Full waveform inversion(FWI)is an extremely important velocity-model-building method.However,it involves a large amount of calculation,which hindsers its practical application.The multi-source technology can reduce th...Full waveform inversion(FWI)is an extremely important velocity-model-building method.However,it involves a large amount of calculation,which hindsers its practical application.The multi-source technology can reduce the number of forward modeling shots during the inversion process,thereby improving the efficiency.However,it introduces crossnoise problems.In this paper,we propose a sparse constrained encoding multi-source FWI method based on K-SVD dictionary learning.The phase encoding technology is introduced to reduce crosstalk noise,whereas the K-SVD dictionary learning method is used to obtain the basis of the transformation according to the characteristics of the inversion results.The multiscale inversion method is adopted to further enhance the stability of FWI.Finally,the synthetic subsag model and the Marmousi model are set to test the effectiveness of the newly proposed method.Analysis of the results suggest the following:(1)The new method can effectively reduce the computational complexity of FWI while ensuring inversion accuracy and stability;(2)The proposed method can be combined with the time-domain multi-scale FWI strategy flexibly to further avoid the local minimum and to improve the stability of inversion,which is of significant importance for the inversion of the complex model.展开更多
In conventional marine seismic exploration data processing,the sea surface is usually treated as a horizontal free boundary.However,the sea surface is affected by wind and waves and there often exists dynamic small-ra...In conventional marine seismic exploration data processing,the sea surface is usually treated as a horizontal free boundary.However,the sea surface is affected by wind and waves and there often exists dynamic small-range fluctuations.These dynamic fluctuations will change the energy propagation path and affect the final imaging results.In theoretical research,different sea surface conditions need to be described,so it is necessary to study the modeling method of dynamic undulating sea surface.Starting from the commonly used sea surface mathematical simulation methods,this paper mainly studies the realization process of simple harmonic wave and Gerstner wave sea surface simulation methods based on ocean wave spectrum,and compares their advantages and disadvantages.Aiming at the shortcomings of the simple harmonic method and Gerstner method in calculational speed and sea surface simulation effect,a method based on wave equation and using dynamic boundary conditions for sea surface simulation is proposed.The calculational speed of this method is much faster than the commonly used simple harmonic method and Gerstner wave method.In addition,this paper also compares the new method with the more commonly used higher-order spectral methods to show the characteristics of the improved wave equation method.展开更多
Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results ...Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results for seismic inversion of heavy oil reservoir. To describe the viscoelastic behavior of heavy oil, we modeled the elastic properties of heavy oil with varying viscosity and frequency using the Cole-Cole-Maxwell (CCM) model. Then, we used a CCoherent Potential Approximation (CPA) instead of the Gassmann equations to account for the fluid effect, by extending the single-phase fluid condition to two-phase fluid (heavy oil and water) condition, so that partial saturation of heavy oil can be considered. This rock physics model establishes the relationship between the elastic modulus of reservoir rock and viscosity, frequency and saturation. The viscosity of the heavy oil and the elastic moduli and porosity of typical reservoir rock samples were measured in laboratory, which were used for calibration of the rock physics model. The well-calibrated frequency-variant CPA model was applied to the prediction of the P- and S-wave velocities in the seismic frequency range (1–100 Hz) and the inversion of petrophysical parameters for a heavy oil reservoir. The pre-stack inversion results of elastic parameters are improved compared with those results using the CPA model in the sonic logging frequency (∼10 kHz), or conventional rock physics model such as the Xu-Payne model. In addition, the inversion of the porosity of the reservoir was conducted with the simulated annealing method, and the result fits reasonably well with the logging curve and depicts the location of the heavy oil reservoir on the time slice. The application of the laboratory-calibrated CPA model provides better results with the velocity dispersion correction, suggesting the important role of accurate frequency dependent rock physics models in the seismic prediction of heavy oil reservoirs.展开更多
The Gaussian beam migration(GBM) is a steady imaging approach, which has high accuracy and efficiency. Its implementation mainly includes the traditional frequency domain and the recent popular space-time domain. Firs...The Gaussian beam migration(GBM) is a steady imaging approach, which has high accuracy and efficiency. Its implementation mainly includes the traditional frequency domain and the recent popular space-time domain. Firstly, we use the upward ray tracing strategy to get the backward wavefields. Then,we use the dominant frequency of the seismic data to simplify the imaginary traveltime calculation of the wavefields, which can cut down the Fourier transform number compared with the traditional GBM in the space-time domain. In addition, we choose an optimized parameter for the take-off angle increment of the up-going and down-going rays. These optimizations help us get an efficient space-time-domain acoustic GBM approach. Typical four examples show that the proposed method can significantly improve the computational efficiency up to one or even two orders of magnitude in different models with different model parameters and produce good imaging results with comparable accuracy and resolution with the traditional GBM in the space-time domain.展开更多
The Qiongdongnan Basin and Zhujiang River（Pearl River） Mouth Basin, important petroliferous basins in the northern South China Sea, contain abundant oil and gas resource. In this study, on basis of discussing impact...The Qiongdongnan Basin and Zhujiang River（Pearl River） Mouth Basin, important petroliferous basins in the northern South China Sea, contain abundant oil and gas resource. In this study, on basis of discussing impact of oil-base mud on TOC content and Rock-Eval parameters of cutting shale samples, the authors did comprehensive analysis of source rock quality, thermal evolution and control effect of source rock in gas accumulation of the Qiongdongnan and the Zhujiang River Mouth Basins. The contrast analysis of TOC contents and Rock-Eval parameters before and after extraction for cutting shale samples indicates that except for a weaker impact on Rock-Eval parameter S2, oil-base mud has certain impact on Rock-Eval S1, Tmax and TOC contents. When concerning oil-base mud influence on source rock geochemistry parameters, the shales in the Yacheng/Enping,Lingshui/Zhuhai and Sanya/Zhuhai Formations have mainly Type Ⅱ and Ⅲ organic matter with better gas potential and oil potential. The thermal evolution analysis suggests that the depth interval of the oil window is between 3 000 m and 5 000 m. Source rocks in the deepwater area have generated abundant gas mainly due to the late stage of the oil window and the high-supper mature stage. Gas reservoir formation condition analysis made clear that the source rock is the primary factor and fault is a necessary condition for gas accumulation. Spatial coupling of source, fault and reservoir is essential for gas accumulation and the inside of hydrocarbon-generating sag is future potential gas exploration area.展开更多
The anisotropic properties of subsurface media cause waveform distortions in seismic wave propagation,resulting in a negative infl uence on seismic imaging.In addition,wavefields simulated by the conventional coupled ...The anisotropic properties of subsurface media cause waveform distortions in seismic wave propagation,resulting in a negative infl uence on seismic imaging.In addition,wavefields simulated by the conventional coupled pseudo-acoustic equation are not only aff ected by SV-wave artifacts but are also limited by anisotropic parameters.We propose a least-squares reverse time migration(LSRTM)method based on the pure q P-wave equation in vertically transverse isotropic media.A fi nite diff erence and fast Fourier transform method,which can improve the effi ciency of the numerical simulation compared to a pseudo-spectral method,is used to solve the pure q P-wave equation.We derive the corresponding demigration operator,migration operator,and gradient updating formula to implement the LSRTM.Numerical tests on the Hess model and field data confirm that the proposed method has a good correction eff ect for the travel time deviation caused by underground anisotropic media.Further,it signifi cantly suppresses the migration noise,balances the imaging amplitude,and improves the imaging resolution.展开更多
In these years,the Upper Jurassic andesitic volcanic reservoirs in Erlian basin,the Lower Cretaceous rhyolitic volcanic reservoirs in Songliao Basin,the Cretaceous rhyolitic,and the Paleogene basaltic and trachytic vo...In these years,the Upper Jurassic andesitic volcanic reservoirs in Erlian basin,the Lower Cretaceous rhyolitic volcanic reservoirs in Songliao Basin,the Cretaceous rhyolitic,and the Paleogene basaltic and trachytic volcanic reservoirs in Bohai Bay Basin,and the basaltic volcanic reservoirs in Subei basin were discovered.With more and more volcanic oil and gas fields being discovered and developed,the volcanic rocks demonstrate a great petroleum potential in eastern basins of China.Five volcanic facies were identified in these basins,including volcanic conduit facies.展开更多
Oil and gas exploration in most areas and major horizons of Songliao Basin have reached a stage of high maturity.Presently,there are few structural trap reservoirs remaining to be drilled in the basin,and major targets
Strong fluctuation of seabed,abrupt variation in depth and dip of seabed bring seismic imaging problems,such as irregular reflection waves,obvious multiple waves,serious lateral wave development,poor imaging on base s...Strong fluctuation of seabed,abrupt variation in depth and dip of seabed bring seismic imaging problems,such as irregular reflection waves,obvious multiple waves,serious lateral wave development,poor imaging on base surface and depression structure,low signal-to-noise ratio of middle and deep layers.In this paper,Gaussian beam migration imaging method is used to analyze the imaging effect of rugged seabed in deep water area,and the ray tracing method of wavefront construction method is used to analyze the kinematic characteristics of seismic waves.By improving the design of seismic data acquisition and observation system,imaging quality of fine structures is improved.展开更多
Compared with conventional seismic data, OVT domain gathers can better analyze the change information of seismic wave propagation in anisotropic media. The five-dimensional interpretation software innovatively puts fo...Compared with conventional seismic data, OVT domain gathers can better analyze the change information of seismic wave propagation in anisotropic media. The five-dimensional interpretation software innovatively puts forward the characteristic technologies such as fracture 3D visual display, azimuth AVO analysis and azimuth oil and gas prediction. Through the research of azimuth anisotropy attribute analysis technology of OVT data and combined with specific technical application, it effectively transforms the actual production capacity of reservoir description technology of wide azimuth seismic data, so as to improve the actual production capacity of small and medium-sized faults in shale, buried hill and other reservoirs micro amplitude structure and high angle fracture detection and description ability, give play to the effectiveness of wide-range seismic data, serve efficient exploration and development, and provide new technical support.展开更多
Buried hill is an important exploration field in Dawangzhuang block. Because Dawangzhuang buried hill has experienced multi-stage tectonic movement, the complexity of tectonic movement determines the diversity of buri...Buried hill is an important exploration field in Dawangzhuang block. Because Dawangzhuang buried hill has experienced multi-stage tectonic movement, the complexity of tectonic movement determines the diversity of buried hill morphology, and the diversity of buried hill structural morphology determines its reservoir forming characteristics. Therefore, the research on the structural style and reservoir forming characteristics of Dawangzhuang buried hill is of great significance in the process of oil and gas exploration at this stage. This paper summarizes the structural style of Dawangzhuang buried hill. On this basis, 67 small fault blocks divided in the study area are classified and counted. Further, according to the seismic profile and logging data, the well data and reservoir profile of characteristic wells are counted and compared, and the reservoir forming characteristics and main controlling factors of Dawangzhuang buried hill are found. The above understanding has certain guiding significance for the further exploration of Dawangzhuang buried hill.展开更多
Under the condition of conventional seismic data, because the thickness of the whole stratum of the second member of Shahejie Formation in the south is reduced, it is wedge-shaped in the south, and the shielding effec...Under the condition of conventional seismic data, because the thickness of the whole stratum of the second member of Shahejie Formation in the south is reduced, it is wedge-shaped in the south, and the shielding effect of the interface between the overlying sand and the bottom layer or the weak seismic reflection signal, it is difficult to identify the overbreak line, which seriously affects the exploration and development of the second member of Shahejie Formation. Based on this, on the basis of target processing of seismic data and cross-well correlation of logging sequences, and combining with seismic structural attributes, the location of stratigraphic superstripping lines is preliminarily determined, and then the accurate location of stratigraphic superstripping lines is finely determined by using the included angle extrapolation technique and seismic stratigraphic method for interactive verification.展开更多
Shallow Guantao Group channel sand body oil and gas reservoir is an important part of Shengli Oilfields oil and gas reserves upgrading, and also an important practical position to increase oil reserves and production ...Shallow Guantao Group channel sand body oil and gas reservoir is an important part of Shengli Oilfields oil and gas reserves upgrading, and also an important practical position to increase oil reserves and production for a period of time. For the evaluation of Guantao Group channel sand body type oil and gas reservoirs, accurate description of oil and gas traps is the key. However, affected by the quality of seismic data, the accuracy of structural interpretation of Guantao Group has always been low, especially the large error of the fault system combination of low order faults, which directly led to the deviation of the subsequent comprehensive evaluation of oil reservoirs and target selection. Therefore, it is urgent to summarize and improve a set of targeted structural interpretation scheme of Guantao Group, and realize the oil and gas evaluation of target reservoirs under the guidance of the accurate interpretation mode, so as to improve the quality of exploration and development. Based on this, this paper takes the Guantao Group in Chengdong area of Zhanhua sag in Jiyang sag as an example, aiming at the difficulties of structural interpretation in this area, with the help of Bonan-2021 full node high-density 3D seismic data, effectively uses high-precision coherence, dip angle, ant body, fault coherence enhancement and other technologies, and finely implements the structural pattern of Guantao Group in Chengdong area through hierarchical control mode, so as to provide detailed basic seismic data for the subsequent fine evaluation of oil and gas reservoirs in this area.展开更多
Based on comprehensive analyses of seismic and tog data, this study indicates that mainty four widespread angutar to minor angutar unconformities （Tg8, Tg51, Tg5 and Tg3） were formed during the Pateozoic. Through th...Based on comprehensive analyses of seismic and tog data, this study indicates that mainty four widespread angutar to minor angutar unconformities （Tg8, Tg51, Tg5 and Tg3） were formed during the Pateozoic. Through the interpretation of structural unconformities, calcutation of eroded thickness, correction of pataeo-water depth and compaction and compiration of the Earty Paleozoic structural maps, the Earty Paleozoic stope break bert （geomorphologic unit） of the Tarim Basin is subdivided into uptift area, subaqueous uptift area, rift slope break belt, flexure stope break bert （stope bert）, depression area and deep basin area. Pataeogeomorphotogy of the Cambrian-Early Ordovician was approximately in EW trend within which three tectonic units inctuding the Tabei Pataeo-uptift, the northern Depressional Belt and the southern Pataeo-uptift developed respectivety and are grouped into two stope break systems namety as the Tabei Pataeo-uptift and the southern Pataeo-uptift. These tectonic units obviousty controt the deposition of isolated platform, open platform, restricted ptatform and deep basin. Influenced by extrusion in the Mid-Late Ordovician, the southern and northern subaqueous uptifts graduat[y etevated and then were eroded. Resuttant[y two slope break systems devetoped, namely as the northern and central Pataeo-uptifts which obviousty controtled the deposition of provenance area, isolated ptatform, mixed continental shelf, slope and basin facies. The intensive extrusion of the Mid-Late Ordovician reads to significant tectonic deformation of the Tarim Basin： large area of uplifting and erosion and development of EW trending anticline and syncline. Deposition of shore, tidal fiat, delta, shallow marine clastics and deep marine facies is obviously controlled by the Tabei, the southern and the Tadong Palaeo-uplifts. Slope break systems control development of stratigraphic unconformity and thus truncation and onlap unconformity zones become favorable areas in a palaeo-uplift and at a palaeo-slope belt for forming important unconformity traps; Whereas slope （slope break） belt along a palaeo-uplift margin is a geomorphologic unit where high-energy sedimentary facies widely develops, such as reef, oolitic sandy clastics or bioclastic limestone beach bar facies, thus litho-structural composite hydrocarbon accumulations usually develop when tectonic condition is suitable. In addition, large-scale palaeo-uplifts are the most favourable areas for hydrocarbon accumulation development.展开更多
Tight oil in the redeposited carbonates was mainly distributed in the Lower Submember of Member 3 of Shahejie Formation in Shulu sag of Jizhong depression,North China.Through high-resolution 3D seismic data,well loggi...Tight oil in the redeposited carbonates was mainly distributed in the Lower Submember of Member 3 of Shahejie Formation in Shulu sag of Jizhong depression,North China.Through high-resolution 3D seismic data,well logging data and drilling data,the Lower Submember of Member 3 of Shahejie Formation was divided into 5 third-order sequences and 15 parasequence sets.The redeposited marl and rudstone were major reserving horizons of tight oil,and ten reserving space types were developed and could be classified into two main categories,i.e.,pores and fractures.Two types of tight oil reservoirs were established,i.e.,the marl hydrocarbon reservoir of the source-reservoir integration and the rudstone hydrocarbon reservoirs of the source-reservoir paragenesis.The assemblage relationship among the high-quality source rocks,system tracts with the source-reservoir configuration was the major control factor for tight oil accumulation in the redeposited carbonates.The lacustrine transgressive system tracts and highstand systems tracts in SQ1 to SQ5 were the favorable horizons for development of the marl hydrocarbon reservoir,the lowstand system tracts in SQ1 to SQ3 were the favorable horizons for development of the rudstone hydrocarbon reservoir.展开更多
基金jointly supported by the National Science and Technology Major Project(Nos.2016ZX05002-005-07HZ,2016ZX05014-001-008HZ,and 2016ZX05026-002-002HZ)National Natural Science Foundation of China(Nos.41720104006 and 41274124)+2 种基金Chinese Academy of Sciences Strategic Pilot Technology Special Project(A)(No.XDA14010303)Shandong Province Innovation Project(No.2017CXGC1602)Independent Innovation(No.17CX05011)。
文摘Full waveform inversion(FWI)is an extremely important velocity-model-building method.However,it involves a large amount of calculation,which hindsers its practical application.The multi-source technology can reduce the number of forward modeling shots during the inversion process,thereby improving the efficiency.However,it introduces crossnoise problems.In this paper,we propose a sparse constrained encoding multi-source FWI method based on K-SVD dictionary learning.The phase encoding technology is introduced to reduce crosstalk noise,whereas the K-SVD dictionary learning method is used to obtain the basis of the transformation according to the characteristics of the inversion results.The multiscale inversion method is adopted to further enhance the stability of FWI.Finally,the synthetic subsag model and the Marmousi model are set to test the effectiveness of the newly proposed method.Analysis of the results suggest the following:(1)The new method can effectively reduce the computational complexity of FWI while ensuring inversion accuracy and stability;(2)The proposed method can be combined with the time-domain multi-scale FWI strategy flexibly to further avoid the local minimum and to improve the stability of inversion,which is of significant importance for the inversion of the complex model.
基金The General Program of National Natural Science Foundation of China under contract No.42074150the National Key Research and Development Project under contract No.2017YFC0601305。
文摘In conventional marine seismic exploration data processing,the sea surface is usually treated as a horizontal free boundary.However,the sea surface is affected by wind and waves and there often exists dynamic small-range fluctuations.These dynamic fluctuations will change the energy propagation path and affect the final imaging results.In theoretical research,different sea surface conditions need to be described,so it is necessary to study the modeling method of dynamic undulating sea surface.Starting from the commonly used sea surface mathematical simulation methods,this paper mainly studies the realization process of simple harmonic wave and Gerstner wave sea surface simulation methods based on ocean wave spectrum,and compares their advantages and disadvantages.Aiming at the shortcomings of the simple harmonic method and Gerstner method in calculational speed and sea surface simulation effect,a method based on wave equation and using dynamic boundary conditions for sea surface simulation is proposed.The calculational speed of this method is much faster than the commonly used simple harmonic method and Gerstner wave method.In addition,this paper also compares the new method with the more commonly used higher-order spectral methods to show the characteristics of the improved wave equation method.
基金supported by NSFC(41930425)Science Foundation of China University of Petroleum,Beijing(No.2462020YXZZ008)+1 种基金R&D Department of China National Petroleum Corporation(Investigations on fundamental experiments and advanced theoretical methods in geophysical prospecting applications(2022DQ0604-01)the Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX2020-03)and NSFC(42274142).
文摘Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results for seismic inversion of heavy oil reservoir. To describe the viscoelastic behavior of heavy oil, we modeled the elastic properties of heavy oil with varying viscosity and frequency using the Cole-Cole-Maxwell (CCM) model. Then, we used a CCoherent Potential Approximation (CPA) instead of the Gassmann equations to account for the fluid effect, by extending the single-phase fluid condition to two-phase fluid (heavy oil and water) condition, so that partial saturation of heavy oil can be considered. This rock physics model establishes the relationship between the elastic modulus of reservoir rock and viscosity, frequency and saturation. The viscosity of the heavy oil and the elastic moduli and porosity of typical reservoir rock samples were measured in laboratory, which were used for calibration of the rock physics model. The well-calibrated frequency-variant CPA model was applied to the prediction of the P- and S-wave velocities in the seismic frequency range (1–100 Hz) and the inversion of petrophysical parameters for a heavy oil reservoir. The pre-stack inversion results of elastic parameters are improved compared with those results using the CPA model in the sonic logging frequency (∼10 kHz), or conventional rock physics model such as the Xu-Payne model. In addition, the inversion of the porosity of the reservoir was conducted with the simulated annealing method, and the result fits reasonably well with the logging curve and depicts the location of the heavy oil reservoir on the time slice. The application of the laboratory-calibrated CPA model provides better results with the velocity dispersion correction, suggesting the important role of accurate frequency dependent rock physics models in the seismic prediction of heavy oil reservoirs.
基金jointly supported by the National Key Research and Development Program of China (2019YFC0605503)the National Natural Science Foundation of China (41821002, 41922028,41874149)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA14010303)the Major Scientific and Technological Projects of CNPC (ZD2019-183-003)。
文摘The Gaussian beam migration(GBM) is a steady imaging approach, which has high accuracy and efficiency. Its implementation mainly includes the traditional frequency domain and the recent popular space-time domain. Firstly, we use the upward ray tracing strategy to get the backward wavefields. Then,we use the dominant frequency of the seismic data to simplify the imaginary traveltime calculation of the wavefields, which can cut down the Fourier transform number compared with the traditional GBM in the space-time domain. In addition, we choose an optimized parameter for the take-off angle increment of the up-going and down-going rays. These optimizations help us get an efficient space-time-domain acoustic GBM approach. Typical four examples show that the proposed method can significantly improve the computational efficiency up to one or even two orders of magnitude in different models with different model parameters and produce good imaging results with comparable accuracy and resolution with the traditional GBM in the space-time domain.
基金The National Key Science and Technology Special Project(13th Five Year Plan)of the Key Technology of Gas and Oil Exploration in Offshore Deep Water Area(Phase 3)under contract No.2016Zx05026
文摘The Qiongdongnan Basin and Zhujiang River（Pearl River） Mouth Basin, important petroliferous basins in the northern South China Sea, contain abundant oil and gas resource. In this study, on basis of discussing impact of oil-base mud on TOC content and Rock-Eval parameters of cutting shale samples, the authors did comprehensive analysis of source rock quality, thermal evolution and control effect of source rock in gas accumulation of the Qiongdongnan and the Zhujiang River Mouth Basins. The contrast analysis of TOC contents and Rock-Eval parameters before and after extraction for cutting shale samples indicates that except for a weaker impact on Rock-Eval parameter S2, oil-base mud has certain impact on Rock-Eval S1, Tmax and TOC contents. When concerning oil-base mud influence on source rock geochemistry parameters, the shales in the Yacheng/Enping,Lingshui/Zhuhai and Sanya/Zhuhai Formations have mainly Type Ⅱ and Ⅲ organic matter with better gas potential and oil potential. The thermal evolution analysis suggests that the depth interval of the oil window is between 3 000 m and 5 000 m. Source rocks in the deepwater area have generated abundant gas mainly due to the late stage of the oil window and the high-supper mature stage. Gas reservoir formation condition analysis made clear that the source rock is the primary factor and fault is a necessary condition for gas accumulation. Spatial coupling of source, fault and reservoir is essential for gas accumulation and the inside of hydrocarbon-generating sag is future potential gas exploration area.
基金financially supported by the National Key R&D Program of China (No. 2019YFC0605503)the Major Scientific and Technological Projects of CNPC (No. ZD2019-183-003)the National Natural Science Foundation of China (No. 41922028,41874149)。
文摘The anisotropic properties of subsurface media cause waveform distortions in seismic wave propagation,resulting in a negative infl uence on seismic imaging.In addition,wavefields simulated by the conventional coupled pseudo-acoustic equation are not only aff ected by SV-wave artifacts but are also limited by anisotropic parameters.We propose a least-squares reverse time migration(LSRTM)method based on the pure q P-wave equation in vertically transverse isotropic media.A fi nite diff erence and fast Fourier transform method,which can improve the effi ciency of the numerical simulation compared to a pseudo-spectral method,is used to solve the pure q P-wave equation.We derive the corresponding demigration operator,migration operator,and gradient updating formula to implement the LSRTM.Numerical tests on the Hess model and field data confirm that the proposed method has a good correction eff ect for the travel time deviation caused by underground anisotropic media.Further,it signifi cantly suppresses the migration noise,balances the imaging amplitude,and improves the imaging resolution.
文摘In these years,the Upper Jurassic andesitic volcanic reservoirs in Erlian basin,the Lower Cretaceous rhyolitic volcanic reservoirs in Songliao Basin,the Cretaceous rhyolitic,and the Paleogene basaltic and trachytic volcanic reservoirs in Bohai Bay Basin,and the basaltic volcanic reservoirs in Subei basin were discovered.With more and more volcanic oil and gas fields being discovered and developed,the volcanic rocks demonstrate a great petroleum potential in eastern basins of China.Five volcanic facies were identified in these basins,including volcanic conduit facies.
文摘Oil and gas exploration in most areas and major horizons of Songliao Basin have reached a stage of high maturity.Presently,there are few structural trap reservoirs remaining to be drilled in the basin,and major targets
基金Supported by projects of National Natural Science Foundation of China (No. 42074150)National Key R&D Program of China (No. 2017YFC0601305)。
文摘Strong fluctuation of seabed,abrupt variation in depth and dip of seabed bring seismic imaging problems,such as irregular reflection waves,obvious multiple waves,serious lateral wave development,poor imaging on base surface and depression structure,low signal-to-noise ratio of middle and deep layers.In this paper,Gaussian beam migration imaging method is used to analyze the imaging effect of rugged seabed in deep water area,and the ray tracing method of wavefront construction method is used to analyze the kinematic characteristics of seismic waves.By improving the design of seismic data acquisition and observation system,imaging quality of fine structures is improved.
文摘Compared with conventional seismic data, OVT domain gathers can better analyze the change information of seismic wave propagation in anisotropic media. The five-dimensional interpretation software innovatively puts forward the characteristic technologies such as fracture 3D visual display, azimuth AVO analysis and azimuth oil and gas prediction. Through the research of azimuth anisotropy attribute analysis technology of OVT data and combined with specific technical application, it effectively transforms the actual production capacity of reservoir description technology of wide azimuth seismic data, so as to improve the actual production capacity of small and medium-sized faults in shale, buried hill and other reservoirs micro amplitude structure and high angle fracture detection and description ability, give play to the effectiveness of wide-range seismic data, serve efficient exploration and development, and provide new technical support.
文摘Buried hill is an important exploration field in Dawangzhuang block. Because Dawangzhuang buried hill has experienced multi-stage tectonic movement, the complexity of tectonic movement determines the diversity of buried hill morphology, and the diversity of buried hill structural morphology determines its reservoir forming characteristics. Therefore, the research on the structural style and reservoir forming characteristics of Dawangzhuang buried hill is of great significance in the process of oil and gas exploration at this stage. This paper summarizes the structural style of Dawangzhuang buried hill. On this basis, 67 small fault blocks divided in the study area are classified and counted. Further, according to the seismic profile and logging data, the well data and reservoir profile of characteristic wells are counted and compared, and the reservoir forming characteristics and main controlling factors of Dawangzhuang buried hill are found. The above understanding has certain guiding significance for the further exploration of Dawangzhuang buried hill.
文摘Under the condition of conventional seismic data, because the thickness of the whole stratum of the second member of Shahejie Formation in the south is reduced, it is wedge-shaped in the south, and the shielding effect of the interface between the overlying sand and the bottom layer or the weak seismic reflection signal, it is difficult to identify the overbreak line, which seriously affects the exploration and development of the second member of Shahejie Formation. Based on this, on the basis of target processing of seismic data and cross-well correlation of logging sequences, and combining with seismic structural attributes, the location of stratigraphic superstripping lines is preliminarily determined, and then the accurate location of stratigraphic superstripping lines is finely determined by using the included angle extrapolation technique and seismic stratigraphic method for interactive verification.
文摘Shallow Guantao Group channel sand body oil and gas reservoir is an important part of Shengli Oilfields oil and gas reserves upgrading, and also an important practical position to increase oil reserves and production for a period of time. For the evaluation of Guantao Group channel sand body type oil and gas reservoirs, accurate description of oil and gas traps is the key. However, affected by the quality of seismic data, the accuracy of structural interpretation of Guantao Group has always been low, especially the large error of the fault system combination of low order faults, which directly led to the deviation of the subsequent comprehensive evaluation of oil reservoirs and target selection. Therefore, it is urgent to summarize and improve a set of targeted structural interpretation scheme of Guantao Group, and realize the oil and gas evaluation of target reservoirs under the guidance of the accurate interpretation mode, so as to improve the quality of exploration and development. Based on this, this paper takes the Guantao Group in Chengdong area of Zhanhua sag in Jiyang sag as an example, aiming at the difficulties of structural interpretation in this area, with the help of Bonan-2021 full node high-density 3D seismic data, effectively uses high-precision coherence, dip angle, ant body, fault coherence enhancement and other technologies, and finely implements the structural pattern of Guantao Group in Chengdong area through hierarchical control mode, so as to provide detailed basic seismic data for the subsequent fine evaluation of oil and gas reservoirs in this area.
文摘Based on comprehensive analyses of seismic and tog data, this study indicates that mainty four widespread angutar to minor angutar unconformities （Tg8, Tg51, Tg5 and Tg3） were formed during the Pateozoic. Through the interpretation of structural unconformities, calcutation of eroded thickness, correction of pataeo-water depth and compaction and compiration of the Earty Paleozoic structural maps, the Earty Paleozoic stope break bert （geomorphologic unit） of the Tarim Basin is subdivided into uptift area, subaqueous uptift area, rift slope break belt, flexure stope break bert （stope bert）, depression area and deep basin area. Pataeogeomorphotogy of the Cambrian-Early Ordovician was approximately in EW trend within which three tectonic units inctuding the Tabei Pataeo-uptift, the northern Depressional Belt and the southern Pataeo-uptift developed respectivety and are grouped into two stope break systems namety as the Tabei Pataeo-uptift and the southern Pataeo-uptift. These tectonic units obviousty controt the deposition of isolated platform, open platform, restricted ptatform and deep basin. Influenced by extrusion in the Mid-Late Ordovician, the southern and northern subaqueous uptifts graduat[y etevated and then were eroded. Resuttant[y two slope break systems devetoped, namely as the northern and central Pataeo-uptifts which obviousty controtled the deposition of provenance area, isolated ptatform, mixed continental shelf, slope and basin facies. The intensive extrusion of the Mid-Late Ordovician reads to significant tectonic deformation of the Tarim Basin： large area of uplifting and erosion and development of EW trending anticline and syncline. Deposition of shore, tidal fiat, delta, shallow marine clastics and deep marine facies is obviously controlled by the Tabei, the southern and the Tadong Palaeo-uplifts. Slope break systems control development of stratigraphic unconformity and thus truncation and onlap unconformity zones become favorable areas in a palaeo-uplift and at a palaeo-slope belt for forming important unconformity traps; Whereas slope （slope break） belt along a palaeo-uplift margin is a geomorphologic unit where high-energy sedimentary facies widely develops, such as reef, oolitic sandy clastics or bioclastic limestone beach bar facies, thus litho-structural composite hydrocarbon accumulations usually develop when tectonic condition is suitable. In addition, large-scale palaeo-uplifts are the most favourable areas for hydrocarbon accumulation development.
基金This work was supported by PetroChina Major Science and Technology Project(No.2017E-015)PetroChina Key Project(No.kt2017-07).
文摘Tight oil in the redeposited carbonates was mainly distributed in the Lower Submember of Member 3 of Shahejie Formation in Shulu sag of Jizhong depression,North China.Through high-resolution 3D seismic data,well logging data and drilling data,the Lower Submember of Member 3 of Shahejie Formation was divided into 5 third-order sequences and 15 parasequence sets.The redeposited marl and rudstone were major reserving horizons of tight oil,and ten reserving space types were developed and could be classified into two main categories,i.e.,pores and fractures.Two types of tight oil reservoirs were established,i.e.,the marl hydrocarbon reservoir of the source-reservoir integration and the rudstone hydrocarbon reservoirs of the source-reservoir paragenesis.The assemblage relationship among the high-quality source rocks,system tracts with the source-reservoir configuration was the major control factor for tight oil accumulation in the redeposited carbonates.The lacustrine transgressive system tracts and highstand systems tracts in SQ1 to SQ5 were the favorable horizons for development of the marl hydrocarbon reservoir,the lowstand system tracts in SQ1 to SQ3 were the favorable horizons for development of the rudstone hydrocarbon reservoir.
