bluuebunny/crossref_metadata_2025_split huggingface dataset:
Installation Qualification for Reeled Electrically Trace Heated Pipe-in-Pipe
Authors: Chalmers Martin , Pratt Ed , Pepin Aurelien , Tkaczyk Tomasz 
Published: April 2020

Abstract
Standard pipe-in-pipe (PiP) technology consists of an inner flowline insulated with high performance dry insulation and an outer carrier pipe that protects the insulation. Electrically Trace Heated Pipe-in-Pipe (ETH-PiP) technology is an adaptation of the standard PiP where electrical trace heating (ETH) and fiber optic (FO) cables are wound around the flowline, under the insulation, to provide active heating and temperature monitoring of the conveyed fluid. ETH-PiP allows operators to optimise field layout and production and minimise the risk of pipeline blockages.
Reel-lay is an efficient installation method for subsea pipelines. Reel-lay is well suited to ETH-PiP as critical fabrication activities can take place onshore and before pipeline installation. Reeled PiP flowlines are subjected to plastic bending. During offshore installation, the flowline may see a combination of this plastic bending and high axial tension due to the catenary. The combined loading leads to permanent elongation of the inner pipe which has the potential to transfer tensile loads into the electrical and optical cables. Moreover, the annulus space between the inner flowline and outer carrier pipe is reduced during reeling which may put electrical components at risk of mechanical damage.
This paper discusses an extensive qualification programme which was performed to quantify the cable loading during installation, and to demonstrate the subsequent cable and splice integrity and fitness for service. A physical bending trial was performed where several ETH-PiP specimens were subjected to plastic bending on a cantilever bending rig while axial tension was applied to the flowline. This represents an industry first for a practical test which realistically replicates the loading conditions experienced by a PiP system during reeled installation.
Throughout the bending trial, the cables were strain-gauged to record axial tension, and the anulus space around the cables/splices was measured to record radial compression. Following bending, the cables and splices were removed from the test specimens and subjected to third party electrical and optical testing to verify integrity. The qualification scope not only verified that cable integrity is maintained throughout reeling, but also quantified the loads involved. Data gathered from the testing was subsequently used to benchmark finite-element (FE) reeling models. These models allow more accurate prediction of cable loading on future reeled ETH-PiP systems, including deep water pipelines.
Balanced Characterisation of Fine-Grained Soils: Application to Carbonate Sediments
Authors: Zhou Hongjie , Sharma Shambhu , Amodio Alessandro , Boylan Noel , Gaunt Peter 
Published: April 2020

Abstract
For subsea structures placed on soft seabed comprising fine-grained sediments, geotechnical design may be equally governed by the foundation settlement and stability requirements. For this reason, the soil stress history parameter, i.e. yield stress (σy), becomes as important as the strength parameter, i.e. undrained shear strength (su). Common practice in characterisation of fine-grained sediments focuses more on deriving the su profile than on evaluating the σy profile. More often, the underlying connections between these two important parameters are overlooked in the interpretation process. As a result, the selected design line of σy may be incompatible to that of su. This paper presents a balanced characterisation of fine-grained soils, focusing on interpretation of in-situ su and σy using a coherent and simple framework underpinned by the Stress History and Normalised Soil Engineering Properties (SHANSEP) relationship. Interpretation procedure, performance and advantages of the proposed framework are demonstrated by a real application to an offshore site dominated by fine-grained carbonate sediments.
In this framework, the two SHANSEP parameters, including normally consolidated normalised strength ratio (S) and empirical constant (m), need to be quantified for the site of interest. This is achieved by performing a series of laboratory strength and consolidation tests on undisturbed samples, with the strength tests being performed respectively under in-situ and elevated stress conditions for determining in-situ su and the values of S and m. Once the SHANSEP parameters and the su profile are derived, the σy profile can be calculated. These two profiles can then be refined further by comparing against the measured su and σy at discrete depths respectively from the strength and consolidation tests.
Since this proposed framework allows the user to consider the results from the in-situ and laboratory tests (including both strength and consolidation tests) holistically, more reliable and coherent interpretation of the su and σy profiles can be achieved. In addition, the framework allows for an easy estimation of consolidation-induced strength gain due to the permanent load applied by the subsea structures by simply using the derived σy profile and updating the vertical stress in the parameterised SHANSEP relationship. This may reduce the conservatism in the foundation design and provide optimisation opportunities.
Combined and Re-Deployable Platform and Storage Solutions for Stranded Reserves
Authors: Mikalsen Kristian , Wassink Alain 
Published: April 2020

Abstract
Unlock marginal and stranded reserves in shallow waters that are far away from existing infrastructure. The solution is a system that employs a jack-up based mobile offshore production unit (MOPU) in combination with a modular subsea storage system. The storage system is an unmanned solution that is designed with an integrated offloading system.
Integrated into a single, integrated system, this robust solution encompasses all necessary components thus reducing both CAPEX and OPEX.
The case is based on standard MOPU designs with compact process modules to reduce weight and cost. Additional cost savings come from standardization and placing fully integrated components subsea. An integrated process train ensures the right quality of oil or condensate is sent to the subsea storage tanks, ready for tanker pick-up. This paper also describes how the associated gas will be handled. The field-proven offloading system is linked to storage, ensuring correct metering and safe mooring for any vessel.
Combining modular subsea solutions with field-proven components gives operators access to technologies that provide an increased return on invested capital.
The storage system is developed based on existing storage solutions. It is an energy-efficient system with a low environmental footprint. Recent engineering studies and testing have proven the feasibility of operating a subsea storage unit with a flexible membrane defining the horizontal interface between oil and seawater.
This paper presents new results from a downscaled subsea storage system model testing conducted by an original equipment manufacturer (OEM) together with a major operator. The innovative cluster design will enable re-deployment of the storage units, which opens new combination possibilities with MOPU's. Interfaces between the various system components have been streamlined to create an integrated system and when deploying these different building blocks in that way, a custom field solution can be provided for marginal field developments – including an option to modify and re-deploy.
Research has shown that replacing the floating storage and offloading vessel (FSU/FSO) with subsea storage reduces offshore manning and the environmental footprint. This technical paper explains the modularity and the economics of an installation-friendly design.
Lower complexity, in combination with cost-effective installation, introduces new opportunities for field developments. The integrated solution is also designed with the option to operate below wax appearance temperature and can make even smaller field developments profitable at a lower cost, in an energy-effective manner, and with a low environmental footprint. With this new solution available, the market can take a whole new view on small pool developments.
Improved Operational Efficiency in Deepwater GOM with Innovative Liquid Cement Additive
Authors: Pearl, Jr William , Bowman Joseph , Agapiou Kyriacos 
Published: April 2020

Offshore cementing operations may require the use of liquid additives for logistical and blending requirements. Some additives should be suspended in hydrocarbon fluid because the active material cannot be readily liquefied in water. These suspensions often exhibit rheological instability and high viscosity, posing issues with shelf life and dosing through delivery lines. This paper describes the use of an innovative liquid cement additive designed to overcome limitations of conventional oil-based suspensions and improve cementing operations.
The new microemulsion fluid loss additive overcomes shelf-life stability and fluid transfer issues inherent to conventional oil-based suspension additives, while providing excellent fluid loss control in cement. Shelf-life stability and fluid transfer rates affect the quality of mixing cement slurry, reduce delivery/pump rates, and extend overall job times. The microemulsion fluid loss additive chemistry was verified to provide improved shelf-life stability and reduced viscosity. Fluid loss, mixability/rheology, and stability tests in cement slurry evaluated the additive performance. Flow tests and calibrations using conventional liquid additive injection pumps were performed before deployment. Benefits of the microemulsion fluid loss additive were validated in a cement design for deepwater offshore work.
Offshore Urban Extension of the Anse Du Portier in Monaco
Authors: Aristaghes Pierre , Compte David 
Published: April 2020

Abstract
As part of the Monaco offshore extension project, Bouygues Travaux Publics is in charge of design & build a maritime infrastructure as the first step of the six-hectare expansion of the city into the sea. This maritime infrastructure consists of a fill enclosed by a band of 18 trapezoid reinforced concrete caissons and will serve as base for construction of the new eco-neighborhood in Monaco. The caisson precasting area is located in the port of Marseilles, using a dedicated floating dock.
The paper focuses on some of the problems which had to be solved, among which : The optimization of promenade level, searching for : ○a compromise between architectural point of view and safety related to storm wave overtopping, taking into account sea level rise and correlations between extreme waves and water levels;○minimal reflection coefficient for vertical concrete caissons, so as to minimize impact on existing Port Hercules wave disturbance.Caissons and rubble mound foundation stability related to waves and seism, including extra seismic forces due to buildings considering the high reclamation height (up to 40 m) and the immediate proximity of building foundations.The presence of a small craft harbor, whose location was fixed for urbanistic reasons, which requested optimizations in detail of anti-overtopping devices as much as possible integrated in the urban context, including a low crested "swimming pool caisson breakwater"Design and build of a dedicated floating yard
Design has required a multidisciplinary approach (urbanists, landscapers, architects, marine infrastructure engineering, biologists), with unconventional infrastructure solutions due to the very specific context (direct exposure to offshore waves, proximity of sensitive port and natural areas, seismic hazard associated with buildings very close to 25 m high concrete caissons …).
Innovative Integrated and Compact Gas Oil Separation Plant for Upstream Surface Facilities
Authors: Soliman Mohamed Ahmed , Salu Samusideen , Al-Zahrani Talal , Ansari Nisar 
Published: April 2020

Abstract
The objective of this paper is to evaluate and analyze energy savings and process optimization opportunities in the gas-oil separation plants (GOSPs) in upstream surface facilities. This approach resulted in the development of a new design for a compact gas-oil separation plant (C-GOSP) to meet the crude oil export specifications with less process equipment and operating costs, and higher oil product yield compared to conventional GOSPs. The new design was materialized as patents granted by the U.S. Patent and Trademark Office (USPTO). The innovative C-GOSP is based on the integration of the gas compression system with production traps to conserve energy consumption and minimize capital cost and increase crude production. Atmospheric and hot discharge gas from low pressure compressors will be rerouted and directly mixed with the incoming wild crude before entering the production traps. This process will result in simultaneously cooling the compressors' discharge gas and heating the incoming crude while increasing crude production. Hysys simulation was used to model and verify the feasibility of the C-GOSP. A 300 MBD production facility was used to benchmark the Hysys simulation model and to verify the feasibility of these promising energy saving opportunities.
The extensive process simulation modelling using Aspen Hysys and benchmarked with the actual plant energy consumption revealed the feasibility of this innovative C-GOSP, which will result in the following benefits:
Lowering the capital cost by eliminating the compressors discharge after coolers, liquid pumps, discharge KO drums and minimize the surface area of the crude heat exchangers. Lowering operating cost by eliminating the after coolers and heating medium required to heat the crude. Increase crude production yield by condensing the heavy hydrocarbon from the gas stream. Minimize the spacing requirements, which make ideal for offshore applications.
The innovative approach of direct heating and cooling by mixing of hot and cold streams is superior to any other optimization approach. Consequently, a patent was granted from the USPTO on July 17, 2018, for the innovative C-GOSP. The patent number is 10023811.
Hydrocyclone Micrometer Sized Separation Technology for Exploitation of Natural Gas Hydrate
Authors: Wu Jiwei , Lin Haitao , Huang Yuan , Wang Hualin , Zhou Shouwei , Fu Qiang 
Published: April 2020

Abstract
Natural gas hydrate is a key future clean energy resource, and sand control is crucial in natural gas hydrate production. However, the sand control is still inefficient, which impedes industrialized development of natural gas hydrate. From production test carried out in the South China Sea, we found the separation of micrometer-sized sand from the fluid is the main challenge in sand control. Based on high-speed motion in our 3D rotating turbulent flow field of hydrocyclone, our study presents a new technology to realize efficient separation of micrometer-sized sand and breaking consolidation between hydrate and sand. As results of hydrocyclone separation experiments, we have the high separation efficiency that is up to 92.23% for silica sand and 98.87% for PP; also only 0.46%~1.05% of PP powder remains in recovered materials. In conclusion, the technology proves the ability of breaking-consolidation and realizes the goal of separation of micrometer-sized particles, and thus improve the sand control in exploitation of marine natural gas hydrate.
Innovative as-Built 3D Model and BIM of Subsea Objects Using Basic Sensors – Application to Seawall Concrete Armour Units
Authors: Bugnet Yoann , Le Bars Steven , Macaigne Vincent , Launay Timothée , Vessiot Thomas , Cartier Rémi 
Published: April 2020

Abstract

Objectives/scope
The control of monolayer concrete armour units on coastal protection breakwaters can be time and cost consuming, especially underwater. It is even more the case when - for maintenance and control purpose - they are conducted long after the completion of the construction (positioning issues, number of units to control, etc).
However, this occurs frequently on construction projects which last for several years, or during the operation and maintenance of such structures. On top of that, the complexity of this type of projects - usually coastal constructions such a dike easily exceeds 6000 units/km - requires precision and productivity for the control inspections.
As a result, specific control solutions have been developed on the NRL project to inspect and monitor the breakwater after its construction.
Study and Optimization of the First Horizontal Well Steamflooding Pilot for Offshore Oilfield
Authors: Han Xiaodong , Zhong Liguo , Liu Yigang , Wang Qiuxia , Chen Cunliang , Wu Xuanren 
Published: April 2020

Abstract
The steam and flue gas co-injection technology is proposed and applied to NN Oilfield whose oil viscosity ranges from 413 to 741mPa.s for field pilot since 2008. With increase of the stimulation cycles, the gas channeling problem had bad influence on the production performance, and the production rate declined rapidly.
To further improve the oil recovery, research is carried out for optimization of the replacement production method. First, the reasons for gas breakthrough are analyzed. Potential methods are all analyzed and compared by reservoir simulation and physical experiments. By considering the equipment capacity, platform limitations and economics, the optimized production method is determined. For the NN Oilfield developed with horizontal wells, the steamflooding is a good way of further exploitation after steam and flue gas co-injection. The key injection and production parameters are all optimized with the results of steam injection rate 300 m3/d, production-injection ratio 1.4, and downhole steam quality 0.4-0.6. To further improve the field performance, the nitrogen foam could be injected to mitigate the steam breakthrough. Simulation study shows that it is significantly effective for the improvement of oil production rate. Detailed project design has been completed and illustrated in detail. Steam flooding would be an effective replacement technology after huff and puff for further enhancing oil recovery of offshore heavy oilfields.
Integrated Technologies in the Floating Hydraulic Fracturing for Unconventional Offshore Reservoir
Authors: Li Shuai , Yi Xinbin , Kuang Ming , Xie Ying , Zhang Ziming , Wang Xiaochao , Gao Yuebin 
Published: April 2020

Abstract
The ultra-high pressure and high temperature (HP/HT) unconventional offshore reservoir in Liaohe Oil Field in Bohai Bay Basin has characteristics of deep depth (4500m), high temperature (145°C), low permeability (1.2mD) and low porosity (9.4%), until now, a floating hydraulic fracturing has been successfully performed in this area and an integrated technology has been formed.
In this paper, we firstly delivered a case history of the hydraulic fracturing treatment, in particularly describing the main problems we met and the main method we take to solve these problems. Then the case study was given in consideration of a geo-engineering integrated fracturing design workflow. (1) Fracturing vessel arrangement to full fill the fracturing demand. (2) Sweet spot prediction and well trajectory optimization were performed based on a fine geological model. (3) Perforation optimization were made in consideration of the ground stress, natural fracture development, well logging and hydrocarbon display. (4) A hybrid fracturing mode (linear gel and crosslinked gel) was applied to connect more natural fractures and build a more complex fracture network. (5) Multi-size sand combination to match different artificial cracks. (6) Mini-frac test to analysis the stress situation and optimize the stimulation schedule. (7) Acid pre-treatment to reduce fracture initiation pressure, proppant multi-stage slug to reduce pumping pressure.
Integrated technologies in the floating hydraulic fracturing for unconventional offshore reservoir in Bohai Bay Basin can be good reference to the hydraulic fracturing treatment of similar reservoirs.
Innovative Use of a Rov to Control Underwater Coastal Protections
Authors: Nicolas Thebaud , Vincent Macaigne , Steven Le Bars 
Published: April 2020

Abstract
The control of monolayer concrete armour units on coastal protection breakwaters can be time and cost consuming, especially underwater. It is even more the case when - for maintenance and control purpose - they are conducted long after the completion of the construction (positioning issues, number of units to control, etc). However, this occurs frequently on construction projects which last for several years, or during the operation and maintenance of such structures. On top of that, the complexity of this type of projects - usually coastal constructions such a dike easily exceeds 6000 units/km - requires precision and productivity for the control inspections.
As a result, specific control solutions have been developped on the NRL project to inspect and monitor the breakwater after its construction.
The NRL project lies in La Reunion (Indian Ocean). It is due to replace the current coastal road, which was built at the foot of a 100m height cliff. Indeed, after heavy rainfalls, rocks are falling from the cliff. The road is also usually closed during storms as the road is submerged by the sea on one side, and by rainfalls on the cliff side.
The objective of the project is to build a new road at sea to secure this vital economical axis between the cities of Saint-Denis - the island capital - and La Possession.
Hydrate Equilibrium Model for Gas Mixtures Containing Methane, Nitrogen and Carbon Dioxide
Authors: Sadeq Dhifaf , Al-Fatlawi Omar , Iglauer Stefan , Lebedev Maxim , Smith Callum , Barifcani Ahmed 
Published: April 2020

Abstract
Gas hydrate formation is considered one of the major problems facing the oil and gas industry as it poses a significant threat to the production, transportation and processing of natural gas. These solid structures can nucleate and agglomerate gradually so that a large cluster of hydrate is formed, which can clog flow lines, chokes, valves, and other production facilities. Thus, an accurate predictive model is necessary for designing natural gas production systems at safe operating conditions and mitigating the issues induced by the formation of hydrates. In this context, a thermodynamic model for gas hydrate equilibrium conditions and cage occupancies of N2 + CH4 and N2 + CO4 gas mixtures at different compositions is proposed. The van der Waals-Platteeuw thermodynamic theory coupled with the Peng-Robinson equation of state and Langmuir adsorption model are employed in the proposed model. The experimental measurements generated using a cryogenic sapphire cell for the pressure and temperature ranges of (5-25) MPa and (275.5-292.95) K, respectively, were used to evaluate the accuracy of this model. The resulting data show that increasing nitrogen mole percentage in the gas mixtures results in decreasing of equilibrium hydrate temperatures. The deviations between the experimental and predictions are discussed. Furthermore, the cage occupancies for the gas mixtures in hydrate have been evaluated. The results demonstrate an increase in the cage occupancy for both the small and large cavities with pressure.