Deep Draft Semi Submersible

2002 ◽  
Author(s):  
Arne Ulrik Bindingsbo̸ ◽  
Arve Bjo̸rset
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Water Depth ◽  
Flexible Riser ◽  
Production Platform ◽  
Steel Catenary Risers ◽  
Riser Design ◽  
Flexible Risers ◽  
Gas Fields ◽  
Preferred Solutions

High Pressure and High Temperature wells together with harsh environmental conditions puts a tough challenge on the flowline and riser design. The flexible riser which has been the favorite choice for many field developments with subsea wells have several technical limitations. Large gas fields such as Ormen Lange require large bore export risers. Steel risers are the preferred solutions with respect to durability and cost. Unfortunately, it is difficult for steel risers to accommodate the vessel motions of a semi submersible or ship. Heave restricted vessels such as TLP or SPAR are used together with toptensioned risers and surface trees. Based on the limitations of flexible risers Hydro is pursuing extensive research on riser and floater technology. As part of this research program a study on the effect on riser design caused by reducing vessel motions. The main goal is to introduce steel catenary risers (SCR) on semi submersible platforms. The typical draft of a semi submersible production platform is 20–25 m. By reengineering the design of such a platform and increasing the draft from 21 m to 40 m the vessel motions were reduced significantly. Hence, an opening for novel riser solutions was made. ULS and FLS analyses for 10″ and 30″ SCR in 300 and 1000 m water depth were carried out. The key result is that the 10Prime; riser satisfies both the ULS and FLS requirement for both vessel drafts and water depth and the 30Prime; riser satisfies the both the ULS and FLS requirement for the 40 m vessel draft at 1000 m water depth.

Experimental Measurements of the Solubility of Hydrocarbons in Compressed Natural Gas Under Pressure (10 – 100 MPa) and Temperature (50 – 150°C).

1983 ◽  
Vol 22 ◽  
Author(s):  
E. Nogaret ◽  
R. Tufeu ◽  
B. Le Neindre
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Natural Gas ◽  
Gas Phase ◽  
Oil And Gas ◽  
Experimental Measurements ◽  
Compressed Natural Gas ◽  
Oil And Gas Fields ◽  
High Pressure High Temperature ◽  
Gas Fields

ABSTRACTAn apparatus to measure phase equilibria under pressure is described. The composition of the gas phase was determined using a high pressure, high temperature sampling cell. We have found that compressed natural gas is a very good solvent of hydrocarbons. A possible application of this study is the understanding of processes which lead to migration of oil and the location of oil and gas fields.

Alternative Method of Buoy Supporting Riser (BSR) Installation

2011 ◽  
Author(s):  
Ricardo Franciss ◽  
Enrique Casaprima Gonzales ◽  
Jose´ Carlos Lima de Almeida ◽  
Jairo Bastos de Arau´jo ◽  
Antonio Carlos Fernandes
Keyword(s):  
Fatigue Life ◽  
Field Test ◽  
Water Depth ◽  
Monitoring Systems ◽  
Deep Waters ◽  
Alternative Method ◽  
Sea Bottom ◽  
Campos Basin ◽  
Steel Catenary Risers ◽  
Flexible Risers

Due to the 2200m water depth and harsher environmental conditions, one option that Petrobras is considering for the production of the Pre-Salt fields is the use of a subsurface buoy known as a Buoy Supporting Riser (BSR). It is composed of a subsurface tethered buoy, flexible jumpers connecting the Floating Production Unit (FPU) to the BSR and Steel Catenary Risers (SCRs) connecting the BSR to the flowlines on the sea bottom. The main advantages of this system are that it decouples the FPU motions from the SCRs, reducing fatigue damage in the touch down zone. It may also be installed independently of the FPU, except for the flexible jumpers, which would reduce the risers load on the FPU. Petrobras has been studying this concept since 1997 and has established, as a final stage of the study, a field test with the actual installation of the BSR. This was performed through an alternative method using only Petrobras AHTS boats, in order to avoid critical and expensive resources such as lift barges. With the purpose of validating this new installation procedure, Petrobras performed the referred installation of a 27.2m × 27.2m square ring shaped buoy in Congro Field in the Campos Basin over a water depth of 500m. The buoy was positioned at 80m depth, where the incidence of loads caused by waves is negligible, thus increasing the fatigue life of risers. After the BSR installation, the riser pull-in procedure was also conduced. This paper describes why this technology is necessary for these fields and the model tests made to validate the installation procedures. It also discusses how Petrobras tested the pull-in operations for two flexible risers after the actual buoy was installed. Monitoring systems were designed to check all forces and displacements during the referred installation. These actions will consolidate the BSR technology for Petrobras leading to another riser system option for production in ultra deep waters.

Design of Steel Lazy Wave Riser for External Turret Moored FPSO

2019 ◽  
Author(s):  
Jingyun Cheng ◽  
Peimin Cao
Keyword(s):  
Water Depth ◽  
Optimal Solution ◽  
Cost Effective ◽  
Fatigue Performance ◽  
Effective Solution ◽  
Field Development ◽  
Riser Design ◽  
Preferred Solutions ◽  
Design Challenges ◽  
Selection Of

Abstract The external turret moored Floating Production Storage and Offloading system (FPSO) is one of the preferred solutions for deepwater fields in mild to moderate environments and far away from existing pipeline infrastructures. This paper presents a design of steel lazy wave riser (SLWR) system for an external turret moored FPSO in the water depth of 1,500 meter. The design challenges and feasibility are discussed. Due to the complexity of SLWR geometry, a systematic configuration approach is introduced to achieve the desired riser extreme and fatigue performance target, as well as external turret layout. The study includes the standardized FPSO, the selection of turret configuration, and riser design. The titanium taper stress joints and the interaction with turret structure are also studied. The study provides an optimal solution of the integrated turret, mooring and riser system. It concludes that external turret FPSO with SLWRs can be a feasible and cost effective solution for field development in mild to moderate environments.

Steel Lazy Wave Riser Design for Semi-Submersible in Harsh Environment

2014 ◽  
Author(s):  
Jingyun Cheng ◽  
Peimin Cao
Keyword(s):  
Water Depth ◽  
Optimal Solution ◽  
Cost Effective ◽  
Harsh Environment ◽  
Depth Range ◽  
Strength Performance ◽  
Field Development ◽  
Steel Catenary Risers ◽  
Riser Design ◽  
Design Guidance

Deep draft production semi-submersible with steel lazy wave risers (SLWRs) has been studied for the 2,625ft water depth in harsh environment. The design challenges and feasibility of steel catenary risers (SCRs) for semi-submersible at relatively shallow water and harsh environment are discussed. The benefits of using SLWRs to improve riser strength and fatigue performance are presented. Due to the complexity of SLWR geometry, a systematic configuration approach is introduced to achieve the desired riser performance target. A comparison study on fatigue and strength performance of various riser configurations is performed. The assessment provides design guidance for the optimal solution of the integrated hull, mooring and riser system. It concludes that deep draft production semi-submersible with SLWRs can be a feasible and cost effective solution for field development at water depth range from 2,297ft to 3,281ft in harsh environment.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

YSS YXM4

Alloy Digest ◽  
2019 ◽  
Vol 68 (11) ◽  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Physical Properties ◽  
Tool Steel ◽  
High Speed ◽  
Temperature Performance

Abstract YSS YXM4 is a cobalt-alloyed molybdenum high-speed tool steel with resistance to abrasion, seizure, and deformation under high pressure. This datasheet provides information on composition, physical properties, and hardness. It also includes information on high temperature performance. Filing Code: TS-780. Producer or source: Hitachi Metals America, Ltd.

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