地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高...地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高斯模拟。在贝叶斯框架下,结合地震数据的约束,利用马尔科夫链-蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法对模拟结果进行随机扰动和全局寻优,获得优化的参数反演结果。模型测试结果表明,基于地震波形约束的初始模型较为精确地刻画了地下储层的空间结构。对其进行迭代优化可以加快马尔科夫链的收敛速度,有效提高反演结果的精度。本文将提出的地质统计学反演方法用于某油田实际地震数据,在随机模拟过程和目标函数的约束中,充分挖掘了地震波形蕴含的地质信息,并为实现多数据联合约束地震反演提供了理论依据。展开更多
The Yangtze River Delta characterized by a dense population and a rapidly developing economy is highly vulnerable to sea-level rise. The data from the China Oceanic Information Network and the Zhejiang Provincial Hydr...The Yangtze River Delta characterized by a dense population and a rapidly developing economy is highly vulnerable to sea-level rise. The data from the China Oceanic Information Network and the Zhejiang Provincial Hydrology Bureau are used to analyze sea-level rise. The rate of sea-level rise in the delta was 2.4 mm per year in 1981-2015. The annual sea-level at Daishan, Dinghai, and Dongtou stations in the south wing of the delta were 4.3, 3.1, and 5 mm per year respectively over the same period. The 10-year averaged results at each station also indicate a perceptible trend of sea-level rise. Sea-level rise is contributed to a larger proportion of intensified erosion, ranging from 3% to 14% in the delta. Meanwhile, the 100-year return period of tidal level has decreased to the 50-year rank at Dongtou and Dinghai stations. Moreover, the arrival time of tidal bores at Yanguan is 4 min earlier under sea-level rise of 0.145 m than that of 0 m. The height of tidal bores and the velocities at the surface and bottom layers have an increase under sea-level rise. The maximum increases of high and low tide levels are 0.122 m and 0.016 m while the maximum increases of the velocities at the surface and bottom layers are 0.07 m s^- 1 and 0.05 m s ^-1, respectively. Sea-level rise will bring about the damage of seawall, thus the design standard of constructing seawalls should adopt a higher level to minimize the associated risks in the Yangtze River Delta and its south wing.展开更多
In the conventional stochastic inversion method,the spatial structure information of underground strata is usually characterized by variograms.However,effectively characterizing the heterogeneity of complex strata is ...In the conventional stochastic inversion method,the spatial structure information of underground strata is usually characterized by variograms.However,effectively characterizing the heterogeneity of complex strata is difficult.In this paper,multiple parameters are used to fully explore the underground formation information in the known seismic reflection and well log data.The spatial structure characteristics of complex underground reservoirs are described more comprehensively using multiple statistical characteristic parameters.We propose a prestack seismic stochastic inversion method based on prior information on statistical characteristic parameters.According to the random medium theory,this method obtains several statistical characteristic parameters from known seismic and logging data,constructs a prior information model that meets the spatial structure characteristics of the underground strata,and integrates multiparameter constraints into the likelihood function to construct the objective function.The very fast quantum annealing algorithm is used to optimize and update the objective function to obtain the fi nal inversion result.The model test shows that compared with the traditional prior information model construction method,the prior information model based on multiple parameters in this paper contains more detailed stratigraphic information,which can better describe complex underground reservoirs.A real data analysis shows that the stochastic inversion method proposed in this paper can effectively predict the geophysical characteristics of complex underground reservoirs and has a high resolution.展开更多
The practical application of 3D inversion of gravity data requires a lot of computation time and storage space.To solve this problem,we present an integrated optimization algorithm with the following components:(1)tar...The practical application of 3D inversion of gravity data requires a lot of computation time and storage space.To solve this problem,we present an integrated optimization algorithm with the following components:(1)targeting high accuracy in the space domain and fast computation in the wavenumber domain,we design a fast 3D forward algorithm with high precision;and(2)taking advantage of the symmetry of the inversion matrix,the main calculation in gravity conjugate gradient inversion is decomposed into two forward calculations,thus optimizing the computational efficiency of 3D gravity inversion.We verify the calculation accuracy and efficiency of the optimization algorithm by testing various grid-number models through numerical simulation experiments.展开更多
Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for...Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.展开更多
基金supported by the National Natural Science Foundation of China[Grant Nos.42174146,42074136,42174144]Innovation Fund Project for Graduate Students of China University of Petroleum(East China)[Grant No.23CX04015A].
文摘地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高斯模拟。在贝叶斯框架下,结合地震数据的约束,利用马尔科夫链-蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法对模拟结果进行随机扰动和全局寻优,获得优化的参数反演结果。模型测试结果表明,基于地震波形约束的初始模型较为精确地刻画了地下储层的空间结构。对其进行迭代优化可以加快马尔科夫链的收敛速度,有效提高反演结果的精度。本文将提出的地质统计学反演方法用于某油田实际地震数据,在随机模拟过程和目标函数的约束中,充分挖掘了地震波形蕴含的地质信息,并为实现多数据联合约束地震反演提供了理论依据。
基金This work was supported by the projects of National Science Foundation of China （41706099, 51779228, 51379190, 41676085）, and the Science and Technology Plans of Zhejiang province （2015F50011, 2016F50017）. The authors acknowledged the anonymous reviewers＇ comments to improve this paper.
文摘The Yangtze River Delta characterized by a dense population and a rapidly developing economy is highly vulnerable to sea-level rise. The data from the China Oceanic Information Network and the Zhejiang Provincial Hydrology Bureau are used to analyze sea-level rise. The rate of sea-level rise in the delta was 2.4 mm per year in 1981-2015. The annual sea-level at Daishan, Dinghai, and Dongtou stations in the south wing of the delta were 4.3, 3.1, and 5 mm per year respectively over the same period. The 10-year averaged results at each station also indicate a perceptible trend of sea-level rise. Sea-level rise is contributed to a larger proportion of intensified erosion, ranging from 3% to 14% in the delta. Meanwhile, the 100-year return period of tidal level has decreased to the 50-year rank at Dongtou and Dinghai stations. Moreover, the arrival time of tidal bores at Yanguan is 4 min earlier under sea-level rise of 0.145 m than that of 0 m. The height of tidal bores and the velocities at the surface and bottom layers have an increase under sea-level rise. The maximum increases of high and low tide levels are 0.122 m and 0.016 m while the maximum increases of the velocities at the surface and bottom layers are 0.07 m s^- 1 and 0.05 m s ^-1, respectively. Sea-level rise will bring about the damage of seawall, thus the design standard of constructing seawalls should adopt a higher level to minimize the associated risks in the Yangtze River Delta and its south wing.
基金the National Science Foundation of China(No.42074136 and U19B2008)the Major National Science and Technology Projects(No.2016ZX05027004-001 and 2016ZX05002-005-009)+1 种基金the Fundamental Research Funds for the Central Universities(No.19CX02007A)China Postdoctoral Science Foundation(No.2020M672170).
文摘In the conventional stochastic inversion method,the spatial structure information of underground strata is usually characterized by variograms.However,effectively characterizing the heterogeneity of complex strata is difficult.In this paper,multiple parameters are used to fully explore the underground formation information in the known seismic reflection and well log data.The spatial structure characteristics of complex underground reservoirs are described more comprehensively using multiple statistical characteristic parameters.We propose a prestack seismic stochastic inversion method based on prior information on statistical characteristic parameters.According to the random medium theory,this method obtains several statistical characteristic parameters from known seismic and logging data,constructs a prior information model that meets the spatial structure characteristics of the underground strata,and integrates multiparameter constraints into the likelihood function to construct the objective function.The very fast quantum annealing algorithm is used to optimize and update the objective function to obtain the fi nal inversion result.The model test shows that compared with the traditional prior information model construction method,the prior information model based on multiple parameters in this paper contains more detailed stratigraphic information,which can better describe complex underground reservoirs.A real data analysis shows that the stochastic inversion method proposed in this paper can effectively predict the geophysical characteristics of complex underground reservoirs and has a high resolution.
基金Financial support by the China Geological Survey Project(Nos.DD20190030,DD20190032)
文摘The practical application of 3D inversion of gravity data requires a lot of computation time and storage space.To solve this problem,we present an integrated optimization algorithm with the following components:(1)targeting high accuracy in the space domain and fast computation in the wavenumber domain,we design a fast 3D forward algorithm with high precision;and(2)taking advantage of the symmetry of the inversion matrix,the main calculation in gravity conjugate gradient inversion is decomposed into two forward calculations,thus optimizing the computational efficiency of 3D gravity inversion.We verify the calculation accuracy and efficiency of the optimization algorithm by testing various grid-number models through numerical simulation experiments.
基金the National Natural Science Foundation of China(Nos.42074136,41674130)National Key S&T Special Project of China(No.2016ZX05027-004-001)the Fundamental Research Funds for the Central University(No.18CX02061A).
文摘Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.
