Parameter Prediction Method for Submarine Cuttings Piles in Offshore Drilling

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1307-1332
Author(s):  
Baojiang Sun ◽  
Zhi Zhang ◽  
Zhiyuan Wang ◽  
Shaowei Pan ◽  
Ze Wang ◽  
...  
Keyword(s):  
Current Velocity ◽  
Geometric Characteristic ◽  
Stable State ◽  
Prediction Method ◽  
Continuous Model ◽  
Ocean Currents ◽  
Ocean Current ◽  
Offshore Drilling ◽  
Before And After ◽  
Drilling Site

Summary The cost of offshore drilling operations can be significantly reduced by discharging drilling cuttings into the seabed. However, this leads to accumulation of cuttings piles on the seabed near the drilling site. A certain thickness of cuttings piles changes the original trend of the seabed terrain undulation condition, thus bringing potential safety hazards to the underwater installation of production manifolds. Moreover, the interaction between cuttings and ocean currents near the cuttings piles causes the geometric shape of cuttings piles to evolve over time, which makes it more difficult to accurately predict their characteristics. On the basis of the force analysis of cuttings, considering the effects of cuttings properties (cutting size, density) and ocean-current velocity on the geometric characteristic evolution of the formed cuttings piles, a continuous model for describing the evolution of the returned cuttings piles is established in this study. This model can quantitatively characterize the functional relationship between characteristics of cuttings piles and relevant parameters (current velocity, cutting size, evolution time), and predict the location and geometry characteristics of the cuttings piles evolving into a stable state in ocean currents. Comparing the measured data in laboratory experiments and at an offshore drilling field, the relative error of the model amounts to less than 10%, which demonstrates its rationality. Simulation results show that there will be significant changes in the geometry of cuttings piles before and after the evolution, in which the intensity is correlated with current velocity and cuttings size, and cuttings piles might even split into several parts under certain conditions. The simulation and analysis of the transport and deposition of cuttings returned from the wellhead on the seabed is highly significant for the guide and optimal design of underwater production manifolds.

Simulated High-Pile Dock Construction on the Impact of Coastal Erosion Based on Theoretical Models and Dou Theory - A Case of Suanshan Dock

2012 ◽  
Vol 160 ◽  
pp. 386-390
Author(s):  
De Yu Luo ◽  
Lei Huang ◽  
Xu Gao
Keyword(s):  
Stable State ◽  
Theoretical Models ◽  
Ocean Current ◽  
Current Field ◽  
Erosion And Deposition ◽  
Theoretical Simulation ◽  
Speed Flow ◽  
Before And After ◽  
Bridge Type ◽  
The Impact

In order to investigate the renovation and expansion of coastal high-pile on the possible environmental impact of erosion and deposition, the changes of ocean current field and bottom erosion before and after the current field of renovation and expansion were simulated in use of an average two-dimensional vertical flow theoretical simulation model and Dou theory, based on ocean current Speed, flow and other measured data, integrated hydrological, meteorological and other historical information. The results showed that after the construction of Suanshan Dock , the increased siltation of Yang gong-shan Dock and Budui Dock code were approximately 1m and 0.5m respectively. Due to the high pile and bridge-type structure of high-pile dock , although the construction of Suanshan Dock would cause coastal area occurring a certain flow pattern changes , there were not significantly changes to the topography of basin . The underwater slope area would remain in a relatively stable state.

scholarly journals POTENTIAL ENERGY OF OCEAN CURRENT FOR ELECTRIC POWER GENERATIONIN COASTAL AREAS OF EAST FLORES, NTT

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Ai Yuningsih ◽  
Achmad Masduki
Keyword(s):  
Potential Energy ◽  
Current Velocity ◽  
Power Plants ◽  
Local Community ◽  
Meteorological Parameter ◽  
Electrical Energy ◽  
Ocean Currents ◽  
Ocean Current ◽  
Coastal Morphology ◽  
Current Energy

<p>The electrical energy is one of the important needs for coastal communities particularly in small islands that has not reached by national electricity network. In order to fulfill this particular electricity needs, we do variety diversification efforts, such as the utilization of the ocean currents. The purpose of this survey is to recognize the morphology of seafloor and characteristic of hydro-oceanography as a fixed reference location in using the current energy. The study area is in the Larantuka Strait between Flores and Adonara islands which is part of the Flores Strait, East Nusatenggara Province. The methods of this study are current measurements, tidal and meteorological parameter observations, condition of coastal morphology and seafloor of the study area. The result show that, the location for turbine position is in area with relatively gentle slope morphology at a 20 meters water depth and it is close to local community. Based on the analysis of ADCP mobile current measurement, the minimum current velocity is 0.004 m/sec and maximum 3.68 m/sec. Whereas, from the ADCP static measurements the current velocity is from 0.002 m/sec to 2.83 m/sec. This condition is closely related to the semi-diurnal tide type in the study area, with two pairs of flood and web events within 24 hours. Therefore, the results of ocean current energy analysis indicate that the study area is very potential for using as a power plant location.</p><p>Keywords: potential energy of ocean currents, power plants, energy diversification, Larantuka Strait, East Flores</p>

scholarly journals POTENTIAL ENERGY OF OCEAN CURRENT FOR ELECTRIC POWER GENERATIONIN COASTAL AREAS OF EAST FLORES, NTT

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Ai Yuningsih ◽  
Achmad Masduki
Keyword(s):  
Potential Energy ◽  
Current Velocity ◽  
Power Plants ◽  
Local Community ◽  
Meteorological Parameter ◽  
Electrical Energy ◽  
Ocean Currents ◽  
Ocean Current ◽  
Coastal Morphology ◽  
Current Energy

The electrical energy is one of the important needs for coastal communities particularly in small islands that has not reached by national electricity network. In order to fulfill this particular electricity needs, we do variety diversification efforts, such as the utilization of the ocean currents. The purpose of this survey is to recognize the morphology of seafloor and characteristic of hydro-oceanography as a fixed reference location in using the current energy. The study area is in the Larantuka Strait between Flores and Adonara islands which is part of the Flores Strait, East Nusatenggara Province. The methods of this study are current measurements, tidal and meteorological parameter observations, condition of coastal morphology and seafloor of the study area. The result show that, the location for turbine position is in area with relatively gentle slope morphology at a 20 meters water depth and it is close to local community. Based on the analysis of ADCP mobile current measurement, the minimum current velocity is 0.004 m/sec and maximum 3.68 m/sec. Whereas, from the ADCP static measurements the current velocity is from 0.002 m/sec to 2.83 m/sec. This condition is closely related to the semi-diurnal tide type in the study area, with two pairs of flood and web events within 24 hours. Therefore, the results of ocean current energy analysis indicate that the study area is very potential for using as a power plant location.Keywords: potential energy of ocean currents, power plants, energy diversification, Larantuka Strait, East Flores

scholarly journals KARAKTERISTIK ARUS LAUT PERAIRAN TELUK BENOA – BALI

GEOMATIKA ◽  
2017 ◽  
Vol 23 (1) ◽  
pp. 37 ◽  
Author(s):  
Try Al Tanto ◽  
Ulung Jantama Wisha ◽  
Gunardi Kusumah ◽  
Widodo S. Pranowo ◽  
Semeidi Husrin ◽  
...  
Keyword(s):  
Current Velocity ◽  
Tidal Current ◽  
High Tide ◽  
Flow Speed ◽  
Ocean Currents ◽  
Ocean Current ◽  
Dominant Factor ◽  
Irregular Pattern ◽  
Current Characteristics ◽  
June July

<p class="judulabstrakindo">ABSTRAK</p><p class="abstrakindo">Perairan Teluk Benoa merupakan kawasan semi tertutup dengan mulut sempit yang memisahkan antara Pulau Serangan dan Tanjung Benoa. Arus laut perairan Teluk Benoa, yang dekat pantai berperan penting dalam proses transpor sedimen di daerah pantai yang merupakan daerah gelombang mulai pecah hingga ke arah garis pantai. Tujuan penelitian adalah mengetahui karakteristik arus laut yang terjadi, analisis dari penyajian secara <em>scatter plot</em> dan <em>stic plot</em>, sehingga diketahui faktor dominan pembangkit arus tersebut. Data arus laut diperoleh dari hasil pengukuran pihak swasta menggunakan alat ukur ADCP. Analisis arus laut dengan <em>scatter</em> dan <em>stic plot</em><em> </em>untuk melihat arah dominan arus, serta melihat hubungan kejadian arus dengan pasang surut air laut, selain itu juga dengan perhitungan kisaran kecepatan arus yang terjadi selama pengukuran. Hasil yang diperoleh adalah arus laut di perairan Teluk Benoa berkisar antara 0,001 - 1,715 m/s (pengamatan bulan Juni - Juli 2015). Kecepatan arus pada mulut teluk lebih besar (maksimal sebesar 1,715 m/s), sedangkan di dalam teluk kecepatan arus lebih rendah (maksimal sebesar 0,883 m/s). Pada saat air pasang, arah arus dominan ke arah dalam teluk dan saat air laut surut arah dominan arus ke arah luar teluk. Kesimpulan yang diperoleh adalah kejadian arus laut di perairan Teluk Benoa lebih dominan berupa arus pasang surut. Saat kondisi bulan purnama kecepatan arus lebih tinggi dari pada saat posisi bulan separuh (kuarter pertama atau ketiga). Pada umumnya, pada mulut teluk memiliki arus yang cukup tinggi sebagai akibat celah sempit, dengan pola yang tidak beraturan akibat pengaruh perlintasan kapal dan aktivitas keluar masuk teluk.</p><p><strong>Kata kunci</strong>: arus laut, karakteristik arus laut, arus pasang surut, Teluk Benoa</p><p class="judulabstraking">ABSTRACT</p><p class="abstraking">Benoa Bay waters is a semi-enclosed area with quite a narrow mouth that separates the Serangan Island and Tanjung Benoa. Ocean currents in Benoa Bay, which is close to the beach plays an important role in the process of sediment transport in the beach area where is the waves began to break up towards the shoreline. The research objective was to know the characteristics of ocean currents that occur, from the analysis of the scatter and stic plot, so it’s known that the dominant factor of the current generator. The data of ocean currents obtained from the measurement of private parties using ADCP measuring instrument. Analysis of ocean currents with scatter and stic plot to see the dominant direction of current, and to see the relationship of current occurrence with the tide, besides also with calculation of current velocity. The results obtained are ocean currents in the Benoa Bay waters ranged from 0,001 to 1,715 m/s (observations in June-July 2015). Flow velocity at the mouth of the bay is greater (maximum of 1,715 m/s), while in the lower bay flow speed (maximum of 0,883 m/s). At high tide, the dominant current direction towards the bay and vice versa during low tide predominant direction of flow towards the outside of the bay. The conclusion is the incidence of ocean currents in the Benoa Bay waters is predominantly influenced by the tidal current. When the full moon conditions the current velocity is higher than at half month position. In general, at the mouth of the bay has a current high enough as a result of the narrow gap, with irregular pattern due to the influence and activities of ship crossings in and out of the bay.</p><p><strong>Keywords</strong>: <em>ocean current, characteristics of ocean current, tidal current, Benoa Bay</em></p>

scholarly journals Physiological and Psychological Effects of Watching Videos of Different Durations Showing Urban Bamboo Forests with Varied Structures

2020 ◽  
Vol 17 (10) ◽  
pp. 3434
Author(s):  
Yuqian Wang ◽  
Mingyan Jiang ◽  
Yinshu Huang ◽  
Zhiyi Sheng ◽  
Xiao Huang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Skin Conductance ◽  
Human Body ◽  
Stable State ◽  
Mean Value ◽  
Psychological Effects ◽  
Physiological Indicators ◽  
Psychological Indicators ◽  
Before And After ◽  
Long Time

This study illustrated the physiological and psychological effects of watching videos of different durations showing bamboo forests with varied structures. Physiological indicators, including EEG (electroencephalogram), blood pressure, skin conductance, and pulse, were monitored in 180 Chinese university students (mean age: 20.72 ± 2.56 years) while they were watching bamboo videos. Before and after watching the videos, their psychological indicators, including positive and negative moods, were measured using the Profile of Mood States questionnaire. After watching the bamboo videos of different durations, all of the physiological indicators responded to the stimulation after only 1 min. The indicators showed different trends at 1, 3 and 5 min. EEG decreased and then was maintained at a stable level after 1 min, and the high β, low β, and α waves had no significant differences between 1, 3 and 5 min. Blood pressure dropped to a stable state after 3 min, and the decline was significantly different greater after 3 min than after 1 min. Skin conductance increased for 1 to 5 min, and it did not stabilize after a long time (5 min). Pulse decreased after 1 min but increased after 5 min. After watching the videos with bamboo of varying structures, the physiological and psychological indicators showed significantly different changes. Skin conductance significantly increased (mean value: 6.78%), and the amount of sweat was more effectively reduced, thereby reducing tension, when the students viewed videos of sympodial bamboo forests compared with monopodial bamboo forests. Bamboo forests with a higher canopy density (0.83–0.85) could significantly decrease α waves (mean value: 1.50 Hz), relaxing the human body. High β and low β waves showed greater decreases, with tension reduced more effectively, when bamboo forests with a low tilt ratio (< 1.5%) were viewed. Bamboo forests with neat undergrowth could have more beneficial physiological and psychological effects on the human body.

Disturbance learning controller design for unmanned surface vehicle using LSTM technique of recurrent neural network

2021 ◽  
pp. 1-11
Author(s):  
Sang-Ki Jeong ◽  
Dea-Hyeong Ji ◽  
Ji-Youn Oh ◽  
Jung-Min Seo ◽  
Hyeung-Sik Choi
Keyword(s):  
Neural Network ◽  
Control System ◽  
Flow Velocity ◽  
Recurrent Neural Network ◽  
Pid Controller ◽  
Short Term Memory ◽  
Ocean Currents ◽  
Ocean Current ◽  
Movement Speed ◽  
Marine Research

In this study, to effectively control small unmanned surface vehicles (USVs) for marine research, characteristics of ocean current were learned using the long short-term memory (LSTM) model algorithm of a recurrent neural network (RNN), and ocean currents were predicted. Using the results, a study on the control of USVs was conducted. A control system model of a small USV equipped with two rear thrusters and a front thruster arranged horizontally was designed. The system was also designed to determine the output of the controller by predicting the speed of the following currents and utilizing this data as a system disturbance by learning data from ocean currents using the LSTM algorithm of a RNN. To measure ocean currents on the sea when a small USV moves, the speed and direction of the ship’s movement were measured using speed, azimuth, and location (latitude and longitude) data from GPS. In addition, the movement speed of the fluid with flow velocity is measured using the installed flow velocity measurement sensor. Additionally, a control system was designed to control the movement of the USV using an artificial neural network-PID (ANN-PID) controller [12]. The ANN-PID controller can manage disturbances by adjusting the control gain. Based on these studies, the control results were analyzed, and the control algorithm was verified through a simulation of the applied control system [8, 9].

Multi-AUV Underwater Cooperative Search Algorithm based on Biological Inspired Neurodynamics Model and Velocity Synthesis

2015 ◽  
Vol 68 (6) ◽  
pp. 1075-1087 ◽  
Author(s):  
Xiang Cao ◽  
Daqi Zhu
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Search Algorithm ◽  
Integrated Approach ◽  
Underwater Vehicle ◽  
Ocean Currents ◽  
Ocean Current ◽  
Cooperative Search ◽  
Search Path ◽  
Negative Effect ◽  
Underwater Target

Ocean currents impose a negative effect on Autonomous Underwater Vehicle (AUV) underwater target searches, which lengthens the search paths and consumes more energy and team effort. To solve this problem, an integrated algorithm is proposed to realise multi-AUV cooperative search in dynamic underwater environments with ocean currents. The proposed integrated algorithm combines the Biological Inspired Neurodynamics Model (BINM) and Velocity Synthesis (VS) method. Firstly, the BINM guides a team of AUVs to achieve target search in underwater environments; BINM search requires no specimen learning information and is thus easier to apply to practice, but the search path is longer because of the influence of ocean current. Next the VS algorithm offsets the effect of ocean current, and it is applied to optimise the search path for each AUV. Lastly, to demonstrate the effectiveness of the proposed integrated approach, simulation results are given in this paper. It is proved that this integrated algorithm can plan shorter search paths and thus the energy consumption is lower compared with BINM.

scholarly journals Modeling on 137Cs Radioactive Dispersion in Gosong Coast as The Candidate Location for Nuclear Power Plant

2021 ◽  
Vol 24 (3) ◽  
pp. 291-301
Author(s):  
Akhmad Tri Prasetyo ◽  
Muslim Muslim ◽  
Heny Suseno
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Marine Pollution ◽  
Ocean Currents ◽  
Ocean Current ◽  
West Kalimantan ◽  
Spring Period ◽  
Candidate Location

The study of radioactive dispersion in the ocean should be conducted to prepare the construction of nuclear power plant (NPP) in Gosong Coast, West Kalimantan. This study estimated the distribution of 137Cs radioactive from various scenarios of radioactive waste dumping if nuclear emergency is occurred during NPP’s operation. These scenarios were distinguished based on their volume discharges of radioactive waste into the ocean, included 10 m3 (Scenario I), 50 m3 (Scenario II), and 100 m3 (Scenario III).  Model dispersions were constructed for 15 days by Delft3D-Flow module. The simulation showed that ocean current directions were not significantly different among spring and neap tide, instead the ocean current during the spring period dominantly increased rather than neap period. Ocean currents at Gosong Coast flowed parallel to the shoreline towards Singkawang Coastal Area during ebb tide. Meanwhile, during flood tide, ocean currents at Gosong Coast flowed offshore through Burung Archipelagic. The dispersed model showed the distribution of 137Cs radioactive for 15 days reaching to coastal areas of Burung Archipelagic, Singkawang, and Southern Sambas Coast. Each scenario of the disposal system did not influence the marine pollution of the West Kalimantan Sea.

scholarly journals Strongly Coupled Assimilation of a Hypothetical Ocean Current Observing Network within a Regional Ocean-Atmosphere Coupled Model: An OSSE Case Study of Typhoon Hato

2021 ◽  
Author(s):  
Luke Phillipson ◽  
Yi Li ◽  
Ralf Toumi
Keyword(s):  
Coupled Model ◽  
Ocean Currents ◽  
Hf Radar ◽  
Ocean Current ◽  
Coastal Current ◽  
Strongly Coupled ◽  
Ocean Atmosphere ◽  
Atmospheric Observations ◽  
Surface Drifters ◽  
The Impact

AbstractThe forecast of tropical cyclone (TC) intensity is a significant challenge. In this study, we showcase the impact of strongly coupled data assimilation with hypothetical ocean currents on analyses and forecasts of Typhoon Hato (2017). Several observation simulation system experiments were undertaken with a regional coupled ocean-atmosphere model. We assimilated combinations of (or individually) a hypothetical coastal current HF radar network, a dense array of drifter floats and minimum sea-level pressure. During the assimilation, instant updates of many important atmospheric variables (winds and pressure) are achieved from the assimilation of ocean current observations using the cross-domain error covariance, significantly improving the track and intensity analysis of Typhoon Hato. As compared to a control experiment (with no assimilation), the error of minimum pressure decreased by up to 13 hPa (4 hPa / 57 % on average). The maximum wind speed error decreased by up to 18 knots (5 knots / 41 % on average). By contrast, weakly coupled implementations cannot match these reductions (10% on average). Although traditional atmospheric observations were not assimilated, such improvements indicate there is considerable potential in assimilating ocean currents from coastal HF radar, and surface drifters within a strongly coupled framework for intense landfalling TCs.

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