bluuebunny/crossref_metadata_2025_split huggingface dataset:
Full-Field Gas Storage Simulation Using a Control-Volume Finite-Element Model
Authors: Sonier Fernand , Lehuen Pierre , Nabil Raouf 
Published: December 2007

Abstract
This paper presents the actual case history of Saint-Clair-sur-Epte (France), a fourteen year old underground gas storage in a very large aquifer. This gas storage shows two topics of interest: it is partially filled with inert gas; the economical interest and the technical feasibility of injecting a significant quantity of inert gas prior to filling the storage with natural gas have been shown.Its geological structure is made with two partially connected reservoirs; the understanding and quantification of gas moving across the two reservoirs are crucial for the management of this gas storage.
The second item, as above, is the subject of this paper. Simulations and history-matches have been performed initially with a finite-difference model using a cartesian local grid refinement technique.
Following this, a general-purpose model including a control-volume finite-element (CVFE) method has been used. The purpose is to check and confirm the ability of this method to perform real reservoir studies, i.e. simulating large 3-dimensional full-field multi-phase reservoirs.
As far as we know, it is the first published full-field study performed with a control-volume finite-element method simulator, and it confirms previous conclusions from theoretical and specific pattern example papers. This type of simulator can be an excellent alternative to flexible gridding techniques used in finite-difference simulators. The following shows some of the advantages over the finite-difference techniques: The entire reservoir can be gridded as required without using any special techniques for local grid modifications.The numerical diffusion is as isotropic as possible, so that the grid-orientation effect is controlled.The representation of zones of interest, singularities and discontinuities is more accurate and flexible.
A New Scaling-Up Method To Compute Relative Permeability and Capillary Pressure for Simulation of Heterogeneous Reservoirs
Authors: Lemouzy P. M. , Romeu R. K. , Morelon I. F. 
Published: December 2007

Abstract
Recent high-resolution tools and novel characterization techniques lead to simulate very detailed geological descriptions of heterogeneous reservoirs. To perform full-field displacement simulations, scaling-up techniques must be used because of the required coarser grids. Pseudoization methods are commonly used to get the relative permeability and capillary pressure curves. But they all consider 2D flow to realize the scaling-up. We propose a three-dimensional approach. When capillary forces are important inside the reservoir, the capillary pressure may be considered as nearly constant inside a coarse grid-block. This assumption enables to compute directly the fine grid-block saturations and the average coarse grid-block saturation for a given capillary pressure. For each fluid phase, we then compute the effective phase permeabilities of the coarse grid-block by means of an absolute permeability scaling-up method applied to phase permeabilities of the fine grid-blocks in 3D. Then renormalizing the resulting phase permeabilities by the average absolute permeability yields the average relative permeabilities curves for the three directions of space.
Application of this technique, using an algebraic computation of average permeability adapted to heterogeneous media, will be presented for complex fluviatile cases, characterized by a large amount of shale inclusion at small-scale. Comparison of numerical simulations of oil-water flow on high-resolution descriptions, and on the corresponding scaled-up coarse models, shows the efficiency of this method. We recommend to apply this method to reservoir with low gravity segregation, with rocks exhibiting medium to low permeability and high capillary forces, and moderate injection rates.
A Simple Cubic Equation of State for Hydrocarbons and Other Compounds
Authors: Mohsen-Nia Mohsen , Moddaress Hamid , Mansoori G. A. 
Published: December 2007

ABSTRACT
A new simple two-constant cubic equations of state for hydrocarbons, hydrocarbon mixtures, and other non-associating compounds is introduced. This equation of state is based on the statistical mechanical information available for the repulsive thermodynamic functions and the phenomenological knowledge of the attractive intermolecular potential tail contributions to the thermodynamic properties. This new two-constant-parameter cubic equation is in the following form: Zm=PvRT=v+1.3191ℓmv-ℓm−(∑i∑jaij)/RTT1/2(v+∑iℓi)
where lm=1/43∑i∑jxixjlij+∑ixilii,, lij=lii1/3+ljj1/33/8; aij=1−kijaii ajj1/2 and aii=0.48748 R2Tcii5/2/Pcii and ℓii = 0.064662 RTcii/Pcii
It is shown that this equation of state is more accurate than the Redlich-Kwong equation, which has been considered to be the best two-constant-parameter cubic equation of state. This new equation is applied for calculation of thermodynamic properties of hydrocarbons and other non-associating fluids and fluid mixtures of interest in the oil and gas industries.
Compressibility Factors for Naturally Occurring Petroleum Gases.
Authors: Piper L. D. , McCain W. D. , Holditch S. A. , Corredor J. H. 
Published: December 2007

ABSTRACT
The Sutton gas specific gravity correlation gives values of pseudocritical properties which, when used with the Dranchuk and Abou-Kassem (DAK) representation of the Standing and Kate (SK) chart, currently provide the most accurate estimates of compressibility factors for naturally occurring petroleum gases. However, other correlations must be used to account for the presence of acid gases. A new gas specific gravity correlation is presented which takes into account the effects of the acid gases and nitrogen. The new correlation provides more accurate estimates of the compressibility factor than can be obtained by current methods and also eliminates the need for involving additional correlations to correct for the presence of acid gases and nitrogen. The new correlation was developed using a set of 1482 data points, ranging in composition from lean sweet to rich acid gases.
Gas Production Improvements Using Ejectors
Authors: Green A. J. , Ashton Kevin , Reade A. T. 
Published: December 2007

ABSTRACT
Falling wellhead pressures drastically reduce the productivity and economics of a well. If there is a supply nearby of high pressure gas, the well productivity can be increased by using the high pressure energy in an ejector.
An extensive programme of laboratory tests and offshore trials has been carried out to prove and optimise ejector design for offshore application. This has included the use of "flexible" multiple nozzles to allow continued effective operation as well pressures reduce. Existing design methods have been significantly improved and embedded into user-friendly software, which has been validated against the results.
Ejectors were installed on two platforms in the Phillips operated Hewett Gas Field in the Southern sector of North Sea. Trials have proven very successful, with increases in gas production ranging from 15 to 25 MMSCF/D. In both cases a payback on investment of only a few weeks was achieved. Further opportunities for ejector installation are now being actively sought. Investigations for the use of ejectors for multiphase boosting are continuing.
An Innovative Approach to Argyll Field Abandonment
Authors: Prise G. J. , Stockwell T. P. , Leith B. F. , Pollock R. A. , Collie I. A. 
Published: December 2007

ABSTRACT
This paper provides the completion/drilling engineer with an innovative perspective on the technicalities of well abandonment and gives an insight into the first major well abandonment project in the UK sector of the North Sea. The paper discusses the planning and preparation of this novel approach to well abandonment. Details of the equipment utilized and an operational overview are also presented.
New Oil-Based Drilling Fluid Reduces Oil on Cuttings
Authors: Oakley D. J. , Halliday George , Begbie R. J. , Turner J. B. 
Published: December 2007

ABSTRACT
North Sea environmental legislation imposes limits on the amount of oil on cuttings (OOC) discharged to the marine environment when using oil-based drilling fluids. This paper presents the laboratory development by International Drilling Fluids (IDF) of a conceptually new type of oil-based drilling fluid designed to reduce OOC, and the results of field trials undertaken by Amerada Hess Limited (AHL) with this fluid.
A recent research study sponsored by the Drilling Engineers Association (Europe), as project DEA(E) 17, identified under controlled laboratory conditions, the critical physical and chemical variables which affect OOC. It was found during this study that the use of conventional oil-wetting surfactants promotes spontaneous imbibition of oil into the internal pores of cuttings, causing an increase in OOC. Minimising or eliminating the use of strongly oil-wetting surfactants in oil-based fluids was identified as a desirable research objective in oil-based mud development, to reduce OOC.
Onward laboratory work has identified polymers, soluble in low-toxicity mineral-oil, such that polymer-based invert oil emulsion drilling fluids can be formulated to provide all the essential properties of 50/50 oil-water ratio oil-based fluids. Two field trials by AHL in Blocks 31/26 and 39/1-2 using this polymeric oil-based fluid resulted in an 18% reduction in OOC to below the critical 100 g/kg limit and a 35% reduction in mud losses per foot on the second trial well. Fluid properties were stable, and the wells completed ahead of schedule. Field trials have validated this new concept in oil-based drilling fluid design to reduce OOC.
The First Successful Downhole Barium Sulphate Scale Dissolving Operation
Authors: de Vries Hans , Arnaud Fabrice 
Published: December 2007

Abstract
An industry first was achieved by successfully dissolving 200 kg of barium sulphate scale from the upper part of the tubing in a well on the Alwyn North field in the North Sea. This well experienced rapid and very severe sulphate scale build-up resulting in the tubing retrievable safety valve being stuck in the open position. A new scale dissolver was used for the first time in this operation and successfully removed enough scale to reinstate the well. A full workover was prevented with a total cost saving of about £1 million.
This paper describes the well history, the investigation, the scale removal alternatives and the laboratory tests performed on the scale dissolver. It discusses the operation design, the operation itself and the scale dissolving results and concludes with a description of the wireline re-instatement operations. It also highlights the continuous advancement in success and capability of the through tubing workover.
Colloidal Silica Cement: Description and Use in North Sea Operations
Authors: Bjordal Audun , Harris K. L. , Olaussen S. R. 
Published: December 2007

ABSTRACT
New cement slurry formulations containing colloidal silica have been used in North Sea primary cementing operations to help control annular gas migration, enhance slurry "turbulent flow" characteristics without solids settling, and aid cement bonding to formation and casing. Colloidal silica slurries have been successfully placed as lightweight lead cements in intermediate casing operations, and have effectively sealed annuli in gas storage wells and in horizontal completions.
Silica cementing additives have been used often for gas migration control, slurry stability, and high-temperature applications in the North Sea. However, because of its extensive specific surface area (500m2/g), colloidal silica adds additional benefits. Colloidal silica is more efficiently handled in offshore operations because less bulk material is required. The reduced volumes also reduce overall slurry cost. Because colloidal silica particles are so fine, there is virtually no settling of the base material in containment offshore.
A discussion of colloidal silica slurry properties is contained in this paper. Performance properties are presented in relation to each of its various well applications. A case history of a horizontal well is also given that describes the practical use of colloidal silica cement.
Optimising Shale Drilling in the Northern North Sea: Borehole Stability Considerations
Authors: Wong Sau-Wai , Kenter C. J. , Schokkenbroek Hans , De Bordes Pieter , van Regteren J. 
Published: December 2007

ABSTRACT
The drilling mud weight and the mud composition are two key operational parameters that can be adjusted to prevent hole-instability problems. This paper discusses the methodology and the borehole-stability model employed for optimising the drilling mud weight for the drilling of deviated wells in the northern North Sea. In the course of the project, a shale coring programme was implemented so that the rock strength could be characterised, and leak-off-test data were analysed to estimate the in-situ stress. A comparison is made with field observations
The Physical and Biological Impact of Processed Oil Drill Cuttings: E&P Forum Joint Study
Authors: Minton R. C. , McKelvie D. S. , Caudle D. D. , Ayers R. C. , Smith J. P. , Cline J. T. , Duff Angus , Blanchard J. R. , Read A. D. 
Published: December 2007

ABSTRACT
This paper reports the key findings of a multidisciplinary study established by the E&P Forum to examine the environmental effects of drill cuttings with different oil concentrations resulting from treatment with solvent extraction and thermal processes. The study examined the physical characteristics of the cuttings, deposition on the seabed and the impacts on the seabed fauna and on fish.
Concentration of oil on cuttings ranged from 15.8% for unprocessed cuttings to less than 1% for thermally treated cuttings. The removal of oil resulted in dry, dispersive cuttings which would be deposited in lesser amounts over a greater area compared to unprocessed cuttings.
Environmental effects were greatest for untreated cuttings. Solvent extracted cuttings showed some effect but there was evidence of recovery of the benthic fauna within the timescales of the study (8 months). For most of the experiments, there was little difference between the thermally treated cuttings and the controls. There was evidence of a threshold for effects at a concentration of oil in sediment of approximately 1000 ppm. Model predictions of cuttings deposition showed that the area of seabed affected by oil concentrations in sediment greater than 1000 ppm was small for both solvent extracted and thermally treated cuttings.
Both solvent extracted and thermal processing of oily cuttings, and the subsequent discharge of the treated cuttings, appears to result in negligible or short term environmental effects.
Recent Advances in the Handling, Makeup, and Running of C.R.A. Tubulars
Authors: Harris David , Jaensch Manfred 
Published: December 2007

ABSTRACT
Significant advances have been made in the last three years in the non-marking handling of Chrome Resistant Alloy (C.R.A.) tubulars both with power tongs and handling tools.
Marking of casing and tubing by the dies of power tongs and the inserts in the slips of spiders and elevators has long been known to be potentially damaging, particularly in wells with corrosive environments.
This paper outlines the developments made in the industry during the last three years and the creation of special tools and power tongs to overcome these problems. Particular emphasis will be made on the complete cycle from pipe mill to running in the hole.
This will cover the make up of couplings to the pipe body in the mill, the transportation of tubulars to the rig site and the handling from pipe rack to rig floor.
Also to be covered will be the make up and testing of downhole completion assemblies prior to the job.
Actual make up of connections with "non marking" power tongs and running with special slips are the major new developments described.
It will be shown how all factors such as joint weight compensation, guidance yoke system, stabbing, etc. can all contribute to the successful running of C.R.A. tubulars.
Rig Automation-Drilling: The Proving of the Concept
Authors: Houston S. J. 
Published: December 2007

ABSTRACT
1993 will see the culmination of six and a half years effort in the development from first principles of the Rig Automation-Drilling Proof of Concept equipment.
It is timely that Offshore Europe ’93, whose venue is adjacent to the International Drilling and Downhole Technology Centre where the project was sited, provides the ideal opportunity to present the results of the project, explore some of the problems encountered, successes experienced and lessons learned.
The most significant aspect of this project is the benefit of collaboration between Operators, Drilling Contractors and Equipment Suppliers to develop and demonstrate that innovative technology proven in other industries is suitable and relevant to the oil and gas drilling operations.
This 1,000,000 lb hook load modular singles rig, hydraulically powered and using programmable logic control, has been installed onshore and has been put through its operational routines with development as necessary to demonstrate the concept. This concept is capable of meeting the increasing needs for maximum safety with minimum cost operations.
The RA-D concept, in whole or part, is applicable to many drilling scenarios whether onshore or offshore, modular or highly mobile. The paper will discuss some of the applications and will show the benefit to Operators and Drilling Contractors. The project demonstrates that the application of the RA-D concept yields cost reductions in the drilling operation and, whilst all these are not yet capable of being physically demonstrated, a number of field studies and individual equipment assessment studies have provided encouraging indicative results.
An Integrated Full-Field Compositional Simulation of an Offshore Deepwater Development
Authors: Olsen O. T. , Cohen M. F. , Nagarajan N. R. 
Published: December 2007

ABSTRACT
This paper describes technical enhancements to an existing compositional reservoir simulator, and the improved simulation results achieved in a full field simulation study of the Smørbukk Sør Field. The paper also describes a multi-discipline approach in the execution of a simulation study, and the cooperation between Mobil's U.S. technical center and a European affiliate.
The technical enhancements made to Mobil's compositional simulator PEGASUS were (a) improved interfacial tension corrections to relative permeability in miscible flooding, (b) a variable bubble-point and composition with depth function based upon chemical equilibrium, and (c) application of the Babu-Odeh analytical horizontal well model. These features were not available in compositional reservoir simulators at the time the study was conducted.
The interfacial tension correction for miscible flooding provided production performance predictions that could be used with confidence in the evaluation and selection of the optimum production mechanism for the Smorbukk Sør field. The variable composition with depth correlation demonstrated that a gas cap is not likely to exist considering the measured bubble point gradient. The horizontal well model function confirmed that improved productivity could be achieved with fewer development wells, thus contributing to the selection of the most cost effective development scheme.
The primary purpose of the study was to compare the impact of gas and water injection on ultimate recovery and production performance. Secondary objectives were to determine maximum productivity with the fewest number of production wells, and to maximize recovery at peak production. While simulation results marginally favored water injection, gas injection was considered the preferred production mechanism because of gas disposal considerations.
Arresting Production Decline in a Mature North Sea Oil Field
Authors: Wolodkiewicz D. E. 
Published: December 2007

ABSTRACT
Classical reservoir engineering techniques were utilised to characterise water movement in the South Brae Field and determine areas of remaining oil reserves. Exploiting these remaining oil reserves has flattened the rate of production decline in this mature North Sea peripheral waterflood. After producing over 115,000 BOPD on plateau, South Brae experienced a severe 76%/year production decline rate. Prolific oil producers experienced water breakthrough and accounted for the dramatic drop in the field oil rate. An interdisciplinary approach to describe the reservoir and review production and injection history led to identification of work to exploit bypassed oil. South Brae oil production decline rate has been arrested and is essentially flat as a result of implementing such work.
The reservoir engineering techniques used on South Brae have identified several areas of the field which were relatively unswept. Exploitation of these areas of remaining oil potential has been accomplished by through-tubing work without the need of costly rig intervention. One area identified as having remaining oil potential has resulted in raising a 200 BOPD well at a 96% watercut to over 2,100 BOPD at less than a 1% watercut. The well has been producing at this higher rate since the work was completed 5 months ago (October 1992).
The techniques used to identify areas of unswept oil potential in South Brae could be used on other mature peripheral waterfloods. Redirection of water injection to affect areas of remaining oil potential has shown positive oil rate benefits at South Brae.
Basal Waterflooding of a Tight Chalk Field With Long Horizontal Fractured Injectors
Authors: Nederveen Nijs , Damm Michael 
Published: December 2007

ABSTRACT
The Gorm Field is a tight chalk oil field, which has been producing for twelve years. This paper describes how the results of a production development study, including reservoir simulation, have been used to conceptually change the water injection strategy as implemented in two earlier pilot projects. Furthermore, the initial results of the first well implemented as part of the revised strategy, namely a waterflood using horizontal basal water injectors, is presented.
Piper Field: Improved Reservoir Characterisation
Authors: Little E. A. , Simlote V. N. , Bedrock Martin 
Published: December 2007

ABSTRACT
This paper demonstrates the benefits of the application of a synergistic approach in furthering the understanding of the layered nature of the Piper Field. Core, log, FMT pressure and fluid redistribution information obtained from the eight well Piper B Redevelopment Predrilling programme are discussed. The integration of the Piper B results necessitated a reassessment of the Piper Alpha data and led to an improvement in the reservoir characterisation in terms of layer permeability definition, flow behaviour, pressure and aquifer influx. This improved understanding of the reservoir led to the definition of an initial selective completion policy for the Piper Field redevelopment. The primary objective of this policy is to reduce the potential for water override in problematic high permeability layers and thereby improve the sweep of the less prolific layers by closer targeting of injection support. Such an approach allows improved reservoir management, greater flexibility in scheduling remedial work and is oriented towards maximising ultimate recoverable reserves by optimising the sweep in individual sand layers prior to their abandonment/isolation for water shut off purposes.