M. Serna, G. A. Espinosa, A. Montoya, Hernán Darío Álvarez Zapata
This paper presents the results about using a methodology that combines two artificial intelligence (AI) models to predict the oil, water and gas production in a Colombian petroleum field. By combining fuzzy logic (FL) and artificial neural networks (ANN) a novelty data mining procedure is implemented, including a data imputation strategy. The FL tool determines the most useful variables or parameters to include into each well production model. ANN and FIS (fuzzy inference systems) predictive models identification is developed after the data mining process. The FIS models are capable to predict specific behaviors, while ANN models are able to forecast an average behavior. The combined use of both tools under few iterative steps, allows to improve forecasting of well behavior until reach a specified accuracy level. The proposed data imputation procedure is the key element to correct false or to complete void positions into operation data used to identify models for a typical oil production field. At the end, two models are obtained for each well product, conforming an interesting tool given the best accurate prediction of fluid phase production.
{"title":"Combined artificial intelligence modeling for production forecast in a petroleum production field","authors":"M. Serna, G. A. Espinosa, A. Montoya, Hernán Darío Álvarez Zapata","doi":"10.29047/01225383.149","DOIUrl":"https://doi.org/10.29047/01225383.149","url":null,"abstract":"This paper presents the results about using a methodology that combines two artificial intelligence (AI) models to predict the oil, water and gas production in a Colombian petroleum field. By combining fuzzy logic (FL) and artificial neural networks (ANN) a novelty data mining procedure is implemented, including a data imputation strategy. The FL tool determines the most useful variables or parameters to include into each well production model. ANN and FIS (fuzzy inference systems) predictive models identification is developed after the data mining process. The FIS models are capable to predict specific behaviors, while ANN models are able to forecast an average behavior. The combined use of both tools under few iterative steps, allows to improve forecasting of well behavior until reach a specified accuracy level. The proposed data imputation procedure is the key element to correct false or to complete void positions into operation data used to identify models for a typical oil production field. At the end, two models are obtained for each well product, conforming an interesting tool given the best accurate prediction of fluid phase production.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79639415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diego L. Gil- Agudelo, Diana Ibarra- Mojica, Ana María Guevara- Vargas, Ramón Nieto- Bernal, Marlon Serrano- Gómez, Erich R. Gundlach, Darío Miranda- Rodríguez
The Environmental Sensitivity Index (ESI) mapping has been used globally for oil spill planning and response purposes in coastal areas since its development in the 1970s. However, application to riverine habitats has been very limited. Following US National Oceanic and Atmospheric Administration (NOAA) formats and adapting them in working sessions held by a multidisciplinary team and in special sessions with experts and consultants in Colombia, this paper describes the development and application of the sensitivity index to develop maps for the conditions of the middle Magdalena River in Colombia. The index developed (ESI-R) is useful for application on other major rivers in Colombia and areas with similar characteristics. The use of the index to develop maps for smaller rivers and streams is likely to require further development.
{"title":"Environmental sensitivity index for oil spills in colombian rivers (ESI-R): Application for the Magdalena river","authors":"Diego L. Gil- Agudelo, Diana Ibarra- Mojica, Ana María Guevara- Vargas, Ramón Nieto- Bernal, Marlon Serrano- Gómez, Erich R. Gundlach, Darío Miranda- Rodríguez","doi":"10.29047/01225383.158","DOIUrl":"https://doi.org/10.29047/01225383.158","url":null,"abstract":"The Environmental Sensitivity Index (ESI) mapping has been used globally for oil spill planning and response purposes in coastal areas since its development in the 1970s. However, application to riverine habitats has been very limited. Following US National Oceanic and Atmospheric Administration (NOAA) formats and adapting them in working sessions held by a multidisciplinary team and in special sessions with experts and consultants in Colombia, this paper describes the development and application of the sensitivity index to develop maps for the conditions of the middle Magdalena River in Colombia. The index developed (ESI-R) is useful for application on other major rivers in Colombia and areas with similar characteristics. The use of the index to develop maps for smaller rivers and streams is likely to require further development.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88544607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main challenge to predict at Field scale the performance of an air injection process is to understand the oil oxidation process and to have a kinetic model of reactions enabling the prediction of process behavior in a reservoir numerical simulator, under different operating conditions. Recently, the Isoconversional Principle has been implemented for studying the kinetics of reactions associated with oil oxidation during air injection, based on Ramped Temperature Oxidation tests (RTO). In different published papers, the isoconversional analysis has been used to study the oxidation characteristics of different rock-fluid systems, identify groups of dominant reactions during the crude oil oxidation process, and estimate the effective activation energy for each of the identified reactions. However, in none of them has a procedure been established for estimating the pre-exponential factor, as this is not a direct measure of isoconversional methods. In this article, a mathematical procedure is proposed for estimating the pre-exponential factor based on the application of Friedman's isoconversional method, inteded for characterizing the kinetics of the reactions associated with the In Situ Combustion process. This procedure was validated with experimental information and a kinetic model proposed in the literature to model the oxidation behavior of heavy crude.
{"title":"Methodology for calculating the pre-exponential factor using the isoconversional principle for the numerical simulation of the air injection process","authors":"Padilla-Reyes Jorge-Mario, Trujillo-Portillo Marta-Liliana, Niz-Velasquez Eider","doi":"10.29047/01225383.151","DOIUrl":"https://doi.org/10.29047/01225383.151","url":null,"abstract":"The main challenge to predict at Field scale the performance of an air injection process is to understand the oil oxidation process and to have a kinetic model of reactions enabling the prediction of process behavior in a reservoir numerical simulator, under different operating conditions. Recently, the Isoconversional Principle has been implemented for studying the kinetics of reactions associated with oil oxidation during air injection, based on Ramped Temperature Oxidation tests (RTO). In different published papers, the isoconversional analysis has been used to study the oxidation characteristics of different rock-fluid systems, identify groups of dominant reactions during the crude oil oxidation process, and estimate the effective activation energy for each of the identified reactions. \u0000 However, in none of them has a procedure been established for estimating the pre-exponential factor, as this is not a direct measure of isoconversional methods. In this article, a mathematical procedure is proposed for estimating the pre-exponential factor based on the application of Friedman's isoconversional method, inteded for characterizing the kinetics of the reactions associated with the In Situ Combustion process. This procedure was validated with experimental information and a kinetic model proposed in the literature to model the oxidation behavior of heavy crude.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90776321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The propagation of seismic waves is affected by the type of transmission media. Therefore, it is necessary to solve a differential equation system in partial derivatives allowing for identification of waves propagating into an elastic media. This paper summarizes a research using a partial differential equation system representing the wave equation using the finite differences method to obtain the elastic media response, using an staggered grid. To prevent reflections in the computational regions, absorbent boundaries were used with the PML method. The implementation of the numerical scheme was made on two computational architectures (CPU and GPU) that share the same type of memory distribution. Finally, different code versions were created to take advantage of the architecture in the GPU memory, performing a detailed analysis of variables such as usage of bandwidth of the GPU internal memory, added to a version that is not limited by the internal memory in the graphic processing unit, but rather by the memory of the whole computational system.
{"title":"Solution of a P and S wave propagation model using high performance computation","authors":"J. Amado, C. Piedrahita, C. Vera-Ciro, C. Parra","doi":"10.29047/01225383.159","DOIUrl":"https://doi.org/10.29047/01225383.159","url":null,"abstract":"The propagation of seismic waves is affected by the type of transmission media. Therefore, it is necessary to solve a differential equation system in partial derivatives allowing for identification of waves propagating into an elastic media. This paper summarizes a research using a partial differential equation system representing the wave equation using the finite differences method to obtain the elastic media response, using an staggered grid. To prevent reflections in the computational regions, absorbent boundaries were used with the PML method. The implementation of the numerical scheme was made on two computational architectures (CPU and GPU) that share the same type of memory distribution. Finally, different code versions were created to take advantage of the architecture in the GPU memory, performing a detailed analysis of variables such as usage of bandwidth of the GPU internal memory, added to a version that is not limited by the internal memory in the graphic processing unit, but rather by the memory of the whole computational system.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77806132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gladys-Cristina Pinto-Santamaría, C. Ríos-Reyes, L. Vargas-Fiallo
Oil spills have been one of the greatest environmental problems worldwide. The contamination of soils due to oil spills generates an oil migration down the soil until reaching groundwater. The research focused on remediation of oil-contaminated soils by Ecuadorian natural and acid-surfactant modified zeolites of the Cayo Formation. The natural and modified zeolites were characterized by wavelength dispersive X-ray fluorescence, X-ray powder diffraction, environmental scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and solid-state magic-angle spinning nuclear magnetic resonance spectroscopy. The natural and modified zeolites were added to an artificially oil-contaminated soil to immobilize and limit the uptake of contaminants by rape through changing soil physical and chemical properties in the pot experiment under greenhouse conditions. Several oil contaminated soil-zeolite mixes were tested in replicated laboratory analyses in terms of their ability to absorb oil. Results indicated that the addition of natural and modified zeolites could increase or decrease soil pH and absorption capacity, with high potential in removing oil from soil. Statistical analysis of the experimental data was performed by the variance test analysis. The absorption process had an efficiency of 46% under well-optimized experimental conditions, with an absorbent dose of 30-M, pH = 3.8 and 15 days of contact time.
石油泄漏一直是世界范围内最大的环境问题之一。石油泄漏对土壤的污染使石油沿土壤向下运移，直至到达地下水。研究了厄瓜多尔天然和酸性表面活性剂改性Cayo组沸石对石油污染土壤的修复作用。采用波长色散x射线荧光、x射线粉末衍射、环境扫描电镜、衰减全反射傅立叶变换红外光谱和固态魔角自旋核磁共振光谱对天然分子筛和改性分子筛进行了表征。在温室盆栽条件下，将天然沸石和改性沸石添加到人工油污染土壤中，通过改变土壤理化性质来固定和限制油菜对污染物的吸收。在重复的实验室分析中测试了几种受石油污染的土壤-沸石混合物的吸油能力。结果表明，天然沸石和改性沸石的加入均能提高或降低土壤的pH值和吸附能力，具有较高的脱油潜力。实验数据采用方差检验分析进行统计分析。在最佳条件下，吸收率为46%，吸收剂剂量为30 m, pH = 3.8，接触时间为15 d。
{"title":"Use of Ecuadorian natural and acid-surfactant modified zeolites for remediation of oil- contaminated soils","authors":"Gladys-Cristina Pinto-Santamaría, C. Ríos-Reyes, L. Vargas-Fiallo","doi":"10.29047/01225383.155","DOIUrl":"https://doi.org/10.29047/01225383.155","url":null,"abstract":"Oil spills have been one of the greatest environmental problems worldwide. The contamination of soils due to oil spills generates an oil migration down the soil until reaching groundwater. The research focused on remediation of oil-contaminated soils by Ecuadorian natural and acid-surfactant modified zeolites of the Cayo Formation. The natural and modified zeolites were characterized by wavelength dispersive X-ray fluorescence, X-ray powder diffraction, environmental scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and solid-state magic-angle spinning nuclear magnetic resonance spectroscopy. The natural and modified zeolites were added to an artificially oil-contaminated soil to immobilize and limit the uptake of contaminants by rape through changing soil physical and chemical properties in the pot experiment under greenhouse conditions. Several oil contaminated soil-zeolite mixes were tested in replicated laboratory analyses in terms of their ability to absorb oil. Results indicated that the addition of natural and modified zeolites could increase or decrease soil pH and absorption capacity, with high potential in removing oil from soil. Statistical analysis of the experimental data was performed by the variance test analysis. The absorption process had an efficiency of 46% under well-optimized experimental conditions, with an absorbent dose of 30-M, pH = 3.8 and 15 days of contact time.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77338172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rómulo Sandoval-Flórez, J. Paredes, F. Vivas, F. Cabrera
An implementation of the Orthogonal Matching Pursuit (OMP) algorithm was used and the results obtained therefrom are presented for simultaneous interpolation and denoising from seismic signals in the framework of sparse signal representation. OMP is an algorithm for sparse signal representation based on orthogonal projections underlying the signal over an over-complete dictionary. This over-complete dictionary was designed using K-times Singular Values Decomposition (K-SVD). In each iteration, OMP calculates a new signal approximation and the approximation error is used in the next iteration to determine the new element. The new element corresponds to the largest magnitude of the inner products between the current residual and the original elements in the dictionary. The implemented algorithm was applied to VSP seismic data and refraction seismic data; results for the application in restored missing traces and denoise signals are presented.
{"title":"Interpolation and denoising of seismic signals using orthogonal matching pursuit algorithm: An aplication in VSP and refraction data","authors":"Rómulo Sandoval-Flórez, J. Paredes, F. Vivas, F. Cabrera","doi":"10.29047/01225383.81","DOIUrl":"https://doi.org/10.29047/01225383.81","url":null,"abstract":"An implementation of the Orthogonal Matching Pursuit (OMP) algorithm was used and the results obtained therefrom are presented for simultaneous interpolation and denoising from seismic signals in the framework of sparse signal representation. OMP is an algorithm for sparse signal representation based on orthogonal projections underlying the signal over an over-complete dictionary. This over-complete dictionary was designed using K-times Singular Values Decomposition (K-SVD). In each iteration, OMP calculates a new signal approximation and the approximation error is used in the next iteration to determine the new element. The new element corresponds to the largest magnitude of the inner products between the current residual and the original elements in the dictionary. The implemented algorithm was applied to VSP seismic data and refraction seismic data; results for the application in restored missing traces and denoise signals are presented.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90161685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The removal and use of multiples have a single shared goal and objective: the imaging and inversion of primaries. There are two kinds of primaries: recorded primaries and unrecorded primaries. For imaging recorded primaries using an industry standard practice smooth velocity model, recorded multiples must be removed, to avoid false and misleading images due to the multiples. Similarly, to find an approximate image of an unrecorded primary, that is a subevent of a recorded multiple, unrecorded multiples that are subevents of the recorded multiple must be removed, for exactly the same problem and reason that recorded multiples are needed to be eliminated. Direct inverse methods are employed to derive this new comprehensive perspective on primaries and multiples. Direct inverse methods not only assure that the problem of interest is solved, but equally important, that the problem of interest is the relevant problem that we (the petroleum industry) need to be interested in.
{"title":"Direct and indirect inversion and a new and comprehensive perspective on the role of primaries and multiples in seismic data processing for structure determination and amplitude analysis","authors":"A. Weglein","doi":"10.29047/01225383.87","DOIUrl":"https://doi.org/10.29047/01225383.87","url":null,"abstract":"The removal and use of multiples have a single shared goal and objective: the imaging and inversion of primaries. There are two kinds of primaries: recorded primaries and unrecorded primaries. For imaging recorded primaries using an industry standard practice smooth velocity model, recorded multiples must be removed, to avoid false and misleading images due to the multiples. Similarly, to find an approximate image of an unrecorded primary, that is a subevent of a recorded multiple, unrecorded multiples that are subevents of the recorded multiple must be removed, for exactly the same problem and reason that recorded multiples are needed to be eliminated. Direct inverse methods are employed to derive this new comprehensive perspective on primaries and multiples. Direct inverse methods not only assure that the problem of interest is solved, but equally important, that the problem of interest is the relevant problem that we (the petroleum industry) need to be interested in.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81438834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Full Waveform Inversion (FWI) is a common technique used in the oil and gas industry due to its capabilities to estimate subsurface characteristics such as material’s density and sound velocity with high resolution. The 2D time domain FWI method involves the modeling of the forward wavefield of the source and the backpropagated field of the difference between the modeled and observed data. Therefore, due to its high computational cost in terms of RAM consumption and execution time, the High Performance Computing (HPC) field is very useful to deal with these problems. There are computational state-of-the-art solutions that allow to increase the execution time such as the parallel programming paradigm that involves the use of multicore processor systems. Furthermore, there are mathematical solutions leveraging on the properties of the algorithm used that make it possible to enhance performance of the method. We propose in this paper a new way to compute the FWI gradient, by taking advantage of an inner product property. Additionally, a computational strategy is combined with this proposal in the inversion scheme, thus improving FWI performance.
{"title":"Accelerated 2D FWI using the symmetry on inner product spaces","authors":"Reynaldo F. Noriega, S. Abreo, A.B. Ramirez","doi":"10.29047/01225383.85","DOIUrl":"https://doi.org/10.29047/01225383.85","url":null,"abstract":"Full Waveform Inversion (FWI) is a common technique used in the oil and gas industry due to its capabilities to estimate subsurface characteristics such as material’s density and sound velocity with high resolution. The 2D time domain FWI method involves the modeling of the forward wavefield of the source and the backpropagated field of the difference between the modeled and observed data. Therefore, due to its high computational cost in terms of RAM consumption and execution time, the High Performance Computing (HPC) field is very useful to deal with these problems. There are computational state-of-the-art solutions that allow to increase the execution time such as the parallel programming paradigm that involves the use of multicore processor systems. Furthermore, there are mathematical solutions leveraging on the properties of the algorithm used that make it possible to enhance performance of the method. We propose in this paper a new way to compute the FWI gradient, by taking advantage of an inner product property. Additionally, a computational strategy is combined with this proposal in the inversion scheme, thus improving FWI performance.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87833649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William Salamanca, Ana Beatríz Ramírez Silva, F. Vivas
Reverse-Time Migration (RTM) is a two-way wave-equation based method used to generate images of the Earth’s subsurface. RTM has been successfully used in seismic imaging as it allows defining complex structural areas. However, RTM is a highly computational expensive algorithm that requires the computation of both the source and the receiver wavefields for each shot. Fortunately, numerical methods that compute the wave propagation using the wave equation are highly parallelizable, so they can take leverage on GPU features. However, the main problem of a GPU-RTM implementation is memory management. To take advantage of the GPU computing capabilities, the transfers to host RAM memory storage, or more expensive hard disk storage must be avoided. We present the analysis of three different strategies to implement RTM using only the memory available on a single GPU: (1) Stored wavefield checkpointing (2) Backpropagation of source wavefield using stored boundaries, and (3) Backpropagation of source wavefield using the two last snapshots and random boundaries, showing that the large amount of memory required in the first two strategies becomes a restriction over the model size. The last method (using random boundary conditions) is shown as a suggested solution to the memory problem of using a single GPU.
{"title":"Comparative analysis of 3D RTM Implementation Strategies for an Efficient Use of Memory in a Single GPU:","authors":"William Salamanca, Ana Beatríz Ramírez Silva, F. Vivas","doi":"10.29047/01225383.83","DOIUrl":"https://doi.org/10.29047/01225383.83","url":null,"abstract":"Reverse-Time Migration (RTM) is a two-way wave-equation based method used to generate images of the Earth’s subsurface. RTM has been successfully used in seismic imaging as it allows defining complex structural areas. However, RTM is a highly computational expensive algorithm that requires the computation of both the source and the receiver wavefields for each shot. Fortunately, numerical methods that compute the wave propagation using the wave equation are highly parallelizable, so they can take leverage on GPU features. However, the main problem of a GPU-RTM implementation is memory management. To take advantage of the GPU computing capabilities, the transfers to host RAM memory storage, or more expensive hard disk storage must be avoided. We present the analysis of three different strategies to implement RTM using only the memory available on a single GPU: (1) Stored wavefield checkpointing (2) Backpropagation of source wavefield using stored boundaries, and (3) Backpropagation of source wavefield using the two last snapshots and random boundaries, showing that the large amount of memory required in the first two strategies becomes a restriction over the model size. The last method (using random boundary conditions) is shown as a suggested solution to the memory problem of using a single GPU.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75647471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low-frequency artifacts in reverse time migration result from unwanted cross-correlation of the source and receiver wavefields at non-reflecting points along ray-paths. These artifacts can hide important details in migrated models and increase poor interpretation risk. Some methods have been proposed to avoid or reduce the number of these artifacts, preserving reflections, and improving model quality, implementing other strategies such as modification of the wave equation, proposing other imaging conditions, and using image filtering techniques. One of these methods uses wavefield decomposition, correlating components of the wavefields that propagate in opposite directions. We propose a method for extracting directional information from the RTM imaging condition wavefields to obtain characteristics allowing for better, more refined imaging. The method works by separating directional information about the wavefields based on the continuous wavelet transform (CWT), and the analysis of the main changes on the frequency content revealed within the scalogram obtained by a Gaussian wavelet family. Through numerical applications, we demonstrate that this method can effectively remove undesired artifacts in migrated images. In addition, we use the Laguerre-Gauss filtering to improve the results obtained with the proposed method.
{"title":"Application of the continuous wavelet transform in the extraction of directional data on RTM imaging condition wavefields","authors":"Juan Guillermo Paniagua Castrillón, O. Montoya","doi":"10.29047/01225383.82","DOIUrl":"https://doi.org/10.29047/01225383.82","url":null,"abstract":"Low-frequency artifacts in reverse time migration result from unwanted cross-correlation of the source and receiver wavefields at non-reflecting points along ray-paths. These artifacts can hide important details in migrated models and increase poor interpretation risk. \u0000Some methods have been proposed to avoid or reduce the number of these artifacts, preserving reflections, and improving model quality, implementing other strategies such as modification of the wave equation, proposing other imaging conditions, and using image filtering techniques. One of these methods uses wavefield decomposition, correlating components of the wavefields that propagate in opposite directions. \u0000We propose a method for extracting directional information from the RTM imaging condition wavefields to obtain characteristics allowing for better, more refined imaging. The method works by separating directional information about the wavefields based on the continuous wavelet transform (CWT), and the analysis of the main changes on the frequency content revealed within the scalogram obtained by a Gaussian wavelet family. \u0000Through numerical applications, we demonstrate that this method can effectively remove undesired artifacts in migrated images. In addition, we use the Laguerre-Gauss filtering to improve the results obtained with the proposed method.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76332268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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