bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Environmental Costs and Liabilities in the Decision Making Process of Oil & Gas Exploration and Production Companies
Authors: Borghini S. , Bartolomeo M. , Molinari M. , Ratti S.
Published: December 2007

This paper investigates the opportunities of using management accounting as an environmental management tool in oil and gas exploration and production industries and in particular its possible relevance in improving both business decision making process and environmental performances. The empirical research relied on the case study of a representative firm: the largest Italian industry involved in the petroleum production (ENI-Agip Exploration & Production Division). The focus of this case study is the corporate environmental costs recording and the role of environmental costs and liabilities in decision making process at unit and corporate level. The results of the research demonstrated that when pooling is done at operating level managers have a good understanding of the environmental costs for which are responsible and that environmental liabilities can be included in the long term project assessment.
Health Aspects of Work In Extreme Cold Within the E&P Industry
Authors: Barbey A. , Clyde D. , Covil M. , Dahl-Hansen E. , Dawson D. , de Jong G. , Dugelay F. , Jones D. S. , Keech J. , Murray W. , Reinertsen R. , Rodier J. , Ross J. , Thomas I.
Published: December 2007

Company and contractor have a joint commitment to health risk management stated in health polices and should develop a health management system which needs to be based on a full and careful appraisal of the health hazards to which personnel will be exposed.

One of these health hazards is the climate in which people live and work. A set of guidelines on cold has been prepared for member companies of the Exploration and Production Forum. Future guidelines are in preparation concerning work in hot climates.

Work in the cold poses a certain number of acute daily problems. As long as the employee is in a protected environment (base, housing, camp), the risk is minimal. However, as soon as he or she steps out into the extreme cold, he or she is exposed to a large number of potential problems.

These guidelines, which target line management as well as the company health professionals, aim at preventing accidents, illness and loss of life by providing useful information.

It is important to remember that these guidelines are primarily aimed at the protection and maintenance of health and that, in certain situations, additional measures may be required to ensure effective and efficient performance.

Staying healthy in the cold for days and weeks is possible, providing one is physically and mentally prepared and has access to the correct equipment. However, one's condition is also dependant on the application of sensible precautions based on knowledge of the local conditions and of personal limitations.
A New, Risk Based Management System for the Health, Safety and Environmental Assurance of Third Party Services
Authors: Pine T. K. , Sealy I. M.
Published: December 2007

Over the past four years a new program for the management of health, safety and environmental performance of companies directly, or indirectly contracted to BPX(Alaska) has been developed. This program introduced substantial and fundamental changes in the roles and responsibilities of the parties involved.

Historically the E&P company, or customer, identified the risks related to a contract. Contractor programs frequently lacked structure, contractual responsibilities were often loosely defined and requirements varied amongst contracts. The introduction of new, global corporate performance expectations, the need to improve contractor incident rates, changing regulatory requirements, fundamental changes in customer - contractor relationships and a desire to achieve a zero-incident workplace were among the motivations for the development of a new contractor HSE system.

The cornerstones of the new program are a uniform set of contractor expectations and the use of contract specific risk identification, performed by the customer and contractor in partnership. An eight step process has been developed: definition of scope-of-work; analysis of gaps between customer expectations and contractor systems; identification of hazards related to contracted activities; assessment of risks associated with identified hazards; development of a Plan to manage risks; agreement of interfaces between customer, contractor and other parties; communication of the Plan and Interfaces; periodic review.

The paper describes, in detail both the development and the application of the new program. The implementation of the program in a group of fifteen contracts, representing direct, third-party or sub-contractor and alliance relationships with BPX(Alaska) is used as a case study. This case study: considers the ability of the various organizations involved in the process to understand and learn from the assurance process; compares the risk based safety management process to the previous, rules based process; reviews the impact of the variety of contractor management systems in use amongst the subject organizations.
A New Model for Integrity in Management Systems
Authors: Hudson P. , Riley E. D. , Gidley J. K.
Published: December 2007

The need for a simplified approach to the development and implementation of management systems is described. The potential benefit to be derived from a set of core organizational and management competencies is outlined. The systems approach and competencies are designed to actively eradicate or minimize the latent or potential causes of operational loss, such as service failures, environmental incidents, and accidents.

This paper discusses the reasoning for adopting an integrated approach to management systems for regulatory compliance, health, environment, quality, and safety. It describes the derivation and development of a "principle" based management process that encompasses the planning, implementation and execution of change and continuous improvement.
Developing an EHS Advantage for International Operations
Authors: Wills Thomas L. , Glencross Colette M. , Farrell Don
Published: December 2007

Texaco International Production (TIP) is an upstream organization with operating companies in a number of non-U.S. locations. These diverse operations present challenges in effectively managing environment, health and safety (EHS) issues in a manner that supports, integrates and aligns with the respective business objectives of the individual country organizations while achieving EHS success. These challenges lie in the diversity among the country organizations. They arise as a result of language and cultural differences, disparate operational needs, the degree of sophistication and self-sufficiency of the EHS component within the country organization, and differences in the legal and regulatory climate among the various countries.

This paper describes TIP's development of a system called EHS Advantage developed to create and roll-out EHS initiatives designed to accomplish the full alignment and integration of EHS issues into the line operations of the company. The process is built on the active involvement of senior management, operations management and EHS professionals within TIP. Further, it includes an array of guidance materials, resources, measures and "tools" that are made available to the country business units in a timely and very usable format. Finally EHS Advantage establishes compelling incentives to all parties to make the system succeed and, as a direct result, enable TIP to succeed. Throughout the system the emphasis of EHS Advantage is placed on promoting support and achievement of TIP business objectives.
Investing in Natural Systems: Using Trees and Forests to Achieve Environmental Objectives
Authors: Falconer John
Published: December 2007

The interaction between man and his natural surroundings has been an issue for millennia as we have sought to build our economy while maintaining the values of our natural resources. Over the past several decades, public perceptions about the need for environmental improvement have focused on limiting the negative impact that humans have on natural values, such as wildlife, biological diversity, and air and water quality. As we approach the end of this millennium, our environmental paradigm is beginning to encompass the use of natural systems to achieve broader objectives.

This paper considers two important environmental issues: Global climate change and urban development. Both issues are tied to population growth and energy use, where many of the response strategies are focused. Below we explore strategies for addressing these issues through forestry projects that provide low cost, multiple benefit alternatives that are good for both business and the environment.
Health, Safety and Environment Integrated Management System in Amazônia
Authors: da Fonseca Venina Velosa , Filho Jorge Amorim Pereira
Published: December 2007

The PETROBRÁS Exploration and Production procedures in Brazilian Amazon Rain Forest started in the 80‘s. In 1987. a group of scientists sponsored by PETROBRÁS visited the area and suggested some actions in order to minimize environment's impacts due E&P activities. A productive pilot project started the Petroleum commercial extraction in 1988 and during the last 10 years these advises have been conducted.

The E&P – Amazon Exploration and Production activities are located in Solimões and Amazon Basin embodying the Urucu's Oil and Gas Province, in the Municipality of Coari. Amazonas State.

Between January 1997 and January 1998 the Exploration and Production management implanted an administration system which linked environment, security and health to the business. His systems is based on normative criterions of NBR IS014001 / 1996 version e BS 8800 / 1996 version The system covers all the Operation Unit in all legal capacity area, it represents a closely total of 2.390.500 square kilometers, allocated in ten states.

In 1998. January the Bureau Veritas Quality International credential the system with the subsequent scope:

"Petroleum and natural gas exploration and production in Amazon region, concerning the following activities: geophysical and geological data acquisition and processing, geological interpretation (evaluation), reserves and reservoir managing, well drilling, oil, gas and diesel, production and processing."
Evaluation Process of the Safety Systems in the Brazilian Oil Industry
Authors: Igrejas Lopes Filho Luiz
Published: December 2007

With the goal to promote the search for continual improvement to the Industrial Safety function in an oil company with 42,000 employees, the Board of Directors of Petróleo Brasileiro S.A. - PETROBRAS established an evaluation process which considers assessment, every two years, of the Industrial Safety Management Systems of facilities. The process includes the rewarding of the operational unit that highlights the best Safety Management System.

The article will describe the methodologies used in the evaluation process, which is based on the British Standard BS 8800 - Occupational Health and Safety Management Systems (1) and on the evaluation procedures of the National Criteria for Performance Excellence which emulates the American Malcolm Baldridge National Quality Award (2). The paper will also present the evaluation process methodology from the beginning: the first requirements, the development of the presentation report, the training scheme of the auditors and the field evaluation step, up to the definition of the facilities which got the most distinction in relation to Industrial Safety Management. The goals achieved by PETROBRAS with the establishment of this award will also be shown.

This work started in 1995 and it is in its second evaluation edition and due to its results PETROBRAS was rewarded with the ALASEHT - Associação Latino Americana de Segurança e Higiene no Trabalho distinction.
Environmental Regulation of the Oil and Gas Industry in Venezuela
Authors: Slocum Dean A. , Sanchez Juan Carlos , Barrios Rosalba
Published: December 2007

The opening ("apertura") process for Venezuela's industries has brought a rush of foreign investment and companies to the country's oil fields, mines, manufacturing enterprises, and other industries. Accompanying these changes, Venezuela's government has sought to clarify its environmental legislation and make it more specific to new industrial activities, including oil industry ventures. The resulting developments in Venezuela's environmental regulations, standards, and expectations has been the subject of much speculation and concern by international oil companies interested in entering Venezuela through the apertura.

This paper provides a perspective of how environmental regulations and expectations affect international oil industry ventures in Venezuela. In addition to highlighting the key features of the present regulations pertaining to the industry, the authors will identify the key stakeholders influencing the application of environmental standards, and consider the implications or impacts of these regulations on the success of oil industry ventures. Some of the impacts that have been observed, for example, include: The increasing stringency in environmental regulation and expectations has not diminished the initiative of international industries to enter into new ventures in VenezuelaMany international companies which have successfully entered ventures in Venezuela through the opening believe that one factor for their success in being selected for entry and gaining necessary financing is their strong environmental programs and track record (i.e., this has been a competitive advantage for them in Venezuela)

Finally, we will present our view of certain environmental management and project management practices that may be particularly successful responses to the challenges presented by the growing expectations.
Crisis Management Systems for Emergency Scenarios in International Operations
Authors: Carrithers Jon R. , DeHart Robert E. , Geaneas Paul Z.
Published: December 2007

A crisis management system has been developed that adapts the Incident Command System (ICS) to the management of a multitude of crisis or emergency scenarios that may impact international exploration and producing (E&P) operations. The system provides processes to mitigate and manage health, safety, environmental, security and business interruption emergencies that may occur to businesses operating in diverse worldwide locations. An Emergency Preparedness Plan (EPP) template was developed to provide the structure and resources to aid venture management and staff to accomplish notifications, establish integrated response teams at tiered levels, identify emergency response actions, implement documentation systems, plan for site safety, organize and track response logistics, and accomplish post-incident assessment. Tactical and strategic issues are defined in detail for seventeen incident scenarios to include terrorism, medical, aircraft, fire and spill incidents, among others. The Emergency Preparedness Plan development process and subsequent training of affiliate personnel is described. Economy of scale benefits to Mobil worldwide businesses and the results of implementation are discussed.
A New Standard in Rig Communication and Safety Signs Designed to Cross National Language and Cultural Boundaries, Enhancing Rig Safety Information and Hazard Awareness
Authors: van Rooyen James F. , Lace Neil
Published: December 2007

This paper presents an innovative rig communication and safety sign standard developed by Schlumberger, Sedco Forex in conjunction with Seaward Safety for use on their Drilling Units operating Worldwide. This standard has been specifically designed to enhance personnel awareness of hazardous areas and operations, mandatory requirements and prohibited actions. Although initially designed for Drilling Operations, the concept for the Safety Sign Standard could be used in any industry throughout the World.

Historically on Schlumberger, Sedco Forex drilling units, safety signs were installed on an "as and when" required basis in various languages and formats often with little or no consideration to content and culture, ergonomic effectiveness and the visual impact of these signs on rig personnel.

The multitude of signs posted at a rig site was compounded by frequent relocation's and movements of the rig from one country to another, from successive clients, each with their own specific requirements for Safety Signs. This often resulted in an over abundance and duplication of Safety Signs leading to a confused appearance with significant loss of visual impact and effectiveness.
Study of World Class HES Practices
Authors: Strand Finn
Published: December 2007

To support company HES policies and goals Statoil in 1996/97 carried out an extensive benchmarking project studying "state of the art" world wide. The project aimed at comparing Statoil with world-class companies in terms of HES performance, but even more important, to identify the practices which had yielded good results at these companies, and then to lay the basis for implementing new and better practices at Statoil. It should be emphasised that the good practice we found in our partners did not represent unfamiliar or revolutionary approaches to HES work. Many of the principles, systems and measures we identified in these companies are known – and have also been adopted in Statoil. However, what characterises HES management at our partners is a consistent, systematic and purpose for use of measures which yield good results.
Environmental Impact Assessment of Deepwater Exploratory Drilling Offshore Nigeria from Desktop Studies
Authors: Imevbore V. O. , Omole O.
Published: December 2007

The need to explore and develop the Nigerian offshore hydrocarbon resource potential has resulted in the award, in the last five years, of Nigerian deepwater offshore-blocks to a number of international oil and gas exploration and production companies. As activities aimed at resource exploitation in developed and developing countries increase, the associated potential environmental degradation continues to generate concern. That economic development and environmental management should be pursued hand in hand, has led to increased oil industry awareness and activities towards complying with a plethora of local and international regulations.

Although not a permit requirement in Nigeria, desktop Environmental Impact Assessments (EIA) have been carried out for a number of deepwater exploratory drilling activities.

The paper presents the typical scope and content of a desktop EIA study for deepwater exploratory drilling offshore Nigeria. The general features of the deepwater physical, chemical, biological and socio-economic environments, the use of oil spill drift and weathering simulations, and based on the perceived activity/environment interactions and resource sensitivity, the impacts of deepwater exploratory drilliing are briefly discussed.

The desktop studies meet basic EIA requirements in that they contain an inventory of pertinent environmental attributes, evaluate activity/environment interactions in terms of potential deleterious effects such activities may have on the environment and recommend environmental degradation mitigation measures where applicable.
Underground Storage of Natural Gas in Unlined Hard Rock Caverns
Authors: Heath S. M. , Hodrien R. C. , Kostakis E. , Harrison J. P.
Published: December 2007

Gas migration through a water filled fracture has been studied. An experimental facility was used which comprised of an acrylic cast of a natural fracture, this allowed viewing of bubble migration. Various pressure and flow rate conditions were investigated, together with the effects of changes in the fracture inclination angle.

A literature review highlighted that there are no models currently available which can estimate bubble growth rate, bubble size at the entrance to a fracture, or for discrete bubble flow. A mathematical model was developed to this end.

This paper describes the experimental processes undertaken, the development of the mathematical model, and a comparison between both experimental and predicted results.
Salt Solution Caverns for Petroleum Industry Toxic Granular Solid Waste Disposal
Authors: Duyvestyn Glenn M. , Davidson Brett C. , Dusseault Maurice B.
Published: December 2007

Placement of solid wastes in dissolved caverns in salt is increasingly being viewed as an environmentally secure technology for low-toxicity wastes such as foundry sands (heavy metals), contaminated soil and other granular solid waste streams. Costs of salt cavern disposal probably eliminates their use for large volumes of non-toxic wastes, but permanent entombment of toxic materials in salt caverns is economically competitive to other alternative disposal or storage approaches. Salt caverns in Alberta and Saskatchewan at depths of 1,200-1,500 m are being used for disposal of non-toxic materials (non-hazardous oilfield wastes) and for storage of natural gas and liquids (propane, glycol, etc.). Low to medium toxicity oilfield wastes can be economically and securely placed in salt solution caverns using an engineered slurry approach. Effective cavern disposal requires a design and monitoring strategy to optimize cavern utilization and to demonstrate environmental security for waste containment.

This article is conceptual in nature; however, its conclusions and observations are based firmly on extensive laboratory, field, and modeling experience in salt rocks, applied to caverns and to underground mines.

P. 239
Modelling of Effects of Drilling Fluid Temperature on Wellbore Stability
Authors: Choi S.K. , Tan C.P.
Published: December 2007

A numerical thermo-poro-elasticity model which can model time-dependent changes in stresses and pore fluid pressure induced by thermal and fluid diffusion has been developed. The model results agree well with analytical solutions for the instantaneous fluid injection of a poro-elastic medium. The results of some simple numerical experiments show that the computed changes in effective stresses, strains and pore pressure satisfy the constitutive equations for the thermo-poroelastic medium used in the model.

The model results showed that difference in temperature between drilling fluid and formation can induce significant changes in pore fluid pressure and effective stresses around the wellbore wall. The extent of the effects vary significantly with thermal diffusivity of the formation. In general, cooling the formation tend to increase the stability of the wellbore while the reverse applies to heating of the formation. The results also show the importance of considering the geothermal gradient, and thermal and fluid transport properties of shales in wellbore stability analysis and development of recommendations to manage instability.

P. 471
Mechanical Strength of Reservoir Materials: Key Information for Sand Prediction
Authors: Zhang Jiaxiang , Rai Chandra S. , Sondergeld Carl H.
Published: December 2007

The mechanical strength of a reservoir formation is the most crucial information required for predicting sand production and recommending sand control completion. The only reliable technique, so far, to obtain the formation strength quantitatively is to perform laboratory tests on core samples. The laboratory tests require substantial volumes of cores which, in most cases, are not available. In this study, we present a new method to avoid this restriction. The significance of this approach is its simplicity and efficiency in constructing a reliable mechanical failure envelope. The key results of this study, based on measurements on a variety of sandstones, are:

Sandstone formations are characterized by a single normalized failure envelope. This universal curve makes it possible to construct the failure envelope for a sandstone formation from the knowledge of critical pressure. There exists a correlation between the critical pressure and the compressional wave velocity (at equivalent depth of burial). The failure envelope for a sandstone formation can then be constructed simply from compressional wave velocities. These velocities are generally accessible from conventional logging data.

P. 291
Three-Dimensional Stress Analysis of a Wellbore With Perforations and a Fracture
Authors: Papanastasiou P. , Zervos A.
Published: December 2007

This study presents results of large scale 3-D elastic analysis of a wellbore with perforations. Both vertical and horizontal wellbores with perforations at different orientations are considered. The extra stresses imposed by a propped fracture at the unfractured perforations are also evaluated. A propped fracture results in increase of the compressive stress around the perforations which is higher in the perforations closer to the fracture and increases with propped width. The increase of compressive stress is much higher at the top/lower faces of perforations which is already less than the existing compressive stress at the lateral faces of the perforations. The results are also discussed in relation to the problem of hydraulic fracture initiation.

P. 347
The Skin Factor as a Rock Mechanics Diagnostic Tool
Authors: Santarelli F.J. , Tronvoll J.T. , Skomedal E. , Bratli R.K.
Published: December 2007

The paper presents a series of well tests performed on various North Sea weak reservoirs and will show how the skin factors measured can be interpreted in terms of sand production. In particular, the results presented show that sand production results in abnormally low skins independently of what the perforation conditions were in terms of under or over balance.

First, a series of tests were performed on injectors after a very limited amount of back production for clean up. Such tests were injection tests followed by clean up and a very good correlation existed between skin factor and under balance conditions. However, after important sand production, the wells were tested again under injection and all showed very low skin factors. Second a series of four production tests were performed on a well shot over balance and the evolution is clearly one of decreasing skin factor indicating sand production. Third, for a given field, all tests performed with a total draw down - i.e. draw down plus depletion - superior to 70 bars show an extremely low skin as the other show high skins. The balance conditions for such wells were very diverse. Fourth, it will be shown how on wells producing sand, the stimulation of the levels that produce sand leads to dramatic flow concentrations from very limited intervals and various PLT results will be presented.

The practical consequences of such results will then be presented and three essential aspects will be dealt with.

The perforation balance policy will be discussed in the light of the results presented above. The use of well test as a systematic mean to predict sand production will be outlined. Finally, it will be shown that test interpretation techniques ought to be refined to achieve a bigger understanding of the results in terms of description of the near wellbore area.

P. 375
Hydraulic Fracture-Initiation in Deviated or Horizontal Openhole Wellbores
Authors: Deeg Wolfgang E.J.
Published: December 2007

It is well known that a, hydraulic fracture preferentially extends in a plane perpendicular to the least principal in-situ formation stress. However, it is not generally recognized that in an openhole completion, the hydraulic fracture will only initiate perpendicular to the least principal formation stress if the well's axis is aligned with the preferred fracture plane throughout the treatment interval, If the well intersects the preferred fracture plane, a hydraulic fracture initiated in an openhole section will intersect both the borehole and the preferred fracture plane.

As the fracture extends away from the well, it turns, realigning itself with the preferred fracture plane. In the immediate vicinity of the wellbore, this turning results in tortuosity and a reduced fracture width, which can lead to premature screenouts or a choke effect during production. The most severe case of this occurrence is in an openhole completion in a well drilled perpendicular to the preferred fracture plane, where a hydraulic fracture initiates longitudinally but rapidly realigns itself with the preferred fracture plane normal to the borehole. Once realigned, the fracture grows back toward the well. As a result, both longitudinal and transverse fractures are present at the wellbore.

Extensive calculations detailing the orientation of the initial fracture relative to the wellbore and the preferred fracture plane are presented for all borehole deviations relative to the preferred fracture plane and the maximum formation-stress direction. Results of laboratory investigations of fracture initiation and propagation from openhole, deviated wellbores are summarized and compared to analytical predictions. The effects of wellbore diameter on fracture orientation and the potential for link-up of multiple fractures are also discussed.

P. 391
The Role of Geomechanics in Reservoir Simulation
Authors: Gutierrex M. , Lewis R.W.
Published: December 2007

The paper presents a discussion on the issues related to the interaction between geomechanics and reservoir simulation in deformable hydrocarbon reservoirs. Geomechanics is important in order to account for rock deformations due to pore pressure and temperature changes resulting from production and fluid injection. Rock deformation can affect the permeability and pore compressibility of the rock. In turn, the pore pressures will be vary due to changes in the pore volume. Geomechanics is also required in order to account for the effect of the non-pay rock surrounding the reservoir on the overall reservoir compressibility and the loads transmitted to the reservoir by the weight of the overburden rock.

The paper gives the formulation and finite element discretization of Biot's equations for multi-phase fluid flow in deformable porous media. Based on this formulation, it is argued that geomechanical response and multi-phase fluid flow are fully-coupled processes in that pore pressure changes affect rock mechanical response and vice-versa, and that the two processes occur simultaneously. By contrasting Biot's equations and its discretization to the corresponding multiphase fluid flow equations used in reservoir simulations, it is shown that reservoir simulators neglect or simplify important geomechanical aspects that can have impact on reservoir productivity. This is attributed to the fact that the only rock mechanical parameter involved in reservoir simulations is pore compressibility. This parameter is not sufficient in representing aspects of rock behaviour such as stress path dependency and dilatancy, which require a full constitutive relation. Furthermore, the pore pressure changes due to the applied loads from the non-pay rock cannot be accounted for by simply adjusting the pore compressibility. Example problems are shown in order to illustrate the value of coupling geomechanics to reservoir simulators. Finally, the practical benefits of using coupled geomechanics and reservoir simulations are discussed.

P. 439
"Coupled" Stress/Fluid/Thermal Multi-Phase Reservoir Simulation Studies Incorporating Rock Mechanics
Authors: Koutsabeloulis N.C. , Hope S.A.
Published: December 2007

Both the mechanical and hydraulic behavior of black oil reservoirs is dominated simultaneously by the properties of the intact' rock and the discontinuities within such masses. When inter-connected, these discontinuities define individual blocks that may become unstable, when subjected to pressure and/or thermal gradients. Studies involving coupled stress, thermal and flow modeling, in reservoir engineering, using both mechanical and hydraulic properties for the rock fabric and incorporating the stress magnitude and its directionality, have demonstrated the concept that preferred directionality during waterflooding is stress related and progressive in time. 2-D and 3-D field applications illustrate that reservoirs are both reactive' and dynamic in nature and substantial changes to both the hydraulic and mechanical constitutive behavior are taking place during waterflooding operations.

P. 449
Strain Hardening and Extensional Failure in High Porosity Chalk
Authors: Risnes R. , Garpestad O.J. , Gilje M. , Oland L.T. , Ovesen M. , Vargervik E.
Published: December 2007

The problem of strain hardening has been approached by preparing series of similar cylindrical chalk samples front outcrop material. The samples in each series could then be given a certain degree of deformation beyond the elastic limit. Afterwards the samples could be tested in standard triaxial tests at different confining pressures in order to determine the resulting yield envelope. Such experiments were performed both under compressional and extensional conditions.

Under compressional conditions the preceding loading resulted in a corresponding stretching of the elastic region as expected. But this apparent strengthening was not strengthening in a general sense. The material cohesion was greatly reduced (like the tensile strength). Under extensional conditions there was little or no effect of previous straining of the samples. It is therefore proposed to replace the words strain hardening by compressional hardening, to indicate that hardening is only hardening towards further compression.

The results from the extension tests defined one single failure line, irrespectively of previous straining, saturation fluid and chalk type. Assuming that the Mohr Coulomb criterion gives a valid description of failure in chalk, it is shown that this failure line corresponds to a critical state line for extension.

Failure criteria like Drucker Prager that are symmetric around the hydrostatic axis in stress space, cannot give a complete description of chalk behaviour.

A general criterion that includes intermediate stress and reflects both compressional and extensional failure, must have more like a convex triangular cross section with the hydrostatic axis in stress space, like the Lade's criterion.

P. 475
Water/Chalk (or Collapsible Soil) Interaction: Part II. Results of Tests Performed In Laboratory On Lixhe Chalk to Calibrate Water/Chalk Models
Authors: Schroeder Ch. , Bois A-P. , Maury V. , Halle G.
Published: December 2007

Ekofisk, Valhall and other North Sea reservoirs are made of water sensitive rocks such as pure high porosity chalk. Production of these fields implying water-flooding leads in several cases to compaction and subsidence.

In order to perform reliable predictions of compaction and subsidence when water-flooding such reservoirs, it is necessary to take into account not only the deformations that come from depletion in the compressible reservoir rocks but also to include additional deformations induced by water saturation (WS) increase.

These additional deformations may eventually be determined by performing water-injection (WI) tests in laboratory.

This paper presents additional tests that have been performed in laboratory in order to understand the mechanical behavior of chalk at the water-front.

It shows the existence of a degree of WS above which chalks mechanically behaves as if it is fully saturated, while chalk with a lower WS looks stronger than if the degree is higher. Greater the WS is, smaller the consolidation pressure Pc0.

Moreover, the deformations induced by water-flooding happen in two steps:

– the first one happens as soon as chalk get into contact with water and is instantaneous. – the second is delayed and looks more like creep as it happens after chalk gets in contact with water.

Observations and tests results are interpreted thanks to Piau's model.

P. 505
Applying Journey Management in the Service Sector
Authors: Corrigan Mark , Regnault Philippe
Published: December 2007

Driving is today the most dangerous activity facing a Schlumberger oilfield employee. In 1997, driving accidents were at the origin of 79% of the total Schlumberger work related oilfield fatalities. In order to address this risk, a comprehensive journey management system is being implemented, which targets not just driving techniques but rather the whole process of getting to and from worksites.

The process starts with a management review of the actual necessity of the trip and explores means of trip minimisation. Once committed, it continues with the assignment of qualified personnel and equipment appropriate to the task. On the hardware side, standards are set for vehicles which now not only include widely accepted devices such as seat belts and rollover protection, but include goals for fitting all vehicles with electronic monitoring systems. Road statistics have however proven that hardware alone will not be sufficient and a rigorous driver qualification process, followed by an extensive driver education program have been put in place. Programs include Defensive Driving courses, commentary drives, use of seat belt convincers, proactive application of data obtained from vehicle monitoring systems and, in the near future, the use of driving simulators.

Procedures have been established to ensure the subsequent journey is properly planned with potential risks evaluated and crews fully briefed. The route is clearly defined and rest stops planned.

Finally, and perhaps most importantly, the success of this initiative is no different to any other, in that it depends on clear management leadership and commitment.
Reversible Invert Emulsion Drilling Fluids - A Quantum Leap in Technology
Authors: Patel Arvind D.
Published: December 2007

A novel, invert emulsion fluid useful in the drilling, completion, and workover of subterranean wells has been invented. The new invert emulsion drilling fluid can readily and reversibly be converted from an invert, i.e., water-in-oil emulsion, to a regular, i.e., oil-in-water emulsion, and back to the original invert emulsion using an acid-base chemical switch.

The surfactants used in the reversible invert emulsion fluids are strong invert emulsifiers in the presence of lime. However, the same surfactants become regular emuisifiers in the presence of water-soluble acid. The reversible emulsion property of these surfactants allows the drilling fluid to be changed from an invert emulsion to a regular emulsion at different stages of the drilling/completion operation. During the drilling stage, the drilling fluid can be an invert emulsion achieving all the performance benefits associated with oil-based muds (OBM's). During the completion stage and afterwards, the emulsion can be reversed by adding water-soluble acid, thus providing excellent filtercake cleanups, improved production in an openhole completion, better cementing, and efficient cuttings cleanup and waste minimization.

The reversible system is simple and easy to run without any exotic changes in current operations or other additives than those commonly used in OBM's. The reversible drilling flu id is versatile and relatively inexpensive and versatile, especially as compared to new, exotic fluids on the market today. The reversible feature allows the mud to achieve performance, production, minimal environmental impact, and cost control.

The paper discusses the overall impact of reversible invert emulsion technology in meeting the environmental and functional requirements of drilling operations. The laboratory data show that this system can provide drilling performance similar to OBM's at various oil/water (O/W) ratios, mud weights, and in the presence of commonly encountered contaminants. This paper compares the new reversible fluids with previous state-of the-art invert emulsion drilling fluids. These new stable, reversible invert emulsion drilling fluids can readily be reversed to regular emulsions using inorganic acids such as hydrochloric acid or organic acids such as citric acid.

The paper discusses the application of reversible emulsion technology on efficient removal of filtercake and improved production in openhole horizontal well completions. The environmental impacts of this system on washing and disposal of drilled cuttings are discussed.

P. 55
Case History on Planning, Drilling and Completing the World Record ERW-XJ 24-3-A14
Authors: Jiang Zhang Ming
Published: December 2007

In recent years, extended reach drilling technology has been successfully used to develop marginal offshore oilfields in other part of the world. This encouraged the field operator Phillips China Inc and its partners China Offshore Oil Nanhai East Corp and Pecten Orient Oil Co. in South China Sea to apply this technology to develop a marginal field named XJ 24-1 which is located about 8 km from an existing platform – XJ 24-3. The XJ 24-1 field was discovered in late 1985. Attempts have been made to jointly develop it with existing fields by either unmanned satellite platform or subsea completion but these concepts were uneconomical due to the size of the field. The feasibility of the project was questionable from inception since the XJ 24-3-A14 well was a unique operation and limited resources were available in South East Asia. Through the team's dedication and perseverance, this project was completed on time and below budget and even exceeded some forecasts on reaching targets. This well was drilled and completed by June 10, 1997 in a total of 101 days reaching a TD at 9,238 m MD with 8,063 m of horizontal displacement.

World records set on this well were: Longest horizontal displacement (8,063 m)Deepest real time transmission of the MWD/LWD data (9,106m)

A series of new technologies specifically developed for extended reach wells have been successfully applied on this well. This paper describes the case history on planning, drilling and completing the world record extended reach well.
The Impact of Compression Forces on Casing String Designs and Connectors
Authors: Jellison Michael J. , Brock James N.
Published: December 2007

The effect of down hole axial compression forces on casing string designs and connectors is a major concern to engineers designing high temperature, high pressure (HTHP), extended reach and horizontal wells. Widespread concern regarding the significance of compression loads on casing string design is relatively recent. For decades engineers were either not aware that high compression loads may occur or were not concerned about the effect of compression on the casing.

This paper discusses the sources of axial compression forces in straight and directional wells. Methods to analyze casing subjected to compression and bending loading are presented including the effect of compression and bending on the von Mises Equivalent (VME) stress state of the pipe.

Connector selection for casing applications where high axial compression loads are anticipated is critical. Compression ratings for API casing connectors have never been addressed in API standards. The paper offers methods to evaluate API connectors for applications with significant compression loading. Compression ratings for premium casing connectors are generally available, but the justification for these ratings varies substantially from one manufacturer to another and the basis for the compression ratings may not be well documented. The paper discusses compression rating methods for various premium connector configurations including threaded and coupled, flush and near flush. Desirable and undesirable premium connector features that relate to compression capacity are reviewed. Results from compression testing of premium connectors are also presented.

The paper benefits engineers involved in the design of casing strings for applications with high compression and bending loading.

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Optimization of Drilling Parameters with the Performance of Multilobe Positive Displacement Motor (PDM)
Authors: Samuel G. Robello , Miska Stefan
Published: December 2007

Recent increase in application of coiled tubing for horizontal wells and in particular underbalanced drilling triggered the necessity of a powerful downhole motor. More often downhole motor stalling and motor replacement is a problem when using with coiled tubing drilling system. To enhance the technology and make the system effective, optimization of drilling parameters is essentially required. The frequent motor replacement during the operation incrementally increases the operating cost despite deriving potential benefits from coiled tubing drilling. The key to improved coiled tubing drilling system is a unified system approach that encompasses motor and bit. This paper presents an analytical study on the optimization of motor performance and drilling parameters. A new simple test called wear-off test is defined to establish an operating window. The practical usefulness of the theory, backed by the fundamental and optimal analysis for roller cone and diamond bits, is demonstrated with numerical examples.

P. 149
Underbalance Drilling Technique Improves Drilling Performance - A Field Case History
Authors: Cunha J.C. , Rosa Fabio S.N.
Published: December 2007

This paper describes the project and execution of a well using Underbalance Drilling (UBD) technique in South Brazil. Due to very hard formation in the intermediary section of the well and a very damage-sensitive reservoir, the use of UBD was considered mandatory for this field. New equipment were specially designed for use in the well including a liquid-gas separator and a new manifold. Since nitrogenated fluid was used as drilling fluid, a membrane was used to on-site generation of nitrogen. The article gives field data obtained in the well and also shows comparison between the results obtained with UBD and conventional drilling. A description of the advantages, problems and shortcomings of the technique also is included in the paper.

P. 213
Reduce Torque, Drag and Wear - Material Selection for Centralizers Used in Highly Inclined and Horizontal Wells
Authors: Kinzel Holger , Colvard R.L.
Published: December 2007

Centralizers for highly inclined and horizontal wells have to fulfill several requirements. Their main task is to provide adequate standoff. Additionally, centralizers have to facilitate casing and liner running and should allow pipe rotation. While bow-type centralizers normally are made of steel, various other alloy materials have been introduced for rigid type centralizers, including aluminium and zinc-aluminium alloys. Investigations have shown, however, that steel is a preferred material also for rigid type centralizers. Friction factors under all mud-wetting conditions of steel versus formations and pipe surface as well as the wear rate are low compared to other materials.

This paper describes the details of the investigations and describes two steel centralizers specifically designed for use in highly inclined and horizontal wells.

P. 217
Steel Body PDC Bit Technology Demonstrates Performance Improvements
Authors: Smith L.M. , Perrin V.P. , Delwiche R.
Published: December 2007

New bit technology was used to create a series of steel body bits which incorporate proven PDC bit design features for improved performance. The bits have achieved field records in fully one-third of the applications in which they were introduced. The technology described includes all aspects of bit application, including new manufacturing processes, advanced design engineering, a unique nozzle configuration and use of a computerized rock compressive strength analysis program to refine application.

Field performance of steel body PDC bits is detailed and compared to conventional matrix body bits to illustrate the resulting performance improvements possible with proper steel body PDC bit application.

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