ABSTRACT
In 2009, the Vito field was discovered in more than 4,000 ft of water approximately 150 miles offshore from New Orleans, Louisiana. The project produces from reservoirs nearly 30,000 feet below sea level. This paper provides an overview of the Hull & Mooring system, executing a minimum technical scope to produce a simplistic design. This paper is part of a Vito Project series at OTC 2023, and the other papers are listed in the references. The original Vito project execution strategy was to replicate the Shell mega-project of Appomattox. As the industry and market began to change in 2015, the project faced significant financial hurdles, and the project team decided to refresh the design concept to reduce cost and simplify. The team regrouped to propose a smaller semi-submersible Floating Production System (FPS) with a simplistic mooring design. The Topsides was designed to be lifted as a single module, with a payload of less than 10,000 st to enable competitive tendering process. The redesigned FPS concept was moored with 12 taut, chain – polyester – chain mooring line system utilizing an in-line mooring tensioner, removing the traditional mechanically complicated and space demanding "on-vessel" winch systems. Vito employed a passive hull system, with all ballasting occurring over the top without hull penetrations. There were no pump rooms within the hull as equipment is accessed from top of column, removing the need for regular hull access to maintain equipment. The hull compartmentation also followed a simple approach, containing only 12 ballast tanks to reduce fabrication cost. The hull design also included simplified ring stiffening for columns which eliminated the traditional orthogonally stiffened systems. Additionally, the structure utilized an upper column frame structure to support the topsides deck and served as a bracing for supporting columns at the top for squeeze-pry loads and bracing for supporting columns during dry tow. The simplification of the stiffening system and topsides deck support design reduced interfaces between hull and topsides and also opened up options for fabrication of topsides and hull. Key challenges included developing installation methods without traditional FPS mooring chain jacks and increasing installation options by not requiring a large installation derrick barge and enabling use of common anchor handler vessels. The project experienced fabrication delays due to COVID-19, which required creative solutions transporting the FPS from Singapore to the Gulf of Mexico. The design team © 2023, Offshore Technology Conference.
ABSTRACT
The Cheleken field offshore Turkmenistan is going through brown field development and challenges with retaining and enhancing production increase every day. Well Interventions are deemed to be a daily necessity to maintain production. Coiled Tubing, Wireline and other rigless interventions have been used directly on platforms resulting in occupying critical spaces, logistic and marine congestion (one Coiled Tubing Move comprises of over twenty lifts), structure integrity limitations, crane and lifting limitation, and a lot more. The need for a self-elevating platform arose and operator search for a proper one within the Caspian Sea ended with disappointments. This paper details the innovative and out of the box solution that was put in place to mobilize the first Lift Boat to the Caspian Sea. A lift boat was identified in the USA in the Gulf of Mexico which was underutilized after the pandemic and oil recession. The Class 230 specifications met the end user's requirements but the challenge was how to mobilize it to the Caspian. In addition, there were a handful of modifications that were requested for the Caspian operation that were not necessarily required in the Gulf. Mobilization of the lift boat must be carried out through the Volga-Don canal locking system which has a width of 57 feet 9 inch (maximum allowable beam for vessels is 56 feet 5 inches). The beam of the lift boat was 78 feet which is too wide to fit through the Volga-Don shipping canal. Hence, it was necessary to disassemble and transport the lift boat in sections. This paper describes the following: • Disassembly requirements necessary to prepare the lift boat for mobilization • The mobilization of the lift boat • • Installation of well service and intervention equipment • Technology and methodology adopted The reassembly requirements once the lift boat reached the shipyard at Caspian Sea The Lift boat was disassembled into three major sections for transportation: a) the center hull module b) the port wing module, and c) the starboard wing module. The wing modules, miscellaneous equipment and containers were loaded onto a barge and sea-fastened for transportation. The center hull module was wet towed to the shipyard located in the Caspian where the lift boat was reassembled, and the well service equipment was installed. The mobilization and assembly happened during the Covid-19 era, and the vessel was hit by Hurricane Ida which impacted the disassembly schedule. Challenges on mobilizing the personnel, equipment, machinery, port clearance, etc. were all extremely tough due to Covid-19. The paper will also cover technical implications on conducting this task by complying with the classification and flag state requirements as per Turkmenistan authority. The main lesson of the paper is the identification of gaps on mobilization and how the improved techniques can be utilized for executing the task on a fast-track manner. © 2023, Offshore Technology Conference.
ABSTRACT
Natural aggregates are being depleted due to the high demand for road and building construction and need to be replaced with alternative materials. This study investigated the potential of using Palm kernel shells (PaKS) as a partial replacement for natural aggregates (NA) and waste plastics (WP) as a binder. The physical and volumetric properties of the different asphaltic mixes (AM) were assessed using the Marshall Method. The bitumen content of the mix design samples was varied from 4.0% to 7.5% of the total weight of aggregates utilized. According to the Marshall parameters, at 5.5% bitumen content, the maximum Marshall Stability value of the different mix designs increased from 9.8 kN to 12.1 kN and the flow value increased from 3.0 mm to 3.7 mm. The experimental results based on the optimum bitumen content determined by the Marshall method demonstrate that PaKS and WP can be utilized to modify AM. However, additional tests will be needed to evaluate the use of this composition in road construction.
ABSTRACT
The COVID-19 pandemic has resulted in an increase in wastewater pollution, due to disposal of metabolites of several drugs (e.g., chloroquine (CQN)). Conventional wastewater treatment is not sufficient to remove these contaminants, posing a threat to the aquatic ecosystem and human health. Thus, soybean hulls residues were functionalized with iron oxide nanoparticles (SBH-Fe3O4) and applied in adsorption processes to remove CQN, for the first time. The functionalization was confirmed through material characterization. The results indicated an equilibrium time of 120 minutes and a maximum adsorption capacity of 98.84 mg g-1 (318 K). The pseudo-first-order and Langmuir models were better fitted to the kinetic and isothermal parameters, respectively. The reuse of the biosorbent was effective for five cycles. Therefore, SBH-Fe3O4 has a high potential for applicability in the treatment of water contaminated by CQN.