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
Tayab, Muhammad (ADNOC Upstream) | Valappil, Suhail (ADNOC Onshore) | Shah, Vishal (ADNOC Sour Gas) | Azhibekov, Takhir (ADNOC GHSE) | Zeinati, Michel (ADNOC GHSE) | Al Ameri, Mohammed (ADNOC GHSE) | Al-Hameli, Fatima (ADNOC Refining)
Over the last 10 years, Oil & Gas operations have come under tremendous pressures due to increasing production demands and economic conditions, demanding higher performance and venturing into technically challenging operating conditions. Operating with aging facilities in harsh environmental conditions and higher crew turnaround, have resulted in higher number of serious incidents. Prevention of incidents remains high on the agenda of oil & gas companies and focus is placed on incident investigations to identify root causes of incidents and development of corrective actions. However, repetition of incidents with similar findings and causes have been observed, raising concerns if right root causes were identified and focused corrective actions were identified and/or implemented.
An extended analysis of over one thousand (1000) incidents was conducted to assess degree of repetition of causes and regrouping of causes to assess linkage of human factors with organizational behaviours. It was found that 31% of incidents were triggered by human errors & mistakes whilst 27% were attributed to violations. All violations were deemed as intentional & routine and further investigation was not undertaken. Management Supervion & Employees Leadership was identified a leading root cause category of incidents and this category contributed 20% of incidents followed by Work Planning (18%) and behaviour (12%). 55 % of incidents were caused by human factors and hauman factors were triggered by errors and mistakes rather than violations.
Often efforts are exerted to to influence individual's behaviour however human attitude (cognitive, emotional and commitment) is overlooked as linkage between attitude change leading to behavior change, not fully explored. However, linkage from behavior change to attitude change is much stronger. If worker consciously change their behavior, it requires re adjustment of associated attitudes to align with the new behavior. Positive reinforcement is an effective tool to influence individual's behaviour. If discipline and punishment are used to discourage unsafe behavior, the intended results are not achieved (e.g., incident or near miss are not reported for fear of sanctions).
Assessment of non-compliant behaviors (Violations, mistakes and errors) & conditions and factors influencing such behaviors are often not evaluated and focused action plans to address abilities and motivations with due consideration to isolated or systemic conditions are instrumental in preventing incicidents.
Prior to 2008, shale gas reservoirs were deemed uneconomical to produce. Hydraulic fracturing and horizontal drilling have shifted this perspective, reducing the flow resistance from the reservoir to the well. Notwithstanding the thousands of shale gas wells currently actively producing around the world, factors controlling the permeability and flow behaviour in shale gas formations are still incompletely understood. A profound understanding of the flow processes manifesting in shale gas reservoirs will contribute to more effective Enhanced Gas Recovery (EGR) schemes, ultimate recovery and accurate gas production forecasting.
Owing to the micro- and nano-size of pores, transport in shale rocks depends on the pore size and predominantly on pore geometry and tortuosity. To gain new insights into the mechanics of gas production from shale formations, we constructed a geometrically accurate model from an actual shale scanning electron microscope micro-image. Taking into account the pertinent rock and gas parameters (e.g., porosity, permeability, viscosity, etc.) we have determined the gas flow rate, the pressure variations and deduced the production rate at the micro-level.
A non-dimensionalization methodology was developed that permits the comparison between micro-scale modelling results with actual core measurements several orders of magnitude larger in special scale. Normalized micro-scale modelling results compare well with actual core data shedding light on some of the important aspects which govern gas flow: geometry, pressure gradient, compressibility, pore throats, and permeability. Moreover, the cumulative gas production for different gases was shown to improve with an increase in the molecular mass of the gases. Ultimately, our efforts aim to tie theoretical understanding with experimental observations deemed significant for boosting the productivity of gas from shale formations.
Incident investigation makes an important contribution to reduce risk by implementing recommendations and Lessons Learned from an investigation. Lessons Learned from an Investigation is an instrument to prevent future reoccurrence and it requires effective implementation. Nevertheless, the implementations of the lessons learned from the incidents require a systematic approach and management methodologies, which include Processes, Procedures and a Robust System, that ensure lessons are captured, validated, implemented and utilized in future activities and projects. In most organizations, lessons are captured only within one segment that lacks an effective mechanism for sharing and implementing Lessons Learned. Therefore, omissions are often repeated from one activity or project to the next. This paper discussed the effective implementation of the Lessons Learned through Pan Company Process and System that positively adds value to an oil and gas organization. The Developed framework with "Common Database System" in ERP platform to facilitate Lessons Learned from various activities is embedded into Common Processes and Procedures. Therefore lessons are pro-actively routed to those who need to see them and take appropriate action. The Common System shall provide the aspects required to identify, assess and take corrective action on any issue and to communicate results for effective implementation across the company. This Process cuts across functional boundaries and allows an organization to learn from both its blunders and triumphs. The Lesson Learned System will support organization in learning efficiently from experiences that will reduce operational risk, increase efficiency, and improve operational effectiveness. In addition, it presents opportunities to save time, money and to add value to company standards. The gains from the idea will usually materialize over the longer term. This is encouraging Knowledge Management (KM) sustainability by learning, exchanging and implementing valuable lessons learned across all aspects of Company business activities. Such lessons shall be referred to prior starting a new activity or project. The paper proposes a novel method to manage Lessons learned from Incidents. An efficient Lessons Learned process could inhibit organization from rerunning their errors and allow organization to repeat their accomplishments. It should be an instrumental part of any organization's overall continuous improvement process.
Operators have used ultra-deep azimuthal resistivity tools for geostopping in landing situations and for geosteering and geomapping in horizontal wells for several years. However, their use in slim boreholes, where 4¾-in. tools are required, is a relatively new application of the technology. Operators often require ultra-deep azimuthal resistivity data, even in wells where pressure changes or stability issues require slim borehole sections to reach a target. In these scenarios, 1D inversion canvasses, which display the position of resistivity boundaries above and below the wellbore, and azimuthal resistivity images, which display changes in the resistivity to the side of the wellbore, are valuable as an aid for optimal well placement and for mapping formation and fluid changes away from the wellbore.
This paper presents early field results for a new 4¾-in. ultra-deep resistivity tool. Verification of the tool results is vital to demonstrate that design changes to accommodate the smaller diameter do not degrade the results relative to larger tool sizes, and that the tool accurately maps the resistivity profile around the well. The case history presented describes a mature field with a complex geology and a history of production and water injection, resulting in fluid boundaries that show significant displacement from their original positions and a complex morphology. It is, therefore, important to verify the ultra-deep resistivity results with multiple additional data sources, such as seismic and other established logging-while-drilling (LWD) tools.
The inversion results show a complex geological structure. Faulting, expected from the seismic data, has resulted in the displacement of formation boundaries, and sharp resistivity boundaries show the influx of water into the reservoir. These significant geological features are evident in the ultra-deep resistivity data. Other data sources, such as seismic, density, and shallow-resistivity data, help to verify the structural features and the fluid boundary positions. Evaluation of azimuthal resistivity images from the ultra-deep tool provides further reservoir understanding, because they can demonstrate that the formations dip across the wellbore and that some of the faults cross the well path at an oblique angle.
Even where the subsurface geology is very complex, as in this case study, the 1D ultra-deep resistivity inversion results successfully represented the position of formation and fluid boundaries. In addition, azimuthal resistivity data from the tool provided additional information that leads to greater reservoir understanding. There is no evidence to suggest that the smaller diameter of the 4¾-in. tool has compromised the quality of the data.
Based on the geophysical survey results, some part of the pipeline were found in free spans conditions. Interpretation from the geophysical survey shows that there were at least 181 free spans area along the pipeline with the length up to 200m and some of the pipeline was shown with span almost 3m above seabed. The ROV survey was then deployed to verify the free spans area and to check the other findings from the previous geophysical survey
Verification of freespan was conducted by setting up coordinates of the suspected area on the navigation software and ROV will start its investigation from the beginning of each free span to the end of it. Dual head scanning profilers, visual cameras which were installed on each side of the ROV and in front of vehicle were used to record pipeline condition along the suspected location. Position and depth of the ROV was overlaid to the video recording and the profile of seabed and pipeline along the inspected area were recorded in the navigation software
Information derived from the ROV inspection will then compared to the geophysical survey result and the final freespan condition were confirmed and results are tabulated for further rectification if required. Generally, there were 181 freespans locations inspected by ROV. Results of freespan from Freespan #1 at KP 3.638 to Freespan #181 at KP 233.978 are listed. There are some miss leading geophysical interpretation for the sample taken at KP 101.108 to KP 101.281, where from the geophysical survey was reported that the free span was found 150.1m but from the ROV visual inspection was found that the pipeline was set on seabed at some points with a maximum distance not more than 35m. Based on the ROV visual inspection, there were 29 freespans were found more than Maximum Allowable Span (MAS)
East Java Gas Pipeline Pipeline (EJGP) is the longest offshore gas pipeline in Indoensia. It transports gas receiving from Central Processing Plant on Pagerungan Island in Kangean Islands through the Madura Strait and onshore via Porong Sidoarjo to Surabaya with the total length of offshore part is 368km. The ROV is the first to be used to inspect this offshore gas pipeline.
The paper presents a rational methodology for the simulation of the maneuvering ability of ships, while accounting for the vessel’s maneuvering properties and the ensuing environmental and navigational conditions. In this context, the effect of different rudders and weather scenarios is demonstrated and a real ship to ship collision accident under adverse weather conditions has been simulated. The presented methodology can form the basis for a decision support tool for ship's navigation in adverse weather conditions and the assessment of ship’s maneuvering devices.
The Norwegian Petroleum Directorate has given clearance to start up facilities at the North Sea field, which straddles the line between the UK and Norwegian sectors. Production is set to begin in September. Hydroniq will deliver a hull-integrated seawater cooling system for a cable-laying vessel the Norwegian shipbuilder Vard is designing and building for Prysmian Group. Construction for the field’s second processing platform begins on the same day the Norwegian authorities approved the plan for development and operation for the biggest field development on the Norwegian continental shelf. The new deals, valued at approximately $2.9 billion over 3 years, cover services for liner hangers, downhole monitoring, and additional completions on the NCS.
ADNOC and CNOOC will explore multiple new opportunities for collaboration across the upstream and downstream sectors in the UAE and China. The laboratory will be used primarily to test the sulfide stress cracking resistance of carbon steel alloys for oil wells and offshore drilling applications. The paper discusses the main factors affecting CO2 corrosion, provides an assessment of what to look for in major equipment, and details recommended material of construction and corrosion mitigation/control methods. This paper focuses on a numerical-modeling analysis of the acid-gas-injection (AGI) scenario in carbonate HP/HT reservoirs, and presents the way in which AGI impacts asphaltene-precipitation behavior. When panels in an instrument equipment shelter kept tripping and the occasional smell of H2S led to an investigation of the rationale.
Models were developed for these wells for future water-production prediction and a spatial analysis was also conducted. This study summarizes hydrate-inhibition practices for these sea lines, and indicates a possibility of using them as indirect thermometers to provide important physical oceanographic data. Results of the experimental and numerical heat-transfer analysis conducted on a T-shaped acrylic-glass pipe, representing a production header in a subsea production system with a vertical deadleg. Oily waste, is an intrinsic byproduct of the oil and gas industry and thermal desorption units with an odor-treatment system can bring technical and economic advantages to the user. The Hail 3D transition-zone seismic survey carried out by ADNOC is located in a UNESCO world-biosphere reserve. Effective environmental and ecological management throughout the project was attained through working procedures and monitoring programs. The understanding of solid-particle flow regimes in pipelines for any operational conditions is important for identifying the nature of particle interaction and movement. In this paper, a comprehensive analysis of solid-particle flow regimes in stratified flow in a horizontal pipeline is presented.