bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appraisal and Development of the Murta Reservoir Using Hydraulic Fracture Stimulation
Authors: Carnell S. J. 
Published: December 2007

Abstract
This paper describes the evolution and field application of fracture stimulation techniques applied to the Murta reservoir in South Australia, where unique conditions govern fracture stimulation design. The use of a minimum viscosity pad fluid has been shown to provide effective fracture height growth constraint and provide for efficient fracture length propagation, resulting in increased productivity index improvement.
Fracture stimulation has proved to be a viable technique to allow economic exploitation of this resource, while allowing its continual appraisal.
Analytical Solutions of Three-Dimensional Flow Near a Wellbore
Authors: Marett B. P. , Inayat-Hussain A. A. , Goldthorpe W. H. 
Published: December 2007

Abstract
Analytical solutions are presented for the pressure field due to Darcy flow induced by a partially perforated cylindrical wellbore, which is perpendicular to parallel boundaries with various boundary conditions. These solutions are used to deduce the effective radius for equivalent line sink representations of the wellbore taking into account effects of boundary separation and zone damage.
Wanafa/Cossack Dynamic Aquifer Model: Multidisciplinary Approach
Authors: Winterhalder J. R. , Hann J. H. 
Published: December 2007

Abstract
Pressure and fluid data acquired during the exploration and appraisal of the Wanaea and Cossack oilfields revealed unexpected anomalies that could not immediately be explained. A multidisciplinary team was established to examine all the data in order to formulate an appropriate geological model and to assess the implications for the proposed development of these fields. The weight of evidence supported a model involving a dynamic aquifer.
Adsorption/Desorption of Multicomponent Gas Mixtures at In-Seam Conditions
Authors: Stevenson M. D. , Pinczewski W. V. , Somers M. L. , Bagio S. E. 
Published: December 2007

ABSTRACT
Adsorption isotherms were measured for binary and ternary mixtures of CH4, CO2 and N2 on coal at 30°C and pressures to 5200 kPa. The data shows that equilibrium gas and adsorbate phase compositions differ considerably and that the total amount of gas mixture adsorbed is strongly dependent on composition and system pressure. The experimental measurements were used to test the applicability of models based on adsorbate solution theory to the prediction of multicomponent adsorption data from pure component isotherms at pressures of interest in coalbed gas applications. It is concluded that IAS theory, which assumes ideality of the adsorbed phase, provides predictions which would be of acceptable accuracy in many coalbed gas applications. Attempts to apply RAS theory to the data show that a clear need exists for the development of models to correctly predict adsorbate activity coefficients for gas mixtures on coal at elevated pressures. The experimental adsorption data reported in the paper will be useful in the development and testing of such models.
Nitrogen Injection With Horizontal Wells for Enhancing Heavy-Oil Recovery: 2D and 3D Model Studies
Authors: Jha K. N. , Chakma A. 
Published: December 2007

ABSTRACT
Gas injection is one of the oldest enhanced oil recovery techniques used for the recovery of light oils. Recently, there has been a growing interest in this technique for both light and heavy oil reservoirs. In order for gas injection technique to be successful in improving the recovery of oil, it is important to have a stable front so that early breakthrough can be prevented. In some cases stable fronts may be obtained by the use of horizontal wells. We have investigated the possible application of gas injection with horizontal wells for the recovery of heavy oils from shallow reservoirs found in the Lloydminster area bordering the provinces of Alberta and Saskatchewan in the laboratory using 2 D and 3 D physical models. This paper provides a comparison of the results obtained from these two physical models. Stable fronts could be achieved easily in the case of the 2 D model whereas, it was virtually impossible to obtain perfectly stable front in the case of the 3 D model. Recovery was found to be higher in the case of the 2D model as compared to the 3D models for all the conditions studied.
Continued Development and Field Testing of the Subsea Wireline Winch System
Authors: Graser J. A. 
Published: December 2007

ABSTRACT
A prototype subsea wireline winch was constructed and run in a test well in 1985, using a borrowed hydraulic power pack1,2. Since then a complete system has been designed and constructed, including a subsea wireline blowout preventor (BOP), subsea electro-hydraulic power and thruster pack and a 3urface heave compensated handling system3. The complete package was first operated in a land test well at Livingston, Scotland. It was then deployed onto a dummy wellhead in the North Sea, beneath the North Sea Pioneer in 385 ft (126.3 m) of water without the use of guidewires.
The improvements and conceptual changes to the system, from the original paper read in 1985, are discussed. The results of the tests show that a wireline winch can be deployed onto a subsea wellhead without guidewires, and that remote monitoring and control of a subsea wireline winch is pr actical.
Adjustable Wellhead Technology Proves Cost Effective Whilst Safety in General is Improved
Authors: van Bilderbeek B. H. , Milne I. F. 
Published: December 2007

Abstract
During the summer of 1988, Plexus Ocean Systems, Ltd. installed the first adjustable mandrel-type wellhead system on a well drilled for Occidental Offshore Pool Harbour with the jack-up rig Inter Ocean II.
The adjustable hanger technology was devised to obviate the need for removal of the BOP stack during surface hanger installation procedures. Conventional technology to that date was limited to using slip-type surface equipment when mudline hangers were required in the casing program.
The Adjustable Hanger System received formal recognition when Plexus was awarded the 1987 Scottish Offshore Achievement Technology Award and the 1989 Special Meritorious Award for Engineering Innovation presented by Petroleum International.
The paper reflects on three (3) years of operational experience gained from sixty-one installations drilled for eighteen different operators in water depths varying from 110 to 300 feet. The data offers insight into the practicality of this new technology which features time saving elements plus superior technical solutions to achieve real safety improvements. The Adjustable Wellhead Technology will be shown to be cost effective in exploration as well as production applications.
The Influence of Oil-Based Drilling Fluid Chemistry and Physical Properties on Oil Retained on Cuttings
Authors: Oakley D. J. , James S. G. , Cliffe S. 
Published: December 2007

ABSTRACT
This paper presents the results and implications of a research project* to study, under controlled laboratory conditions, the influence of oil based mud physical properties and chemical composition on the quantity of oil retained on cuttings. Substrates, representing common rock types drilled, were exposed to different oil mud formulations in which one variable was altered as far as possible independently of other properties. The most influential parameters were found to include the use of strong oil wetting agents such as amidoamines and imidazolines (which promote oil imbibition), the percent oil in the formulation and the water activity imbalance between formation and oil mud. Less influential, but nevertheless an important consideration for oil mud formulation, is the effect of plastic viscosity and intermediate oil wetting surfactants. Mud weight and HTHP fluid loss have a minor effect.
Imbibition of oil into the internal fabric of cuttings is an important process which is largely dependent on the choice and concentration of surfactant, fluid temperature and exposure time. Minimising or eliminating strongly wetting surfactants in oil based mud formulations is thus a desirable objective for oil based mud development.
A new concept in oil based mud design is presented, in which all the essential properties of an oil based mud are achieved utilising oil-soluble polymers. Laboratory tests suggest oil on cuttings can be reduced by up to 30% on current 50:50 oil:water ratio fluids.
Blowdown of Pipelines
Authors: Richardson S. M. , Saville G. 
Published: December 2007

ABSTRACT
A computer program has been developed which can be used to simulate the emergency blowdown of a pipeline containing hydrocarbons. The program can predict pressures, temperatures and multi—phase compositions within the line and rates of efflux from the line, all as functions of time. The effect of including sub-sea isolation valves within the line can also be modelled.
Calculation of Total Skin Factors
Authors: Pucknell J. K. , Clifford P. J. 
Published: December 2007

ABSTRACT
This paper shows how total skin factors can be calculated in wells which are perforated, damaged, partially completed and deviated. Horizontal wells and the effect of material within the wellbore radius (eg open hole gravel packs) can also be evaluated. Results are provided for both isotropic formations and those with a different horizontal and vertical permeability.
The theory presented extends work published by others for particular cases. These calculations are needed to design cost-effective completions.
Coil-Tubing Milling/Underreaming of Barium Sulphate Scale and Scale Control in the Forties Field
Authors: Brown A. D. F. , Merrett S. J. , Putnam J. S. 
Published: December 2007

ABSTRACT
Barium sulphate scale formation can occur readily in the wellbores of the Forties field when produced water containing a high barium ion concentration mixes with injection sea water of a high sulphate ion concentration. Typically scale formation begins with the onset of sea water breakthrough into a wellbore and can lead to very rapid production declines.
To date, seven coiled tubing scale millouts have been performed on producing wells in the Forties field. These operations have resulted in a combined 39,000 bbl/d (6201 m3/d) increase in production.
This paper describes the mechanism of barium sulphate scale formation and the mechanical removal of the scale using coiled tubing with downhole motors, bits and underreamers. A scale millout case history is presented and the successful prevention of scale formation via scale inhibitor treatments is discussed.
Fines Migration within a Stressed Proppant Bed Detected Using a Linear Flow Cell
Authors: Smart B. G. D. , MacGregor K. W. , Somerville J. M. 
Published: December 2007

ABSTRACT
The relationship between the permeability of proppants and applied crushing stresses are conventionally determined using a linear flow cell compresses a 1" wide bed of proppant between platens. As well as inlet and outlet pressure for the fluid flowed through the proppant, the cell has three pressure measuring ports which enable the pressure drops to be measured separately across an upstream portion of the proppant bed and a downstream portion. Usually these readings are averaged and used to produce a single permeability of the proppant bed at any given closure stress. The paper describes the equipment used and presents results obtained by conducting "routine" fracture permeability tests on a variety of proppants. It is shown that the previously unreported downstream migration of proppant fines in the linear flow cell can have a considerable effect on the fracture conductivity and permeability.
Coiled-Tubing Pressure and Tension Limits
Authors: Newman K. R. 
Published: December 2007

ABSTRACT
The use of Coiled Tubing (CT) for servicing oil and gas wells is increasing rapidly. Larger CT sizes are being developed to meet new service requirements. The CT is being pushed closer to its performance limits for many of these services. To avoid CT failures in the field, it is important that these limits are well understood.
There are three major types of CT limits: Life limits due to fatigue and corrosion [1].Pressure and tension limitsDiameter and ovality limits
These limits are interrelated in some ways but can be analyzed separately. The corrosion effect on the CT must be considered for the first two limitations, but, the fatigue life of the CT does not significantly affect the pressure and tension limits.
The diameter and ovality limits are determined based on present surface hardware such as the stripper bushings and BOP inserts. Real-time monitoring of the CT diameter is necessary to locate mechanical damage, such as dents and ballooning, which can not be predicted by computer modelling.
This paper addresses the pressure and tension limits. It describes a mathematical model which is used to determine these limits. Test data used to validate the model is also presented.

Selectipn of Limiting Criteria
A criterion must be chosen as the limiting criteria for determining the pressure and tension limits. For this model, the initiation of yielding for a straight section CT with no residual internal stresses was chosen as the limiting criterion. This criterion is discussed further in the Incipient Yield Criteria section of this paper.
The incipient yield criterion was chosen because it is well accepted in the industry; it is relatively simple to calculate; and it agrees well with test data. In fact, this criterion is not entirely accurate in representing CT.
CT is plastically deformed when it is "bent" onto and off of the reel and over the gooseneck of the injector head [1]. This plastic deformation causes significant residual stresses which are not considered by this yield criterion. These residual stresses cause yielding to begin much earlier than this yield criterion would predict. This yielding due to the residual stresses acts to relieve the residual stresses; however, it is not this yielding that is being considered for determining the CT limits but the yielding that would occur if the CT did not have any residual stresses.
The Use of Digitised Tubing Caliper Data for Workover Planning
Authors: Kolthof W. J. , van der Wal D. 
Published: December 2007

ABSTRACT
Routine reports with the results of multifinger tubing caliper surveys normally provide a very basic view on the corrosion attack in which only one Or two data points per joint are given.
A computer model has been developed which allows the use of all digitised data available from both computerised data acquisition systems, the ‘electric’ caliper, and data from the video image decoder reading the caliper stylus imprints on a metal chart, the ‘mechanical’ caliper.
These data sets are used to verify the performance of the caliper tools by checking the response of the individual feelers, Checking the eccentricities and making necessary corrections if required.
Plotting routines are available to study in detail images of pits, lines of pits, wireline grooves, ring corrosion, damage to connection make-up or tubing accessories such as safety Valve landing nipples and wireline profiles.
The results of these detailed studies can give an early indication of possible corrosion problems with equipment or with the methods used and can subsequently lead to preventive or corrective action.
Probability plots from critical areas are used to monitor and predict corrosion progress and subsequent reduction in wall thickness and remaining strength. This together with production forecasts and flow parameters are used to calculate the prevailing pipe body stress at any given moment in time. These values can be shown in the von MISES load ellipse for the corroded tubing. A cut-off criterium of 80% of minimum yield stress can used and when predicted the tubing should be listed for replacement.
This decision support system can be used to provide an overview of
– planning of future caliper surveys – work-over requirements e.g. rigs, tubulars, accessories etc.
Reservoir Souring: An Analytical Model for H2S Generation and Transportation in an Oil Reservoir Owing to Bacterial Activity
Authors: Ligthelm D. J. , de Boer R. B. , Brint J. F. , Schulte W. M. 
Published: December 2007

ABSTRACT
Reservoir souring refers to the generation of hydrogen sulphide (H2S) in originally sweet reservoirs that have been subjected to production operations such as (sea)water flooding. The most plausible cause of reservoir souring is the growth of sulphate-reducing bacteria (SRB) in the zone where seawater mixes with formation water. In the mixing zone the components that support the SRB's life - oxidant and nutrients - are present.
Inorganic reactions are not considered important in the generation of H2S. They are important, however, in the scavenging of H2S, since many iron-containing minerals are capable of reacting with H2S, forming pyrite or pyrrhotite. For this reason, the types and quantities of iron-containing minerals within the reservoir have been studied using petrographic and isotopic techniques.
As a first step towards quantifying the effects of H2S production by SRB, a 1D analytical transport model has been developed. It describes the production of H2S in the mixing zone and the compound's transport through a reservoir. The partitioning of H2S between the fluid phases and the possibility of scavenging by iron-containing minerals have also been included in the model.
The model has served to calibrate a numerical simulator, which can be used for modelling souring under more realistic settings. It is demonstrated how the distribution of nutrients, sulphates and H2S actually observed in a producing field can be used to assess the existence of souring chemical reactions as well as the mechanisms that give rise to them.
Installation of Concentric Subsea Completions from a Jack-Up in the Welland Field: A Case History
Authors: Sanders R. O. 
Published: December 2007

ABSTRACT
During the Spring/Summer of 1990, Arco British Limited., on behalf of the Welland Partnership, carried out the installation of three subsea completions from a jack-up in the Welland Field which is located in the UK sector of the Southern North Sea. The subsea completion was of the concentric type and utilised a first of its kind metal to metal sealing annulus valve in the tubing hanger for annulus access/isolation. The completions were landed in wellheads that had been installed during the previous summer as part of the conversion process from three manufacturer's mudline suspension systems (MLS) to a single type subsea wellhead incorporating a common profile. This paper will present a summary of the pre-planning and experience gained during the installation activities of both the wellhead conversion equipment and the completion equipment.
Insight into the problems that arose will be covered as well as highlights of the successes achieved. Recommendations for future completions of this type will be presented.
A Systems Integrity Study of the Forties Production Plant
Authors: Davison P. , Longhurst M. 
Published: December 2007

Abstract
A team of BP engineers made a systematic study of the Forties platforms, examining the safety of interfaces where pressure drop occurs in piping or plant containing hydrocarbons between high and low pressure. Their recommendations are being implemented by operations staff, a dedicated engineering group, and as part of other projects. Making the changes to the existing plant has required an intensive design effort. The high cost of the retrofits, £12 million per platform, reflects the difficulty in modifying an offshore process plant.
CRASH: Computerised Prediction of Ship-Platform Collision Risks
Authors: Spouge J. R. 
Published: December 2007

ABSTRACT
This paper describes the latest advances in computerised prediction of the risk of collisions between passing merchant ships and offshore installations. Although there have been no major accidents yet in the North Sea as a result of collisions, there have been sufficient collisions from small ships and sufficient incidents of errant and drifting large ships to demonstrate that the accident potential is significant.
To quantify the risk of such accidents, the Department of Energy commissioned Technica to develop a computer model CRASH, which has since been widely used to provide input to offshore risk analyses. Recently, responding to concern that the collision risks may have been over-estimated, Technica have reviewed the model and validated it against actual collision experience.
The paper outlines the collision risk model, presents some typical results, and describes the CRASH program which runs on a personal computer and makes the collision risk prediction technique available to offshore operators.
Personnel Development in the 1990's: Preparing the Next Generation Rig Professionals
Authors: Burt G. L. , Stibbs W. 
Published: December 2007

ABSTRACT
The decade of the 1980s saw dramatic changes in the Drilling Industry worldwide; from record high utilization rates for mobile rigs to total depression and bankruptcies; from a strong market in the Gulf of Mexico to the steady flow of rigs to operating locations outside North America.
What has been the effect of the last decade on the "people" side of the business? To what extent has the technical ability of the drilling contractor been limited in the early 1990s resulting from the permanent departure of the seasoned technicians of the 80s? Where will the experienced people come from as worldwide rig utilization steadily grows and stabilizes? What role will the labor forces of lesser developed countries play in the future of manpower planning and development? What risk of safety and environment will we bear as an industry in this manpower rebuilding mode?
A major drilling contractor operating on land and offshore, long known as an industry leader in training, has tripled its employee development efforts in the last five years to prepare for this challenge. This paper describes the Contractor's current program of training and highlights the commitment in resources required in order to provide for the operational continuity, manpower capability and safety objectives of the future. The paper will clarify the relationship it anticipates beteen the coming manpower shortage, development of personnel and the safety of its people and environment. It will discuss plans already in place to effectively develop drilling expertise in lesser developed countries of operation.
Further, it will provide case study results of a proven method of accelerated training which ensures the development of senior rig personnel expeditiously without sacrificing safety. Finally, the paper will summarize a worldwide effort to develop an even higher calibre of personnel to ensure total quality rig performance.
The Decay of Resuscitation Skills Following Training
Authors: Norman J. N. , Johnson I. W. B. , Brebner J. A. 
Published: December 2007

Abstract
89 personnel were Instructed in resuscitation skills for 2 hours by the same experienced instructor in groups of 10. Their performance was assessed, thereafter, and then after an interval of 4, 8 and 12 weeks. By 4 weeks there was a marked deterioration in performance and this was sustained in all cases.
Evaluation of a Health Care Program for a Remote Oil and Gas Exploration Project
Authors: McDougall J. D. 
Published: December 2007

Abstract
The standard of health care for workers in remote worksites is a major concern for both workers and their employers. This paper details the logistics of setting up a health care system for a remote oil and gas exploration project. The site geography, the regulations and the level of care for these workers will be described. Analysis of the medical problems and the cost of the medical care will be discussed. I will draw conclusions and make recommendations for future remote site health care programs.