To discuss how to responsibly conduct a Comparative Assessment/Decommissioning Options Assessment (CA/DOA) that is fit for purpose and is scientifically sound and robust, allowing for the study to be successfully validated by an external third party.
The most stringent International Best Practice Guidelines should be applied to all CAs. Decommissioning activity, internationally, is under public scrutiny and in many regions, in the very early stages of development. Application of industry proven approaches is essential to successful decommissioning planning.
Such documentation is important to demonstrate that the potential impacts (e.g. safety, social, environmental) that may arise from decommissioning activities have either been removed or are reduced to As Low As Reasonably Practicable (ALARP).
Statements and decisions made in the CA should be justifiable to scientifically sound supporting information. Contributing information shall include, but is not limited to, Quantitative Risk Assessments (QRAs) such as Potential Loss of Life, Individual Risk Per Annum and Fatal Accident Rate.
Good understanding of the condition of the facilities to be removed through asset integrity assessments and ROV inspection studies is essential. Furthermore, it is equally important that there is good understanding of the nature and condition of the seabed, from which the facilities, are to be removed. In addition to understanding what sensitive species may be present to properly inform management measures.
For environmentally sensitive cases or when Rigs to Reef is considered as an option, it is recommended that dedicated side studies are performed using industry proven techniques such as the Net Environmental Benefit Analysis (NEBA).
Once all the necessary documentation is gathered, the CA can take into consideration supporting information to appropriately inform the decommissioning options to be considered; the sub-criteria to be assessed and the rankings and weightings applied. It may be necessary to apply assumptions in lieu of the availability and/or transparency of data. Assumptions should be based on informed judgement and must be scientifically sound and justifiable to Project activities or to other similar activities conducted in a similar environment.
Strategic partnerships should be developed to ensure that the necessary skill sets and capabilities are available to appropriately conduct the CA. Impacts to Project cost, schedule and public perception are to note just a few of the consequences of an improperly applied assessment process.
A thorough and comprehensive approach to decommissioning planning and options assessment allows for the development of a Flagship Decommissioning Project. Careful consideration of international Best Practice procedures and the incorporation of scientifically sound supporting data, provides a demonstrably robust assessment process. In environments where national legislation and national experience is lacking, operators can look to other international examples of successfully and responsibly applied decommissioning programmes for guidance.
The Kinsale Head gas field offshore Ireland was discovered in 1971 and bought on stream in 1978. After 40 years of continuous gas production, a detailed plan for decommissioning of the field facilities is now being implemented.
Kinsale Head and a number of satellite gas fields, all operated by PETRONAS subsidiary PSE Kinsale Energy Limited, are the only producing facilities in the North Celtic Sea Basin, off the south coast of Ireland. The facilities include two fixed platforms, 10 subsea wells and extensive subsea infrastructure including 150 km of subsea pipelines and 80 km of subsea umbilicals, as well as an onshore reception terminal. Careful and innovative field management has extended the producing life from an originally estimated 20 years to over 42 years at time of Cessation of Production forecast to occur in 2020. The paper describes some of the methods used to prolong field operating life. Planning for decommissioning commenced in 2015-2016 and the paper describes the engineering and regulatory planning process followed. As this is the first-offshore field to be decommissioned in Ireland, extensive and detailed engagement with the regulatory authorities was undertaken prior to the submission of the decommissioning plan in 2018.
The paper demonstrates how a systematic and logical approach to both the regulatory approval process and the physical execution plan helps to de-risk the project. In particular, a comprehensive Environmental Impact Assessment (EIA) process was followed to underpin the selected strategy and to demonstrate a ‘best-in-class’ approach to the decommissioning program.
As part of the EIA process, a number of analytical techniques were used including Net Environmental Benefits Analysis (NEBA) and Comparative Assessment (CA); this is believed to be the first time these techniques were used for offshore projects in Ireland.
Decommissioning trends in South East Asia (SEA), demonstrate variation in approach between countries, despite local environmental conditions being somewhat similar. The best decommissioning option will vary subject to local aspects, such as key stakeholders, waste management and disposal facilities, available technologies and the application and interpretation of decommissioning guidelines. This paper will review case studies of the latest decommissioning projects conducted across the SEA region. The aim will be to provide an analysis of some of the latest trends and potential emerging decommissioning approach patterns. Furthermore, this study will discuss whether the emerging decommissioning trends are strategic, pragmatic in approach and add value to an already complex process.
The decommissioning of offshore fields includes pipelines, flexible flowlines, umbilical lines, and other subsea infrastructure. Decommissioning decision makers often need to determine the best and most practicable options for these structures, including leave-in-place strategies or removal. Collectively, pipelines can be constructed from several different materials, including steel and plastics, and other metals (i.e., stainless steel and copper). This study presents results from several evaluations of pipelines, flowlines and power cables using state-of the science methods such as NEBA, HHERA, and CEA to support the determination of the environmentally superior decommissioning options.
This paper assesses regulatory rules associated with drilling and completions activities in Queensland unconventional oil and gas plays. This assessment is based on a typology that classified rules into defined categories, defining their structure and what types of activities are required to assure them. This paper also reviewed a sample of ‘as built’ Well Completion Reports (WCR) to understand the self-assurance activities conducted by operating companies as well as to identify trends in compliance against a sample of rules.
The typology assessment identified that rulemaking was generally consistent across documents, and a clear balance existed between rules focused on design and rules focused on field operations. The assessment also identified the actual wording of rules could benefit by more standardisation in some areas. Importantly, this assessment also identified the large volume of complex assurance activities faced by inspectors.
The ‘as built’ data review identified a clear commitment to the written rules and evidence of self-assurance activities being consistently conducted by operators. This review also confirmed the value of WCR analysis and the potential to use them to measure compliance.
Whilst this paper has provided valuable insight into rule making and the approach to self-assurance taken by some operators, there are many areas of the wider regulatory system that would be well served by further analysis. This paper has proposed some recommendations for such analysis to help make a more holistic assessment of effectiveness in the future.
Undershultz, Jim (University of Queensland) | Mukherjee, Saswata (University of Queensland) | Wolhuter, Alexandra (University of Queensland) | Xu, Huan (China University of Petroleum, East China and The University of Queensland) | Banks, Eddie (Flinders University) | Noorduijn, Saskia (Flinders University) | McCallum, Jim (University of Western Australia)
There is an increasing need to understand the influence of faults in both gas production performance and the resulting potential impact on adjacent groundwater resources.Faults can exhibit a wide variety of hydraulic properties. Where resource development induces changes in pore pressure, the effective stress and thus the permeability can be transient. In this study, w explored strategies for characterizing fault zone properties for the initial purpose of evaluating gas production performance. The same fault characterization can then be incorporated into regional groundwater flow models to more accurately represent stress, strain and the resulting transmissivities when assessing the impact of gas development on adjacent aquifers.
Conventional fault zone analysis (juxtaposition, fault gouge or shale smear, fault reactivation) is combined with hydrodynamic analysis (distribution of hydraulic head and hydrochemistry) and surface water hydrology and hydrochemistry to evaluate across fault or up fault locations of enhanced hydraulic conductivity at specific locations of complex fault systems.
The locations of identified vertical hydraulic communication from the hydraulic analysis are compared with the fault zone architecture derived from the 3D seismic volume overlain with the
Many application and operational methods have been developed for applying carbonate matrix acidizing to successfully stimulate heterogeneous and long horizontal openhole zones. These methods have also been implemented during acid fracturing to various degrees of success. This paper discusses in detail the laboratory assessment of a biodegradable material for acid diversion in highly fractured formations.
Diversion in fracture acidizing is extremely challenging because of the high pumping rate, extreme pressures, and larger volumes of acid compared to matrix acidizing. To effectively stimulate natural or pre-existing fractured formations, the diverting agent should be able to bridge not only at the perforations, but inside the fracture system, too. Historically, several methods have been implemented for acid-fracturing diversion, such as ball sealers, viscous fluids, packers, etc., resulting in limited success in formations with natural or pre-existing fractures. This paper discusses the use of an acid diverter that consists of biodegradable particles with different sizes and hardness. The particle size ratios are specifically designed where large particles will bridge in the fractures while the smaller particles "nest" in the pore throat of the bridged larger particles. This leads to quick, efficient blockage of fractures and acid diversion.
The laboratory assessment of this biodegradable material was conducted at various temperatures up to 300°F and consists of (1) degradation in 3% KCl, live 15 wt% HCl, and spent 15% HCl, and (2) fluid loss using slotted disks at different diverter concentrations. The fractures were mimicked in the laboratory using a stainless steel slotted disk in a high-pressure/high-temperature (HP/HT) cell.
The dissolution rate of the particles was observed to be a function of time and temperature. The dissolution rate of the diverter was higher in water as compared to 15 wt% HCl acid. The stability of the biodegradable diverter was conducted at 300°F. The filter cake was stable up to 30 minutes when 1.0 ppt of the biodegradable diverter was used.
The results of this study indicate that the biodegradable diversion material can be used as an effective alternative diversion method to seal natural or pre-existing fractures.
Albraiki, Ahmed (ADNOC Gas Processing) | Al Ahmad, Alya (ADNOC Gas Processing) | Al Awadhi, Ibrahim (ADNOC Gas Processing) | Kant Nath, Nahum (ADNOC Gas Processing) | Mohamed Ismail, Mohamed Sulaiman (ADNOC Gas Processing)
ADNOC Gas Processing (AGP) plays a strategic role in ADNOC and the UAE hydrocarbon value chain by contributing significantly for the development of the Emirates. AGP operates and manages an integrated Pipeline Network of approximately 3200km length of Pipelines with the mission of uninterrupted supply to its Customers without any impact on the upstream plants. Various fluids are transported via pipelines such as Sales gas, Crude oil, NGL, Condensate, Water, Nitrogen and associated gases wherein majority of network contains Sales Gas. Pipeline Network is scattered over Ruwais, Habshan, Buhasa, Asab, Shuwaihat, Jebel Danna, Al Maqta, Taweelah, Jebel Ali, Al Ain, Ghantoot, Al Dhabbaya, Al Romaitha, Saadiyat Island, Yas Island, Mussafah and in some other areas within the Emirate of Abu Dhabi.
The Sales gas pipeline network connects gas plant facilities to consumers/ADNOC Plants through pipeline Distribution Facilities (Manifolds). The NGL pipeline network connects NGL plant facilities with manifolds to onward supply of NGL to AGP plant for fractionation into various products such as ethane, butane, propane and naptha etc.
These manifolds are old and highly critical, hence their safety and reliability are paramount to ensure shareholders commitment to various consumers in UAE and abroad. Failure of these manifolds will have a major impact on upstream & downstream production chain. Shut down of these manifolds are not possible as there is no bypass arrangement or back up manifold for business continuity. Failure of any of the manifold will have major impact on AGP Business and reputation.
Some of theses manifolds were constructed in late 70’s and have completed their design life. In line with current business scenario and fit for purpose approach being adopted by ADNOC, it is prudent to understand methods to assess the condition of existing ageing assets and apply techniques to enhance the reliability and integrity of the same. Ageing equipment is challenging and a systematic approach is necessary to decide on the life of ageing assets. AGP is one of the largest gas processing companies in the world, and it is considered as the major energy and feedstock supplier for the majority of the power, hydro carbon, and petrochemical industries based in the UAE.
In view of the above, AGP has carried out an Integrity/Adequacy assessment study to check fitness for service of the manifolds with due consideration to business continuity, the impact on upstream/downstream production, Company reputation, asset integrity, process safety and HSE aspects etc.
This paper presents the challenges faced and best practices adopted for ensuring/enhancing Process Safety (Prevention of Loss of Containment), improve integrity/reliability of the manifolds, minimize impact on normal operation and maintenance and reduce the risk of business interruption.
AGP best practices are based on the requirements of Pipeline Codes, International Standards, industry practices, ADNOC Gas Processing Specifications/Standards, and good engineering practices etc.
The Best Practices followed in this study have ensured the safety, efficiently and reliablty of operation of these manifolds. Confidence level in assuring integrity of againg facilities is boosted. Similar approach will benefit the oil and gas industries for ensuring safety and integrity of old ageing facilities.
Yonebayashi, Hideharu (Inpex Corporation) | Sasaya, Kazuyo (Inpex Corporation) | Watanabe, Takumi (Inpex Corporation) | Inamura, Takashi (Inpex Corporation) | Kobayashi, Atsushi (Inpex Corporation) | Iwata, Takao (Inpex Corporation)
As a part of laboratory Health, Safety and Environment (HSE) management system, the working environment control is applied to eliminate exposure hazards for workers. This control is a continuous effort in our laboratory as the working environment management system. Volatile organic compounds (VOC)s are ones of very common exposure hazardous factors in petroleum R&D laboratory. To better working environment control, the working environment measurement additionally to the chemical risk assessments is conducted at first to assess the concentration of VOCs in accordance with the guideline of domestic act. The measurement design is optimized on the basis of actual chemical use in the monitoring objective laboratories. The chemical records has been tracked in the chemical inventory management system. The measurement is conducted by two methods to assess both of average and the maximum VOC concentrations in the objective laboratory. Based on the measurement results, the objective laboratories are classified into three ranks. If necessary, counter actions will be taken: for instance, ventilation system improvement as building management, and consideration of substitute. Furthermore, the working record what types of chemical used and how long hours to handle them are linked to the health management system in which the workers who handle solvents must take a semi-annual special medical check. Further potential improvements were debated by adopting the process safety management in laboratory phase, and installing flexible exhaust system.
The working environment management is important for protecting employee's health. The system is not independent and linked to other HSE management systems. Therefore, a well-organized grand design is worthy as total management system which includes each management system for waste, inventory, procurement, building maintenance, and so on. Because this paper discussed a practical example of HSE management system from both of detailed and high level. The discussion should be useful for considering HSE in laboratory.
Production of Oil, Gas and Petrochemical from production units is becoming very competitive every day. As products are sold in open market, production cost drives an organization's profitability. To keep a plant available for production as much as possible, Asset Performance Management (APM) or Asset Integrity Management (AIM)is the key. Risk based inspection (RBI) is a decision making tool that deals with integrity management of static equipment and piping through focus on prioritizing inspection based on the risk.
Review of published guidelines for RBI such as API RP 580/581, ASME PCC3, DNV-RP-G101, EN 16991 etc., suggests that they provide either oversimplified or complex explanations which makes it difficult for beginners to grasp all the aspects that are critical for a successful RBI project. Therefore, this paper is aimed to provide and discuss the essential elements for effective RBI implementation project in a simplified way. RBI project can be divided into four major phases i.e project initiation and pre-requisites, workshops & trainings, RBI analysis phase and post RBI actions. Each of these stages is discussed with details in this paper.
An overview of successful RBI program used within the industry and from the ADNOC LNG RBI implementation experience, is provided with details. Project management approach for RBI program implementation is conveyed by dividing project into different phases and highlighting the inputs/outputs and activities for each phase. Objectives, time and resources such as data and personnel required, software features that are essential, project planning and monitoring are provided.
RBI program implemented efficiently in accordance with suggested plan, results in an overall optimization of inspection for static equipment/piping while maintaining their integrity as part of a broader APM or AIM strategy.