bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas Well Optimization: Using Velocity As The Key Component in Choosing Tubing Size
Authors: Cox Sidney G.
Published: December 2007

Because depletion drive and partial water drive gas-condensate reservoirs diminish in pressure with production, flow conditions are continuously changing. Choosing the optimum tubing size for this type of wells can be made easier by use of a nodal analysis program to aid in identifying production velocities. More specifically, the seemingly intuitive conclusion that smaller tubulars will always be required during the latter stages of production in order to unload liquids may not be correct. In particular, when flowing bottom hole pressures on high productivity wells reach the low values of 500 to 1,000 psi, fluid loading considerations can become insignificant when compared to frictional losses caused by the unusually high velocities found at these low pressures. Nodal analysis is indispensable for identifying these situations. By performing a few basic sensitivity runs on bottom hole pressure and liquid yields, a confident recommendation can generally be made on whether one tubing size will serve the life of the well or if a size change is advised later in the well life.
Is There a Hope for Adsorbed Natural Gas (ANG) Vehicles ?
Authors: Cárdenas A. R. , Lagoven S. A. , Pilehvari A. A. , Heenan W. A.
Published: December 2007

In light of tighter restrictions on vehicle emissions and the existence of abundant resources, natural gas represents a highly attractive transportation fuel. Worldwide, there are currently more than 976,000 natural gas-vehicles, most of which are located in Europe and South America.1 At present, Compressed Natural Gas (CNG) is the technology most widely used, which stores gaseous fuel at very high pressures (about 3,000 psig). However, short driving ranges and questions of safety and cost have limited the penetration of Natural Gas Vehicles (NGV) into the transportation market in the U. S. This is in spite of the relatively lower price of natural gas compared with other fuels on an energy basis. A new technology called Adsorbed Natural Gas (ANG) is being developed, which contains the gaseous fuel in a dense form at a moderate pressure (500 psig). The lower pressure utilized by ANG allows the usage of conformable tanks which overcomes the short driving range of CNG. Nonetheless, the hope for ANG vehicles depends on further development in the areas of heat management and gas conditioning, in order to preserve the gas tank capacity.
Advanced Type Curve Analysis for Low Permeability Gas Reservoirs
Authors: Cox D. O. , Kuuskraa V. A. , Hansen J. T.
Published: December 2007

This paper presents new performance type curves for hydraulically fractured wells. The new curves are similar to the Fetkovitch curves for decline curve analysis, but have been developed specifically for fractured wells with linear flow instead of conventional wells with radial flow. Hydraulically fractured wells exhibit different flow regimes than conventional wells, including a skin-dominated period during clean-up, bilinear flow, linear flow, pseudo-radial flow, and boundary- or interference-affected flow. The type curves were constructed in Laplace domain for constant reservoir properties, and were then inverted numerically. The effect of varying reservoir properties was incorporated using an average compressibility determined from material balance.

The type curve methodology provides a new tool for the reservoir engineer to perform rapid analysis of reservoir properties (kh), fracture effectiveness (Xf), and well drainage area (A) for fractured wells. The impact of skin on performance is considered, along with the effect of reservoir geometry (alternative length-to-width ratios) that enable these type curves to be used on lenticular formations. The type curves also include variable compressibility and viscosity that are missing in prior work. More than 1000 tight gas wells in the Green River and Piceance basins have been analyzed using the type curves, and relevant examples from these two basins are presented.
Global Optimization Techniques in Gas Allocation for Continuous Flow Gas Lift Systems
Authors: Buitrago S. , Rodríguez E. , Espin D.
Published: December 2007

Continuous flow gas lift is one of the most common artificial lift methods in use. It works by injecting a continuous volume of high pressure gas into the tubing or tubing/casing annulus to lighten the column of oil and thus facilitate extraction. Excessive gas input is costly because of high gas prices and compressing costs. Inefficient gas allocation in a field with limited gas availability also reduces production and profitability.

Historically, a sensible allocation was achieved using a technique called the equal slope allocation method. This method uses graphical procedures to optimally allocate gas to a group of wells in order to optimize total oil production. However, there is a disadvantage in this method, as it can not be applied to wells where there is not an instantaneous response to gas injection.

The purpose of this paper is to present a methodology for automatically determining the optimum gas injection rate for a group of wells in order to maximize the total oil production rate for a given total amount of gas.

The search algorithm proposed is a combination of stochastic domain exploration and a heuristic calculation of a descent direction, in order to avoid stopping the algorithm at a local optimum.
Well-Surface Connection Controls for Gas Reservoir Simulator
Authors: De Moegen H. , Nabil R. , Lehuen P. , Sonier F.
Published: December 2007

History matching on a 'well by well' basis of the measured and simulated results is obtained from standard general-purpose reservoir simulator.

Predictions of performance and deliverability of a gas storage reservoir, design of a gas storage reservoir and simulation of peak requirements are very man-time intensive and cannot be accurate enough without correct handling of the well-surface connection.

This paper describes the recent development of the well-control options which generalises and facilitates the use of Gaz De France's in-house 'multi-gas'/water underground gas-storage reservoir simulator.

Description of the conditions, constraints, and actions at each level (well, platform and terminal station) and solutions are rigorous. All rate and pressure conditions at the wells, target rate and a common single pressure at the platforms and terminal are solved with no approximations, because, for gas storage reservoir simulations, the results and solutions of typical scenarios are extremely sensitive to a very small change in pressure; therefore, the solution must be as accurate as possible.

A comprehensive range of features, constraints and actions is available on pressures, rates, rate ratios, gas concentrations, volumes, saturations, pipes, compressors and gas treatment.

Full-field study and example applications show the utility of this important option.

Introduction

Compared with improvement of simulators, with features such as, for example, fully implicit scheme, naturally fractured reservoir description, compositional modelling, flexible gridding, history matching, etc. for helping the user during the matching stage of a reservoir study, it seems that up to 1995, very little progress has been made about the prediction or the pre-development planning stage of the reservoir study.

The utility of integrating surface facilities to the reservoir model for 'well management' has been set out in some early publications in the 1980's and also in some commercial simulators showing features that include well-centre field-control and target facilities. A paper described an integrated surface facilities/reservoir simulator for the gas storage industry. In 1995, three papers were presented at the 13th SPE symposium on Reservoir Simulation:

P. 461
Horizontal Well Applications in the Guymon-Hugoton Field: A Case Study
Authors: Granger M. J. , Strickling R. W. , El-Rabaa A. M. , Ortez Y. P.
Published: December 2007

Horizontal well activity has increased in the United States and has proven successful in numerous applications. This paper presents the steps undertaken to optimize the application of fractured horizontal technology in a shallow, low pressure gas reservoir. An application of limited entry technology to create a longitudinal propped fracture through a predrilled liner was developed. Available data for fracture direction, acoustic logs, and mechanical property measurements were used in designing the fracture treatment. Tagging the pad, sand, and resin coated sand with isotopes was used to verify the fracture extended along the entire horizontal lateral.
Laboratory NMR Relaxation Measurements for the Acquisition of Calibration Data for NMR Logging Tools
Authors: Ohen Henry A. , Ajufo Austin O. , Enwere Paulinus M.
Published: December 2007

This paper presents results of laboratory studies of nuclear magnetic resonance (NMR) relaxometry for NMR log calibration aimed at enhancing petrophysical measurements in oil wells. Relationships between NMR longitudinal relaxation parameters and the Hydraulic Units (HU) concept for predicting petrophysical properties from wireline logs have been established previously. However, modern NMR logging tools measure the transverse relaxation parameters. Hence in this paper, we show that measurements of the transverse component of the NMR signal can provide the same information as the longitudinal.

Laboratory NMR transverse relaxation characteristics of water in rock samples were measured with CoreSpec-1000. The NMR data were used to validate models for predicting permeability and producible fluid in clastic rocks. The predictive model for permeability includes the rock surface area to grain volume (Sgv) the tortuosity of the flow paths (), the shape factor (Fs), the transverse relaxation time (T2), relaxivity (), and porosity (). The models were used to develop the required NMR log calibration. The transverse relaxation parameters were used with core analysis data of permeability, porosity, and mercury injection capillary pressures to sort the rock samples into hydraulic (flow) units. Protocol for the use of laboratory NMR core spectrometry and core analysis data for NMR log calibration is presented.

Relationships between T1 and T2, and between flow zone indicators (FZI) and relaxivity () were established. It was observed that T2 cut-off (T2c) is related to T1 cut-off (T1c) in the same way that T2 is related to T1. Relaxation time cutoffs are used for determining producible fluid (free fluid porosity or free fluid index, FFI). The results show that reliable prediction of permeability and producible fluid from NMR logging tools requires calibration of the tools with laboratory NMR measurements on representative rock samples. We demonstrate the use of T2c for determining FFI from T2 distributions. The methodology for identification and characterization of HU within geological facies based on NMR T2 was validated.

Introduction

The (HU) concept has successfully been integrated with laboratory core NMR measurements for evaluating petrophysical properties from wireline logs (Ohen et al.). The HU and NMR techniques were linked through the FZI and NMR relaxation parameters, because both the FZI and the relaxation parameters are related to the rock surface phenomenon which controls the microscopic attributes of the rock. Ohen et al. measured the longitudinal (spin-lattice) relaxation time (T1) on a number of reservoir rock samples at a Larmor frequency of 1 MHz with the CoreSpec-1000.

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A Technical and Economical Evaluation of Steam Foam Injection Based on a Critical Analysis of Field Applications
Authors: Delamaide E. , Kalaydjian F.
Published: December 2007

The use of foam to improve sweep efficiency during gas or steam injection has been studied since the end of the 50s. Foam reduces the mobility of gas or steam and this effect is amplified when the permeability increases, thereby correcting the effect of heterogeneity. However, although the consequences of the process are now generally recognized, it is still impossible to quantify them in terms of increase in oil production or reduction of quantities of gas/steam injected. The analysis of the field tests that have been performed in the past 20 years can help in the quantification and forecast of foam performance.

This paper presents conclusions resulting from a comprehensive analysis of steam-foam field tests. They show that, at the present time, steam-foam injection is most efficient in layered reservoirs. Injection of slugs of surfactant with steam in this type of reservoirs can yield an average 3.9bbl of incremental oil per kilogram of surfactant injected. The process is economically attractive even in these times of low oil prices, with a cost of $2 to $3 per barrel of incremental oil.

Continuous injection of surfactant with steam, more adapted to in-depth mobility control in non-stratified, heterogeneous reservoirs. It is a much less efficient method, with an average efficiency of 0.3 bbl of incremental oil per kilogram of surfactant injected, and is not economical.

Finally, guidelines for the design of steam-foam injection tests are provided, and injection pressure during steam-foam is related to steam quality and concentration of the surfactant.
Stimulation by Defoaming Increases Thermal Oil Production
Authors: Juprasert Max S. , Davis Bruce W.
Published: December 2007

Foamed oil emulsions can exhibit significant increases in apparent viscosity due to the entrainment of gas bubbles in the oil. Crude asphaltic components act as natural foaming and emulsifying agents. Their influence causes a large portion of the dissolved gas, which would otherwise be liberated as free gas, to remain entrapped in the water-in-oil emulsion as small bubbles. Such in-situ generation of foamy oil emulsions in the vicinity of the wellbore can have a profound effect on well productivity.

This type of formation damage has been found to be fairly common in low gravity oil reservoirs where steamflooding or steam stimulation is used to enhance oil recovery. A novel well stimulation technique, applying a blend of defoaming and demulsifying surface active agents with a bullhead squeezing technique, has proven to be successful in the Cymric and McKittrick fields, California. The cost of incremental oil gained is less than $1.00 per barrel.
Forecasting Future Domestic Gas Supply
Authors: Garrett Ralph
Published: December 2007

Forecasting future gas supply requires a careful analysis of the historical discovery experience. Since 1967, the AGA annual gas reserve report of reserves by discovery year has provided a key analytical tool. Total reserve provided a key analytical tool. Total reserve additions are dependent on the rate of discovery of new fields but with considerable and varying time lag. The first step in predicting reserve additions is to predict new field discovery rates, where the significant factors are the availability of attractive exploration opportunities and field prices for gas.

Introduction

The future energy requirements of our country and the manner in which these requirements will be met is a matter of great concern to us all. One of our energy sources, natural gas, provided one-third of the U.S.'s energy in 1970. Yet at a time when over-all demand is going up, our inventory of supplies of gas is not keeping pace.

In 1968 industry added less gas reserve than any prior year since 1954. 1969 gas additions were the lowest ever reported by the AGA since its inception in 1945. Without the Prudhoe Bay field in Alaska, 1970 would have been almost as low as 1969.

It would appear that gas supply in the U.S. is currently undergoing a dramatic change. To forecast future supplies in this environment is difficult and very risky. Yet there has never been a greater need for "a look ahead". A careful analysis of the historical sources of supply can help us build a realistic model of our future.
A Safety Management System for an Offshore Azerbaijan Caspian Sea Project
Authors: Brasic Michael F. , Barber Steven W. , Hill Alvin S.
Published: December 2007

This presentation will describe the Safety Management System that Azerbaijan International Operating Company (AIOC) has structured to assure that Company activities are performed in a manner that protects the public, the environment, contractors and AIOC employees.

The Azerbaijan International Oil Company is a consortium of oil companies that includes Socar, the state oil company of Azerbaijan, a number of major western oil companies, and companies from Russia, Turkey and Saudi Arabia. The Consortium was formed to develop and produce a group of large oil fields in the Caspian Sea.

The Management of AIOC, in starting a new operation in Azerbaijan, recognized the need for a formal HSE management system to ensure that their HSE objectives for AIOC activities were met. As a consortium of different partners working together in a unique operation, no individual partner company HSE Management system was appropriate. Accordingly AIOC has utilized the E & P Forum "Guidelines for the Development and Application of Health Safety and Environmental Management Systems" as the framework document for the development of the new AIOC system.

Consistent with this guideline, AIOC has developed 19 specific HSE Management System Expectations for implementing its HSE policy and objectives. These specific expectations are the key elements under which HSE standards and operating procedures are developed. As AIOC operations increase and expand; additional standards and procedures will be progressively implemented based on a prioritized risk assessment. The objective is to establish and continue to maintain operational integrity in all AIOC activities and site operations.

An important feature is the use of structured Safety Cases for the design engineering activity. The basis for the Safety Cases is API RP 75 and 14 J for offshore facilities and API RP 750 for onshore facilities both complimented by "Best International Oilfield Practice".

When viewed overall, this approach provides a fully integrated system of HSE management from design into operation.
Health and Safety Issues Related to Remote Operations
Authors: Shrimpton Mark , Storey Keith
Published: December 2007

A number of issues related to the remoteness of commute operations have implications for safety and health. These include issues related to: operating in a hazardous environment; the hazardous nature of the commute; the use of extended shifts and rotations; the stressful nature of the commute system; the consequences of accidents and health emergencies; and ensuring safe and healthful work environments and practices. Petroleum and mining industry approaches, policies and practices respecting these are discussed; those of the mining industry are highlighted as being of potential value to those planning and managing remote petroleum operations.
Risk Assessment of New Added Facility at an Offshore Gathering/Processing Plant
Authors: Benmebarek S. , Gray T.
Published: December 2007

A Risk Assessment exercise was carried out on a new High Pressure Fuel Gas Compressor system in order to identity, prior to start up and commissioning, the potential hazards that might be induced on the running plant.

As designed, the system is intended to take medium pressure Fuel Gas at 300 psig and compress it through a single stage compressor to 600 psig. HP Fuel Gas is then distributed via a Buffer tank to two Turbo Generators and one High Pressure Sea Water Injection Pump Turbine.

After collecting up-to-date reference information that identifies the various equipment functions in the package, the system boundaries were defined with respect to their interface with the rest of the plant.

Using the Failure Modes and Effects Analysis technique, a system review was performed and results systematically recorded on appropriate formats, to reduce the possibility of omissions and enhance the completeness of the analysis.

The new HP Fuel Gas Compressor unit start up and operation should take place once all deficiencies, with an identified high Risk Priority Code, are rectified
Managing Drilling Operations in a Sensitive Wetlands Environment
Authors: Kudla M. S. , McDole B. W.
Published: December 2007

This paper discusses progressive construction and operational techniques which can be employed to minimize impacts from drilling operations in sensitive wetland environments. Some of the techniques to be discussed include: Use of previously impacted wetlands for access routes;Modified culvert design and placement criteria;Specialized secondary and tertiary spill containment systems;Closed-loop and containerized mud system;"Environmentally friendly" substitutes for hydraulic fluids and lubricating compounds;Integrated waste minimization practices; andInnovative restoration alternatives.

Natural resource trustees have come to expect the use of such techniques when permitting access to custodial wetland areas. While some of these innovations add to the overall cost of the project, others may actually reduce total project cost. Combined with careful planning, these techniques can provide improvement in environmental protection at little incremental cost.
Prevention of Offshore Pollution from Drilling Fluids
Authors: Hayward Bobby S. , Williams R.H. , Methven N.E.
Published: December 2007

Drilling fluids in offshore areas must be handled so as to avoid water pollution. To accomplish this, it has pollution. To accomplish this, it has been necessary to improve operating practices and mud handling facilities. practices and mud handling facilities. These improvements have been made and have led not only to a cleaner, nonpolluting operation but also have tended to minimize mud losses and treating costs. Both water base and oil mud systems are being utilized in sustained drilling operations without polluting the water. polluting the water. Water base mud systems, some containing small amounts of emulsified oil, have been used pollution-free offshore without difficulty. In most cases the drill cuttings are disposed directly into the water, although a precautionary seawater wash is used in precautionary seawater wash is used in the Santa Barbara channel.

Oil muds are being used in clean offshore drilling operations with a combination of good housekeeping practices and cuttings disposal methods. practices and cuttings disposal methods. The oil drill cuttings are being handled by collecting and transporting them to shore for disposal, and by washing the oil from the cuttings and then disposing of the cleaned cuttings into the water. Both methods have proven workable. proven workable. A cuttings collection system, designed to facilitate handling, storage, and transportation for onshore disposal, has proven very successful with oil mud. The system also includes a cuttings conveyor unit but so far the containers have been adapted to the rig shaker discharge with no conveyance needed.

Two basic methods have been tried in an effort to clean the oil from drill cuttings. These are by heating and washing. The heating method has not been successful. Solvent washing of the cuttings to remove oil has proven workable. Diesel oil has proven a good solvent.
Work Force Competence
Authors: Bonn R. J. C.
Published: December 2007

New regulations in the United Kingdom are prompting the petroleum industry to focus on the topic of work force competence. At the same time, many institutions are together developing a national system of competence assurance that will cover a wide range of occupations. Many companies are considering the benefits of aligning their assurance methods with the national system.

This paper discusses some of the issues involved, particularly the link between competence assurance and safety. The discussion will focus on the following areas: The national approach to competence assurance will improve the accountability of competence and may encourage people to broaden their skills. However, there is some doubt that it will reduce the frequency of incidents.There are several competence issues involved in the majority of reported incidents, but formal assurance systems do not appear to address them.To make a significant contribution to safety, employers will need other tools and solutions. Several are suggested.
Reducing the Environmental Impact of 3D Seismic
Authors: Hansen Wolfgang
Published: December 2007

BEB has in the context of a comprehensive environmental impact study investigated all environmental issues in connection with the operation of 3D seismic to arrive at an environmentally more acceptable operation. This is mainly achieved through changes in the planning procedure and through precautions taken before the start of the operation. Special attention has been given to environmental impact of materials used in seismic like bentonites, explosives and equipment but also to the procedures in the field. A major step ahead was the development of a secure shot hole plugging technique. Further successful development of drilling rigs together with the high flexibility in the positioning of shot points and geophone groups enables 3D seismic to meet the strictest environmental regulations. This is shown in a case study of a 3D survey in an highly evironmentally protected area.
Enteric Parasites and Ova in Returning Expatriate Employees
Authors: Frisch J. D. , Molenaar D. M. , Dore M. A.
Published: December 2007

As international exploration and production zones become increasingly remote, the risk for parasitic infection in repatriating employees and their families of petroleum companies has increased. A population of 98 expatriate employees and family members from nine international locations (Philippines, China, Myanmar, Indonesia, Syria, Thailand, Netherlands, Venezuela, and Azerbaijan) was screened by the Union Oil Company of California between January 1, 1994 and December 31, 1995. The overall detection rate for enteric parasites was 53%, with non- pathogenic parasites detected in 39% of the study group, pathogens in 3%, and both pathogenic and non-pathogenic parasites in 11%. Thirteen species of parasite were identified, with the largest varieties identified in repatriated personnel from Indonesia (11 species) and Syria (7 species). Highest infection rates were observed in expatriates returning from Thailand(67%), Syria(79%), and Indonesia(56%), although this result may be skewed because of the small number of expatriates from some countries. A short questionnaire on eating and drinking habits was sent to these personnel, and the results will be compared to infection status In order to control the risk of parasitic infections, expatriate employee health programs may include education concerning both the prevention of parasitic infection and the meaning of a positive parasite screen, particularly for non-pathogenic infection.
An Environmental Approach
Authors: Geerling Chris
Published: December 2007

The Shell Petroleum Development Company is operating in southern Nigeria in the delta of the Niger River This delta covers an area 70,000 square km of coastal ridge barriers, mangroves, freshwater swamp forest and lowland rain forests Over the past decades considerable changes has occurred through coastal zone modifications, upstream urban and hydrological infrastructure, deforestation, agriculture, fisheries, industrial development, oil operation, as well as demographic changes.

The problems associated with these changes are: over-exploitation of renewable natural resources and breakdown of traditional management structures,impact from industry such as pollution and physical changes, anda perception of lack of social and economic equity

SPDC has taken a three-pronged approach to counter these problems: its long-standing environmental programme addresses the problems related to its operations,a community affairs programme, with an outgoing attitude, showing commitment to support the communities through training, provision of school, hospitals, etc., and agriculture and fisheries extension programmes, andthe initiation of an independent and objective study, the Niger Delta Environmental Survey, which will provide the environmental framework in the wider sense for SPDC's operations.

This Survey has as its mission to undertake, in concert with communities and other stakeholders, a comprehensive environmental survey, in order to establish the causes of ecological and socio-economic change over time and to induce corrective action and encourage relevant stakeholders to address specific environmental and related socioeconomic problems identified in the course of the Survey.
Developing a Management Framework for Sustainable Development in the Gulf of Mexico
Authors: Waible Ellen I. , Mangan Andrew T. , Stinson Christopher H.
Published: December 2007

From rapidly-increasing populations to diminishing natural resources, the Gulf of Mexico faces a complex array of threats that require a new, collaborative approach toward resource management. This paper describes a project that will create a preliminary Ecological and Developmental Assessment Model at the regional, national, and international scale for the Gulf and its bordering states. This model ultimately is intended to provide a broad group of decision makers and stakeholders accurate, timely and relevant information about the present and future states of the Gulf. This paper describes the project’s current development, objectives, expected results, and benefits with special reference to the petroleum industry.
Present Status of the Synthane Coal-to-Gas Process
Authors: Forney A.J. , Haynes W.P. , Corey R.C.
Published: December 2007

The U.S. Bureau of Mines has developed a process to make a high-Btu gas from coal. The development work at the Bureau currently involves a fluid-bed gasifier plus a tube-wall reactor methanator. The unique features of the gasifier are: it can operate with any type of coal, including caking coals; it yields a very high content of methane in the product gas; and it operates with low oxygen product gas; and it operates with low oxygen consumption. The gas from the gasifier has to be shifted to make the necessary H2/CO ratio for the methanator, then purified to remove sulfur compounds and CO2. The purified gas is then fed to the methanator for upgrading from 500 to 900 Btu per cu ft of gas, a satisfactory content for a substitute natural gas. The advantages of the tube-wall methanator developed by the Bureau are high throughputs, low pressure drop, excellent temperature control, long life, and good product yields.

The other steps needed in the process—the water-gas shift and the hot carbonate purification—are already commercial operations. purification—are already commercial operations. A prototype plant to operate at 1000 psi is being designed.

Introduction

The Synthane Process is a gasification system converting bituminous, subbituminous, or lignitic coal to a methane-rich gas of pipeline quality. The basic sequence of process steps in the system is: (1) coal pretreatment to destroy caking properties, (2) gasification of the pretreated coal in a fluidized bed, (3) shift conversion of the product gas to a hydrogen-carbon monoxide ratio of product gas to a hydrogen-carbon monoxide ratio of 3:1, (4) purification of the product gas, and (5) catalytic conversion of the clean gas to methane.

The Synthane Process has been described in recent Bureau of Mines publications with particular emphasis on the gasification step. This report describes the Bureau's engineering development of all steps except shift conversion, which is commercial, and presents the current status of the process and future plans.

Because the need for a coal-based process to supplement our natural gas reserves has been extensively documented further detailed discussion is unnecessary. The situation can be summarized by emphasizing that the role of high-Btu gas in the U.S. energy requirement is expanding rapidly to meet the demand resulting from dwindling natural gas reserves. The gas demand is accentuated by accelerating restrictions on high-sulfur fuels for central-station and industrial power generation. power generation.
There's More to the Toxicity of Natural Gas than H2S!
Authors: Drummond Ian
Published: December 2007

Three workplace accidents are described. The accident investigations identified an area of incomplete knowledge about the ability of hydrocarbon gases to intoxicate people. The effects of the gases include reduction in reasoning and decision making ability as well as physical coordination. This work has been published (Light Hydrocarbon Gases: A Narcotic, Asphyxiant or flammable Hazard? by lan Drummond, App.Occ.Environ.Hygiene, 8(2), 120-125, 1003).

Since that time additional evidence has been obtained from an emergency room physician, from other accident investigations, and from the field of substance abuse. Further work is anticipated to compare the ability of propane and ethyl alcohol to impair task performance.

Imperial Oil Limited has adopted the following occupational exposure limits for Cl to C3 gases:

Maximum allowable concentration 10% Lower Explosive Limit (LEL); 15 minute Short Term Exposure Limit, 1500 ppm; Full shift (8 or 12 hour) time weighted average. 1000 ppm

Among the actions taken by Imperial to control exposures to the hydrocarbon gases, area combustible gas detectors have been set to 10% LEL for lire first level alarm and operators are required to wear self-contained breathing apparatus when responding to the alarms. For locations that do not have area combustible alarms the use of personal LEL alarms is encouraged, and periodic industrial hygiene surveys tire performed to identify leaks.

Better understanding of the health effects of the hydrocarbon gases has allowed a clearer definition of the dividing line between "sour gas" where the toxic effects of hydrogen sulfide are most important, and "low H2S" gas where the toxicity of the hydrocarbons is most important. The development of a Code of Practice for hydrocarbon/H2S mixtures is described.
Draugen HSE-Case - Occupational Health Risk Management
Authors: Glas J. J. P. , Kjaer E.
Published: December 2007

The Draugen HSE-Case serves as a risk management tool. Originally, risk management included only major safety hazards to personnel, environment and assets. Work environment risks such as ergonomics, psycho-social factors and exposure to chemicals and noise, was not given the same attention. The Draugen HSE-Case addresses this weakness and extends all work environment risks. In order to promote line responsibility and commitment, relevant personnel is involved in the Case development. "THESIS", a software application, is used to systematise input and to generate reports. The Draugen HSE-case encompasses: - HSE risk analyses related to specific activities, - Control of risk related to work environment, - Established tolerability criteria, - Risk reducing measures, - Emergency contingency measures, - Requirements for Competence and Follow-up.

The development of Draugen HSE-Case is a continuous process. It will serve to - Minimise the potential of occupational illnesses, - Raise general awareness, - Make occupational health management more cost-effective.
Experiences in Use of the NORSOK Standard on Working Environment in Project Work
Authors: Kjellen Urban
Published: December 2007

This paper is based on experience in the implementation of the NORSOK standard on the working environment in two off-shore projects. Expectations for the standard and the main principles behind it are presented together with a general out-line of the standard. The paper reviews the initial experiences with the standard regarding needs for competence, execution of analyses and evaluations, implementation of design requirements, cost consequences, and customer satisfaction.

It is concluded that the standard promotes increased atten-tion to working environment aspects and contractors' acceptance of responsibilities to meet the oil companies' expectations and regulatory requirements. The full benefits of the standard will only be achieved when contractors have ac-quired the necessary experience and developed efficient pro-cedures and instructions for the new work processes that are required by the standard. A means of systematic compilation of detailed working environment experience during operation and communication of this experience to contractors and ven-dors need to be further developed.
Recommended Guidelines for Systematic Follow-Up of Working Environment on Mobile Installations Operating on the Norwegian Continental shelf
Authors: Smith C. C. , Boehlerengen M. , Sjoeberg G. A. , Berntsen M. , Teige K. , Rimstad H.
Published: December 2007

The 1977Norwegian Working Environment Act entered fully into force in the Norwegian petroleum industry on 1 January 1993. Since 1979 only parts of the Act, valid since 1977 for onshore activities, was in force for the offshore petroleum industry. Some minor parts of the Act does still not apply to the petroleum industry offshore, but they are irrelevant to this paper.

In order to provide for a working environment (WE )in accordance with the requirements set out in the Working Environment Act the Norwegian Petroleum Directorate issued 8 March 1995 a Regulation relating to the Systematic Follow-Up of the Working Environment in the petroleum activities.

In order to create a set of Guidelines for the Norwegian rig- and shipowners industry the Norwegian Shipowners Association formed a group from 4 rigowners employees to write a " handbook " on how to follow-up the Acts and Regulations on the mobile offshore installations.
Safety Management Systems - The Next Steps?
Authors: Blackmore G. A.
Published: December 2007

The leading companies in the UK oil and gas industry operate well developed management systems within an advanced legislative framework It is generally perceived that health and safety has improved under this regime but preventable fatalities and accidents are still occurring, in the wider aspect of management, successful international companies claim to have achieved their success by creating a culture where people lower down the organisation take ownership for activities and their direction This is the next challenge in the management of safety
A Novel Retrofit Solution for Oily Cuttings Slurrying and Re-Injection on the Ula Platform
Authors: Minton R.C.
Published: December 2007

Within the North Sea area there are many platforms nearing the end of their initial drilling phase but with the likelihood of significant, if infrequent, sidetracking operations in the future. For a number of these, oil based drilling fluids still offer a cost effective solution, particularly where tortuous trajectories are proposed. The Ula platform is a case in point, but, as with all operations in the Norwegian sector, unprocessed oily cuttings can not be discharged. Cuttings slurrying and re-injection resolves this problem and has been successfully used by BP Norway on the Gyda platform for the last 5 years. The challenge, therefore, was to design a slurrying system for the Ula platform, recognising both the space limitations and the cost constraints. This paper reports on the novel solution adopted, the costs involved and the subsequent performance of the installation.

Introduction

The Ula field, located in block 7/12 of the Norwegian sector of the North Sea, (Fig. 1), was discovered in 1976 by the semi-submersible drilling rig "Nordskald". It is a jurassic reservoir, at some 3200M vertical depth below sea-bed with total recoverable reserves estimated at 435 million barrels of oil equivalent. The PDQ (Production, Drilling, Quarters) jackets were installed in 1985 and first oil was produced in 1986. In the intervening ten years, over 300 million barrels of oil have been produced. The production rate is presently about 50-55,000 barrels of oil per day, with a water injection rate of about 200,000 bpd. Eighteen slots are available and, at present, there are 11 wells on production, six are water injectors and one is temporarily abandoned.

The first seven wells on the field were drilled using a KCl/Polymer drilling fluid system. However, major problems were encountered in drilling the Tertiary shale interval, so much so, that Low Toxicity Oil Based Muds (LTOBMs) were used for the 12 1/4" and 8 1/2" sections of the latter wells. The resultant fluid costs were reduced by 36%, on a comparable cost per meter basis, the average ROP increased 74% (Table 1) and the drilling problems were significantly reduced.

However, there remained the issue of the oily cuttings. A cuttings cleaning plant was, therefore, installed, and it succeeded in reaching the then specified limit of 10% oil, on a weight by dry weight basis. Efforts were subsequently made to reduce the residual oil on the cuttings further, so as to comply with the interim 6% limit, that was to be introduced.

P. 519
Environmental Performance Indicators - the Line and Management Tool
Authors: Jones Murray G. , Hartog Jan J. , Sykes Richard M.
Published: December 2007

Shell companies have their own separate identities. In this paper the collective expressions 'Shell' and 'Group' and 'Royal Dutch/Shell Group of Companies' may be used for convenience where reference is made to the companies of the Royal Dutch/Shell Group in general. Those expressions are also used where no useful purpose is served by identifying the particular company or companies.

The Objective of the presentation is to make the audience aware of the value and approach to Environmental Performance Indicators (EPI) for both internal and external use.

The premise is that EPI are of benefit in a number of ways including:–measuring performance against targets–gaining internal credibility–ensuring what gets measured gets done and reported–providing information to the various stakeholders–meeting external demands for reporting–responsible corporate citizen

A key theme will be the need to report (information, data) at the level where key stakeholders are concerned i.e. this is at the Shell Operating Company level as the companies must work with their neighbours, governments and local NGO's. It is also crucial to note that the report is an internal communication vehicle - you want/need the employees on side.

Recognition that companies must move into EPI as their information base becomes available. This is only just the case in many companies. Concerns with aggregating data will be mentioned (i.e. loss of specific information, different means of accounting, ability to interpret). Reference will be made to move of companies into public environmental reporting as the information base becomes available. This is only just the case in many companies.

Content aspects will include:–the need for quality data–the need to present information that is also used within the Company (e.g. Targets, Objectives) thus of value added not additional work–the use of EPI in external reports

'Good' examples of EPI will be provided from within the Shell EP World including Shell EP Companies from Canada, Netherlands, Norway and Oman. The development of EPI by industry associations will also be addressed.

Introduction

Environmental Performance Indicators (EPIs) are a principal means of measuring and recording environmental achievement over time. The move to the use of EPIs in Shell EP Companies is complimentary with the programme of performance data gathering that has been underway for 3 years and with the needs and requirements of a Health, Safety and Environmental Management System (HSE MS). Currently available environmental data includes air emissions, wastes, effluents, potential liabilities and spills. Smaller amounts of information are emerging on effects. EPIs should be chosen to reflect those areas in which the Company has identified the need for environmental management and control.

P. 537
The Lifecycle Approach to Hazard Management
Authors: Dalzell Graham A.
Published: December 2007

The Cullen report into the Piper Alpha disaster recommended a change from prescriptive legislation to a goal setting approach. The new legislative approach is -described in Ref (1). The preparation of the regulations covering fire, explosion and emergency response Ref. (2) which would support the Safety Case coincided with an initiative by UKOOA, the United Kingdom Offshore Operators Association, to develop guidance on hazard based design to protect against fires and explosions. Agreement was reached with the UK Health and Safety Executive and the drilling and design contractors to work together to develop it into the technical guidance to support the new regulations. This set a precedent for UK offshore safety legislation. Previously, the regulators had developed, and had been the custodians of such guidance. It also marked a new era in positive co-operation between the "ruler and the ruled".

The UKOOA Fire and Explosion Hazard Management (FEHM) guide Ref. (3) is the product of that initiative. Initially, the authors set out to prepare guidance for designers of fire and explosion protection systems to encourage them to specify systems to match hazards. It soon became apparent that there was no overall guidance describing an integrated approach for managing hazards. The result was the development of the lifecycle hazard management concept. This paper outlines the lifecycle and highlights the main features of a risk management system which is based upon it. The approach can be applied not only to fires and explosions but to all major accident hazards including these involving toxins or pollution.
Employee Assistance Programs for Expatriate Employees
Authors: O'Donnell William J. , Wilson Dixie B.
Published: December 2007

With the rapid expansion of the global market, there is an increasing need to identify, develop, and support expatriate talent. The literature reveals that 20% of American expatriates fail in their assignments. Each failure can cost a company up to a million dollars. It makes good business sense to find ways to protect these investments. This presentation will focus on the delivery of EAP services to expatriates through a consortium model, as well as recommend a six-step process - a comprehensive HR approach to help insure successful expatriate assignments.
The Pattern of Accidents on Offshore Drilling Rigs in the North Sea
Authors: Forbes M. J.
Published: December 2007

As part of the effort to reduce accidents on drill floors, the pattern of fifteen years of retrospective accident data involving North Sea drill crews was studied. Of the various patterns examined it was found that there was an increase in accidents in the 0000 - 0400 hours period, and also that accidents rose to a peak in the middle of a two-week shift. Possible factors are discussed and suggestions made to decrease the accident peaks.
A New Solution to ILU Preconditioning Parallelization and Its Applications in Reservoir Simulations
Authors: Xing Jian , Ma Yuan Le
Published: December 2007

This paper presents a new parallel ILU preconditioned It is based on the technique of Sequential Staging of Tasks (SST) which overcomes the difficulty of recursiveness arising from ILU factorization. This new parallel ILU preconditioner is easy to reconstruct from the sequential version. The only requirement is to insert the synchronization codes of stages of tasks into the sequential version, and any other modifications to the original serial codes are not needed. The characteristic of matching various ordering schemes is still maintained, and the new merit of handling different numbers of processors is obtained. Numerical results were obtained using a thermal model with different grid system. The parallel speedup is satisfactory.
The Migration of CADE Software for Oilfield Application to Laptop Computers
Authors: Ward V. L.
Published: December 2007

The popularity of Laptop computers has dramatically increased because of their portability, low cost and increasing competitiveness with Workstations and mini-computers’ performance. As a result, many organizations are beginning to migrate their engineering applications to Laptop Computers. In 1994 Schlumberger Dowell started to migrate the full suite of mini-computer based CADE (Computer Aided Design and Evaluation) applications to Laptop computers. This paper chronicles the issues faced and resolved during the successful migration of the software.