bluuebunny/crossref_metadata_2025_split huggingface dataset:
Egina Deep Water Development: Isolation Barrier Valve Case Study
Authors: Forrest G. , Morand C. , Johnson K. , Okengwu V. , Chaloupka V. 
Published: March 2018

A major operator manages multiple deep water projects in the Gulf of Guinea. This paper describes the latest 44-well project in Nigeria. The operator required an ISO 28781 qualified bi-directional subsurface isolation barrier valve (IBV) (Fig. 1) to be installed in each well. This work presents results of IBV deployment in the field.
The wells were drilled and completed from sixth generation drillships. To comply with the operator's dual barrier policy, a bi-directional IBV was installed in each well to help ensure reservoir isolation for temporary well suspension or before running upper completion and tree installation. Careful attention to well fluid cleanliness, sound quality assurance/quality control (QA/QC), and operational procedures were considered paramount to successful remote opening of the IBVs and were identified as best practices by both parties.
The IBV is run in the open position as an integral part of the lower completion. A collet shifting tool closes the ball isolating the formation, enabling inflow and positive pressure testing to be performed. The reservoirs are isolated by the closed ball in the IBV, allowing safe installation of the upper completion from a floating rig or well suspension without a subsea tree. The use of an ISO 28781 Type CC V1 qualified IBV provides both zonal isolation and fluid-loss control. Once a well is completed and the subsea tree installed, the IBV is remotely functioned to the open position by applying multiple tubing pressure cycles.
The first batch of wells were drilled and completed with lower completions and suspended while waiting for subsea tree deliveries. Later, wells were drilled and completed with both lower and upper completions, and trees installed later from an offshore inspection maintenance and repair (OIMR) vessel. IBVs were successfully closed and inflow and pressure tested during the lower completion phase.
IBVs are run in sieved non-aqueous based mud (NABM). Filtered high viscosity pills are spotted across the IBV before closing. Once closed, the casing above the IBV is displaced to filtered completion brine at a rate ensuring any debris is lifted to the surface. The wells remain suspended with IBVs closed until the operator performs flowback and injectivity testing from a drillship. Additional injectivity testing was also performed from an OIMR vessel. Well suspension duration with IBVs closed varied between two months and 2.5 years. All valves cycled opened without issues. Four coiled tubing (CT) interventions were performed in the field, passing through the open ball without issue, confirming the IBVs were in the fully open position.
This paper describes full QA/QC and operational procedures, which led to successful deployment and excellent functionality of the IBVs.
Fracture Characterisation Through Image Log Conductive Feature Extraction
Authors: Xian Hong , Tueckmantel Christian , Giorgioni Maurizio , Wei Lingli , Lai Chee-Pan 
Published: March 2018

AbstractAn approach is presented for fracture porosity, fracture aperture and permeability evaluation through extracting conductive image features from FMITM borehole image logs.The methodology of image feature and in particular fracture recognition, extraction and characterisation is based on the borehole image tool button response simulation model originally developed by Luthi (1990) for the water-based mud system and the principle of 2D fracture intensity (P32) to 3D fracture intensity/volume (P33) transformation. The extracted conductive image features allow us to distinguish open fractures and karst features. Fracture aperture is calculated as a function of the button resistivity, tool current & voltage, mud resistivity and background rock resistivity. Fracture porosity is computed with consideration of fracture type, well type and condition. Fracture permeability is estimated by taking fracture aperture, type and intensity into account.The results for naturally fractured tight carbonate reservoirs are demonstrated. Various types of conductive features are successfully recognised and characterised using the new approach. Sedimentary features like bedding and shale boundaries are identified too. Drilling induced or borehole breakout features have been distinguished and excluded from true nature formation features. The robustness of the fracture characterisation can be demonstrated through various field examples and reservoir model implementation.The new approach provided independent fracture characterisation inputs for discrete fracture network (DFN) and dynamic models of the fractured reservoir examples shown.
Additive Manufacturing Metal 3D Printing for the Marine and Offshore Sector - Paving the Path from Lab into the Field
Authors: Wistance William , Lee Jeremy 
Published: March 2018

Abstract
Additive manufacturing has been heralded as a revolutionary process set to change the face of manufacturing forever. However, after all the hype dies down, the reality is that taking this technology from the laboratory and applying it to real world applications in the field can be more challenging than some news reports might lead to people to believe. The idea of a plug and play machine is still a way off, although it will one day become a reality.
This paper highlights some of the challenges facing the marine and offshore industry's adoption of the technology, how these challenges can be overcome and the potential benefits that this technology can yield. Based on the experiences of working with manufacturers and end users that have utilized this technology to manufacture products to meet demanding industry requirements, this paper will show that the technology can be adopted safely. There is a need to improve quality control, production consistency and further develop the complete supply chain. The development of international standards and the greater adoption of independent certification are ways to give confidence to the offshore industry to adopt this technology. Although there are challenges to overcome, the potential benefits can be substantial, both technically and economically.
Revealing Uncertainty and Maximizing Mature Field Production—A Novel Approach to Addressing Well Conformance Issues/Well Integrity Evaluation: Case Study from Offshore Sarawak, Malaysia
Authors: Parashar Sarvagya , Goenawan Fransiska , Jagannathan Srinivasan , Lee Chung Yee , Iyer M. S. , Wu Ivan Zhia Ming , Aggarwal Gaurav , Amin M. Farid B. M. , Juan Saw Li , Hui Nicholas Foo Kwang , Wei Gan Teik , Ismail W. Rokiah , Razman Nur Faradilla M. 
Published: March 2018

Abstract
This paper introduces and evaluates a next-generation acoustic conformance-monitoring system that helps identify the depth and accurate radial location of undesirable leaks in a well. Determining the leak's flow pattern in and around the wellbore is also used to understand activity within the surrounding wellbore region.
The acoustic conformance tool was run employing a memory slickline operation in a well located offshore Sarawak, Malaysia. The tool successfully acquired both low- and high-fidelity data, which were subsequently used for leak characterization analysis. Using an array of acoustic sensors, the tool is capable of detecting undesirable flow throughout the well structure. The vertical accuracy is within inches and estimates the radial location around the wellbore. Before the operation, careful and thorough prejob design is necessary for data acquisition to help reduce uncertainty in post-interpretation. These include detailed operational sequences in terms of leak stimulation of various annuli in the well to obtain optimum results. Subsequently, the signals are analyzed using a beam-forming method to identify leak distances and a flow map to further understand flow characteristics.
The study well is a gas producer completed with a 7-in. single string. Post-data processing and interpretation revealed a continuous high-frequency noise spectrum from the bottom of the logging interval to the surface, indicating gas movement, which was further confirmed by two-dimensional (2D) flow map analysis. Results indicated gas movement in Annuli C and B. Based on results, production logging sensors, and well completion statuses, inferences were made regarding this gas movement and its possible sources—a cement window in Annulus C and cement channel in Annulus B.
This technology accurately identifies and pinpoints leak sources, assisting the asset owner with planning and designing remedial work to help reduce undesirable fluid, which benefits total production.
Prediction of Hydrate Phase Equilibrium Conditions for Different Gas Mixtures
Authors: Sadeq Dhifaf , Iglauer Stefan , Lebedev Maxim , Barifcani Ahmed 
Published: March 2018

Abstract
Gas hydrate formation poses a significant threat to the production, processing, and transportation of natural gas. Accurate predictions of gas hydrate equilibrium conditions are essential for designing the gas production systems at safe operating conditions and mitigating the problems caused by hydrates formation. A new hydrate correlation for predicting gas hydrate equilibrium conditions was obtained for different gas mixtures containing methane, nitrogen and carbon dioxide. The new correlation is proposed for a pressure range of 1.7-330 MPa, a temperature range of 273-320 K, and for gas mixtures with specific gravity range of 0.553 to 1. The nonlinear regression technique was applied to develop the correlation based on 142 experimental data points collected from literature, validated with 85 data points not used for developing the correlation. The statistical parameters analysis showed an average absolute error (AAPE) of 0.2183, a squared correlation coefficient (R2) of 0.9978 and standard deviation (SD) of 0.2483. In addition, comparing the new correlation results with the experimental data and with those calculated by other correlations show an excellent performance for the investigated range.
From Compliance To Commitment: The Impact of Human Psychology on Safety Culture
Authors: Mahmood Sadaqat , Mahmood Kashif , Abdullah Muhammad 
Published: March 2018

Abstract
Surrounded with life threatning hazards, establishing the safety culture in its true spirit is extremely important for oil companies. The lessons from past require us to make no compromise on this. A good safety culture provides clear guidelines to the employees, is accepted by all, addresses all issues and concerns, has proper monitoring systems and is just in its implementation. To establish this, employee conformity stands as the biggest challenge as no program can be applied if not accepted by the employees. This acceptance of any change is what we categorize as commitment to comply; where employees have inner motivation to comply with safety guidelines and programs. In this paper we have tried to explore the same. In view of available literature, we developed two separate questionnaires for employees and HSE professionals. The results clearly demonstrate that employees want to know why a safety program is being implemented and efficiency of any program relies on inner motivation of the employees. Based on same we have presented our self regulation model that helps in the success of any safety program.
An Innovative, Low Cost Solution for Sampling in Highly Deviated Wells
Authors: Aryusanil Thanawat , Rakela Tribor , Azevedo Marcelo , Costam Yosef Ronald , Fadjarijanto Ari 
Published: March 2018

Abstract
Sampling in a highly deviated well involves additional risks that can compromise efficiency and costs. Operators and service companies have developed options to overcome the technical challenge of going from tubing-assisted logging to tractor-conveyed operations.
Tubing-assisted logging will mitigate the issues and stuck risks caused by wireline key seating, differential sticking, swelling formations, heavy muds, borehole breakout, doglegs, ledges, and cuttings but will require slower operations resulting in additional rig time and therefore costs. Tractor conveyance, on the contrary, can be efficient but will add costly operating rates and higher cost exposure if the tools are lost in hole.
An operator in offshore Southeast Asia had an objective to perform formation evaluation by means of pressure tests with pump out to obtain clean samples for CO2-level measurements in a slim well geometry (6 1/8-in. hole) with 73° deviation. Sampling wheels that configure with the wireline formation tester tool were introduced to the operator to reduce the contact area, keep the tool body off the low side of the borehole wall, and aid gravity descent.
The operation objective was successfully accomplished and reached the target depth (TD)/reservoirs by performing five pressure tests, setting up three fluid characterization stations, and retrieving six samples in approximately 12.5 operating hours, resulting in savings of more than USD 350,000 for the operator.
Improved Calculation Method of Soil Bearing Capacity of Jack-Up Rig Based on Field Simulation Experiment
Authors: Yin Qishuai , Yang Jin , Hu Nanding , Shi Shanshan , Ma Yongqi , Wang Junxiang , Yang Yuming , Pang Da , Zhang Tianwei , Jiang Menglei 
Published: March 2018

Abstract
The spudcan penetration depth is directly determined by the soil bearing capacity which is the basis of punch-through analysis. Through the analysis of the SNAME method, it is found that it has great limitations: without considering lateral friction, preloading speed, soil backfill effect and group effect of spudcans. The predictive accuracy of soil bearing capacity increases by 40% through the improved calculation method based on field simulation experiment with the above four factors into consideration.
The field experiment was conducted in the Bohai shallow sea to simulate actual penetrating process. Firstly, there were 9 sampling positions and 10 soil samples per meter were obtained from each position. Secondly, the soil pressure sensors were inlaid into the spudcans at the bottom and side. Thirdly, the bearing capacity was studied by changing the preloading speed of 2t/h, 4t/h, 6t/h, 8t/h and 10t/h. Fourthly, the bearing capacity was researched by changing the soil backfill ratio of 0%, 10%, 20%, 30% and 40%. Fifthly, the group effect was observed when the three spudcans were ballasted one by one.
The vertical soil stress is obtained by the bottom sensors and the vertical soil bearing capacity is calculated. The radial soil stress is gained by the side sensors and the lateral friction is calculated. The field simulation experiment shows that the lateral friction makes up about 3% of the total bearing capacity. The larger the preloading speed is, the smaller the bearing capacity is. In addition, the excessive preloading speed may lead to punch-through. The larger the soil backfill ratio is, the smaller the bearing capacity is. The group effect is obvious when the three spudcans are ballasted one by one and the penetration depth of the third spudcan is the shallowest normally. This improved method has been effectively applied to EP oil field for HYSY941 and DF HTHP gas field for HYSY944. The EP and DF are typical layered soil in South China Sea. The case studies were carried out to verify the method, the results showed that the maximum relative errors of spudcan penetration depth were within 5% and the method successfully avoided several punch-through accidents.
The novelty of this paper is to introduce an improved method based on field simulation experiment. The predictive accuracy of spudcan penetration depth is higher and the punch-through accidents can be successfully avoided by the proposed method considering lateral friction, preloading speed, soil backfill effect and group effect of spudcans. The improved method is consistent with the actual engineering and satisfies the real need of field operations.
Subsea Compression: Reliable and Proven Solution to Increase Gas Fields Recovery
Authors: Yeaw Si Huai , Storstenvik Anders , Vesterkjaer Rune 
Published: March 2018

Abstract
After years of development, qualification and engineering, Subsea Compression Technology is now a proven solution for increased field recovery for offshore gas developments. The world's first subsea compression system was installed at the Aasgard field in the Norwegian Sea, and started up successfully on the 17th of September 2015. This represents an important milestone for the oil and gas industry, as it not only demonstrates the successful developments of new subsea processing technologies, but also proves itself as a viable alternative field development solution for oil and gas operators.
This paper will briefly review the development timeline of the technology up to the first application project, namely on the Aasgard field in the North Sea, then present the working principle of the subsea compression system. Highlights on the key features of the technologies will be provided, with specific focus on the benefits the technology brings to the market.
In addition, the paper will also describe the ongoing development activities to optimize the subsea compression system, with particular focus on the unit size and weight optimization without requiring any qualification activities of new technologies. This new generation of subsea compression system will extend the applicability of this technology to a much wider range of fields and offshore regions.
Membrane Compatibility and its Characterization to Determine the Potential Applicability for H2S Separation
Authors: Tamidi A. M. , Yasin N. H. , Halim M. H. M. , Isa M. A. , Mat T. M. U. T. 
Published: March 2018

Abstract
Development of new technology in the area of separation process is essential in order to deal with with product quality, environmental issues, energy efficiency, cost reduction and increasing safety. In membrane separation processes, membrane contactor has attained considerable attention due to the wide range of its applications. Since most of chemical separation processes are related to the contact of two different phases (liquid-liquid or gas/vapor-liquid), the operations such as gas absorption and stripping, liquid-liquid extraction, distillation, heterogeneous reactions, emulsification, demulsification, humidification and dehumidification can be conducted through a membrane contactor system (Drioli et al. 2005). Development of membrane contactor for acid gas removal is an emerging technology recently especially to overcme the disadvantages of commercial packed towers and bubble columns. Physical solvents such as DEPG (Selexol™ or Coastal AGR®), NMP or N-Methyl-2-Pyrrolidone (Purisol®), Methanol (Rectisol®), and Propylene Carbonate (Fluor Solvent™) are well known as commercial gas treating solvents, especially for acid gas removal. Physical solvents tend to be favored over chemical solvents when the concentration of acid gases or other impurities is very high (Burr and Lyddon 2008). Among the physical solvents, Selexol shows the highest H2S solubility. However, due to Selexol solvent is less hazard as compared to NMP, this compatibility study was conducted using Selexol as the solvent for H2S removal with various types of polymeric membrane material. The main objective of the study was to test the stability of potential porous membrane material with the selected physical absorbent for H2S removal. From the physical characterization consist of physical abservation, Fe-SEM, FTIR and contact angle that have been conducted on the membranes that have been immersed in the physical absorbent for 1 month, it is found that 3 membrane materials are most stable and compatible with the selected physical absorbent. The 3 shortlisted membrane material are PTFE, PP and PEEK membrane that could be further developed for H2S removal using membrane contactor technology.
High CO2 Blowdown During Emergency Depressurization EDP at Offshore Environment
Authors: Rahman Fadhli Hadana , Isa Faudzi Mat , Salihuddin Radin Suhaib , Jalani M Yazid Jay , Karim Fatimah , Hashim Wan Mahsuri Wan 
Published: March 2018

Abstract
Natural gas produced from many major reservoirs can contain significant amounts of carbon dioxide (CO2) and must be treated to meet typical specifications for pipelines or liquefaction plant feed. The treatment process selected was low temperature CO2 distillation which involve high pressure operation and formation of highly concentrated CO2 streams. Pressure protection for high pressure, low temperature and high CO2 systems have been challenging to date because of potential solid CO2 formation during pressure let down and the consequent plugging.
Blowdown or depressuring of process equipment during an emergency or planned shutdown is a critical process safety operation. It may be necessary in the event of fire, leak, pipe rupture or other hazardous situations, as well as for planned shutdown. Devices such as blowdown valves, relief valves, restriction orifices, rupture disks, and safety valves transfer the potentially hazardous content of process equipment to a safe lower-pressure location or to the flare/vent system for controlled combustion or safe venting.
To ensure blowdown will be executed safety and effectively, a number of design concerns must be addressed such as low temperature solid CO2 identification and Minimum Design Metal Temperature (MDMT) for piping and equipment material selection. Rapid depressurizing and gas expansion can potentially put equipment at risk of brittle fracture if the temperature goes below its ductile-brittle transition temperature of the selected material and potential plugging due to solid CO2 formation. In addition, the entire pressure relief system including safety valves, relief orifices, flare piping and knockout drums, must be sufficiently sized to handle the flowrates that occur during blowdown, in addition to the piping and capacity of the flare/vent system.
Accurate prediction on the minimum vessel wall temperature during blowdown is important for selecting the appropriate construction material, for reducing overdesign and consequently lowering project cost. Similarly, having an accurate prediction of the maximum flow rate during blowdown reduces overdesign associated with the relief valve/network, without compromising on safety.
The paper will address the potential of solid CO2 formation based on proprietary software for blowdown and proposed some mitigation plan with respect to solid CO2 formation within the process piping and equipment.