the crosslink delay time of the fluid.
This report presents an overview of the technology available to control delay time with an emphasis on the types of processes used in current commercial systems.
Control of delay time requires control of either the pH or the availability of borate ions or both. To date, control of pH can be effective in freshwater systems. Control of borate is effective in both fresh water and seawater. This may be accomplished by using low-solubility borate species or complexing the borate with a variety of organic species.