bluuebunny/crossref_metadata_2025 huggingface dataset:
Productivity and Coning Behavior of Phased Horizontal Completions
Authors: Karakas M. , Ayan C.
Published: December 2007

In this study, productivity and coning behavior of phased horizontal completions were investigated. We define phased horizontal completions as multiple horizontal drainholes positioned with respect to each other at a certain angle. In addition, each drainhole can be displaced vertically.

Single phase cases were simulated to investigate the productivity increase compared to single horizontal and vertical wells. It was observed that a 90 degree phased completion can achieve about 70 % areal productivity of a comparable horizontal fracture. Additionally, due to improved vertical convergence, vertical skin is significantly reduced on thick formations.

To study the water and gas coning behavior of phased horizontal completions, several two-phase cases were modeled using a commercial simulator. It was observed that coning/cusping problems can significantly be minimized with the suggested completion technique.
Decline-Curve Analysis of Hydraulically Fractured Wells in Dual-Porosity Reservoirs
Authors: Aguilera R. , Ng M. C.
Published: December 2007

Constant producing pressure semi-analytical solutions have been developed for decline curve analysis of hydraulically fractured wells with finite or infinite conductivity in dual-porosity systems. The solutions have led to the identification of the following flow periods: A linear flow period characterized by a straight line with a 0.5 slope in a log-log crossplot of qD vs. tD. This occurs in the case of an infinite conductivity vertical fracture. If the fracture has finite conductivity, the early straight line has a slope equal to 0.25.A transition period due to flow from the matrix into the fractures.A pseudo radial flow period toward the hydraulic fracture.A pseudo steady state flow period when the outer boundaries of the reservoir are reached.

It is concluded that recognition of these flow periods can lead to calculation of fracture permeability, hydraulic fracture half-length, distance between natural fractures, and the parameters omega and lambda.

Type curves have been developed to facilitate reservoir characterization. Their use is illustrated with an example.
Performance Prediction for the M-6 Area of the Tia Juana Field Using a Rate-Dependent Pore Volume Compressibility Model and Extended Material Balance
Authors: McLendon T. H. , Sawyer D. N.
Published: December 2007

Because the dependency of compaction on the rate of depletion is ignored, currently used procedures for predicting compaction are inaccurate. A partly analytical, partly empirical model is presented for calculating oil and gas production, subsurface compaction, and surface subsidence from compacting reservoirs with rate-dependent compressibilities and all major drive mechanisms active. A compacting Bolivar coast reservoir is simulated with excellent results.

Limitations include zero water production, piston-like gas and water influx, and negligible gravity drainage.
Detecting Compartmented Gas Reservoirs through Production Performance
Authors: Lord M. E. , Collins R. E.
Published: December 2007

A technique for using production data to detect and quantify poorly drained compartments in gas reservoirs is described. The method is based upon a multi-compartment, tank-like model with well performance specified by an in-flow relationship. The technique is validated against a detailed finite element simulation. Field examples are presented illustrating the utility of the technique to improve reservoir development strategies.
Miscible Displacement of Fluids Within Fractured Porous Reservoirs
Authors: Zakirov S. N. , Shandrygin A. N. , Segin T. N.
Published: December 2007

The results of experimental and theoretical investigations of miscible displacement process of compressible fluids within fractured porous media are reported. On the basis of these studies the fluids miscible filtration mechanism within naturally fractured reservoirs is established.The influence of such factors as reservoir performance, dynamic characteristics of displacement process including displacement rates, the magnitude of rock pressure and rates of its variation on the displacement effectiveness was revealed. The considerations on the efficiency decrease of fluids extraction from fractured porous reservoirs assuming the use of different technological solutions: selection of optimal techniques of wells position, regulation and redistribution of injection rates and production rates of wells, and also cycling pressure variation within rocks are expressed.
Slug Testing in Multiple Coal Seams Intersected by a Single, Vertical Fracture
Authors: Rushing J. A. , Blasingame T. A. , Johnston J. L , Lee W. J.
Published: December 2007

This paper examines the transient pressure response from slug tests in wells completed in multiple, hydraulically fractured coal seams. We developed a model for stimulated wells producing from commingled reservoirs, i.e., reservoirs in which the layers communicate only at the wellbore and not in the fracture or reservoir. With this model, we have investigated the effects of various reservoir properties on the slug test pressure behavior and have found that the characteristic pressure response depends more on the contrast between layer properties than their absolute values. We also present a method for correlating the slug test pressures from multi-layer and single-layer reservoirs, thus allowing us to use single-layer type curves to analyze slug tests.
Analysis of a Tertiary CO2 Flood Pilot in a Naturally Fractured Reservoir
Authors: Beliveau D. , Payne D. A.
Published: December 2007

Typical EOR screening criteria suggest that naturally fractured reservoirs are poor candidates for miscible CO2 flooding. Despite this rule of thumb, the unusual geology and considerable EOR target of the fractured Midale field persuaded its owners to study implementation of CO2 flood technology.

The 31,000 acre Midale field (Figure 1) is part of a trend of Mississippian carbonate reservoirs in southeastern Saskatchewan. Since 1962, the Midale Unit waterflood has recovered 20% of the 500 million barrels of original oil in place (OOP); ultimate waterflood recovery is expected to be 24%. The reservoir section consists of a heavily-fractured vuggy limestone (the "Vuggy") overlain by a less-fractured chalky dolomite (the "Marly"). Although naturally fractured, well productivities are modest, with average rates of 75-100 STB/D.

In 1984 the Unit owners began a 4.4 acre tertiary miscible CO2 flood pilot. Important pilot data sources included residual oil measurements; single- and multi-well pressure transient tests; fluid analyses; time-lapse logging programs at injectors, producers, and observation wells; chemical, radioactive, halogen, and alcohol tracer programs; phase behavior studies focussing on wax-asphaltene deposition; geotomographic efforts to track flood fronts and displacement insitu; and core/CATSCAN studies of CO2 diffusion in Midale core. The $18.6 million pilot project was completed in 1989.
Fluid, Lithology, Geometry, and Permeability Information From Ground-Penetrating Radar for Some Petroleum Industry Applications
Authors: Baker P. L.
Published: December 2007

Ground penetrating radar is a high resolution geophysical technique that can provide fluid, lithology, geometry and permeability information for environmental assessment, reservoir geology, petroleum engineering and construction. Frequency dependent radar pulse propagation is modelled in conjunction with dielectric mixing laws. Several examples are enhanced and interpreted using adapted seismic techniques. Since borehole radar will be especially valuable in horizontal holes, surface radar examples can be used to identify reservoir applications. Necessary developments in borehole radar hardware are outlined.
Appraisal and Development of the Murta Reservoir Using Hydraulic Fracture Stimulation
Authors: Carnell S. J.
Published: December 2007

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Skin Diseases Among Workers of Exploration and Production Department, South Sumatra, Indonesia
Authors: Harjono Harjono , Djati I.
Published: December 2007

As a State Oil Company in Indonesia PERTAMINA has many fields of operation, and one of them is located in South Sumatera. The exploration and production activities are carried out in three fields, such as in Prabumulih, Bajubang (Jambi) and Pendopo, which are situated in a tropical jungle of South Sumatera Area. To support the operational activities, each locations are facilitated with Medical Services for the workers and their family.

By studying Medical Records of the workers retrospectively during five years (1985-1990) the results shown that 154 workers were suffering from Skin Diseases (population of the workers : 2,675), they are as follows: Dermatomycosis (40,0%)Contact Dermatitis (.38,0%)Other Skin Diseases (16,5%)Skin Infections (06,5%)

Those diagnoses have been stated by General Practisioner Doctors who were in charge in each field.

From the classification, Dermatomycosis takes the first problems, because this kind of disease is coused by dominant factors, such as tropical climate of the area. The second prob lem is Contact Dermatitis which caused by the workers' habits washing hands with solvents, after working. Skin Infection diseases are still found, but in small percentage. Other Skin diseases are Psoriasis, Herpes Zoster, etc., but no skin malignancy is reported.

The conclusion of the paper is that skin disease problem among workers of Exploration and Production Department are relatively low , and its patterns are different from those of other countries.

From the experience, by providing Medical far- cilities in each field of operations,health con dition of the workers and their family can be maintained and improved, and hence the target of Oil Company can be reached effectively and productively.
Management of Occupational Health Worldwide
Authors: de Jong G.
Published: December 2007

As a consequence of general policy guidelines on health, safety and the environment, specific guidelines on the management of occupational health were issued in 1989. The objective of these 'Occupational Health Management Guidelines' is to assist the management of operating companies in fulfilling their responsibility to maintain high standards of occupational health, thereby ensuring compliance with legislation and adherence to company policy. The guidelines present the key elements of an occupational health programme. They clearly describe occupational health as a management responsibility that can be managed in the same manner as safety and other aspects of the business.

To obtain a better idea of current standards and practices of occupational health management, Shell companies were requested to report on the contents, objectives and results of their occupational health programme, preferably in the format of an annual internal occupational health report. Analysis of the data received shows that, over a two-year period, considerable progress has been made. However, it also transpires that a planned, logical approach in occupational health is still lacking in several companies and most companies need to review their programme according to the philosophy of the Occupational Health Management Guidelines. In particular, a greater emphasis should be placed on proper health risk assessment, the basic step in an occupational health programme. There is often also an unnecessary reliance on medical examinations with an usually inadequate analysis of data generated and subsequent justification of these procedures.
A Dietary Survey to Measure Energy and Nutrient Intakes in a Group of Offshore Workers
Authors: Fenn C. E. , Ballantine B.
Published: December 2007

This paper describes a dietary survey, carried out on two offshore platforms, to measure the energy and nutrient intakes of a group of offshore workers. Anthropometric measurements and a blood sample were taken from each volunteer. The results show that the mean percentage body fat was above the desired level and the group could be classified as overweight. The mean daily energy intake was 3,091 kcals which is above the UK Government dietary reference value of 2,550 kcals for men aged 19-49 years, assuming low activity levels at work and leisure. The mean total blood cholesterol concentration was 6.2mmoll-1 which is greater than the value of 5.2mmoll-1 considered desirable by the World Health Organisation. These results suggest that the study group may be classified as at risk from developing coronary heart disease and it is recommended that health promotion strategies are implemented offshore.
A New Database of Health Facilities Abroad
Authors: Hogg Q. E. , Levin J. , Clarke P. D.
Published: December 2007

This paper discusses the development and design of a new database on health care facilities worldwide from its initial planning stage to its first few months of operation, during which time it was used by many of the UK's major companies. It outlines the practical problems that were encountered in establishing and operating the database and how these were overcome. Problems associated with identifying the needs of end users to the difficulty of collecting and evaluating information are discussed.

The database provides information on medical facilities in over one hundred and twenty five countries in the developing world and should prove a useful tool to all those involved in managing medical problems overseas. The growing awareness of the need to assess health facilities abroad has been spawned by the increasing spread of AIDS and the growing demand from employees for better health care management while overseas.

We believe that the establishment of this health care facilities database is an important first step in the creation of an independent network of accredited health facilities worldwide.
Major Accidents in Oil and Gas Industries
Authors: Drogaris G. K.
Published: December 2007

The Major Accident Reporting System (MARS) has been established by the Commission of the European Communities for collecting in a structured way information on Major Accidents in industrial installations involving dangerous chemical substances occurring in the territory of Member States and for distributing the experience gained from them to all Member Countries for improving their accident and loss prevention policies and practices.

By the middle of 1991, about six and a half years after the SEVESO-Directive was enforced, a total of onehundred eleven (111) accidents had been notified by the National Competent Authorities and registered in MARS. Analysis of the accident reports underlines the importance of the following two factors for an effectiveaccident prevention: managerial attitude to safety;application of a structured hazard identification procedure.

A total of thirty five (35) accidents, more than one third of the accidents notified, refer to oil and gas installations.

This paper contains the major conclusions of the study of the accidents after their classification according to various parameters (e.g. type of activity, type of accident, substances involved, consequences, causative factors). Further study of the accident reports enables the extraction of lessons to be learned from them that can be applied for preventing similar occurrences or mitigatingthe conbsequences of such accidents.Illustrative lessons learned from accidents involving gas and oil products are also presented.
The Incident Potential Matrix
Authors: Booth M. J.
Published: December 2007

Adopted for use in Shell Expro in 1989, the Incident Potential Matrix is a tool used to assess an incident in terms of ‘what might have happened’, the initial assessment being made by the immediate line supervisor and the appropriate category of ‘potential’ entered on the Incident Report Form. This may be reviewed and confirmed, eg by the incident investigation team and/or line management.

The category of ‘potential’, known as the Potential Matrix Factor, can be used to assist management to determine the appropriate level of incident investigation and to target efforts to prevent a recurrence.

All incidents reported within Shell Expro are assessed in this way, and the results collated for statistical purposes and to enable management to form a judgement as to the significance of the types and nature of incidents occurring.

Evidence showed that the Lost Time Injury Frequency Rate, whilst considered to be a key indicator of safety performance, represented only a small minority, circa 10%, of total injury and damage incidents reported in Shell Expro.

Furthermore the significance of the Lost Time Injury in terms of its potential for escalation was neither identified or recorded.

In 1988 the idea of constructing a device to provide a broader, more meaningful indicator of safety performance, which would assist management to focus on the more significant incidents, was developed, and introduced the following year.

The paper will explain the use of the Matrix with worked examples and elaborate on how the results are analysed. The benefits of this approach will be balanced against some of the problems experienced to date in its use.
Thermal Requirements for Emergency Suits
Authors: Pasche A. , Holand B.
Published: December 2007

Acceptance testing of emergency suits used at sea is in many countries based on the IMO requirements. For an uninsulated suit, it is required that the suit be capable of protecting the wearer from a core temperature drop of more than 2°C and that skin temperatures measured at the hand, foot and lumbar region do not drop below 10°C for a test period of 1 hour. The test should be performed in cold water of temperatures between 0 and 2°C. It is clear from the regulations that the tests are to be performed using human subjects.

Test results of suits are not only of interest to the approving authorities, but naturally also to the manufacturers. Rectal temperatures of the test subjects wearing the suit are commonly used as an "index" of the suit's thermal qualities. Unfortunately, rectal temperature does not always reflect the real properties of the suit when measured for a limited time.

Experiments have been carried out comparing the thermal qualities between completely dry suits and suits which had been pre-wetted inside with 0.6 1 of water prior to the start of the immersion period. Results indicated that the rectal temperature of the subject with the wetted suit stayed higher than that of the same subject in the dry suit. A Ventile fabric suit tested with or without a thinsulate inner lining showed the same confusing results: no difference in rectal temperatures was indicated. The explanation for the rather unexpected results for rectal temperature change is the fact that in the colder suits shivering will compensate for the increased heat loss.

A series of qualification tests of immersion suits indicated that the acceptance levels established by IMO were rather low with regards to thermal requirements and that any suit would meet these requirements. To test this, a "suit" was made by taping together plastic bags (0.5 mm thickness) and tested according to the IMO test protocol. The suit fulfilled the requirements for thermal protection.
The Safe Use of a Workboat for In-Sea Equipment Maintenance in Marine Seismic Operations
Authors: Baardsen Ø. , Hansen H.
Published: December 2007

The need to repair, change parts or do other such work on in-sea equipment first arose in the middle of the 1980's. This was when 2 streamers were introduced1. Previously, the equipment was taken on board for repair. This was easy to do, and did not require much time to perform the work. After we started using 2 steamers, the work of repairing the equipment became more complicated, since there was a longer delay.

In the beginning, a small boat was used to reach the steamer in order to carry out the necessary work.

To begin with we used a MOB-Harding2. After a while, this type of boat proved to be unsuitable for this purpose since it was very slow. It's maximum speed was between 6-8 knots.
Alternative to Fire-Fighting Halons
Authors: Waterfall K. W.
Published: December 2007

The commercial development and availability of halocarbons, particularly halons in the 1960s, as fire fighting agents was seen as an ideal means of reducing fire losses. The fire protection industry was at last able to apply an electrically non conductive, residue free and relatively non-toxic agent for extinguishing fires in most classes of combustible products.

The ease of handling and applying the product led to its widespread application in the militaryand industry, particularly in the upstream (E&P) sector of the oil and gas industry. The discovery that CFCs, including halons, could damage the earth’s ozone layer has, however, ledto policies to phase out their use. This paper explores the response taken by E&P, particularly Shell companies to find alternative approaches to the use of halocarbons for fire fighting.
Carbon Monoxide Accumulation in Closed, Manned Environments
Authors: Bolstad G. , Jakobsen K.
Published: December 2007

Carbon monoxide (CO) is a colourless, odourless and tasteless gas slightly less dense than air. Its main health significance as a contaminant is that it combines with hemoglobin (Hb) and other oxygen transporting proteins in the body and, thus, impairs the oxygen-carrying capacities of these. CO is produced by incomplete combustion of carbon-containing fuels, but is also continuously produced by the body, mainly through breakdown of heme, one of the constituents of Hb in the red blood cells. Accumulation of CO has been monitored in two different isolation studies with different atmospheric pressures, 1) at 150 kPa(ISEMSI study), lasting 28 days, and 2) at 4600 kPa (IGLOO ’88), lasting 33 days. Two different groups of six male subjects were isolated. In the high pressure investigation (HPI), the Threshold Limit Value (TLV) as given by the Norwegian Petroleum Directorate (NPD), i.e. 2 Pa (20 ppm) bar, was exceeded on isolation day nine, upon which a CO-catalyst was introduced. In the low pressure investigation (LPI) the TLV value was not reached during the study, requiring no such intervention. CO accumulated faster in the first 10-12 days, than in the later part of the LPI. CO accumulation in the LPI averaged 82 mPa/day, corresponding well with the endogenous production rate published by others. CO accumulation rate was slightly faster, i.e. 103 mPa/day, in the HPI than in the LPI, possibly due to a decrease in Hb of approximately 9% during the first 10 days. In both isolation studies, venous blood samples were collected for caboxy- hemoglobin analysis. It is concluded that partial pressure of CO may reach values that calls for intervention during saturation dives as well as in other situations where people are enclosed for longer periods of time. Operational procedures to prevent this from happening should therefore be introduced.
A Diving Safety Management System for Offshore Operators
Authors: Wood N. E.
Published: December 2007

North Sea diving operations are routinely carried out under difficult conditions as an ongoing and essential part of oil industry operations in the North Sea. They can only be carried out safely if effective management systems are in place for their control.

As a basis for such systems the paper initially describes the historical background to the industry and it’s present situation from the point of view of both the Diving Contractors and the operating companies (their clients). Implications of the Cullen report and the requirements forquality systems are also discussed.

The elements of a Diving Safety Management System are then discussed, based on Safety Management Criteria and the procedures and policies necessary for attainment of those criteria. The objectives of the system, Safety Management Criteria and elements, and the basis/content of a typical Diving Procedures Manual are then described to indicate how the management system works in practice.

The system is workable, practicable and applicable to diving operations anywhere in the world.