scholarly journals Application of Geological Risk Fine Identification Technology in Exploration Drilling

2021 ◽  
Vol 8 (8) ◽  
pp. 49-51
Author(s):  
Baisong Tang ◽  
◽  
Kun Xu ◽  
Zhankui Li ◽  
Jinting Zhu ◽  
...  
Keyword(s):  
Risk Prediction ◽  
Bohai Sea ◽  
Design Stage ◽  
Good Effect ◽  
Seismic Profiles ◽  
Tectonic Zone ◽  
The Bohai Sea ◽  
Actual Operation ◽  
Exploration Drilling ◽  
Fractured Well

As exploration progresses, complex block formations and mid-deep formations have become the main target areas in Bohai oil fields. In this context, well leaks and well wall instability due to special lithology are becoming more and more likely to occur, and have become the most common complications affecting the safety of drilling operations and production timing in the Bohai Sea. Geological risk prediction can give engineering hints at the design stage, so that the engineering is in a position to prepare for the risks, but because the risk prediction given on conventional seismic profiles is relatively rough, the practical application deviates greatly and cannot be closely integrated with the actual operation. In this paper, we analyze the data of leaking wells in the Bohai exploration wells, summarize the leaking well tectonic background and stratigraphy, and divide the leak-prone tectonic zone. By extracting suitable seismic attributes such as variance and waveform, fine prediction of weak (fractured) well sections is realized, and a set of fine identification techniques is formed to "avoid", "prevent" and "plug" well leaks. "avoid", "prevent" and "plug" well leakage. This technology has been applied in several exploration wells in the Bohai Sea, and it has played a good effect and is of great significance to promote.

Keystone species of fish community structure in the Bohai Sea

2018 ◽  
Vol 25 (2) ◽  
pp. 229
Author(s):  
Zhongyi LI ◽  
Qiang WU ◽  
Xiujuan SHAN ◽  
Tao YANG ◽  
Fangqun DAI ◽  
...  
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Bohai Sea ◽  
Keystone Species ◽  
Fish Community Structure ◽  
The Bohai Sea

Species Diversity and Eco-geographical Distribution of Dinoflagellate Cysts in the Bohai Sea, China

2012 ◽  
Vol 47 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Wang Yan ◽  
Huang Lin ◽  
Gu Haifeng ◽  
Li Shuang ◽  
Li Shaoshan
Keyword(s):  
Species Diversity ◽  
Geographical Distribution ◽  
Bohai Sea ◽  
Dinoflagellate Cysts ◽  
The Bohai Sea

scholarly journals Storm Surges in the Bohai Sea: The Role of Waves and Tides

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1509
Author(s):  
Yuanyi Li ◽  
Huan Feng ◽  
Guillaume Vigouroux ◽  
Dekui Yuan ◽  
Guangyu Zhang ◽  
...  
Keyword(s):  
Storm Surge ◽  
Bohai Sea ◽  
Storm Surges ◽  
Wave Force ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Coastal Regions ◽  
The Bohai Sea ◽  
Tidal Phase ◽  
Set Up

A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this study, we set up a storm surge model, considering coupled effects of tides and waves on the surges. Validation against measured data shows that the coupled model is capable of simulating storm surges in the Bohai Sea. The simulation results indicate that the longshore currents, which are induced by the large gradient of radiation stress due to wave deformation, are one of the main contributors to the higher surges occurring in some coastal regions. The gently varying bathymetry is another factor contributing to these surges. With such bathymetry, the wave force direction is nearly uniform, and pushes a large amount of water in that direction. Under these conditions, the water accumulates in some parts of the coast, leading to higher surges in nearby coastal regions such as the south coast of the Bohai Bay and the west and south coasts of the Laizhou Bay. Results analysis also shows that the tidal phase at which the surge occurs influences the wave–current interactions, and these interactions are more evident in shallow waters. Neglecting these interactions can lead to inaccurate predictions of the storm surges due to overestimation or underestimation of wave-induced set-up.

Molecular characterization of harmful algal blooms in the Bohai Sea using metabarcoding analysis

Harmful Algae ◽  
2021 ◽  
Vol 106 ◽  
pp. 102066
Author(s):  
Hailong Huang ◽  
Qing Xu ◽  
Kate Gibson ◽  
Yang Chen ◽  
Nansheng Chen
Keyword(s):  
Molecular Characterization ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Bohai Sea ◽  
The Bohai Sea

scholarly journals Nitric oxide (NO) in the Bohai Sea and the Yellow Sea

2019 ◽  
Vol 16 (22) ◽  
pp. 4485-4496 ◽  
Author(s):  
Ye Tian ◽  
Chao Xue ◽  
Chun-Ying Liu ◽  
Gui-Peng Yang ◽  
Pei-Feng Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Surface Layer ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Limit Of Detection ◽  
Bottom Layer ◽  
The Yellow Sea ◽  
The Bohai Sea ◽  
Significant Difference ◽  
Average Flux

Abstract. Nitric oxide (NO) is a short-lived compound of the marine nitrogen cycle; however, our knowledge about its oceanic distribution and turnover is rudimentary. Here we present the measurements of dissolved NO in the surface and bottom layers at 75 stations in the Bohai Sea (BS) and the Yellow Sea (YS) in June 2011. Moreover, NO photoproduction rates were determined at 27 stations in both seas. The NO concentrations in the surface and bottom layers were highly variable and ranged from below the limit of detection (i.e., 32 pmol L−1) to 616 pmol L−1 in the surface layer and 482 pmol L−1 in the bottom layer. There was no significant difference (p>0.05) between the mean NO concentrations in the surface (186±108 pmol L−1) and bottom (174±123 pmol L−1) layers. A decreasing trend of NO in bottom-layer concentrations with salinity indicates a NO input by submarine groundwater discharge. NO in the surface layer was supersaturated at all stations during both day and night and therefore the BS and YS were a persistent source of NO to the atmosphere at the time of our measurements. The average flux was about 4.5×10-16 mol cm−2 s−1 and the flux showed significant positive relationship with the wind speed. The accumulation of NO during daytime was a result of photochemical production, and photoproduction rates were correlated to illuminance. The persistent nighttime NO supersaturation pointed to an unidentified NO dark production. NO sea-to-air flux densities were much lower than the NO photoproduction rates. Therefore, we conclude that the bulk of the NO produced in the mixed layer was rapidly consumed before its release to the atmosphere.

scholarly journals Characterization of Bacterial Communities in Bioaerosols over Northern Chinese Marginal Seas and the Northwestern Pacific Ocean in Spring

2019 ◽  
Vol 58 (4) ◽  
pp. 903-917 ◽  
Author(s):  
Manman Ma ◽  
Yu Zhen ◽  
Tiezhu Mi
Keyword(s):  
Pacific Ocean ◽  
Yellow Sea ◽  
Bacterial Communities ◽  
Bohai Sea ◽  
The Yellow Sea ◽  
Northwestern Pacific ◽  
Particle Sizes ◽  
Marine Aerosols ◽  
Northwestern Pacific Ocean ◽  
The Bohai Sea

AbstractStudies of the community structures of bacteria in marine aerosols of different particle sizes have not been reported. Aerosol samples were collected using a six-stage bioaerosol sampler over the Bohai Sea, the Yellow Sea, and northwestern Pacific Ocean in the spring of 2014. The diversity and composition of these samples were investigated by Illumina high-throughput sequencing, and 130 genera were detected in all of the samples; the most abundant bacterial genus was Bacteroides, followed by Prevotella and Megamonas. The Chao1 and Shannon diversity indices ranged from 193 to 1044 and from 5.44 to 8.33, respectively. The bacterial community structure in coarse particles (diameter larger than 2.1 μm) was more complex and diverse than that in fine particles (diameter less than 2.1 μm) in marine bioaerosols from over the Yellow Sea and northwestern Pacific Ocean, while the opposite trend was observed for samples collected over the Bohai Sea. Although we were sampling over marine regions, the sources of the bioaerosols were mostly continental. Temperature and wind speed significantly influenced the bacterial communities in marine aerosols of different particle sizes. There may be a bacterial background in the atmosphere in the form of several dominant taxa, and the bacterial communities are likely mixed constantly during transmission.

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