bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliability of Well Completion Equipment
Authors: Moines Einar , Sundet Inge 
Published: December 2007

Abstract
This paper presents the methodology and results from a major research project on well completion equipment reliability. Historical data were collected and analysed from a large number of installations represented by 17 participating oil companies.
The data were analysed using a purpose designed software package for reliability analysis (CERED). A standardized reliability data collection format was defined for the most critical items of downhole completions and implemented in this software package.
Generic and detailed reliability data are presented for entire completions as well as specific items, such as tubing, annulus safety systems, electrical submersible pumps and downhole permanent gauge systems. The paper also discusses the potential benefit of using reliability data as a decision basis, with consideration of limitations in data quality. The database established in this project represents nearly 800 completion equipment failures covering some 6600 well years of operation.
A separate database is established and maintained by SINTEF on Surface Controlled Subsurface Safety Valves (SCSSV). The paper also describes some long term trends in SCSSV reliability extracted from this database which now holds information on some 1400 failures. The latest update of this database was completed and reported in February 1992 as an integral part of the well completion study.
The cooperation with the participating oil companies and the major completion equipment manufacturers was instrumental in obtaining useful results in the study and is described in detail in the paper.
Win 90's in Practice: Implementation and Results
Authors: Crozier S. C. , Hoekstra Piet , Blake A. J. , McKee J. D. A. 
Published: December 2007

ABSTRACT1991 saw the implementation of a new approach to well construction in the U K sector of the North Sea with Well Engineering in the Nineties (WIN 90s). With this new approach the responsibility for drilling is devolved to drilling contractors, allowing the operator to concentrate on core business. This has provided the opportunity to streamline the drilling process through integration and improved supply chain management. The use of teams is building close customer – supplier relationships throughout the supply chain, and developing a common purpose focused on the needs of the operator.After 18 months of WIN 90s operations, there are clear signs of benefits to the operator, the drilling contractor and the drilling service contractors. This paper discusses the results achieved so far in the development of new relationships, the reorganisation due to the shift of responsibility to the drilling contractor and the implementation of quality management. The results of the initiative are measured in terms of safety, drilling performance and productivity. The paper also discusses the work required to take WIN 90s to the next stage, and the opportunities available for further improvements.
Mud Flow Compensation System for Floating Vessels
Authors: Hatleskog J. T. 
Published: December 2007

Abstract
On a floating vessel or rig, heave can cause severe disturbances in the returning mud flow from the marine riser into the Flow Line. This effect is due to the changing height of the outflow point of the marine riser with respect to the sea bed. Thus the heave can be considered a volumetric flow disturbance, which for short intervals in the heave cycle, can be several times greater than the pump flow making accurate measurement very difficult.
Roll and pitch can also have a disturbance effect the flow in the Flow lines, this depends on the length and the fall in the Flow Line and the way the levels in the tanks and pits are measured.
These environmental effects can at times obscure and make the task of measuring the flow even more difficult than otherwise. The common method of obtaining a sufficiently accurate measure is either by averaging over longer periods or to revert to static measurements. That is, to stop the pumping process which means that it is the dynamic content of the measurement that tend to be lost.
Unfortunately, it is this absence of precise dynamic content in the flow measurement that can make cross correlation techniques, using the heave information to predict the flow development, rather uncertain.
This paper outlines a prototype Flow Compensator System (FCS) with the objective to minimise the effect of heave and to provide an optimum measurement point of flow in and out of the well.
The paper goes on to discuss the initial design requirements, installation, field operation and performance of the prototype equipment, outlining the lessons learnt and their influence on the development of a FCS for general use.
Biodegradable Muds: An Attractive Answer to Environmental Legislations Around Offshore Drilling
Authors: Degouy Didier , Argillier J-F. , Demoulin André , Velghe Firmin 
Published: December 2007

ABSTRACT
For many years, oil based muds have shown proof of efficiency towards hostile drilling cases especially water – sensitive shales or high temperature wells. However, their use is subjected to more and more constraints due to the fast evolution of environmental legislations. One of the possibilities to avoid this problem while keeping the advantages of oil muds consists in substituting mineral oils by biodegradable vegetable oils such as fatty acid esters.
The esters used in these new oil-based muds have an aerobic biodegradability of more than 85 % after 4 weeks and an anaerobic biodegradability of more than 60 % after 2 months.
An original formulation has been developed, presenting very good properties up to 140°C. Its performances are based on a properly choice of ester quality, emulsifying system and additives types, and on a severe control of lime concentration to avoid any risks of ester hydrolysis in conjunction to pH and temperature.
Its behavior has been studied under bottomhole conditions, using an home made HT/HP flow loop, during aging. Contamination tests demonstrated the ability of ester-based muds to resist to possible contaminations i.e., sea water, drilled solids, cements during the drilling process.
Successful Completion Operations on Ravenspurn North Development
Authors: Prise G. J. , Stewart D. R. , Bird T. M. , Holland Brian , Wilson W. W. 
Published: December 2007

ABSTRACT
This paper presents an overview of how the Completion performance on Ravenspurn North Development (RND) has been dramatically improved resulting in significant savings in well costs. With reference to performance statistics, four key aspects are reviewed. These are the Completions Team, the Design Optimisation, the Procedural Optimisation and the Performance Optimisation.
The P/12 Compression Operating Lease Agreement: A Tailored and Flexible Approach to Capital Equipment Financing
Authors: Zoon R. B. 
Published: December 2007

ABSTRACT
Mobil Producing Netherlands, Inc. as Operator for the P/12 Group of Dutch Offshore block P/12 recently concluded an Operating Lease Agreement for the supply of a compression module with the Dutch engineering contractor ABB Global Engineering b.v. Because of the envisaged short term use of the equipment, leasing of the complete module proved to be a cost effective alternative to purchasing. Leasing presented a tailored and flexible approach to capital equipment financing.
The module is compressing gas coming from two small gas fields in Dutch offshore block P/12 with total reserves of some 150 Bscf. The 250 ton module was installed on the Mobil operated P/6-A gas production platform during fall of 1992. The module includes a 4 MW single stage compressor skid and is capable of compressing 100 MMscf/d of gas from a minimum suction pressure of 500 psi to pipeline pressure of 1500 psi.
The lease agreement was constructed as an Engineering, Procurement, Installation and Commissioning (EPIC) type contract and included detailed egineering, procurement and supply of all equipment, module fabrication, single lift installation, and hook-up and commissioning. One main contractor had full responsibility for getting the module built, installed and operational.
The lease has a three year base term, after which the term can be extended on a yearly basis, or the lease can be terminated by either purchasing the module for a pre-determined price, or by returning the module to the owner. The lease is the first of its kind in the North Sea area.
The financial and economic benefits of the lease concept are explained, and the roles and responsibilities of the different parties involved in the lease agreement are discussed.
The Angus Field: Development to Abandonment
Authors: Morel E H , Scott G C 
Published: December 2007

Abstract
The Angus field, with 7.3 MMstb original expected oil reserves is small by UK North Sea standards. It was discovered in 1983, but was left undeveloped until 1990 when a two well appraisal programme demonstrated that the field could be economically produced from these wells using the Petrojarl 1 floating production and storage offtake vessel, with tanker offloading. This novel arrangement allowed the project to be developed rapidly from appraisal, minimised capital investment, and financial risk, to the Angus partnership.
The performance of the field surpassed expectations, with ultimate recovery of 10.6 MMstb being recovered in 18 months. This, combined with the excellent operating performance of the Petrojarl, ensured the excellent financial performance of the development, and has demonstrated one way small isolated oil accumulations can be profitably exploited in offshore areas such as the UKCS.
This paper describes the Angus development, and also some of the technical and management problems caused by the relatively short field life. These included measures to reduce risk, and having to choose the field abandonment date while still on plateau.
The paper also discusses Angus profitability, and the effect UK tax changes will have on future exploration of small prospects.
F3-FB Production Platform
Authors: Boon Wilbert , Spiekerman Joop , Berkhoff Jo 
Published: December 2007

Abstract
This paper describes the design, fabrication and installation of the gas and oil production facilities for the "Nederlandse Aardolie Maatschappij B.V." (NAM) F3-FB complex on the Dutch continental shelf of the North Sea. NAM carried out the basic conceptual design for the complex and prepared the execution plan for the project development. FLUOR DANIEL B.V. was chosen to be the engineering contractor for the topsides and started in conjunction with NAM to develop the Project Specification followed by the detailed design for the F3-FB complex. This paper is prepared by FLUOR DANIEL B.V. and presents an overview on the technical aspects of the F3-FB complex. The reader should realize that a number of aspects presented here, where developed and defined by NAM before authors of this paper where involved in the project, but are added for completeness of the paper. The paper is intended to be a structural presentation of the design, fabrication and installation of the production platform deck, but a number of other interesting developments are presented.
GYDA: Recovery of Difficult Reserves by Flexible Development and Conventional Reservoir Management
Authors: Rothwell N. R. , Sørensen Astrid , Peak J. L. , Byskov Kristian , McKean T. A. M. 
Published: December 2007

Abstract
Gyda is a 200MMstb field, located in the North Sea Central Trough, offshore Norway. The field was discovered in 1980, and first oil was produced in 1990. It is one of the deepest, hottest and poorest quality oilfields in the North Sea. The structurally complex field contains three different fluid types, and the crude is asphaltene rich. The shallow marine sandstone reservoir is gently dipping, wedge-shaped, with an oil column of 500m. The field receives no aquifer support and is being developed by waterflood. The connate water/injection water mix has a severe scaling tendency.
Development of the field is set against a background of tight cost control within the industry generally, and within the Operating company in particular. With six wells drilled per year, a current offtake rate of 70Mstbpd, and areas of the field showing early mature performance, the challenge is to maintain production whilst keeping costs low. The development is therefore managed by maintaining maximum flexibility in drilling locations, sequence and well use, by use of appropriate technology, and by the innovative use of conventional techniques to exploit the field's characteristics.
This paper describes: 1. reservoir complexity; 2. the technologies employed to meet the reservoir management challenges; 3. development philosophy; 4. field management history; and 5. value generation.
The Influence of Interfacial Tension on Liquid Mobility in Gas Condensate Systems
Authors: Ali J. K. , Butler Sarah , Allen Lilas , Wardle Peter 
Published: December 2007

ABSTRACT
Coreflooding experiments have been performed using 1 metre long, sandstone cores and a synthetic, six component (C1, C2, C3, C5, C8 and C16) gas condensate fluid, with a dewpoint close to 4,500 psia. The efficiency of equilibrium gas injection for the mobilisation of liquid condensate has been examined under both high and low interfacial tension (IFT) conditions. The volume of liquid recovered and the composition of both phases have been monitored throughout each experiment and the results used to validate a compositional simulator.
Under conditions of maximum liquid dropout and high IFT (σ ≈ .92 mN/m), an average of 6.5% volume of liquid condensate was mobilised in an equilibrium gas injection in a horizontal core, resulting in reduced recovery of the heavier components of the fluid. An improved recovery of 17.2% was obtained in the vertical injection.
Under conditions of low IFT (σ ≈ .04 mN/m) however, 24.1% of the liquid was recovered during injection in a horizontal core and 51.6% of liquid was recovered with vertical injection, giving a much increased yield of the heavier ends.
The recovery efficiency in a straight depletion on a horizontal core to abandonment pressure averaged 18.8%. This is much lower than for the low tension gas injection.
These results are in agreement with other recent studies concerning the influence of IFT and the effects of gravity on gas condensate flow.
Active Ultrasonic Monitoring of Laboratory-Scale Hydraulic Fracturing Experiments: Numerical Modelling vs. Experiment
Authors: Savic Milos , Cockram M. J. , Ziolkowski A. M. 
Published: December 2007

Abstract
A state-of-the-art data acquisition system has been built at Delft University of Technology which allows rapid acquisition of reflection, pulse-echo and transmission records during hydraulic fracturing experiments on cement or rock samples. Recent experiments show that it is possible to observe clear acoustic signals from a hydraulic fracture that is very thin compared to the wavelength of the illuminating elastic waves. Imaging with reflected compressional signals produces a clear image of the fracture. The signals diffracted from the fracture tip enable accurate calculation of the radius-time diagram. The variation of the amplitude of the compressional waves transmitted through the fracture is mainly caused by the interference between transmitted and scattered wave-fields. However, a subtle difference between numerically calculated and observed wavefields suggest that it might be possible to infer the length of the non-penetrated zone. The material type has a major influence on the fracture visibility after shut-in.
Expert System for Selection of Optimum Artificial Lift Method
Authors: Espin D. A. , Gasbarri S. , Chacin J. E. 
Published: December 2007

Abstract
Artificial lift is used worldwide in approximately 85% of the wells, thus its impact in overall efficiency and profitability of production operations can not be overemphasized. Selection of a particular lift method for a given application is carried out, to a large extent, by production engineers utilizing the method more readily available to them both in terms of their past experience and current access to knowledge and technology. It has been recognized for a long time, that this is a shortcoming of most engineering disciplines and results, more often than not, in sub-optimal designs. Expert systems can help engineers in quickly selecting, from updated technology, the best options available to them for the problem at hand.
The work presented here describes knowledge gathering and coding techniques, general program structure, program validation runs, and field verification of SEDLA, an expert system developed to help in the selection of the best lift method for a well or group of wells.1
Optimizing Gas injection into Naturally Fractured Reservoirs
Authors: Qasem F. H. , Ershaghi I. 
Published: December 2007

Abstract
This study examines the necessity of pressure maintenance by immiscible gas injection into solution gas naturally fractured reservoirs. Gas injection is shown to be a controlling tactor to minimize resaturalion of down structure matrix blocks. Spatial variability in matrix properties influences the overall recovery. Realization of recovery optimization amid spatial variability is illustrated for some idealized reservoir structures.
Producing Extra Heavy Oil from the Orinoco Belt by Electrical Submersible Pumping System - A Pilot Test
Authors: Gonzalez R. , Reina M. 
Published: December 2007

Abstract
Heavy and extra-heavy oils have been traditionally produced using sucker rod pumping. However, this production method is inefficient, highly energy consuming, and the useful life of the equipment is short. Therefore, other methods of artificial lift have to be evaluated, in order to exploit the heavy oil reserves more efficiently and economically.
In this paper, the results of a pilot test using an electrical submergible pump to produce extra-heavy oil (9.2 °API) in the Orinoco Belt, Eastern Venezuela, are presented. The maximum production rate obtained was 1,170 BOPD (186 M3/D), which is 700 BOPD (111 M3/D) higher than the maximum rate obtained with sucker rod pumping in the same well. No diluent was used in this particular test.
The pumping efficiency obtained (37.7%) indicates that with a higher capacity pump, production rates of up to 2,000 BOPD (318 M3/D), without the use of diluent, can be achieved.
3-D Analytical Model for Displacement of Oil Using Horizontal Wells
Authors: Bedrikovetsky P. G. , Magarshak T. O. , Shapiro A. A. 
Published: December 2007

ABSTRACT
The purpose of this work is to develop an analytical model that produces results close to numerical 3D model for miscible displacement using horizontal wells. An analytical model has been developed for three-dimensional flow in system of horizontal wells. Different systems of horizontal injection and producing wells are discussed. The analytical model includes 3D picture of flow between injection and producing wells, bottom and top of the a reservoir, different viscosities of displaced and injected fluids. The model automatically calculates location of displacement front, breakthrough time and composition of fluid produced. It allows to compare sweep efficiency with different locations of injection and producing wells.
A computer floppy disk for 386 PC is available that contains software with PASCAL programs of the model, and sample data files. Files listing the results with graphical representation are also included.
A Study of Sensitivity of Relevant Parameters to Predict Sand Production
Authors: Ghalambor A. , Hayatdavoudi A. , Koliba R. J. 
Published: December 2007

ABSTRACT
A sensitivity analysis was carried out during a course of study to develop a model for predicting sand production from gulf coast gas wells which produce free water. A multiple linear regression analysis was used to incorporate data from producing gas wells and log derived properties of reservoir rock in a usuable model. This model fits field data of water producing gas wells. It will be a risky proposition to analyze each individual parameter related to sand production by itself when designing sand control measures. The study shows that the combined effects of these parameters are making a significant contribution in the process. The results indicate that: (1) the volume of water is not correlatable, but the presence of free-water (non condensed from gas phase) increases the sanding tendencies of most gas wells; (2) as a reservoir depletes, its tendency to produce sand increases; (3) efforts to reduce sanding should be directed toward reducing the drawdown across the completion; and (4) many of the log derived parameters that show merit in correlating dry gas wells have no value in water producing gas wells.
When the optimum decision concerning gas production rate and the need for sand control can be made at the time of initial completion, more profit can be realized from the project.
Drilling String Improvement in Horizontal Wells in Neuquen and Mendoza Basin
Authors: Cagnolatti E. F. 
Published: December 2007

ABSTRACT
This paper describes our experience and the analysis done in the desing of the drill string of 18 horizontal wells drilled in Neuquén and Mendoza basin, Argentina. It also refers to heavy wate, drill pipe and drillcollars distribution in horizontal, curved and vertical sections; caliper analysis during curved section drilling and at the end of the well in terms of drilling days; buckling effect in horizontal wells; and the application of a torque and drag program.