bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Solutions to Gas Flow through Porous Media
Authors: Babu D. K. , Bansal P. P. , El-Rabaa A. M. , Jasti J. K.
Published: December 2007

The equations describing the flow of gas through porous media are non-linear due to the dependence of coefficients on pressure. Several techniques have been applied in the past to deal with the non-linearity. The topic continues to generate research activity, and points to the need for developing more efficient and accurate techniques of handling the non-linearity in the gas equations. Drawing upon the ideas and approaches from the previous studies, a new solution methodology to the non-linear equations governing gas flow is presented in this paper. Whereas the previous studies had access to the non-linear gas solutions (numerical solutions), and could correlate back to the liquid-mode (linear) solutions, we approached the problem differently: to transform the liquid-mode solutions to the unknown and correct solutions of the non-linear equations. The time transformation was completely redefined. New equations were derived to relate the liquid time to the gas time scale. Low-pressure reservoirs were found to require special analytical formulas. The new solution methodology was validated using numerical simulator results.
New Developments in the Measurement of Induction Time for the Formation of Gas
Authors: Siyong Zhang , Lui Sun
Published: December 2007

A new gas Hydrates formation apparatus was developed and experimental data on hydrate formation kinetics, including induction times for N2, CO2, CH4, C2H6, C3H8 and a mixture of this gases are presented. The results indicate that the induction time is strongly dependent on the stirring rate and the driving force. Experiments conducted at the same time stirring rate and with a high driving force seem to show that the induction time varies exponentially with the size of the driving force. At lower driving force other parameters apparently also play an important role in determining the duration Period. Some qualitative theories concerning which other parameters might influence the nucleation time are proposed and discussed.

P. 593
Alkaline/Surfactant/Polymer Flood Predictions for the Karamay Oil Field
Authors: Delshad M. , Han W. , Pope G. A. , Sepehrnoori K. , Wu W. , Yang R. , Zhao L.
Published: December 2007

An alkaline/surfactant/polymer (ASP) pilot in the Karamay field was designed using a reservoir simulator with detailed chemical mechanisms modeled. The Karamay field is an onshore oil field in China. Oil recovery was predicted for different processes, designs, and operating parameters of this 13-well pilot. In particular, the benefits of adding sodium carbonate to the injected surfactant/polymer slug were evaluated. Oil recovery predictions were made for continued water, polymer, alkaline, surfactant/polymer, and ASP flooding with the best results, 24% of OOIP incremental oil recovery, obtained for the ASP process. The simulator used in this study has previously been used to simulate ASP corefloods, but this is the first time that three-dimensional reservoir simulations have been done with the detailed chemistry of the UTCHEM simulator. Alkaline agents such as sodium carbonate react with the acid in crude oils to form surfactant in situ. Such agents are inexpensive compared with manufactured surfactants. The pH of such fluids under the conditions that we studied is about 11, and which reduces the surfactant adsorption. However, the alkaline agent is partly consumed by undesirable reactions with calcium and other cations in the brine, cation exchange with the clays, and dissolution reactions with various formation minerals. A total of 26 chemical species were needed to model these reactions.

The phenomena modeled included the reduction of surfactant adsorption with increasing pH, aqueous-phase chemical reactions of the alkaline agent and consequent consumption of alkali, the in-situ generation of surfactant by reaction with the acid in crude oil, surfactant phase behavior, reduction in interfacial tension, and cation exchange with clay and with surfactant micelles. ASP coreflood data were first matched to validate model parameters. The reservoir description was provided by the operator and included the use of a stochastic permeability field. This study shows that it is feasible to make affordable field-scale mechanistic simulations of ASP flooding in three dimensions. This is a major achievement since such modeling is of great value in selecting the best improved oil recovery process and then optimizing this process.
Reproduce Wettability Alteration of Low-Permeable Outcrop Chalk
Authors: Graue A. , Viksund B.G. , Baldwin B.A.
Published: December 2007

A total of 41 chalk core plugs, cut with the same orientation from large blocks of outcrop chalk, have been aged in crude oil at 90 C for different time periods, in duplicate sets. Different filtration techniques, filtration temperatures and injection temperatures were used for the crude oil. Oil recovery by spontaneous, room temperature imbibition, followed by a waterflood, was used to produce the Amott water index for cores containing aged crude oil and for cores where the aged crude oil was exchanged by fresh crude oil or decane.

The main objective was to establish a reproducible method for altering the wettability of outcrop chalk. A secondary objective was to determine mechanisms involved and the stability of the wettability change.

The aging technique was found to be reproducible and could alter wettability in Rordal chalk selectively, from strongly water wet to near neutral wet. A consistent change in wettability towards a less water wet state with increased aging time was observed.

P. 193
Probabilistic Reserves Assessment Using a Filtered Monte Carlo Method in a Fractured Limestone Reservoir
Authors: Stoltz L. R. , Jones M. S. , Wadsley A. W.
Published: December 2007

A new approach to the estimation of reserves in a fractured limestone reservoir is presented and verified with a lookback analysis over the past five years of production from the field. This approach uses a filtered Monte Carlo method to integrate independent reserves calculations based upon volumetric, material balance, well pressure survey analysis, and well decline estimates of oil in place and recovery. For the Waihapa-Ngaere field, two estimates of oil in place are available: a volumetric estimate obtained from mapped gross reservoir volume and formation parameters; and a material balance estimate obtained from pressure decline and production data. Independent estimates of oil recovery can be obtained from estimation of recovery factors based upon areal and vertical sweep in the fractured reservoir, and recovery obtained from extrapolation of well decline. The approach taken, that is to integrate all of the available information and only accept parameter sets which are consistent, led to an estimate of reserves and production potential from the field which has proved remarkably accurate as a predictor of field performance and recovery over the past five years.
Simplified Approach for Predicting Pressure Profiles in a Flowing Well
Authors: Palisetti Ramana V. , Heinze Lloyd
Published: December 2007

Accurate prediction of pressure profiles in a flowing well can greatly improve the design of production facilities in petroleum engineering. This can in turn lead to improvement in the artificial lift system design. Rigorous theoretical models are often complex and inconvenient. They depend on many variables and require detailed information about the fluid composition. This paper describes a simplified approach which is suitable for quick calculations to predict pressure profiles in multiphase flowing wells. The empirical model assumes steady state flow and is developed using a database consisting of measured data from more than 100 wells. No attempt was made to determine holdup for the purposes of simplification and therefore, oil, water and gas were considered to be a single phase. The total energy loss term was assumed to be constant over the entire segment length under consideration and was varied for various segment lengths due to the insitu fluid properties and velocity. Nearly all pressure drop prediction from this approach are based on data with flowrates in the range of 90-3000 bpd and 2 and 2.5 inch nominal tubing. This paper is an extraction of work done in relation to the masters' thesis by Palisetti1 and review of previous work published by other authors in the field of multiphase flow.
A Strategy for Additional Developments in the Burgos Basin: The Arcabuz-Culebra Gas Field
Authors: Berumen Sergio , Sanchez Juan M. , Rodriguez Fernando
Published: December 2007

This work analyzes technical-economical options to massively develop the Arcabuz-Culebra gas field located at the Burgos Basin in northeastern of Mexico. This mature field has been a gas producer since 1971 from Wilcox and Mount Selman formations, the same gas sand producers of some South Texas fields. An integrated reservoir study was conducted in order to establish the most appropriate developing plan for the Arcabuz-Culebra field according to the new production strategy of the Burgos Basin. The interpretation of 3-D seismic has improved substantially the reservoirs characterization and, along with an efficient application of hydraulic fracturing technology and the reservoir simulation of the Wilcox sands, the production has been increased dramatically. The spatial representation of hydraulic fractures in the simulation study was approximated by using a moderate local grid refinement in such a way that the quality of the numerical solution were acceptable with respect to the corresponding analytical solution during the time of interest. The study shows a procedure to analyze strategies of well spacing based on numerical simulation by reservoir sectors and the corresponding economic analysis under different well spacing. It was found that well spacing varies widely along the reservoir, and is strongly governed by local permeability, pay thickness, current pressure and associated costs. Using advanced technologies in drilling, fracturing and geosciences have proved their technical benefits in this gas field. However, results of this study demonstrate that the cost of implementing advanced technologies in drilling and hydraulic fracturing may importantly impact, under certain economic circumstances, in the well spacing strategy, and consequently in the recovery factor of these low permeability formations. The additional development plan of the Arcabuz-Culebra gas field, although profitable, resulted to be strongly dependent of new technologies and their associated costs. The field development plays a strategic role in the redevelopment of the Burgos Basin, since provides approximately one third of the production of the basin.
The Combined Effect of Near-Critical Relative Permeability and Non-Darcy Flow on Well Impairment by Condensate Drop-Out
Authors: Blom S.M.P. , Hagoort J.
Published: December 2007

We present a comprehensive numerical method to calculate well impairment based on steady-state radial flow. It incorporates near-critical relative permeability and saturation dependent inertial resistance.

Example calculations show that near-critical relative permeability and non-Darcy flow are strongly coupled: Inertial resistance gives rise to a higher capillary number, which makes the use of proper near-critical relative permeability curves all the more important. In its turn, the improved mobility of the gas phase due to a higher capillary number enhances the importance of the inertial resistance.

The combined effect of condensate drop-out and non-Darcy flow may cause large skins in gas condensate reservoirs. Well impairment may be grossly overestimated if the dependence of relative permeability on the capillary number is ignored.

P. 181
Fracpack Completion of Gas-Storage Wells for Enhanced Deliverability
Authors: Peebles Bill , Kelley Robert , Ritter Wes , Fitzpatrick Harvey
Published: December 2007

This case-history paper presents results of installing fracpack (one-step tip screenout1 fracture stimulation and gravel-pack operations)2–5 completions in gas-storage wells in the West Clear Lake Field of Harris County, Texas. Using the fracpack technique, operators have fracture-stimulated six wells (new drills and workovers) in the past 3 years as part of an overall facility upgrade. Gas is injected daily into the Frio formation (5,500 ft) of the field and withdrawn at high rates during peak demand periods. A strong waterdrive can "water-out" production at the end of peak-season gas withdrawal, and water recedes when withdrawal is ended and gas volume and pressure in the reservoir are restored by injection. The paper presents (1) fracpack installation techniques, (2) performance comparison of conventional methods and ffracpacks, and (3) completion technique selection to achieve high production efficiency.

New wells completed with fracpacks in 1994 have yielded rates up to 100 MMcff/D each with about 500 psi drawdown pressure. In 1995, a well capable of producing at 25 MMcf/D with a gravel pack was recompleted with a fracpack, which increased its rate capacity to 49 MMcff/D. Because of the performance of the first three wells, three more wells were completed with ffracpacks in 1997. The fracpack completion has proven superior to other sand-control methods in providing high-rate deliverability in the West Clear Lake Field. Fracpack completions have, in general, provided a two-fold increase in daily production rate.

Fracpack completions and recompletions can be applied in gas-storage wells where high production rates are needed and sand-control measures are necessary for the life of the well.

This paper provides guidelines and results associated with fracpacking by demonstrating the importance of selecting completion techniques that will provide high-efficiency production from gas-storage wellspresenting case histories of fracpack-stimulated gas-storage well performance over a relatively long time periodcomparing well performance of conventionally completed and fracpack-completed gas-storage wells producing at high ratesproviding insight into operational aspects of fracpack completions
Interferences with Produced Water Treatment for Dispersed Oil Removal
Authors: Bansal K. M. , Caudle D. D.
Published: December 2007

This paper discusses the chemistry of interferences with produced water treatment processes for dispersed oil removal, and recommends potential solutions for enhancement of the efficiency of the treating process. A better understanding of the chemistry of the interferences is essential in optimizing the performance of the water treatment equipment to meet increasingly more stringent disposal and injection requirements. Both regulations and technological considerations are demanding increasingly cleaner water.

The best available technology (BAT) prescribed by the US Environmental Protection Agency National Pollutant Discharge Elimination System (NPDES) permits for oil and grease in produced water discharges to US waters and the North Sea limitations are based on the performance of flotation equipment. But, hydrocyclone technology currently is the equipment of choice for many offshore operations. The chemistry of produced water and its constituents can detrimentally affect these two processes. These effects will be discussed with special emphasis on impacts to the basic principles of process equipment operation and limitation of the technologies.

Some factors that can cause significant interferences with produced water treatment processes are: (a) non-produced fluids, (b) iron and its interaction with oxygen, (c) loss of carbon dioxide and its effect on scaling tendencies, (d) the effect of the presence of soluble oil and (e) the effect of process flow variability. These factors can cause enhanced oil droplet stability, result in the inhibition of the droplet coalescence rate, and consequently reduce the dispersed oil removal efficiency.

The combined effects of oxygen, dissolved iron compounds (e.g. corrosion products) and pH of the receiving waters could cause sheen in the disposal of treated produced water. Experience from field studies and operations will be used for illustrating interferences and their effects.

The limitations of the water treating processes and common interferences will be used to suggest guidelines for optimum operation of the equipment. A "total system approach" is recommended in developing the solution to water treating problems.
Waste Management and Disposal of Cuttings and Drilling Fluid Waste Resulting from the Drilling and Completion of Wells to Produce Orinoco Very Heavy Oil in Eastern Venezuela
Authors: Getliff J. M. , Silverstone M. P. , Sharman A. K. , Lenn M. , Hayes T.
Published: December 2007

During the next decade and beyond, a large number of wells will be drilled in Eastern Venezuela in order to produce very heavy oil. Because of both the nature of the reservoir and the length of the horizontal section, water based drilling fluids will become contaminated with anywhere from 3–20% crude oil during the drilling process. The result will be the need for disposal of large quantities of oil contaminated water base mud and oil soaked cuttings.

This paper discusses the options that are available for the disposal of the cuttings and focuses in particular on biological methods of cleaning the cuttings, including land farming and the use of composting biopiles. We also discuss the potential use and development of a mobile bioreactor that can be located on the drilling site. This reactor will contain the waste during the degradation process and maintain conditions that will result in virtually total degradation of the organic compounds with carbon dioxide and water being the main by-products.
A Model for Promotion of a Constructive Alcohol and Drug Culture
Authors: Leitao Joao
Published: December 2007

In 1991 Shell International developed the first version of its guidelines for an updated Alcohol & Drugs (A&D) policy. During our work with A&D, several difficulties with this policy have emerged; problems with the boundaries between work and leisure time, poor transformation to local culture, problems with the definitions of "safety positions" and poor results of testing programmes. In this paper we presents a new model for the development of a A&D policy that handle these difficulties and define an A&D culture that promote the constructive ways of using A&D and prevent destructive use.
Aids Education in the Workplace: The Escravos Tank Farm Experience
Authors: Faleyimu B. L. , Fagade O. A.
Published: December 2007

Safety is a major subject in the Oil and Gas Exploration and Production Sector as it is in Reproductive health. With the emergence of the HIV/AIDS epidemic, safety and health of the work force are being jeopardized. The implication of this for the Oil and Gas Exploration and Production Sector is quite enormous since labor is one of her main productive resource.

The Escravos Tank farm is the operational headquarters for the Escravos operations of Chevron Nigeria Limited (CNL), a part of Chevron Corporation – an international Oil company based in San Francisco. On the Tank farm, the resident population is approximately 650 with about 1000 Contract Staffs that are scattered in settlements and villages around the Tank Farm. There is a regular interaction between the Tank Farm workers and the settlements. This interaction is believed to oil the rig of sexual network amongst the various subsets.

A pre-program key-informant interviews and focus group discussions amongst the different cadres of Staff revealed a poor awareness and an alarming number of misconceptions about HIV/AIDS amongst 84 percent of the employees.

A well-articulated multi-pronged AIDS EDUCATION program at the Workplace was initiated at the Escravos Tank Farm bearing in mind that AIDS education may yet be the only safe vaccine available for now. This forms the main thrust of this paper. This consisted of series of AIDS awareness lectures, use of posters; video shows on AIDS (The Silent Epidemic); question and answer sessions. In addition, counseling sessions were arranged and comprehensive handouts on STDs/HIV/AIDS and Safer Sex practices were given to participants. In the nearest future plans are on to extend this program to the surrounding settlements and network subsets using all available means of mass communication, and to start Peer education program. By and large CNL is also responding largely to the economic, medical, psychological, safety, and legal issues surrounding AIDS in the Workplace.
Malaria and Malaria Chemoprophylaxis Among Expatriates In Swamp And Offshore Operations – Our Experience
Authors: Ajayi P. A. , Babalola R. O. , Fadeyi O. T.
Published: December 2007

A lot of information on malaria, some conflicting, is available to the international traveler from many sources. Between December 1994 and August 1997, 23 expatriates were treated for malaria in our clinic at the Escravos Terminal. 17 of these were on malaria chemoprophylaxis and 4 started after the attack. We recently noted a decline in the rate at which expatriates collected antimalarials from our clinic and this survey was carried out to find out the experience of our swamp/offshore expatriate staff with malaria preventive measures especially chemoprophylaxis. 200 questionnaires were sent out to determine among other things, pre-travel counseling, antimalarials taken, side effects, compliance and their perception of the malaria issue. 136 questionnaires were returned. 53% of responders were Americans and 37.5% were Britons. 75% of responders had pre-travel counseling, 66% started on malaria chemoprophylaxis before traveling. 98 (72%) took antimalarials at one time or the other, and of these, 32% took chloroquine/paludrine combination, 55% took mefloquine, 8% took proguanil only. 1% each took doxycycline and pyrimethamine. Of the 98 who took antimalarials, 52 had stopped their medication for various reasons. Mefloquine was stopped in 60% of cases and chloroquine/proguanil in 27%. Of the 46 presently taking antimalarials 60% have taken drugs for 1 to 3 years. The most commonly experienced side effects for the various drugs are outlined, as well as respondents’ perception of malaria and the various preventive measures advocated.

Of the 136 respondents 27 (19.9%) had had one or more attacks of malaria before. 61% will advise first time visitors to Nigeria to take prophylactic antimalarials.

The second part of the study will compare these findings with the experience of our expatriate staff resident in Nigeria. The need to streamline malaria preventive measures and the information available to expatriates traveling to the tropics is stressed.
Heat Stress In Oman: People, Exposures and Data Acquisition
Authors: Boelens P. R. M. , Senior P. L.
Published: December 2007

Acquiring seismic data and its subsequent computer analysis is a key stage in the assessment of new oil or gas prospects. In Oman, seismic operations are often conducted in an extreme thermal environment. Seismic workers in the desert consistently identify heat stress as a major health hazard. Providing information on heat stress and control measures is in the hands of supervisors. In particular during the summer, cases of heat related disorders are reported and recorded in the desert field clinics. It is recognized that heat exposures in Oman can exceed the ACGIH guidelines and that the empirical formulae for determining maximum heat exposures may not be fully applicable for the Oman environment. A six month study on seismic crews was carried out with the objective of reviewing the current work practices and to identify possible adverse health effects in relation to environmental conditions and workload.
Systematic Working Environment Review and Verification Experience on New and Existing Offshore Installations
Authors: Smith Chr. Cappelen
Published: December 2007

When designing new offshore installations, built at a number of different shipyards throughout the world, with the objective of creating healthy and sound working environment in order to mitigate possibilities for occupational injuries and occupational diseases, it has proven necessary to have regular follow-up reviews and verification activities throughout the concept, design, construction, commissioning and operating phases of each ongoing project.

The necessity of close follow-up is enhanced by the fact that the installations will be working in different locations around the world, and thus a large variety of local government regulations as well as rules of the industry and the operating companies and the entrepreneur will have to be satisfied. In addition the rules of the chosen classification society must be satiesfied. It may seem easy to chose the stricter of these possibilities, but since economy always play an important role, the picture becomes more complex. For existing offshore installations the type of reviews, verifications and follow-up of the working environment factors in operations and during major reconstruction must be done, but a different approach is chosen to ensure reaching the goal.

Working in many different parts of the world when planning, constructing and operating offshore installations gives a whole range of different experiences. This experience transfer is of great value when systematically applied in the industry.

The well-being and safety of the employees plays a very important role with regards to efficiency and operations regularity for offshore installations- and the safeguarding of the working environment in the broadest sense for each individual as well as for the installations as such is good economy. An important signal about company attitude towards the indidual employee is also a strong enhancer of good working environment appreciation.
Produced Water in the North Sea: a Threat for the Environment or a Threat for the Industry?
Authors: Garland E. M.
Published: December 2007

An increase in the amount of oil released to the North Sea in produced water has led some littoral countries and Non-Governmental Organisations to call for tightening the control measures on discharges. The E&P Industry has reviewed the recent information on the fate and effects of produced water discharge on the marine environment (more than 100 papers) as well as progress in handling produced water, including reinjection and shut off techniques.

There clearly has been a concerted research effort to provide greater understanding of the management of produced water. Nevertheless, there is much less new information than might have been expected. But even so, there is now a clearer understanding on the fate and effects of produced water. The composition and properties of produced waters discharged to the North Sea are now well established. Major improvements have been made in the determination of groups of organic substances such as volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH) and phenols, and robust methods for their determination are now available.

Discharge volumes and loads have stabilised and are expected to remain at the present level for around 5 years. Alternative management solutions are being researched and major advances in re-injection and shut-off techniques are expected in the next few years although they will take time to implement on a wide scale. The quality of discharged water has also remained stable with an oily content of around 30 mg.l−1 despite the rapid increase in the quantity of water treated offshore. Moreover, the other contaminants from discharges of produced water are not a major component of the total input of contaminants to the North Sea.

In terms of fate and effects of the discharges, greatest emphasis has been put on impacts arising from chronic exposures, including bioaccumulation and biomagnification. Recent focus on the effects of endocrine mimicking substances is being incorporated into research programmes.

In the second part of the paper, the assessment of the new measures that the Contracting Parties to the Oslo and Paris Convention envisage confirms the need for an integrated approach to produced water management, and shows that additional severe constraints on produced water discharges would have a negative impact on the E&P Industry without any net benefit for the marine environment
The Impact of Shallow-water Seismic in Sensitive Areas
Authors: Webb C.L.F.
Published: December 2007

This paper aims to up-date some of the misconceptions concerning the impact of shallow-water seismic operations. It will also provide an insight into the planning, organization and special technical features implemented for operations in an environmentally sensitive area and a number of key lessons learnt.

The North European Wadden Sea coast, bordering Denmark, Germany and the Netherlands is a region of extremely high environmental and political sensitivity. The successful development of the Mittelplate oil field in a National Park off the west coast of Germany, provides an excellent example that oil exploration and production can be tailored to the demands of such sensitive and protected areas.

During 1996 and 1997, exploration Seismic was carried out in the tidal flats and saltmarshes of the Wadden Sea National Park. This was the first survey of its kind in Germany and attracted a high degree of interest from both public and industry alike. The physical and environmental constraints of the location called for specially designed equipment and a number of unique planning and organizational features to be implemented in the surveys. Extensive monitoring was carried out above and below water to determine the effect of the Seismic activities on the marine life. The Survey has provided the opening company and the authorities with new information for use in future Seismic programmes, not only in Germany but also in other protected coastal areas around the world.
Considerations for Oil Field Construction: Erosion Potential Adjacent to Morichales in Central Venezuela
Authors: Meyer G. D.
Published: December 2007

The northern and central portion of the Venezuelan state of Anzoátegui has been the site of substantial oil field development activities for many years. Now the Orinoco Heavy Oil Belt, in the southern part of this state, is receiving attention. This attention is being been accompanied by a heightened concern for the environment.

The southern portion of Anzoátegui is in the central plain of Venezuela and consists primarily of mesas dissected by river valleys. The upland areas are tropical savanna with the typical grassland and sparse trees. Adjacent to the streams are local dense jungles known as "Morichales" that exhibit a different assemblage of fauna and flora from the upland areas.

Due to certain soil, hydrogeologic, and topographic conditions, specific areas along the escarpments and the valley slopes appear to have high erosion potential. The proximity of the environmentally sensitive Morichales to these erosion prone upland areas poses a plausible oil spill scenario that should be considered in the design and placement of new facilities. Early identification and evaluation of erosion problems in project areas can help avoid potential costly situations.
Process Control Interface Issues in the Upstream
Authors: Danz-Reece M. E. , Noerager J. A.
Published: December 2007

With advancing technology, the operator interfaces to computerized distributed control systems (DCS) include features such as multiple windows on a single screen, higher resolution for text and graphics, numerous available colors, and many levels of alarms and notifications. Although these features allow more information to be presented to the operator than ever before, there is potential for overloading the operator with too much, or confusing, process information. Examples of typical interface issues described in industry and government reports include cluttered data screens, overuse of color, inconsistent alarm priority assignments, alarm flooding and inconsistent or unclear labeling, color coding and equipment symbols. This paper summarizes an approach for implementing an optimal operator interface for new or upgraded computerized DCS. The approach includes training the applications team, developing project interface standards, testing prototypes, training operators and continuous interface improvement.
Training for Safe and Efficient Lifting Operations
Authors: McMorran Paul
Published: December 2007

Accidents involving cranes and lifting gear are among the most potentially catastrophic to drilling and production operations. Their scope for serious injury, damage to the environment and downtime is often underestimated. The role of the Crane Operator, it seems, has been particularly undervalued. This paper describes a new approach to training those involved in lifting operations on rigs world-wide. Developed by a major international drilling contractor, this addition to a well established on-the-job training program sets a new standard for in-house certification of Crane Operators. This is achieved using all-new training source material, combining self-study with practical instruction at the rig site. Demonstrated competence is the target, and well-defined assessment criteria supported by comprehensive guidelines for supervisors provide the means to assure it.
The Faroes GEM - An Ideal Case of an Oil Industry Co-Operation Prior to a First Licensing Round
Authors: Walls Anne , Leggett Ian , Evans Trevor , Jakuppstovu Hjalti I.
Published: December 2007

The Faroe Islands are planning to open their territorial waters to oil exploration and production in 1998, when they have their first licensing round. The Faroese economy is presently dependent upon fisheries, with fishing, fish farming and processing accounting for almost 95% of all exports. The seas surrounding the Faroes are renowned for their cleanliness, and are of importance for cetaceans and seabirds as well as fish.

In a unique collaboration, 23 oil companies have already started to work together in conjunction with the Faroese Petroleum Administration and Institutes in order to gather data on the environment around the islands. The main objective of the joint industry/institute group is to gather sufficient data to enable operators to carry out environmental risk assessments for future exploration drilling offshore the Faroe Islands.

This paper describes the work and philosophy of the Faroes GEM, whose workgroups are studying the Geotechnical, Environmental and Metocean aspects of prospective areas of interest on the Faroese Continental Shelf.
An Analysis of Human Settlement Along the Xan Oil Road in Laguna del Tigre National Park, Guatemala
Authors: Musinsky John N. , Reining Conrad C. S. , Rosenfeld Amy B. , Thomsen Jorgen B.
Published: December 2007

A study is made of deforestation rates based on proximity to the Xan oil road in Laguna del Tigre National Park, Petén, Guatemala. Results from a time-series analysis using Landsat Thematic Mapper imagery from 1986 through 1995 and aerial photography from 1997 indicate a high degree of correlation between the oil road and settlement patterns within the national park.
Environmental Risk Assessment - Case Study of an Offshore Petroleum Development
Authors: Pinceratto E. , Casey J.
Published: December 2007

Environmental impact assessment has traditionally been based around a review and assessment of identified impacts and issues. Strategies to mitigate, control and monitor these impacts are also addressed at this stage.

BHP Petroleum has employed a risk based, hazard identification (HAZID) approach at the start of projects to ensure that actual and potential environmental impacts and concerns are identified at the conceptual stage. The benefit of using a HAZID approach is that impacts are identified in a systematic manner through a brainstorming session comprising a multi-disciplinary team. It is at this session that the source of the impacts are identified and methods for their prevention, control and/or mitigation are discussed. An environmental risk matrix has been developed for use in this exercise to prioritise risks in order of their likelihood, and of their impact upon the environment and the Company's business.

This is a valuable exercise which allows the environmental impact assessment process to effectively and comprehensively address all environmental risks. It has the added advantage that it allows all members of a project team to get up to speed with the environmental issues and ensure that methods for prevention and control are addressed during project design. It also takes into account the local environmental sensitivities in all phases of the project, from site selection to construction, operation and decommissioning.

This paper examines this approach in the context of a petroleum development in an offshore marine environment which includes localised complex ecosystems.
Building Consensus for Sustainable Use and Management of Oil Resources
Authors: Tomei Manuela
Published: December 2007

The lands and natural resources in areas inhabited by many indigenous and tribal peoples, especially in Asia and the Amazon countries, are increasingly being prospected and/or exploited by public and private oil and gas companies. Evidence shows that, if not properly handled, this will have severe repercussions on many of those peoples. Livelihood systems can be wiped out, community safety nets dismantled, economic and social infrastructure affected, and kinship ties undermined.

The major challenge is to reconcile the rights and legitimate aspirations of indigenous and tribal peoples with the equally legitimate development needs of the country and the business interests of oil companies. Consultations and negotiations conducted in good faith and through appropriate procedures can help accommodate conflicting interests. This requires an enabling environment, and adequately prepared social parties.

In most cases, however, the institutional capacity to devise, implement and enforce effective environment and social safeguards is terribly weak. Mechanisms for consultation with affected indigenous peoples, prior to and during project execution, tend to be non-existent or inadequate. The principles, requirements, and responsibilities with regard to compensation and rehabilitation schemes, or concerning disputes settlement procedures over compensation or oil operation-related injuries are either lacking or vague. As a result, and because of national and international pressure, several oil companies have adopted measures to minimize social conflicts and adverse social impact. Despite the use of specialized assistance, social issues tend to be beyond the expertise and experience of oil project developers. If and when consultations are conducted, the devised social interventions are generally short-lived and welfare-oriented. Indigenous peoples very often are unaware of their rights, and of relevant provisions under environmental law and/or oil development legislation and regulations. They are equally unequipped to engage in meaningful dialogue and negotiation with oil companies and relevant government agencies. The paper will explore the extent of the problem, outline some of the consequences, discuss a few cases and offer some suggestions
Finding Common Ground for E&P Operations in Indigenous Communities
Authors: Mendez S. , Wasserstrom R. F. , Parnell J. A.
Published: December 2007

In 1994, representatives of ARCO Oriente Inc., the Organization of Indigenous Peoples of Pastaza (OPIP), and Oxfam America began discussions on social and environmental questions arising from the company's proposed development of a major oil field at Villano, Block 10, located in the rainforests of Pastaza Province, Ecuador. Despite considerable complications, ARCO and OPIP forged an innovative agreement that serves as an example of one attempt to move from a culture of confrontation to a culture of dialogue, and to establish appropriate and meaningful parameters for stakeholder participation in E&P projects. The focus of this agreement has been the newly formed "technical environmental committee" or "comité técnico ambiental" (CTA), composed of members from ARCO/Agip, Petroecuador, and three major Indian organizations. This paper describes how this agreement was reached, where it has led since 1994, new issues that have emerged, and whether this committee might offer a model for relations between hydrocarbon companies and native peoples.
Maintaining a Mutually Beneficial Relationship with Host Communities: Our Unique Way
Authors: Ajayi P. A. , Kpiasi E. O. , Wilkie D.
Published: December 2007

Chevron Nigeria operates in the Niger Delta region and has its operational headquarters at the Escravos Terminal which has all the facilities of a small community. One of such facilities is a well-equipped and staffed industrial clinic for the employees. Prior to 1992, this clinic provided emergency health care for the host communities surrounding this terminal because there was no other health facility for them. In 1992, Chevron Nigeria built, commissioned and donated an 18-bed cottage hospital to the host community comprising of about 7 villages and with a population of about 50,000. The community could not run the facility satisfactorily for several reasons and in July 1996, Chevron Nigeria took over the day to day running of the hospital. In the present dispensation, the community provides staff and pays staff salaries and Chevron provides drugs, dressings, hospital equipment, some staff incentives and maintains the facility. Treatment is provided free and no form of identification is required. Since Chevron's intervention, daily attendance jumped from a paltry 4–5 to over 40 and the community is quite satisfied. In the 12 month period between August 1996 and July 1997, total attendance was 14,925.

This paper discusses our mode of operating the facility, community perception, services provided, clinical cases commonly encountered, problems and future plans.
Local Stress Estimates and Far-Field Stress History, Ordos, China
Authors: Luo Y. , Dusseault M.B.
Published: December 2007

Monitoring acoustic emission behaviour during core restressing is a means of collecting stress history information, but this effect (the "kaiser" effect) for rocks cannot he used alone for paleostress reconstruction. Therefore, an integrated approach including regional geological and geophysical information such as magnetic, gravitational, and image data has been implemented in combination with core measurements and imaging logs. This analysis leads to a prohable history of far-field loading, and allows greater confidence in the interpretation in that numerous independent sources seem to suggest that the interpretation is consistent. For details of local stress distributions, Kriging methods are used, based on knowledge of the ancient landforms and erosional geometry. Practical applications of paleostresses in the context of basin analysis seem feasible if fractures can be linked to hydrocarhon migration and accumulation. To demonstrate this, the method is applied in the Ordos Basin in North China to establish the relationships between far-field and local stresses, and to link the stress and fracture history to the migration and accumulation of the large gas field found in the central Ordos area.

P. 527
Reservoir Stress Path: The Depletion and the Rebound
Authors: Santarelli F. J. , Tronvoll J. T. , Svennekjaer M. , Skeie H. , Henriksen R. , Bratli R. K.
Published: December 2007

The paper presents a field case based upon a reservoir operated by Saga Petroleum in the North Sea. The reservoir stress path was determined from a series of minifrac and fall off analyses and step rate tests on various appraisal tests and injection wells. The results show a strong heterogeneity of the stress path with a large difference between the heavily faulted Southern part of the field and the more quiet Central part of it. The stress path was further confirmed by a series of mud loss incidents during drilling that are briefly summarised.

Furthermore, in the case of two injectors, the step rate tests were performed after a significant re-pressurisation of the reservoir -i.e. 30 and 70 bars respectively. Such tests gave extremely low fracturation pressures compared to what was the reservoir stress path upon depressurisation. In fact, the fracturation pressures measured are consistent with the maximum depletion but not the reservoir pressure at the time of the test. In other words, the total minimum stress in the reservoir seems to be governed by the maximum depletion of the zone and not by the present level of pore pressure. Two wells from another North Sea reservoir will also be presented showing a similar behaviour upon repressurisation. Note that such an observation is consistent with one measurement performed on Ekofisk and published earlier on.

These observations of heterogeneous and irreversible stress paths will be analysed and compared to other observations such as the behaviour of surface subsidence during aquifer depletion and repressurisation.

In particular, it is shown that the reservoir stress path is compatible with a rigid plastic behaviour of the rock mass that has already been more or less observed in the case of the Venice subsidence. However, core measurements do not seem to obey such behaviour. The difference can then be attributed to scale effects as the stress measurements via fracturing tests affect large rock volumes.

As a consequence, the results reported here give an insight about what could be the rheological behaviour of a reservoir rock mass at a very large scale. Possible applications to large scale rock mechanics modeling such as compaction, subsidence, hydraulic fracturing, are then highlighted. Finally, the practical consequences of such a state of affairs in terms of reservoir management are drawn.
State-of-the-Art Sand Prediction Based on an Intranet "Push the Button" Interface
Authors: Viken R. , Kjorholt H.
Published: December 2007

Accurate sand prediction in deviated and perforated wells in an anisotropic stress field is not possible with simple analytical models. An advanced finite element model (FE model) has the capability to simulate any geometry and nearly any material behavior, but has, due to its complexity, in the past only been applied by a few specialists. By adding a user-friendly interface based on Internet technology, and letting the user select from a collection of predefined FE models, the user is now able to perform advanced sand prediction simulations from a WEB page. The user is required to specify formation properties, rock stresses, reservoir and well pressures and completion geometry as input parameters. From this input and a library of FE meshes, the simulator generates the finite element model and starts the simulation. The results are presented to the user in a WEB page. The results are presented in a standard and consistent way, which ensures good quality control in the interpretation of the results. By using this sand prediction simulator, complex modeling of the sand production potential is now available for all production engineers involved in well completion design in Statoil.

P. 271
Compressional Wave An Isotropy Caused by Single and Multiple Fractures
Authors: Pyrak-Nolte Laura J. , Shiau Jing-Yen
Published: December 2007

Compressional wave anisotropy caused by a single fracture and three parallel fractures was measured using an acoustic imaging system. The measured compressional wave transmission coefficients are compared with theoretically predicted transmission coefficients from the displacement discontinuity theory. Deviations from the displacement discontinuity theory occur at glancing angles of incidence to the fracture. The anisotropy in the transmission coefficient is observed to be frequency dependent and results in an apparent frequency-dependent stiffness.

P. 299