The picking efficiency of seismic first breaks(FBs)has been greatly accelerated by deep learning(DL)technology.However,the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-nois...The picking efficiency of seismic first breaks(FBs)has been greatly accelerated by deep learning(DL)technology.However,the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-noise ratio(SNR)situations.To address this issue,we propose a regression approach to pick FBs based on bidirectional long short-term memory(Bi LSTM)neural network by learning the implicit Eikonal equation of 3D inhomogeneous media with rugged topography in the target region.We employ a regressive model that represents the relationships among the elevation of shots,offset and the elevation of receivers with their seismic traveltime to predict the unknown FBs,from common-shot gathers with sparsely distributed traces.Different from image segmentation methods which automatically extract image features and classify FBs from seismic data,the proposed method can learn the inner relationship between field geometry and FBs.In addition,the predicted results by the regressive model are continuous values of FBs rather than the discrete ones of the binary distribution.The picking results of synthetic data shows that the proposed method has low dependence on label data,and can obtain reliable and similar predicted results using two types of label data with large differences.The picking results of9380 shots for 3D seismic data generated by vibroseis indicate that the proposed method can still accurately predict FBs in low SNR data.The subsequent stacked profiles further illustrate the reliability and effectiveness of the proposed method.The results of model data and field seismic data demonstrate that the proposed regression method is a robust first-break picker with high potential for field application.展开更多
Manually picking regularly and densely distributed first breaks(FBs)are critical for shallow velocitymodel building in seismic data processing.However,it is time consuming.We employ the fullyconvolutional Seg Net to a...Manually picking regularly and densely distributed first breaks(FBs)are critical for shallow velocitymodel building in seismic data processing.However,it is time consuming.We employ the fullyconvolutional Seg Net to address this issue and present a fast automatic seismic waveform classification method to pick densely-sampled FBs directly from common-shot gathers with sparsely distributed traces.Through feeding a large number of representative shot gathers with missing traces and the corresponding binary labels segmented by manually interpreted fully-sampled FBs,we can obtain a welltrained Seg Net model.When any unseen gather including the one with irregular trace spacing is inputted,the Seg Net can output the probability distribution of different categories for waveform classification.Then FBs can be picked by locating the boundaries between one class on post-FBs data and the other on pre-FBs background.Two land datasets with each over 2000 shots are adopted to illustrate that one well-trained 25-layer Seg Net can favorably classify waveform and further pick fully-sampled FBs verified by the manually-derived ones,even when the proportion of randomly missing traces reaches50%,21 traces are missing consecutively,or traces are missing regularly.展开更多
随着油气勘探程度的不断提高,已陆续发现一些以火山岩和火山碎屑岩为储集层的油气田。但是,由于火山岩对地震信号屏蔽作用明显,地震波在不同层系、不同类型火山岩中的速度差异大,导致火山岩发育区的速度建模和成像极其困难。EP地区处于...随着油气勘探程度的不断提高,已陆续发现一些以火山岩和火山碎屑岩为储集层的油气田。但是,由于火山岩对地震信号屏蔽作用明显,地震波在不同层系、不同类型火山岩中的速度差异大,导致火山岩发育区的速度建模和成像极其困难。EP地区处于阳江—一统断裂带,资源潜力大,且发育大量构造圈闭,同时,该地区发育古近系及上覆地层的多期火山岩,以往处理成果中火山岩内幕成像不清晰,难以刻画火山岩相和准确评估火山岩对油气生、储、盖条件的影响。为此,针对火山岩多次波压制、火山岩下弱信号恢复、火山岩速度精细刻画等方面的关键问题开展新的处理技术探索。首先采用MWD(Model based Water-layer related Demultiple)技术预测火山岩多次波;然后利用AVO剩余振幅补偿和低频算子外推随机噪声衰减技术提高火山岩下弱信号质量;最后,联合应用初至波层析和反射波网格层析技术构建精确的叠前深度偏移速度模型。重处理后的叠前深度偏移成果显示,火山岩及下伏地层成像质量显著提高,表明所提重处理技术方案对提高火山岩发育区地震成像质量有较好的借鉴意义。展开更多
基金financially supported by the National Key R&D Program of China(2018YFA0702504)the National Natural Science Foundation of China(42174152)+1 种基金the Strategic Cooperation Technology Projects of China National Petroleum Corporation(CNPC)and China University of Petroleum-Beijing(CUPB)(ZLZX2020-03)the R&D Department of China National Petroleum Corporation(2022DQ0604-01)。
文摘The picking efficiency of seismic first breaks(FBs)has been greatly accelerated by deep learning(DL)technology.However,the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-noise ratio(SNR)situations.To address this issue,we propose a regression approach to pick FBs based on bidirectional long short-term memory(Bi LSTM)neural network by learning the implicit Eikonal equation of 3D inhomogeneous media with rugged topography in the target region.We employ a regressive model that represents the relationships among the elevation of shots,offset and the elevation of receivers with their seismic traveltime to predict the unknown FBs,from common-shot gathers with sparsely distributed traces.Different from image segmentation methods which automatically extract image features and classify FBs from seismic data,the proposed method can learn the inner relationship between field geometry and FBs.In addition,the predicted results by the regressive model are continuous values of FBs rather than the discrete ones of the binary distribution.The picking results of synthetic data shows that the proposed method has low dependence on label data,and can obtain reliable and similar predicted results using two types of label data with large differences.The picking results of9380 shots for 3D seismic data generated by vibroseis indicate that the proposed method can still accurately predict FBs in low SNR data.The subsequent stacked profiles further illustrate the reliability and effectiveness of the proposed method.The results of model data and field seismic data demonstrate that the proposed regression method is a robust first-break picker with high potential for field application.
基金financially supported by the National Key R&D Program of China(2018YFA0702504)the Fundamental Research Funds for the Central Universities(2462019QNXZ03)+1 种基金the National Natural Science Foundation of China(42174152 and 41974140)the Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX 2020-03)。
文摘Manually picking regularly and densely distributed first breaks(FBs)are critical for shallow velocitymodel building in seismic data processing.However,it is time consuming.We employ the fullyconvolutional Seg Net to address this issue and present a fast automatic seismic waveform classification method to pick densely-sampled FBs directly from common-shot gathers with sparsely distributed traces.Through feeding a large number of representative shot gathers with missing traces and the corresponding binary labels segmented by manually interpreted fully-sampled FBs,we can obtain a welltrained Seg Net model.When any unseen gather including the one with irregular trace spacing is inputted,the Seg Net can output the probability distribution of different categories for waveform classification.Then FBs can be picked by locating the boundaries between one class on post-FBs data and the other on pre-FBs background.Two land datasets with each over 2000 shots are adopted to illustrate that one well-trained 25-layer Seg Net can favorably classify waveform and further pick fully-sampled FBs verified by the manually-derived ones,even when the proportion of randomly missing traces reaches50%,21 traces are missing consecutively,or traces are missing regularly.
文摘随着油气勘探程度的不断提高,已陆续发现一些以火山岩和火山碎屑岩为储集层的油气田。但是,由于火山岩对地震信号屏蔽作用明显,地震波在不同层系、不同类型火山岩中的速度差异大,导致火山岩发育区的速度建模和成像极其困难。EP地区处于阳江—一统断裂带,资源潜力大,且发育大量构造圈闭,同时,该地区发育古近系及上覆地层的多期火山岩,以往处理成果中火山岩内幕成像不清晰,难以刻画火山岩相和准确评估火山岩对油气生、储、盖条件的影响。为此,针对火山岩多次波压制、火山岩下弱信号恢复、火山岩速度精细刻画等方面的关键问题开展新的处理技术探索。首先采用MWD(Model based Water-layer related Demultiple)技术预测火山岩多次波;然后利用AVO剩余振幅补偿和低频算子外推随机噪声衰减技术提高火山岩下弱信号质量;最后,联合应用初至波层析和反射波网格层析技术构建精确的叠前深度偏移速度模型。重处理后的叠前深度偏移成果显示,火山岩及下伏地层成像质量显著提高,表明所提重处理技术方案对提高火山岩发育区地震成像质量有较好的借鉴意义。
