INTRODUCTION.In recent years,with the steady development of offshore energy exploration technology,submarine gas seepage sites,and their products are gradually being identified and analyzed.The submarine cold seep is ...INTRODUCTION.In recent years,with the steady development of offshore energy exploration technology,submarine gas seepage sites,and their products are gradually being identified and analyzed.The submarine cold seep is a seepage phenomenon in which hydrocarbon gases stored deep in the seafloor are transported to seawater by gushing or seepage under the action of tectonic compression(Roy et al.,2019;Tinivella and Giustiniani,2016).展开更多
The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic explora...The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.展开更多
0 INTRODUCTION China's external dependence on oil and gas remains high,making the independent exploration and development of oil and gas resources crucial for ensuring national energy security and the sustainable ...0 INTRODUCTION China's external dependence on oil and gas remains high,making the independent exploration and development of oil and gas resources crucial for ensuring national energy security and the sustainable development of the economy and society.In 2023,China continued to step up its efforts in offshore oil and gas exploration and development,with offshore crude oil production surpassing 62 million tons,accounting for about 70%of the national increase in crude oil production.Deepening offshore oil and gas exploration and development is of great significance for guaranteeing national energy security.展开更多
0 INTRODUCTION Scholte wave dispersion curves contain rich information regarding seafloor media and have therefore attracted increasing attention(Wang et al.,2022;Dong et al.,2021;Du et al.,2020).Ocean bottom seismome...0 INTRODUCTION Scholte wave dispersion curves contain rich information regarding seafloor media and have therefore attracted increasing attention(Wang et al.,2022;Dong et al.,2021;Du et al.,2020).Ocean bottom seismometer(OBS)data are widely used in the study of seafloor medium information(Wang et al.,2024),and contain rich surface wave information.展开更多
INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibi...INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibit a dispersion phenomenon,which implies that their velocity varies with frequency.Low-frequency Scholte waves can propagate over long distances on the seabed with little attenuation(Bohlen et al.,2004).The particle mo tion of Scholte waves in a solid medium changes from a retro grade to a prograde ellipse(Klein et al.,2005;McMechan and Yedlin,1981).展开更多
The paper develops a multiple matching attenuation method based on extended filtering in the curvelet domain,which combines the traditional Wiener filtering method with the matching attenuation method in curvelet doma...The paper develops a multiple matching attenuation method based on extended filtering in the curvelet domain,which combines the traditional Wiener filtering method with the matching attenuation method in curvelet domain.Firstly,the method uses the predicted multiple data to generate the Hilbert transform records,time derivative records and time derivative records of Hilbert transform.Then,the above records are transformed into the curvelet domain and multiple matching attenuation based on least squares extended filtering is performed.Finally,the attenuation results are transformed back into the time-space domain.Tests on the model data and field data show that the method proposed in the paper effectively suppress the multiples while preserving the primaries well.Furthermore,it has higher accuracy in eliminating multiple reflections,which is more suitable for the multiple attenuation tasks in the areas with complex structures compared to the time-space domain extended filtering method and the conventional curvelet transform method.展开更多
基金funded by the National Natural Science Foundation of China (grant no.42074149)the Natural Science Foundation of Jiangsu Province (grant no.BK20201318)。
基金supported by the Key Research and Development Project of Guangdong Province(No.2020B1111510001)。
文摘INTRODUCTION.In recent years,with the steady development of offshore energy exploration technology,submarine gas seepage sites,and their products are gradually being identified and analyzed.The submarine cold seep is a seepage phenomenon in which hydrocarbon gases stored deep in the seafloor are transported to seawater by gushing or seepage under the action of tectonic compression(Roy et al.,2019;Tinivella and Giustiniani,2016).
基金Supported by the National Natural Science Foundation of China(No.42276195)the Natural Science Foundation of Zhejiang Province(No.LQ22D060006)the Science Foundation of Zhejiang Sci-Tech University(No.21022092-Y)。
文摘The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures.The highresolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure,and identify geohazard.To optimize the performance of sparker seismic source,we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers.Results show that the sound source level increased with the increase of the charging voltage,whereas the main frequency decreased when the charging voltage increases.In addition,it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did.Although the load energy decreased with increasing electrode number,the sound source level still increased but the main frequency decreased.Meanwhile,the primary to bubble(P/B)ratio increased with the increase of the electrode number.To gain a deeper insight into the electro-acoustic characteristics,we investigate the relationship between sound source level and power peak,from which a good correlation was observed.A more practical statistical analysis on the rise rate of current was processed,and a perfect logarithmic function was derived.Furthermore,we found that the main frequency was most possibly subjected to the electrical energy,especially the charging energy per electrode.The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz.At last,the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ.This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.
基金supported by the National Science and Technology Major Project(No.2016ZX05024)the Project of Strategic Research and Consulting Projects of the Chinese Academy of Engineering(No.2022-XBZD-08-01)。
文摘0 INTRODUCTION China's external dependence on oil and gas remains high,making the independent exploration and development of oil and gas resources crucial for ensuring national energy security and the sustainable development of the economy and society.In 2023,China continued to step up its efforts in offshore oil and gas exploration and development,with offshore crude oil production surpassing 62 million tons,accounting for about 70%of the national increase in crude oil production.Deepening offshore oil and gas exploration and development is of great significance for guaranteeing national energy security.
基金supported by Major Research Project on Scientific Instrument Development,National Natural Science Foundation of China(No.42327901)the research project of the China National Petroleum Corporation(No.2021ZG02)+2 种基金the National Natural Science Foundation of China(Nos.42004091,62127815,42150201)Beijing Natural Science Foundation(No.8222030)sponsored by the Chinese“111”Project(No.B20011).
文摘0 INTRODUCTION Scholte wave dispersion curves contain rich information regarding seafloor media and have therefore attracted increasing attention(Wang et al.,2022;Dong et al.,2021;Du et al.,2020).Ocean bottom seismometer(OBS)data are widely used in the study of seafloor medium information(Wang et al.,2024),and contain rich surface wave information.
基金supported by the research project of the China National Petroleum Corporation(No.2021ZG02)National Natural Science Foundation of China(Nos.42004091,62127815,42150201)+1 种基金Beijing Natural Science Foundation(No.8222030)sponsored by the Chinese“111”project(No.B20011).
文摘INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibit a dispersion phenomenon,which implies that their velocity varies with frequency.Low-frequency Scholte waves can propagate over long distances on the seabed with little attenuation(Bohlen et al.,2004).The particle mo tion of Scholte waves in a solid medium changes from a retro grade to a prograde ellipse(Klein et al.,2005;McMechan and Yedlin,1981).
基金funded by the Wenhai Program of the ST Fund of Laoshan Laboratory (No.202204803)the National Natural Science Foundation of China (Nos.42074138,42206195)+1 种基金the National Key R&D Program of China (No.2022YFC2803501)the Research Project of the China National Petroleum Corporation (No.2021ZG02)。
文摘The paper develops a multiple matching attenuation method based on extended filtering in the curvelet domain,which combines the traditional Wiener filtering method with the matching attenuation method in curvelet domain.Firstly,the method uses the predicted multiple data to generate the Hilbert transform records,time derivative records and time derivative records of Hilbert transform.Then,the above records are transformed into the curvelet domain and multiple matching attenuation based on least squares extended filtering is performed.Finally,the attenuation results are transformed back into the time-space domain.Tests on the model data and field data show that the method proposed in the paper effectively suppress the multiples while preserving the primaries well.Furthermore,it has higher accuracy in eliminating multiple reflections,which is more suitable for the multiple attenuation tasks in the areas with complex structures compared to the time-space domain extended filtering method and the conventional curvelet transform method.
