bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiphase Pumps for Light Oil Steam Flood, from Design and Operation Perspectives
Authors: Putra Erwinsyah
Published: December 2007

Caltex Pacific Indonesia began operation of a Light Oil Steam Flood (LOSF) project in the Minas Oil Field, Sumatra. Multiphase pumps (MPP) are utilized as the casing vapor collection system. Three twin-screw MPP's have successfully operated since June 2000. The MPP's were designed to handle high sand-rate. By means of closed loop control, the MPP's actively control production wellhead pressure, critical for optimizing electrical submersible pump operation in the tubing side. Closed loop control also provides the ability to handle hydrodynamic slugging in the incoming lines. This paper describes the design, testing and successful field operation of the Multiphase pumps in the Minas Light Oil Steam Flood Project.
Cementing Considerations for Deep Wells in the Appalachian Basin
Authors: Peters F. W. , Schindler R.
Published: December 2007

As drilling operations penetrate deeper horizons in the Appalachian Basin, wellbore construction faces new challenges. Larger and deeper hole sections, higher temperatures, higher formation pressures, and naturally flowing high rate gas zones result in wells that cannot be properly or safely completed with conventional Appalachian Basin cementing techniques.
An Analytical Model for Gas-Water-Coal Particle Flow in Coalbed-Methane Production Wells
Authors: Guo Boyun
Published: December 2007

Coalbed methane (CBM) plays an important roll in US energy market. Prediction of CBM well performance is vitally important for enhancing CBM production. It is highly desirable to have a simple and accurate tool to do the prediction job.

Assuming homogeneous mixture flow of liquid, gas, and solid in pipes, a simple analytical model was developed for simulating 3-phase flow in production strings. Liquid holdup effects were considered by applying a tuning factor to friction factor. The tuning factor was defined as a function of gas-liquid ratio (GLR) and vertical depth. The analytical model was coded in a spreadsheet program and calibrated with measurements from a full size physical well model. The calibrated analytical model was used for predicting performance of CBM wells during gas-lift dewatering operations and proven to be accurate for upward flow of CBM gas and water in a 2-7/8" tubing.
Use of Wellhead-Pressure Data to Establish Well-Inflow Performance Relationship
Authors: Guo Boyun
Published: December 2007

Inflow performance relationship (IPR) of wells is an essential piece of information required in production well modeling and optimization. A reliable IPR is usually established based on bottom hole pressure measurements. However, such measurements are often very expensive. It is highly desirable for production engineers to be able to establish well IPR from wellhead-pressure measurements.

This paper demonstrates that a mechanistic model originally developed for modeling gas, water, oil, and solid particle 4-phase flow in borehole drilling can be employed for establishing IPR of oil wells when bottom hole-pressure measurements are not available. Two cases with field measurements are presented. The results indicate that, using the 4-phase flow model, the well IPR curves constructed based on the wellhead-pressure measurements are accurate. The error in bottom pressure prediction is less than 2%. The error in productivity index determination is less than 10%.
4-D Mapping of Porosity and Investigation of Permeability Changes in Deforming Porous Medium
Authors: Karacan C. Ozgen , Grader Abraham S. , Halleck Phillip M.
Published: December 2007

Reservoir rock near wellbore experiences substantial changes in the poroelastic stress field due to presence of the well itself and later to changes in effective stress conditions as reservoir pore pressure is depleted. Hydraulic fracturing or other stimulation treatments may introduce further stress changes. Although such stress changes may lead to macroscopic rock failure, even under less severe loading, substantial changes in the pore structure. Such stress- and time-dependent deformation of the porous structure is known to change important properties of the rock such as porosity, and permeability.

In this study we investigate the porosity and permeability changes in deforming porous rock using X-ray CT imaging. We used a specially designed X-ray-transparent tri-axial cell enabling fluid flow at the same time. We scanned the samples at successively higher differential stress to observe stress-dependent changes in porosity and permeability. Since the presence and value of confining pressure changes the deformation behavior of the rock, we applied different constant confining stresses on the samples to change the deformation regime and map the porosity in the failure regions.

Results showed that the stress condition applied to the porous medium changes the rock and fluid transport properties compared to the sample measurements done without stressing the sample. Medical and industrial high resolution X-ray scanners enabled us to quantify and map local porosity changes, locate compaction band and where shear location occur and how the inner structure of the rock changes during different modes of deformation. We also compared the properties of sandstone with limestone under deforming stresses.
A Comprehensive Approach to Completion Optimization
Authors: Venkitaraman A. , Manrique J. F. , Poe B. D.
Published: December 2007

The completion selection process is a critical step in ensuring well productivity. It is shown how this can be optimized by a decision tree based approach along with a combination of predictive analytical tools.

The completions are broadly divided into those that would be limited by sanding issues over the producing life of the well as opposed to those that would not. Available sanding prediction models are used for this decision step. For wells where sanding could be an issue two separate options are analyzed: sand control and sand prevention. Sand control implies completions that incorporate some means to physically prevent the transport of sand along with the flowing fluid. On the other hand sand prevention uses predictive models to generate completion and production parameters that minimize the risk of sand production. Where sanding is not an issue, traditional completion options are evaluated: open-hole, natural (cased-perforated) and stimulated (fractured) completions.

Once the above process is complete, the best completion option is determined using three steps: i) quantifying the impact of different options on well productivity, ii) production forecasting, and iii) economics and risk analysis. Predictive tools combined with prior experiences are used to determine the impact of different completion choices on well productivity. Using this information single well production forecasting is carried out using mathematically rigorous and computationally efficient well performance simulation model. Lastly, economic analysis that combines the upfront costs and predicted production data is used to determine the best completion choice for the well. In addition to economic analysis, this step also considers risk - in the form of uncertainty in key parameters.
The Design and Deployment of Enhanced Scale Dissolver/Squeeze Treatment in Subsea Horizontal Production Wells, North Sea Basin
Authors: Jordan M. M. , Hiscox I. , Dalton J. F. , Mackie J. , Kemp S.
Published: December 2007

This paper presents an overview of life cycle flow assurance management for a subsea development by focusing on scale control. To illustrate this approach field results from 6 dissolver/squeeze treatments using novel solvent packages to enhance the performance of both carbonate/sulphate scale dissolvers are cited. Subsea horizontal production wells were stimulated and protected using this treatment method. The dissolver and squeeze treatments applied to the horizontal wells utilised a thermally degrading wax divertor to temporarily impair injectivity in the heel region thus allowing propagation of chemical along the wellbore.

The paper will outline the principles by which dissolvers function and the increase in dissolver efficiency made possible with the use of a surfactant package. The practical concerns about deployment methods within subsea production wells are also emphasised.

The deployment technology developed for these treatments was adopted to allow the dissolver surfactant packages to be placed into the near wellbore region so stimulating production prior to application of future squeeze treatments. This paper clearly shows that it is possible to improve dissolver effectiveness by the use of surfactant packages while having minimum impact on treatment cost. The deployment of the dissolver chemicals in all cases stimulated production in the wells, which resulted in the cost of the treatment being recovered between 2 and 23 days. The deployment methods used for these treatments into sub-sea horizontal wells reduced the need for expensive coiled tubing intervention so improving the economics of this method of scale management in a maturing oilfield
Comparative Study of Different Barite Dissolvers: Technical and Economic Aspects
Authors: Lakatos I. , Lakatos-Szabó J. , Kosztin B.
Published: December 2007

An extensive research programme was launched with the aim at evaluating the potential of seven different polyamino carboxylic acids (PACAs) using both technical and economic aspects. Dissolving capacity of each compounds was determined under equilibrium conditions as a function of concentration for barite and reservoir rock (sandstone). The absolute and relative selectivity of dissolution, viz. the matrix effect of formation rock were precisely analyzed. Dissolution of barium sulfate, calcium and magnesium carbonate and iron compounds was followed in time, and thus, the kinetic calculation could also be made.

Results of the research programme provided reliable data for comparison of dissolution capacities under identical chemical (equilibrium, kinetic, dissociation, etc.) conditions. On the basis of the experimental findings it was concluded that the sequence of dissolution capacity is different if the results were evaluated in technical or economic senses. It was also shown that the preferentially used compounds (e.g. DTPA, and particularly EDTA) are not the best choices when technical considerations are only enforced. The economic grounds, however, may partly justify their application at the expense of poor efficiency. The systematic analysis of the mentioned dissolvers may open new vistas in mitigation of formation damage caused by barite or barium sulfate scales and accelerate the search for more effective mixtures of complex-forming agents to be applied under field conditions.
Pushing the Envelope: Successful Hydraulic Fracturing for Sand Control Strategy in High Gas Rate Screenless Completions in the Jauf Reservoir, Saudi Arabia
Authors: Solares J. Ricardo , Bartko Kirk M. , Habbtar Ali H.
Published: December 2007

Hydraulic Fracturing for sand control techniques in screenless completions have been successfully attempted, predominantly in oil wells, by operators the world over; whereas, frac-packing has rapidly become the preferred option for high rate gas wells in highly permeable reservoirs.

Saudi Aramco is currently undertaking one of the largest gas development projects in the world comprising a large number of new deep wells, four world-class gas plants, and massive development of new infrastructure.

The Jauf reservoir, one of several forming part of the gas development project, is a sandstone with unique characteristics, because it exhibits low to moderate permeability but high sanding tendency caused by high degree of rock unconsolidation under high pressure and temperature conditions. Frac-packing was considered as a potential sand control technique early during the planning phase, but the relatively low permeability encountered upon testing of the first Jauf reservoir producers clearly indicated that highly conductive, long half-length hydraulic fractures would be required to meet gas rate project targets. Hence, the decision to pursue fracturing for sand control techniques with screenless completions techniques was made.

This paper presents the results of a performance driven process, successfully implemented by Saudi Aramco in partnership with Schlumberger, which has achieved sand and solids free gas production in a score of wells treated to date. A detailed description of the combination of effective techniques applied as part of the process is provided, and lessons learned throughout the fracturing campaign are shared. The solids free gas production rates achieved in the wells discussed herein range from 10 to 50 MMSCF/D at high condensate yields. All wells were repeatedly cycled and, in some cases, limitation on the testing equipment used prevented testing wells at higher solids free rates to achieve full potential.
Development of the Alba Field – Evolution of Completion Practices, Part 2 Open Hole Completions; Successful Outcome – Drilling with SBM and Gravel Packing with Water Based Carrier Fluid
Authors: Murray G. , Morton K. , Blattel S. , Davidson E. , MacMillan N. , Roberts J.
Published: December 2007

Chevron has been successfully drilling and gravel packing open hole horizontal wells on the Alba Field (central North Sea) since 1998 and 13 open-hole gravel packed (OHGP) wells drilled with water based mud(WBM) are currently in production with no history of sand production. Although these wells have been hugely successful with significant net present value (NPV) returns it was recognised that the future, mature redrill and infill targets cannot sustain the current costs associated with traditional OHGP completions. The challenge was to develop alternative techniques to maintain the benefits of OHGP wells but to achieve a low cost well and completion concept to assist in realising new drilling opportunities.

To drill the shale above the top of the reservoir and the productive interval in a single hole section would remove the conventional requirements to set an additional casing string and change over to a water based system prior to drilling into the reservoir. This would save costs but raise a question over the gravel packing operation. Hitherto, attempts to gravel pack involving á/â placement techniques using an aqueous carrier fluid following drilling with oil based systems have had only limited success.

The prospective problems were examined by extensive laboratory tests carried out by Baroid and Chevron in co-operation. A new synthetic oil based mud (SBM) formulation was developed and compatible displacement fluids and procedures were devised.

Based on this work, 1500 ft of shale and reservoir were drilled; a liner was installed – predrilled over the reservoir section - and screen was run inside the liner. Gravel was pumped using brine as carrier fluid and complete gravel placement was achieved. The well has achieved productivity levels at least as good as existing WBM wells. A second well completed in the same manner has given similar performance.

This combination of a liner system and SBM fluids offers several advantages. There is the prospect of considerable savings with respect to operating time, cementing and drilling fluids. Also the liner gives protection to the screen.

This new approach which represents potential large savings in costs and excellent productivity is considered to be very applicable for expandable sand screens (ESS), multi-lateral completions and additional redrill targets both on Alba and worldwide.
Balance Between Formation Damage and Wellbore Damage: What is the Controlling Factor in UBD Operations?
Authors: Guo Boyun
Published: December 2007

Underbalanced drilling (UBD) has been considered as an effective means of formation damage control during drilling. However, there is a trade-off between formation damage and wellbore damage in UBD. The wellbore damage includes borehole collapse, cave-in and washout associated with the lowered bottom hole pressure. The damaged wellbore results in the increased drilling cost and also brings in completion problems such as poor cement bonding quality and/or cement collar being too thick to be penetrated during perforating job.

While the highest bottom hole pressure during normal drilling condition affects the degree of formation damage, the lowest bottom hole pressure during pipe connection controls severity of the wellbore damage. Both the highest bottom hole pressure and the lowest bottom hole pressure are controlled by the combination of the liquid and gas flow rates. In order to minimize both the formation damage and wellbore damage problems, it is highly desirable to have an easy-to-use approach to generate balanced design of combinations of liquid and gas flow rates under given drilling conditions. The content of this paper fills the gap.

This paper presents an innovative procedure to approach the optimum design of liquid and gas flow rates combinations for UBD under given geological constraints. The optimum flow rate combinations are selected from a liquid-gas rate window. The liquid-gas rate window is an envelope in the liquid flow rate vs. gas flow rate plot. In developing the liquidgas rate window, formation fluid pressure limits the upper bound of the flowing bottom hole pressure and wellbore collapse pressure serves the lower bound of the circulation breaking bottom hole pressure. The window is closed by fluid's cutting carrying capacity and wellbore washout criteria.

This paper first time provides drilling engineers with an easy-to-understand procedure to optimize mud and gas flow rates in UBD.
Gravel Pack Designs of Highly-Deviated Wells with an Alternative Flow-Path Concept
Authors: Sanders M. W. , Klein H. H. , Nguyen P. D. , Lord D. L.
Published: December 2007

Alpha-Beta gravel packing procedures have been used with a moderate degree of success in highly-deviated wells. Incorrect concentrations of gravel and/or pump rates can result in bridge formation in the open hole/screen annulus and Beta wave initiation prior to reaching the toe. If there is a high leakoff zone, gravel concentration will increase, and there may be insufficient velocity to transport the solids farther down the well. Either factor or a combination of the two can lead to formation of a bridge in the openhole/screen annulus and an early initiation of the Beta wave. Other effects that could lead to bridge formation include: flow restriction and blockage from collapse of an unstable open hole section, and changes in annular velocity transition from one hole size to another. Incomplete gravel placement and the presence of voids around the screen can result from all of the complications described above. To overcome these, an alternative flow-path system has been developed. If a bridge forms, the alternative path allows the slurry to bypass it. A number of physical models have been used to design and examine the effectiveness of the system, which has been validated in field applications.

A numerical model has also been developed to assist with the gravel pack designs in highly-deviated wells. The model simulates the alternative flow-path concept as well as conventional gravel packing in open hole or cased-hole completions of arbitrary deviation. Details of the alternative flow-path scheme as well as the formulation of the numerical model are presented in this paper. Simulation results were compared to observations in the physical models.
The Optimization Of The Productivity Index And The Fracture Geometry Of A Stimulated Well With Fracture Face And Choke Skins
Authors: Romero Diego J. , Valko Peter P. , Economides Michael J.
Published: December 2007

The post-treatment performance of hydraulically fractured wells has been a recurring theme in the petroleum literature, covering the spectrum of understanding the physics of flow to the optimization of design. Optimization itself has taken different hues meaning comprehensive economic, or just the reduction of execution costs, or the maximization of the production or injection rates.

Irrespective of the ultimate criterion, the magnitude of the reservoir permeability has been central to the fracture morphology. Long fractures are warranted for low-permeability reservoirs; wide but short fractures are indicated for high-permeability formations. For a given reservoir of known permeability and dimensions the mass of proppant injected to the pay describes a unique and constant proppant number for which a maximum well productivity index can be achieved at the optimum dimensionless fracture conductivity. The proppant number and the optimum dimensionless fracture conductivity determine exclusively the optimum fracture dimensions.

However, damaged hydraulic fracture performance deviates substantially from that of undamaged fractures. Two types of damage are considered, fracture face, often caused by fluid leakoff into the reservoir and choke fracture, which is caused by proppant flow-back, over-displacement or polymer damage. These damages, described by skin effects cause a departure, at times substantial, from the indicated undamaged optimum fracture geometry.

In this work, the performance of a fractured well is calculated using a direct boundary element method. The method calculates the dimensionless productivity index and the model allows for the presence of the two different skin effects. The fracture face skin effect was found to have a significant detrimental effect on the dimensionless productivity index, especially for high-permeability reservoirs. The effect of the choke skin was found to be potentially also very detrimental, but less complex to account for, because it can be represented as an apparent reduction to the proppant number.
Last Chance Production Enhancement Opportunities for Near-Depleted Zones
Authors: Sobernheim D. W. , Page W. H. , Womack A. L.
Published: December 2007

As part of an over-all reservoir management strategy, production enhancement techniques for near-depleted wells fit in to a pre-abandonment analysis step for determining if additional gas or oil can be economically recovered prior to well or field abandonment using some form of workover intervention.

It is widely recognized that over time, a near wellbore skin may develop in completions that were relatively undamaged originally. We present methodology for determining appropriate candidates for production enhancement in nearly depleted, declining, high-skin oil and gas wells. Our case studies include candidate recognition, job economics, and practical execution information related to performing stimulation workovers in low-pressure wells with significant skin. Wells with pressure gradients as low as 0.1 psi/ft have been successfully stimulated with these skin reduction techniques and returned to production. To work properly, the stimulation must use energized and/or foamed fluids, the chemistry of the treatment must be optimized for maximum stimulation and clean-up, and a reliable and rapid flowback procedure must be implemented.

The new technique relies upon pressure transient testing or advanced decline-curve analysis for the skin diagnosis, the current average reservoir pressure, and an analytic production prediction model combined with production system analysis to project the results of an intervention. This technical analysis ties into an economic one, which seeks to determine if an economically beneficial intervention is possible and to assign a risk profile to the project
Role of Starch in Designing Nondamaging Completion and Drilling Fluids
Authors: Simonides Hylke , Schuringa Gerhard , Ghalambor Ali
Published: December 2007

Starch is a polymer that is widely used in all types of water based drilling fluids. With the development of specialty drilling and completion technologies, starch is also chosen as one of the main components of drill-in fluids. This paper presents laboratory results obtained from experimental work on chemically modified potato starch. The results show, that properties like heat and shear resistance can be improved by chemical modification.

The main functions of starch are fluid loss reduction and rheology control. In drilling fluids the polymer interacts with solid particles to enhance the seal of the filtercake on the wellbore, and to provide the required rheology. Reasons for choosing starch are its versatility, and compared to many biopolymers, its relative low cost. During drilling operations the fluid rheology has to be controlled over a large temperature interval. Like many polymers, starches tend to degrade at high temperature. The degradation will lead to increased fluid loss and changes of the fluid viscosity, which can result in fluid failure and lead to formation damage. It is well known that one of the factors affecting the thermostability of a drilling fluid is the composition of the drilling fluid. Another factor is the nature and the chemical modification of the starch. The starch has been modified by cross-linking and carboxymethylation in order to improve the properties in drilling fluids at ambient and elevated temperature.

Fluid properties such as fluid loss and viscosity will be presented as a function of the level of cross-linking. The results indicate that high molecular weight starch exhibits the best fluid loss control combined with a shear thinning rheology, but there is an optimum for both when increase of the molecular weight is obtained by crosslinking. Crosslinking does positively affect the heat stability. The effects of substitution and cross-linking on the resistance to heat and pH are discussed for several fluid compositions. The fluids have been aged at elevated temperatures under dynamic conditions.

A new heating apparatus was developed to perform these tests. This apparatus consists of a bath equipped with a mechanical device to rotate fluid containers, like in the traditional hot air roller ovens. The bath is filled with silicon oil, which is circulated, rendering a homogeneous temperature profile. The dynamic aging results thus obtained have proven to be more reliable than those obtained with conventional hot air ovens. A detailed description of the new apparatus will also be presented.
Formation Damage Caused by a Water Blockage Chemical: Prevention Through Operator Supported Test Programs
Authors: Nasr-El-Din H. A. , Lynn J. D. , Al-Dossary K. A.
Published: December 2007

Recently, a Saudi Arabian well producing out of a carbonate reservoir was squeezed with a scale control chemical (a phosphonate-based inhibitor). The target zone has a low permeability of nearly 20 mD. The treatment adversely affected oil production, and the damage was attributed to water blockage after the treatment. Several solvents that can remove water blockage were tested, including ethylene glycol monobutylether (EGMBE) and a proprietary chemical designated as E-2. The latter chemical is a patented blend of glycol ethers and has been proven successful in many field applications in the North Sea environment. The chemical is typically applied as a 15 percent by volume mixture in appropriate brines. On this occasion, however, the vendor recommended the chemical be squeezed "neat" into the formation. Concerns as to the effectiveness of the chemical as well as concerns about the cost caused the authors to question the use of the chemical "neat".

In house laboratory test programs demonstrated that using the "neat" E-2 chemical would have resulted in severe formation damage from two newly identified mechanisms. The first is precipitation of salts from the formation brine, and the second is the formation of a tight, stabilized emulsion with the native crude oil, possibly stabilized by the precipitated salts. These additional problems would have exacerbated the water blockage problem. The chemical E-2 precipitated salts even when it was co-mingled with the field mixing water. Phase separation of salts was noted at room temperature and reservoir temperature (200-220°F). By comparison, the use of the "neat" EGMBE did not result in precipitation of salts nor emulsion formation.

Core flood studies confirmed loss of oil production due to water blockage where relative permeability to oil deceased by nearly 50%. In addition, testing of the neat E-2 chemical showed a loss of approximately 85 percent of the original permeability of reservoir core samples, following treatment. This significant drop in relative permeability to oil was attributed to the formation of a tight emulsion stabilized by precipitated salts.

The use of the E-2 chemical at 15 percent concentration was compatible with the formation brine and the field mixing water. It also showed a significant recovery of permeability, however, the efficiency was no better than the EGMBE. Surface tension measurements, and water blockage studies all confirm the effectiveness of the E-2 chemical up to 15 volume percent. E-2 has not been shown to be a cost effective alterative in most applications on Saudi Arabian carbonates. In house evaluation of this chemical prevented extensive formation damage, and resulted in the development of a non-damaging and a cost effective treatment.
The Environmental Impact Assessment from Administrative Obligation to a Real Management Tool
Authors: Sutton C. , Morillon A. , Murray M. , Vidalie J. F.
Published: December 2007

In addition to its administrative purpose, the Environmental Impact Assessment (EIA) is a real management tool for projects and development studies.

This integrated approach consists in a process of continuous assessment and must include firstly, a set of environmental measures representing a contractual basis for the development and the construction phase and secondly, a genuine commitment for the future exploitation phases.

Several examples of recent field developments (including deep offshore projects) are presented as case studies to demonstrate the approach used to fully integrate the preparation of the EIA into the project engineering process and the benefits that can be achieved from it.

The key environmental issues for those projects are defined during the concept selection/definition phase by means of a first emissions assessment and an independent environmental review or preliminary EIA. In this process, the good knowledge of the environment through site surveys is fundamental. Formal EIA studies are then initiated simultaneously as the other Basic Engineering activities. The first phase of work encompasses an identification of gaseous and liquid emissions and wastes, and is then immediately followed by an analysis of the impacts. This provides detailed environmental information to the engineering team at a very early stage of the Basic Engineering process.

The first draft of the EIA is issued shortly before the completion of Basic Engineering and the final version completed prior to starting the formal procedure of the administrative approval.

The key for the success of such an approach is good planning, detailed preparation and the successful early integration of Environmental Specialists into the project teams.
An Outbreak of Chronic Mass Psychogenic Illness at Workplace: A Case of Mental Control Over Physical State
Authors: Razavi Jalees K.
Published: December 2007

The paper describes a Health Hazard Evaluation (HHE) of a Mass Psychogenic Illness (MPI) outbreak that occurred at an office complex late in the fourth quarter of 1996 and continued well into 1997.

In essence, a group of employees experienced a variety of health problems that they were totally convinced were directly related to exposure to residual organophosphate pesticide contamination.

The paper describes the intriguing series of events that took place from the time of the pesticide application and the timeline analysis. It explains what the author believes were the initial factors that initiated the MPI outbreak: those that caused the chronicity of the outbreak and also its maintenance over a prolonged period of time. It illustrates the adverse effects on the outcome, by means of social pressures and economic loss.

A combined team of an Occupational Medicine Specialist physician and 2 Industrial Hygienists from the National Institute for Occupational Safety and Health (NIOSH) conducted the HHE in February 1997, revisiting the site in April of the same year.

The paper describes the author's definition of "the rainbow syndromes"(those diseases that present with subjective signs and symptoms without objective clinical findings, including laboratory findings and other building-related syndromes.

Results. The results of the medical investigations undertaken were derived from a review of medical records from local hospitals and other health facilities visited by the employees and also medical evaluations conducted by the NIOSH Team.

The results of the industrial hygiene investigations undertaken at the facilities were derived from surface sampling, air sampling and bulk sampling.

Conclusion. The medical investigator concluded that there was no evidence to substantiate chronic organophosphate poisoning. The events did in fact indicate an outbreak of MPI and resulting anxiety that continued for a long period of time due to factors such as: workplace/socio-economic stresses; family stresses; co-morbidities; and secondary gain.

The paper asserts the view that judicious and timely risk assessment and management of exposure can minimize financial loss, human anguish and distress.
Safety Practices for Servicing Wells with Hydrogen Gas Generated in the Wells Annuli
Authors: Zainalabedin K. A. , Al-Habib N. S. , Ahmad G.
Published: December 2007

This paper will relate Saudi Aramco's operational experience with pressurized hydrogen gas in the annuli of wells equipped with cathodic protection. The presence of hydrogen gas in the effluent samples from the annuli of cathodically protected wells was confirmed in the laboratory and appropriate steps were taken to ensure the safety of wells. These steps include training of personnel involved with well servicing, limitations on welding in the vicinity of these wells and any other activity that could generate a flammable mixture.

This paper will discuss the practices of Saudi Aramco in handling this material in a safe manner. Hydrogen gas found in the annuli of cathodically protected wells represents a potential safety hazard since hydrogen gas mixed with air forms an explosive mixture. This odorless and colorless gas is generated as a result of electrolysis of water in the annuli of wells equipped with impressed current cathodic protection to protect the casing from external corrosion.
Experiences in the Management of Drilling Fluids and the Regulatory Control of Associated Cuttings in the Nigerian Oil and Gas Industry
Authors: Agha G. U. , Irrechukwu D. O.
Published: December 2007

One environmental issue that has continued to receive increasing and significant attention in the Nigerian Oil and Gas Industry over the past decade is the management of drilling fluids and control of the disposal of the associated cuttings in the different ecological zones where exploratory activities take place. The development of the framework for the relevant regulatory control criteria have been based on scientific understanding of the potential environmental impacts and consideration for the sensitivities of the communities of the host regions.

The tortuous process of selection and approval of drilling fluids for each ecological zone and the respective set limits are described against the backdrop of available waste treatment technologies. This paper also reveals the peculiarities of the evolving concepts of development of regulations based on science, experiences of the international industry and local social issues as a means of striking an acceptable though delicate balance among stakeholders in drilling waste management.

The constraints in effective implementation of such policies within the economic bounds that characterize a mono product developing economy (as Nigeria) are discussed.
Accurately Measuring Discharged Drilled Cuttings and Retained Fluids
Authors: Valentine Anthony V.
Published: December 2007

In October 1999 Chevron assumed operatorship of Block B8/32 in the Gulf of Thailand. The continuing slimhole drilling program involves monobore production, horizontal production, horizontal injection and exploration wells, all of which typically have 2D or 3D well paths. Consequently, due to its inherent lubricity and hole stability, IEM (Invert Emulsion Mud) is used for drilling all 6⅛" reservoir hole intervals. Over the first several months of operatorship it became apparent that the UK DTI (United Kingdom Department of Trade and Industry) method used to measure the mass of cuttings and retained fluids discharged with the cuttings was inaccurate. Mass balances of fluid and materials consumed on various wells indicated the calculated IEM and base fluid discharge figures were notably less than that actually discharged.

As part of the TFM (Total Fluids Management) process, an in-house program was initiated to accurately measure the mass of cuttings and retained fluids discharged with cuttings. The testing methodology, calculations and reporting format were developed over a period of 12 months during which time over 30 wells were drilled with a single rig. To date, results from slimhole drilling operations indicate that the method currently used by the industry throughout much of the world, generally in compliance with government regulations, significantly underestimates the mass of cuttings and commercial solids discharged to the environment.
The Sustainability Assessment Model (SAM)
Authors: Baxter Tom , Bebbington Jan , Cutteridge David
Published: December 2007

Business has a fundamental role to play in delivering Sustainable Development – the process needed to achieve a sustainable society. Sustainable Development is becoming an important issue for the oil and gas industry to address. There is, however, a lack of tools for improving decision making in this area. The paper outlines a tool (the Sustainability Assessment Model – SAM) which has been developed to assess whether or not a project can be said to be "sustainable". A project focus has been adopted in developing the tool because we believe that greater control over impacts can be achieved at this level. However, the tool can be used to aid specific design decisions (eg development scheme selection or concept selection) and also to assess an organisation's overall performance. The SAM assesses the social, environmental, economic and resource usage impacts of a project over its full life cycle. In the case of a hydrocarbon development this includes the design, construction, installation and commissioning of the facilities, the production of oil and gas and the eventual decommissioning of the facilities. This part of an oil and gas development is (usually) within the control of the operator. The SAM, however, extends the analysis beyond exploration and production and also assesses impacts from hydrocarbon refining, the manufacture of products and the eventual product use. It also addresses the possibility of remediation and restoration options. The SAM monetises all the impacts so that they can be compared on a like-for-like basis. This also allows the impacts to be combined into a single measure (which we have called the SAMi, or Sustainability Assessment Model indicator) which reflects overall whether a project is "sustainable" or not.
Zero Discharge Philosophy: A Joint Project Between Norwegian Authorities and Industry
Authors: Marthinsen I. , Sørgård T.
Published: December 2007

With the aim to reduce the impact from discharges to the sea from offshore oil and gas activities by the year 2005, a zero discharge work was started by the authorities in 1997. The initiation of the work was a White Paper from the Norwegian Ministry of Environment: Environmental Policy for a Sustainable Development (1996–97), in combination with the objectives agreed upon at the North Sea Conference in Esbjerg, Denmark in 1995. In order to reach the zero discharge goal by the year 2005 as stated in the White Paper, a Zero Discharge Philosophy project was also initiated in 1997. Norwegian authorities, oil companies and the supply industry took part in this joint effort project which was a part of the zero discharge work. The report from the project which ended in 1998, concluded that the aim of the zero discharge work is to reduce the impact, and not necessarily the discharges themselves, either by reducing the content of harmful components in the water, or the amount of chemicals and water itself. In addition, a reduction in the discharges offshore should not lead to increased pollution in other areas. For instance, if transportation to shore is chosen, increased emissions to air and the consequences of handling the waste on land should be considered.

As a part of the zero discharge work and based on the results from the Zero Discharge Philosophy project, the operators were required to look into existing offshore activities to evaluate possible initiatives to reduce the impact from the discharges. Most of the proposals have been connected to traditional lines of thinking such as reducing the use of chemicals in the water treatment plants, injection instead of discharges of produced water, and different cleansing techniques for oil and chemicals. The operators have to implement measures according to the plans they have presented to the authorities. Their efforts will be followed closely, and formal requirements will be imposed in 2003 if their actions do not seem to be sufficient to reach the goal of no harmful discharges to the sea by the year 2005.
Safety Training For The Employees Of The Exploration & Production Companies: Are They Really Worth?
Authors: Mukundan Ashok P.
Published: December 2007

The E&P industry is unique by its nature of operations. Accidents create – pain to the injured; mental sufferings to the parents, children, dear & near one's of the injured; sufferings to the fellow workers & superiors; production delays & interruptions; legal expenses, penalties & compensations; material/equipment damage; environment pollution, all of which costs quite high for an E & P Company. The E & P operations extend both onshore & offshore; also extend to deserts, jungles & extremely cold climatic conditions. Most of the E & P companies take care of their employees as an invaluable asset. If so, the employee health and life should be considered precious by these companies.

This paper gives a brief outline about the safety training needs and model safety training for an E & P Company. A brief insight is also given on general safety training requirements and content for new recruits, managers, supervisors, safety representatives and contractors. The overall rationale for safety training and education in an E & P company is to improve awareness of associated safety hazards related to E & P operations, to expand knowledge of the causes of the accidents and to promote the implementation of effective preventive measures. Thus, the specific purpose and impetus for safety training will however vary for different target audiences, locations (offshore and onshore) and the environment.

As training is an important part of any management programme, it also has to be an essential part of a safety management for the E & P companies. This includes making sure that the latest knowledge is imparted to those responsible for designing, operating and maintaining E & P installations and the supporting services in the safest manner. Competent employees i.e. those possessing the knowledge, skill and motivation to perform their work properly, are likely to be the Safest Employees for the organization.
Management of Indigenous Communities Health Issues at the Villano Project in the Ecuadorian Amazon Region
Authors: Vacas Francisco , Gonzalez Mario , Sanabria Vinicio , Madera Angelo
Published: December 2007

Agip Oil Ecuador B.V. (AOE), as the operator of Block 10 in the Ecuadorian Amazon region, is faced with a number of indigenous community health issues. Most of these communities belong to the Quichua ethnic group with other groups like the Huaorani and Shuar-Ashuar also represented. AOE's health programs include more than 6,000 people, including some 3,000 colonists that had settled in the region.

The program is now in full development since its original inception more than two years ago and intends to improve the quality of living of the people by providing primary health care. AOE is involved in disease prevention and control, health education, basic sanitation and safe water distribution, vaccination, nutrition, maternal and child care, treatment of common disease and injuries, access to essential medicines, emergency evacuation. In addition a new program is now being implemented with the objective of rescuing the local traditional natural medicine.

AOE's program is supported by the local branch of the Ministry of Health and NGO's such INNFA (The National Institute for the Child and Family), and SNEN (The National Malaria Eradication Institute).

As a result, this program has successfully reduced the morbidity and mortality rate in the region and at the same time protects the fragile environment surroundings the area, respecting the culture and traditions of the people.
Successful Implementation of an Intranet Web-Based, Secure, Real-Time, Project-Knowledge Repository System
Authors: Drnec M. L. , Andrea M. D.
Published: December 2007

This paper presents the successful implementation of an intranet Web-based, secure, real-time, project-knowledge repository system. The system, based on the Storage Area Network (SAN) concept, optimizes project document generation, flow, distribution and storage. The system offers an easy way to interact, build and access project knowledge. Project data are not locked to local hard drives (e.g., laptops or desktops) or client-server-based Local Area Networks (LANs).

Data are hosted and managed on a secure Web server, eliminating the need for distribution to project team members; e.g., as an e-mail attachment. Data are accessed through a secure Web portal to make user access, data analysis and integration easy. Users do not need to download and store project information on their machines, saving disk space and reducing the risk of a security breach. To access project information, they visit a virtual workspace: a one-stop shop for all team members. The collaborator is led to the content rather than the content to the collaborator. Everybody is on the same (Web) page.

Electronic document processing makes possible an extended support structure for maintaining day-to-day operations, as well as performing data storage for future use and organizational learning. The system preserves knowledge, handling it as a valuable asset and making it, at the same time, as easily accessible as a commodity.

Information technology (IT) specialists are responsible for 24/7/365 support of the system, data mirroring, backups, best-in-class security, database administration, emergency recovery procedures and state-of-the-art storage methods. Project knowledge is protected and preserved for generations: macro, instead of micro, data management of integrated oilfield projects as a long-term, strategic approach of secure knowledge preservation. Currently, nearly 200 projects worldwide use the system.