The Effects of Solid-Liquid Internal Flow on the Dynamic Behavior of a Reduced-Scale Jumper for Deep-Sea Mining

Abstract For the exploitation of seafloor massive sulfides, we have investigated the dynamic behavior of the jumper, a piece of flexible pipe that connects the seafloor mining tool to the subsea slurry pump. In this article, we present the results of the experiment using a 1/5 reduced-scale model of the jumper. This experiment was carried out in Deep-Sea Basin. During the experiment, a slurry fluid was conveyed throughout the jumper’s model. In addition, an oscillator generated harmonic motion on the top end of the model. In terms of instrumentation, we installed load cells on the top and bottom ends of the model and a 3D visual measurement system tracked the motion of measurement stations attached to the model. We present the experimental results measured by the 3D visual measurement system, loads cells, and differential pressure gauges in the cases where a vertically forced oscillation is imposed on the top of the jumper. In this experiment, we could observe the effects of slurry on the jumper reduced-scale model. Since the slurry has a larger density than the single liquid phase, the slurry flow changed, as expected, the static shape of the jumper compared to a jumper conveying only water. The vertical top force average and differential pressure average increase with the volume concentration of solid, while their amplitudes increase quadratically with the forced oscillation frequency.

Download Full-text

Experimental Analysis of Reduced-Scale Jumper for Deep-Sea Mining

Volume 6: Ocean Space Utilization ◽

10.1115/omae2019-95990 ◽

2019 ◽

Author(s):

Marcio Yamamoto ◽

Tomo Fujiwara ◽

Shigeo Kanada ◽

Masao Ono ◽

Satoru Takano ◽

...

Keyword(s):

Deep Sea ◽

Numerical Models ◽

Oscillation Amplitude ◽

Internal Flow ◽

Differential Pressure ◽

Scale Model ◽

Pressure Amplitude ◽

Flexible Riser ◽

Flexible Pipe ◽

Reduced Scale

Abstract In the Deep-Sea Mining, the seafloor mining tool is connected to the subsea slurry pump by a piece of flexible pipe named jumper. The jumper’s shape is similar to a steep-wave flexible riser. Compared to a flexible riser, the jumper is a reinforced hose and has a shorter length. Numerous studies shed light on the dynamic behavior of flexible riser; however, all studies were carried out by the way of numerical analysis. We carried out, in the Deep-Sea Basin, an experiment using 1/5 reduced scale model of the jumper. Unhappily, the model’s bending stiffness had to be distorted. During the experiment, an oscillator generated harmonic motion on the top end of the model and a centrifugal pump circulated water throughout the model. In addition, we installed load cells on the top and bottom ends of the model. Our Basin is equipped with a visual measurement system. Thus, we measured the displacement of targets attached to the model. The initial results show that axial tension amplitude increases with the frequency of the top end oscillation. This response is due to the drag force on the lower bend increases with the frequency of top motion. We also could observe that the internal flow may increase the vertical motion amplitude. The jumper’s motion generates an oscillation on the internal differential pressure between both ends and the flow velocity. The differential pressure amplitude increases with the top oscillation frequency, but it is proportional to the top end oscillation amplitude. We will use these experimental results to validate our numerical models. Further, it is important to understand the internal flow effects to design the actual pump used to convey the slurry through the jumper.

Download Full-text

The Effects of Solid-Liquid Internal Flow on the Dynamic Behavior of a Reduced-Scale Jumper for the Deep-Sea Mining

10.1115/1.0000968v ◽

2021 ◽

Author(s):

Marcio Yamamoto ◽

Tomo Fujiwara ◽

Shigeo Kanada ◽

Masao Ono ◽

Satoru Takano ◽

...

Keyword(s):

Dynamic Behavior ◽

Deep Sea ◽

Internal Flow ◽

Solid Liquid ◽

Reduced Scale

Download Full-text

A Model Experiment of a Free Standing Riser in the Deep-Sea Basin

Volume 4A: Pipeline and Riser Technology ◽

10.1115/omae2013-10577 ◽

2013 ◽

Author(s):

Marcio Yamamoto ◽

Sotaro Masanobu ◽

Satoru Takano ◽

Shigeo Kanada ◽

Tomo Fujiwara ◽

...

Keyword(s):

Deep Sea ◽

Model Experiment ◽

Scale Model ◽

Vertical Pipe ◽

Free Standing ◽

Visual Measurement ◽

Smooth Cylinder ◽

Induced Motion ◽

Reduced Scale ◽

A Current

An experiment using a 1/70 reduced scale model of a Free Standing Riser (FSR) was carried in the Deep-Sea Basin of the National Maritime Research Institute in Japan. For instance, the model’s vertical pipe was about 32m long and the jumper was about 8m long. The FSR model had several measurement stations attached along the vertical pipe, subsurface buoy and jumper; and the motion of each station was measured in 3D by the Visual Measurement System. During the experiment, the effects of the jumper’s top end oscillation on the whole system were investigated. In this case, the top oscillation had propagated along the jumper; however the top oscillation had a reduced effect on the dynamics of the subsurface buoy and vertical pipe. In another experimental case, a current was generated in order to investigate the Vortex Induced Motion (VIM) on the FSR’s Subsurface Buoy. The VIM experiment was repeated for two different buoy models (a smooth cylinder and a cylinder with 3-start heli-coidally strakes) and the results were compared. In this article, some of the experimental results are presented and discussed.

Download Full-text

An Experimental Study of the Interaction Between Pipe Structure and Internal Flow

Volume 3: Pipeline and Riser Technology ◽

10.1115/omae2009-79312 ◽

2009 ◽

Author(s):

Marcio Yamamoto ◽

Motohiko Murai ◽

Katsuya Maeda ◽

Shotaro Uto

Keyword(s):

Gas Flow ◽

Petroleum Industry ◽

Internal Flow ◽

Scale Model ◽

Offshore Platforms ◽

Drilling Mud ◽

Well Drilling ◽

Hydrocarbon Production ◽

Flow Effects ◽

Reduced Scale

Nowadays pipes are widely deployed in the offshore environment especially in the petroleum industry where rigid and flexible pipes are used for well drilling and hydrocarbon production. Whereas during drilling, a mixture of drilling mud, rock cuttings and sometimes gas flows through the drilling riser, during production mono or multiphase (comprising oil, water and gas) flow takes place within the system. However up till now, most of the studies on offshore pipelines and risers have been focused on the pipe structure and its interaction with hydrodynamic forces and offshore platforms. In particular for numerical computation studies and reduced scale model experiments, the pipe is usually modeled as a tensioned beam and sometimes only the internal pressure is taken into account with other effects due to its internal flow being neglected. This paper deals with the interaction between the pipe structure and its internal flow. In order to verify the internal flow effects, an experimental analysis was carried out not using a reduced scale model. In particular, mono-phase fluid flows into the pipe and a parametric analysis using the flow rate was carried out. Discussion about the experimental results and numerical applications is also included.

Download Full-text

Dynamic Behavior of Submarine Pipelines Under Laying Operation

Journal of Energy Resources Technology ◽

10.1115/1.3230421 ◽

1982 ◽

Vol 104 (4) ◽

pp. 313-318 ◽

Cited By ~ 7

Author(s):

N. Suzuki ◽

N. Jingu

Keyword(s):

Experimental Study ◽

Dynamic Behavior ◽

Water Depth ◽

Forced Oscillation ◽

Bending Moment ◽

Scale Model ◽

Regular Waves ◽

Wave Response ◽

Dynamic Bending

Theoretical and experimental study on dynamic behavior of submarine pipelines under laying operation with articulated stingers is described in this paper. Wave response tests in regular waves and forced oscillation tests in still water were conducted using the 1/20 scale model of 406.4 mm o.d. (16 in. o.d.) pipeline laid in 150 m (500 ft) water depth. The results show that: 1) the maximum dynamic bending moment of pipeline MDmax occur at a stinger roller, 2) dynamic bending moment of pipelines MD at shorter periods are larger than those at longer periods, 3) the values of MD in an over-bend region depend highly upon stinger motion, 4) those of MD in a sag-bend region are less than MD max in an over-bend region, 5) the values of MD/HMY increase as the stinger volume increases and that 6) stinger motion at shorter periods are different from those at longer periods.

Download Full-text

Experimental Investigation of the Effects of a Pulsating Internal Flow on the Dynamics of a Submersed U-Shaped Flexible Pipe

Volume 3: Pipeline and Riser Technology ◽

10.1115/omae2012-83069 ◽

2012 ◽

Author(s):

Marcio Yamamoto ◽

Shotaro Uto ◽

Tomo Fujiwara ◽

Motohiko Murai

Keyword(s):

Dynamic Response ◽

Flow Rate ◽

Deep Sea ◽

New Technologies ◽

Fluid Pressure ◽

Internal Flow ◽

Flexible Pipe ◽

Hydrocarbon Production ◽

Petroleum Production ◽

Single Well

In the past of the offshore petroleum production, each riser had conveyed the hydrocarbon production from a single vertical well; the riser’s internal flow rate was relatively low and only the internal fluid pressure was taking into account for the riser analysis. Other internal flow effects, such as internal fluid’s linear moment, and Coriollis effects, were neglected. However, the paradigm for petroleum production in ultra-deepwater is shifting nowadays. New technologies, such as horizontal wells, have increased the production rate from a single well. In addition, a subsea booster system can increase both pressure and flow rate of the riser’s conveyed fluid. Further, the Offshore Mining is rising as a new industry and will demand riser systems to convey, at high flow rates, the mineral ore’s slurry from the seafloor up to the production support vessel. In a previous experiment, the effects of the internal flow on a vertical riser were investigated. In the current experiment, the main objective is to investigate the effect of the internal flow on the dynamic response of a pipe in “jumper configuration”. The experiment was carried out at the Deep Sea Basin of the National Maritime Research Institute using a 10 m long flexible pipe. The actual “jumper” is a piece of flexible riser, in U-shaped configuration, that connects the main structure of “Self-Standing Hybrid Riser” to the production vessel. During the experiment, fresh water was pumped into the model by positive displacement pump; and an oscillator applies a harmonic vibration on one pipe’s end. Then the pipe’s dynamic response is measured by the Deep Sea Basin’s 3D Visual Measurement System. Results for different internal flows and oscillations are compared.

Download Full-text

Investigation on Similarity between Dynamic Behavior of a Reduced-Scale One Span Historical Masonry Arch Bridge Model and Prototype Bridge

10.36937/cebel.2020.001.002 ◽

2019 ◽

Vol 1 (1) ◽

pp. 5-11

Author(s):

Emre Alpaslan

Keyword(s):

Dynamic Behavior ◽

Scale Model ◽

Mode Shapes ◽

Experimental Investigations ◽

Masonry Arch ◽

Arch Bridge ◽

Bridge Model ◽

Historical Masonry ◽

Reduced Scale ◽

Masonry Arch Bridge

Experimental investigations of large and complex structural systems can be carried out by reduced-scale models in terms of convenience, time-saving and economical. This can be applied to different fields of study such as vibration, impact and explosion problems in structural engineering and allows reliable analysis to understand the static and dynamic behavior of real structures called a prototype. This study aims that a 1/3 reduced-scale model is created in the laboratory environment considering similitude requirements by selecting a single span historical masonry arch bridge as a prototype structure. For this purpose, the Operational Modal Analysis (OMA) Technique is utilized for experimental study to determine modal parameters of the prototype and model bridges. The similarity of the dynamic behavior of the reduced-scale bridge model and prototype are investigated. The analysis of the similarity in the dynamic behavior of the prototype and model bridge consists of comparing the natural frequencies and mode shapes by utilizing the modal assurance criterion (MAC) corresponding to the translational, bending and torsional modes. As a result of the study, it is concluded that the dynamic behavior of the reduced-scale bridge model is similar to the dynamic behavior of the prototype bridge.

Download Full-text