The caprock is one of the key factors for a reservoir, especially for a gas reservoir. Whether the caprocks can block off the gas is of significance for the accumulation and preservation of the gas reservoir. In this ...The caprock is one of the key factors for a reservoir, especially for a gas reservoir. Whether the caprocks can block off the gas is of significance for the accumulation and preservation of the gas reservoir. In this paper, we use the Amplitude versus offset （AVO） seismic technique to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The essence of this technique is to detect the variations of the reservoir bed physical properties by monitoring the variations of the reflection coefficient of seismic waves upon the interfaces between different lithologies. Generally it is used to indicate hydrocarbon directly. For the hydrocarbon concentration sealing caprocks, the change of hydrocarbon concentration may cause the change of physical properties of the caprocks. Therefore it is possible to evaluate the hydrocarbon concentration sealing ability of the caprocks by AVO. This paper presents a case study using AVO to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The result shows that this method is helpful for the exploration of the region.展开更多
The tight sandstones in the Permian Lower Shihezi Formation of Shilijiahan area in the Ordos Basin was taken as study object in this research to quantitatively determine the effects of burial depth, burial time and co...The tight sandstones in the Permian Lower Shihezi Formation of Shilijiahan area in the Ordos Basin was taken as study object in this research to quantitatively determine the effects of burial depth, burial time and compaction strength on porosity during densification of reservoir. Firstly, sandstone compaction profiles were analyzed in detail. Secondly, the theoretical study was performed based on visco-elasto-plastic stress–strain model. Thirdly, multiple regression and iterative algorithm were used respectively to ascertain the variation trends of Young's modulus and equivalent viscosity coefficient with burial depth and burial time. Accordingly, the ternary analytic porosity-reduction model of sandstone compaction trend was established. Eventually, the reasonability of improved model was tested by comparing with thin-section statistics under microscope and the models in common use. The study shows that the new model can divide the porosity reduction into three parts, namely, elastic porosity loss, visco-plastic porosity loss and porosity loss from cementation. And the results calculated by the new model of litharenite in He 2 Member are close to the average value from the thin-section statistics on Houseknecht chart, which approximately reveals the relative magnitudes of compaction and cementation in the normal evolution trend of sandstone porosity. Furthermore, the model can more exactly depict the compaction trend of sandstone affected little by dissolution than previous compaction models, and evaluate sandstone compaction degree and its contribution to reservoir densification during different burial and uplift processes.展开更多
随着移动互联网的快速发展,三维GIS(geographic information system)应用的用户终端设备类型日趋多样化,现有单一的网络可视化方法难以适应多样化终端需求.针对上述问题,本文首先设计了基于B/S(browser/server)模式的自适应三维可视化架...随着移动互联网的快速发展,三维GIS(geographic information system)应用的用户终端设备类型日趋多样化,现有单一的网络可视化方法难以适应多样化终端需求.针对上述问题,本文首先设计了基于B/S(browser/server)模式的自适应三维可视化架构,然后重点探讨三维数据的多样化组织、自适应四叉树组织与动态索引构建、三维场景自适应调度等关键技术,最后基于WebGL技术构建原型系统并进行案例实验.实验结果表明:桌面端设备笔记本电脑的可视化渲染帧率最终稳定在40帧/s左右;移动端设备平板电脑、智能手机的可视化渲染帧率最终稳定在20帧/s左右;不同类型终端上进行网络可视化均能保证较高的可视化帧率及效果,证明了本文提出方法的有效性与可行性.展开更多
文摘The caprock is one of the key factors for a reservoir, especially for a gas reservoir. Whether the caprocks can block off the gas is of significance for the accumulation and preservation of the gas reservoir. In this paper, we use the Amplitude versus offset （AVO） seismic technique to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The essence of this technique is to detect the variations of the reservoir bed physical properties by monitoring the variations of the reflection coefficient of seismic waves upon the interfaces between different lithologies. Generally it is used to indicate hydrocarbon directly. For the hydrocarbon concentration sealing caprocks, the change of hydrocarbon concentration may cause the change of physical properties of the caprocks. Therefore it is possible to evaluate the hydrocarbon concentration sealing ability of the caprocks by AVO. This paper presents a case study using AVO to determine the lateral extension of the hydrocarbon concentration sealing caprocks. The result shows that this method is helpful for the exploration of the region.
基金Supported by the National Natural Science Foundation of China(4167212441502147)PetroChina Science and Technology Major Project(2016ZX05047001-002)
文摘The tight sandstones in the Permian Lower Shihezi Formation of Shilijiahan area in the Ordos Basin was taken as study object in this research to quantitatively determine the effects of burial depth, burial time and compaction strength on porosity during densification of reservoir. Firstly, sandstone compaction profiles were analyzed in detail. Secondly, the theoretical study was performed based on visco-elasto-plastic stress–strain model. Thirdly, multiple regression and iterative algorithm were used respectively to ascertain the variation trends of Young's modulus and equivalent viscosity coefficient with burial depth and burial time. Accordingly, the ternary analytic porosity-reduction model of sandstone compaction trend was established. Eventually, the reasonability of improved model was tested by comparing with thin-section statistics under microscope and the models in common use. The study shows that the new model can divide the porosity reduction into three parts, namely, elastic porosity loss, visco-plastic porosity loss and porosity loss from cementation. And the results calculated by the new model of litharenite in He 2 Member are close to the average value from the thin-section statistics on Houseknecht chart, which approximately reveals the relative magnitudes of compaction and cementation in the normal evolution trend of sandstone porosity. Furthermore, the model can more exactly depict the compaction trend of sandstone affected little by dissolution than previous compaction models, and evaluate sandstone compaction degree and its contribution to reservoir densification during different burial and uplift processes.
文摘随着移动互联网的快速发展,三维GIS(geographic information system)应用的用户终端设备类型日趋多样化,现有单一的网络可视化方法难以适应多样化终端需求.针对上述问题,本文首先设计了基于B/S(browser/server)模式的自适应三维可视化架构,然后重点探讨三维数据的多样化组织、自适应四叉树组织与动态索引构建、三维场景自适应调度等关键技术,最后基于WebGL技术构建原型系统并进行案例实验.实验结果表明:桌面端设备笔记本电脑的可视化渲染帧率最终稳定在40帧/s左右;移动端设备平板电脑、智能手机的可视化渲染帧率最终稳定在20帧/s左右;不同类型终端上进行网络可视化均能保证较高的可视化帧率及效果,证明了本文提出方法的有效性与可行性.
