bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Non-uniform Fracture Spacing and Fracture Half-length on Well Spacing for Unconventional Gas Reservoirs
Authors: Sahai Vivek , Jackson Greg , Rai Rakesh 
Published: June 2014

Abstract
Early in the development of a shale gas resource, optimal well spacing remains unknown as wells are sparsely drilled to hold leases by production. Developing the acreage requires operators to select locations, specify drilling plans, and design completions for multi-stage horizontal wells to maximize the operating metrics as defined by the company.
This paper builds on our earlier work which presented sensitivity analysis for optimal well spacing with respect to permeability, fracture spacing and half-length under the assumption of uniform and symmetric completion configurations. The well spacing sensitivity to heterogeneity in completion configurations (i.e., non-uniform fracture half-length and asymmetric fracture spacing) are presented in this paper using forward and stochastic modeling approaches.
Forward modeling results show a strong bias towards the longest repeated fracture half-length in determining the optimal well spacing. Higher reservoir permeability abates the impact of fracture heterogeneity. Fracture modeling, constrained by production logs, temperature logs, and/or microseismic, can be used to aid in the identification of the longest repeated half-length.
This paper demonstrates the challenges associated with stochastic modeling of well performance. Examples from synthetic and field case studies are presented to illustrate uncertainty in reservoir and completion parameter determination. The spacing optimization workflow used captures this uncertain range to effectively determine the impact on recovery factor and Net Present Value (NPV). The importance of the quantity of production history needed to determine optimal well spacing is also presented. Results reveal that with increasing heterogeneity longer production history is required for reliable determination of optimal well spacing. Finally, a field case study applying a production log and fracture modeling is examined to identify the impact of non-uniform fracture spacing and fracture half-length heterogeneity.
These conclusions, via the application of deterministic and stochastic modeling on production from field cases and synthetic wells, will aid operators in answering the multi-billion dollar question: how many wells should be placed in a given area? The workflow described in this paper not only can answer this question but also help us to understand how to maximize economic return and the ultimate gas recovery.
Strategy and Planing EOR for Caracara Sur Field, Colombia
Authors: Cubillos H. , Stofferis M. , Vanegas G. , Lager A. , Rolf A. 
Published: June 2014

Abstract
The Caracara Sur Field (Llanos Basin, Colombia) consists of multilayered compartmentalized fluviodeltaic reservoirs. Sands have Darcy-level permeability, contain a medium-quality oil (21° API), and are subject to very strong aquifer support. The reservoirs are produced with artificial lift, either selectively or commingled. After six years of development, oil production is expected to decline. Ongoing efforts to maintain the production plateau include infill and horizontal attic oil drilling and selective completions. However, there is a limit to what can be achieved considering the strong aquifer drive and unfavourable mobility ratio. This encouraged the investigation of enhanced/increased oil recovery (EOR/IOR) methods which has resulted in screening a number of EOR processes and the planning of a pilot project in the field.
EOR/IOR screening evaluation identified chemical EOR processes as the most suitable techniques for the field. Polymer, alkaline-polymer (AP), Alkaline-Surfactant-Polymer (ASP) and surfactant-polymer (SP) are the technologies under consideration.
A careful and complete project plan has been developed, customized for the field’s most challenging characteristics: fresh formation water, in-situ oil viscosity of 12 cP, relatively high reservoir temperature (above 175 °F), the need to inject and produce commingled, (up to six stacked reservoirs) and most importantly the strong and drifting aquifer, which is expected to influence sweep efficiency.
The plan includes laboratory studies, multi-scale high-resolution reservoir simulation, single-layer single-well tests of injectivity and residual oil saturation, and a multi-layer inter-well pilot prior to full-field deployment. Tracer technology has been developed in-house to support the project. Back flow tracer tests and single-well tracer tests will be conducted in the field to evaluate aquifer drift and to determine the remaining oil saturation. Comprehensive evaluation will permit the design of an efficient vertical injection profile, appropriate injectivity and chemicals displacement in a multi-reservoir field.
The planning stage of the Caracara Sur EOR strategy, including the screening evaluation and the first project results, provides guidelines and solutions that can be used on other EOR projects in similar fields and facing similar challenges, not only within the Caracara Block itself, but within the Llanos Basin and elsewhere:
A ‘fast-track’ program, whereby screening and field studies are done partly in parallel targetting shortened elapsed time for the pilot evaluation. If results are technically successful this will allow profitable full-field EOR implementation. Use of an in-house project team supported by integrated laboratory expertise (leveraging CEPSA’s petrochemicals experience) is proving to be efficient and successful in delivering a high quality technical solution.
A New Interpretation of CO2 Diffusion Experiments
Authors: Potsch K. , Toplack P. , Gumpenberger T. 
Published: June 2014

Abstract
The injection of CO2 underground has been investigated by many scientists, be it for sequestration or enhanced oil recovery. When CO2 enters the reservoir, the main questions, into which phase the CO2 concentrates first (oil or water) and in which amounts it is going into solution, will be answered. Both, numerical and experimental studies in the literature report two different diffusion parameters, differing by more than one order of magnitude. These findings are confirmed in our experiments. In the literature, rapid dissolution is attributed to the appearance of natural convection due to density differences of the CO2-enriched liquid, entrailing a faster mixing, sometimes being called super-diffusion. This paper reviews the physical effects appearing during CO2 injection and investigates the mathematical basis for the determination of solubility and diffusivity together with the assumptions made in this case. We come to the conclusion that a parabolic diffusion law cannot explain the two different diffusion constants, but a hyperbolic law can. In a detailed dimensional analysis of the Navier-Stokes equation dimensionless groups are formed, the magnitude of which determines the importance of the different terms, in our case the importance of convection. Using the parameters of our physical setup we find that the convection is only prevalent in a thin layer close to the interface of gas and liquid. This is in contrast to present belief. Stability considerations for the onset of convection complete the scope of this work.
Offshore Environmental Management: Monitoring Guidelines in Oil&Gas Activities
Authors: Buffagni Melania , Cova Carlo Alberto , Pedroni Luisa Valentina , Zappacosta Ilaria , Aiello Gennaro 
Published: June 2014

Abstract
Offshore Environmental Monitoring can be defined as technical and institutional activity aimed at measuring, evaluating and tracking potential physical, chemical and biological environmental changes which could be induced by operative activities or by external causes.
By carrying out this activity, the oil company can take the appropriate corrective measures for creating a Monitoring Plan related to the offshore e&p projects and operations.
According to this approach, the baseline information on pristine conditions is compared against exploration drilling, development and post-development impacts. Efficiency of mitigation and restoration measures can be assessed through the monitoring activity.
Since early ‘90s, eni has carried out several environmental monitoring campaigns around its offshore installations worldwide aiming at evaluating changes in the current state of the interested area and in order to assessing evolutionary trends of environment. These surveys were able to provide early warning of any potentially serious impact and to provide data for strategic decisions. Besides they have been supporting to determine whether any detected change in physical, chemical and biological components was caused either by e&p activities or by natural occurrences.
Based on the above considerations, this paper introduces guidelines on strategy approach carried out by eni in offshore environmental monitoring, during the project life-cycle.
Changing in the Dark with Your Fingers Crossed: Safety Interventions Without Diagnosis and Evaluation
Authors: Bowen Mathew , Maneotis Sarina 
Published: June 2014

Abstract
Safety culture refers to the implicit assumptions, values, and beliefs that employees hold about workplace safety. Essentially, it is "the way things are done around here when it comes to safety." This is a simple definition for a complex concept that has been the focus of decades of research within Occupational Health Psychology. This presentation focusses on the sound research methods and measurement strategies that can be used to more effectively design and evaluate safety culture interventions.
Organisations spend significant resources implementing initiatives with the goal of improving the safety culture. Too often, critical steps of the intervention, namely diagnosis and evaluation, are not thoroughly considered or completed with the necessary rigour. For instance, an organisation may design an intervention based on the assumed cause of a debilitating safety culture, rather than going through the proper due diligence to diagnose the cause. Furthermore, organisations often scramble after the intervention to identify what safety metrics, most notably global lag indicators, are available to demonstrate that the intervention had an impact.
This presentation offers solutions to these challenges by providing attendees with the knowledge and skills to engage in more thorough diagnostic and evaluation practices when trying to improve an organisation’s safety culture.
The following specific topics will be addressed in this presentation:
Defining and modelling safety culture Qualitatively and quantitatively diagnosing safety culture challenges Developing an efficacy framework to evaluate the effectiveness of safety culture interventions
To illustrate these topics, the presenters will use findings from applied safety culture research projects focussed on diagnosing the areas for improvement within organisations’ safety culture and evaluating safety culture interventions.
Although safety culture is often seen as a "soft" concept, there is a significant opportunity to use more structured processes and sophisticated measurement techniques when designing, implementing, and evaluating safety culture interventions.
A Recommended Fitness Standard for the Oil and Gas Industry
Authors: Milligan G.. , House J. R. , Tipton M. J. , Hildenbrand B.. , Maeso M.. 
Published: June 2014

AbstractFitness standards are becoming common practice in industry and the emergency services. Such standards are used by the Fire and Rescue services, the Royal National Lifeboat Institution and the Military amongst others. These standards include measures of strength, endurance, anthropometrics, flexibility, motor skills and cardiac and metabolic fitness.The main benefit to introducing a fitness standard into the workplace is to ensure that an employee is physically capable of completing the essential tasks of the job to at least the minimum acceptable standard, thus the risk of employing physically unfit individuals in physically demanding jobs is minimised, and the associated human and economic effects (e.g. through injury) are reduced. Furthermore, standards ensure selection is based solely on ability to complete the essential tasks and is therefore fair and unbiased. The Energy Institute (EI) is the professional body for the energy industry, delivering good practice and professionalism across the sector. On behalf of the EI’s Health Technical Committee (HTC) work was undertaken by the University of Portsmouth (Department of Sport and Exercise Science) to provide an introduction to fitness standards and to make recommendations for a minimum fitness standard for the Oil and Gas Industry (OGI).The findings of this work are presented in the EI’s 2010 publication ‘A recommended fitness standard for the oil and gas industry’. Minimum standards have been evaluated based on the essential tasks with a significant physical fitness component e.g. manual handling, casualty handling and ladder/stair climbing. The evidence-base for the standards is contained within the report, as is guidance on administering the tests. The report does not provide guidance on policy issues or implementation strategies as this is considered to be a matter for individual companies.
Demonstrating Adequate Management of Risks: The Move from Quantitative to Qualitative Risk Assessments
Authors: Bower-White Graham 
Published: June 2014

Abstract
This paper will demonstrate that the use of quantitative risk analysis (QRA) has limitations and does not, in isolation, demonstrate adequate management of risks. The only way to demonstrate that risks are being appropriately managed is to identify all hazards; understand the level of risk; identify all prevention, control and mitigation barriers; and then demonstrate that those barriers are adequate and effective in managing that risk to a level that is as low as reasonably practicable.
This paper is applicable to all process industries and, in particular, those industries operating under a legislated safety case regime. Under these safety regulations we have a legal obligation to demonstrate that we are managing risk to levels that are demonstrably ALARP.
In summary this paper will show that QRA has its place in demonstrating adequate management of risks; however, it should not be used in isolation. Having a QRA conducted can sometimes provide a false sense of security that risk is being managed. The UKOOA Risk-based Decision Making Framework is a useful tool in demonstrating the small part that QRA plays in managing risk. The answer to managing risk effectively lies in demonstrating that adequate and effective controls are in place. Not only do we need to identify the controls that are required to manage risk effectively, we also need to demonstrate that those controls are actually in place, are performing as they should and that competent people have confirmed that this is the case.
In the process industry, post-Macondo & Montara, it is essential that operators move away from just demonstrating that they understand the level of risk that personnel and the environment are exposed to. We all need to move towards demonstrating that we have adequate and effective barriers and controls in place to manage that risk effectively.
Defensive Driver Training (Does e-learning have a Roll to Play)
Authors: Fee Wayne , Morrison Gareth , Berg Brodie Von 
Published: June 2014

Abstract
Land transportation-related accidents continue to be the highest cause of fatalities within the oil and gas industry, as shown in the International Association of Oil & Gas Producers (OGP) 2011 performance indicators. Despite widespread efforts, performance improvements have been slow to realize.
This presentation discusses the effectiveness of Instructor Led Defensive Driver Training (ILDDT) in reducing the number of Land Transport Fatalities whilst exploring the impact of supplementing current training methodologies with e-learning. The presentation will discuss the traditional and e-learning models covering, what is currently available, the pros and cons of both options and how the two methods can be used together to increase awareness and improve behavior. Currently OGP 365 Land Transport Safety Recommended Practices recommend initial theoretical training followed by refresher training based on risk exposure and drivers’ performance with a refresher at least every 3 years. This paper challenges the recommended frequency given the significance & implications of transport related incidents whilst providing affordable options to regularly provide supplementary training at frequent intervals. Additionally the presentation will highlight some perceived gaps in ILDDT and provide recommendation on how e-learning can potentially address those gaps in terms of its ability to continually and regularly keep driving relevant and ‘top of mind’, its flexibility in being able to deliver specific and individualized content, its alignment with best practices in adult learning and its ease of deployment. Finally the presentation will explain the role e-learning can potentially play in areas such as corporate liability & social responsibility as well as explaining its effectiveness as a stand alone application in other verticals and how this effectiveness can be translated to the Oil & Gas sector.
Management Systems Approach to Managing Human Rights Issues
Authors: Nguyen Tam , Fokkema Bert , Vallat Julie , Cleland Roper 
Published: June 2014

Abstract
Recently there has been a proliferation of external guidance and guidelines for managing human rights issues. While these are useful tools to inform the management of potential risk, at best they may offer abstract concepts or normative aspirations of performance. There are a range of external expectations for companies to demonstrate how they respect human rights, including having business processes in place to prevent or mitigate potential human rights issues that may be caused by the company’s projects or operations. The paper describes how IPIECA, the global oil and gas industry association for environmental and social issues, has responded to the emergence of external guidelines in connection to implementing human rights due diligence by improving existing management systems and processes.
Updated Requirements to Area Based Cooperation in Emergency Response Reflecting 10 Years of Norwegian Success
Authors: Vinnem Jan Erik 
Published: June 2014

Abstract
Requirements to area based emergency response arrangements were published in 2000. An updating of the Guidelines for area based emergency response arrangements (OLF?) has been carried out in the period 2010–2012, with the main emphasis on review of experience and the need for revised requirements. The requirements address water and air born resources within established areas for cooperation, and do not address the requirements to each installation’s resources. Experience with the existing requirements has been collected from operators of offshore installations, work force representatives, authorities plus a large number of experts and personnel with essential emergency response qualifications and roles. An extensive supporting documentation has been prepared, based on analyses, discussions and evaluations. A revised Guideline has been issued with response and capacity requirements. During the process, the need for one additional emergency response scenario to be standardized in the offshore industry was found, and new requirements have been formulated for the emergency response relating to helicopter crash on the installation. The experience with these emergency response arrangements is clearly very positive, and includes a number of lives that have been saved each year. The requirements are regarded by the authorities as the best practice in relation to emergency response arrangements, and increase in the area of application is one of the vital evaluations for the future. The paper will describe and discuss the requirements and report on the experience gained through more than ten years of operation, as well as identify and discuss future challenges which may lead to future revisions.
Modelling the Options for Managing Drill Cuttings Piles on Decommissioning
Authors: Hayes Sean , Galley Liz 
Published: June 2014

AbstractThis paper describes advanced modelling that has been applied to the decommissioning of a major North Sea drill cuttings pile to support the decommissioning programme. The environmental impacts associated with North Sea drill cuttings piles were examined in the 1990s and 2000s with agreement to manage cuttings piles based on simple estimated oil loss and footprints. Options for managing the piles must be considered on decommissioning, and piles may be disturbed during removal operations and from the ultimate collapse of any remaining structures.Advances in modelling techniques now allow us to predict long-term trends in cuttings pile characteristics and environmental risks quantitatively, providing firm direction in mitigating risks. This is key in determining appropriate decommissioning options for the piles and nearby structures. Modelling involving fluid dynamics, soil mechanics, scientifically verified 3D dispersion modelling, contaminant degradation and seabed recovery was used in several scenarios: the extant pile; moving the pile across the seabed using suction pumps; backflush discharges relating to retrieving the pile; and disturbance from remaining jacket footings ultimately falling into the pile after several hundred years.The existing 15.3 metre high pile was re-created in the model domain with a good correlation using the original drilling discharge data from 54 wells and recent survey data. Long term characteristics and risk aspects were then modelled twenty years into the future, and extrapolated several hundred years to calculate persistence footprints, oil loss, and the contributing elements to environmental risk, such as toxicity, grain size change and dexoxygenation. This approach identified key risk factors and enabled quantitative option comparison. Water column impacts were also calculated.The process generated valuable lessons regarding using survey data, generating input data, managing uncertainties and combining different modelling types. To date, there have been limited opportunities to evaluate cuttings pile impacts at the point of decommissioning and this will assist others and advance understanding and reasoning in this field.