The research about subsurface characteristics by using transient electromagnetic method（TEM） and high density resistivity method（HDRM） were already conducted in Ordos. The objective of this research is to detect c...The research about subsurface characteristics by using transient electromagnetic method（TEM） and high density resistivity method（HDRM） were already conducted in Ordos. The objective of this research is to detect coalmine goaf areas based on rock resistivity. The data processing using wavelet transform, three point smoothing, RES2 DINV and Maxwell processing software to obtain 2D resistivity structure. The results showed that the layers with maximum resistivity values（30e33 U m on Line 1, 30e31 U m on Line 2, 32e40 U m on Line3） are founded at station 1e7, and 14e20 on Line 1,13e18 on Line 2, and 8e13 and 16e20 on Line 3 which is predicted as goaf layer, and the minimum resistivity values（20e26 U m of TEM, 45e75 U m of HDRM） at the other layers. This resistivity difference was caused by the geology and characteristics of the study area which is located close by the cleugh with rich coal, so the goaf area distinguishable with aquifer layer and coal seam. The results were also significant accidents and serious destruction of ecological environment.展开更多
The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the hig...The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.展开更多
High-density resistivity method is a new, efficient electrical prospecting method, which can complete a two-dimensional （vertical and horizontal） prospecting process, possesses certain imaging functions for the geo-...High-density resistivity method is a new, efficient electrical prospecting method, which can complete a two-dimensional （vertical and horizontal） prospecting process, possesses certain imaging functions for the geo-electric structure, and integrates electric profiling method with electric sounding method together. In this paper, the basic principle, data processing, and result explanation and inference of high- density resistivity method are introduced by taking the application of high-density resistivity method to the prospecting project in the slope of Gongchangling Open Pit, Liaoyang. The result of the prospecting result map analysis showed that the prospecting result was basically in line with the actual situation and proved the great significance of high-density resistivity method to the evaluation on the slope stability of Gongchangling open pit.展开更多
Based on the relationship between the diameter and buried depth of goal, the authors establish the forward modeling by Res2dmod and inverse the model by Res2dinv. Thus, three kinds of models are obtained ： the model ...Based on the relationship between the diameter and buried depth of goal, the authors establish the forward modeling by Res2dmod and inverse the model by Res2dinv. Thus, three kinds of models are obtained ： the model of single resistivity anomalous body, model of double different distance resistivity anomalous body, and model of layered resistivity anomalous body. Using forward and inversion, the image of detection is simulated, and the reliability is proved by comparing with the engineering examples.展开更多
As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequen...As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequently occurred in the graph of apparent resistivity pseudo-section or inverted geoelectrical section obtained from high-density electrical technique,and are difficult to remove.In this study,the authors explain the mechanism of the false anomalies and put forward the horizontal differential field method to identify the false anomalies.Based on the analysis of modeling results,this method is applied in the surveying data in Xinlei Quarry of Jiuquan,and the results confirm the effectiveness of the horizontal differential field method.展开更多
The Jiaoshiba shale gasfield is located in the Fuling area of the Sichuan Basin,with the Upper Ordovician Wufeng-Lower Silurian Longmaxi Fm as the pay zone.At the bottom of the pay zone,a high-quality shale gas reserv...The Jiaoshiba shale gasfield is located in the Fuling area of the Sichuan Basin,with the Upper Ordovician Wufeng-Lower Silurian Longmaxi Fm as the pay zone.At the bottom of the pay zone,a high-quality shale gas reservoir about 20 m thick is generally developed with high organic contents and gas abundance,but its resistivity is relatively low.Accordingly,the gas saturation calculated by formulas(e.g.Archie)using electric logging data is often much lower than the experiment-derived value.In this paper,a new method was presented for calculating gas saturation more accurately based on non-electric logging data.Firstly,the causes for the low resistivity of shale gas reservoirs in this area were analyzed.Then,the limitation of traditional methods for calculating gas saturation based on electric logging data was diagnosed,and the feasibility of the neutronedensity porosity overlay method was illustrated.According to the response characteristics of neutron,density and other porosity logging in shale gas reservoirs,a model for calculating gas saturation of shale gas was established by core experimental calibration based on the density logging value,the density porosity and the difference between density porosity and neutron porosity,by means of multiple methods(e.g.the dual-porosity overlay method by optimizing the best overlay coefficient).This new method avoids the effect of low resistivity,and thus can provide normal calculated gas saturation of high-quality shale gas reservoirs.It works well in practical application.This new method provides a technical support for the calculation of shale gas reserves in this area.展开更多
基金supported by the Institute of Seismology Foundation, China Earthquake Administration (201326126)
文摘The research about subsurface characteristics by using transient electromagnetic method（TEM） and high density resistivity method（HDRM） were already conducted in Ordos. The objective of this research is to detect coalmine goaf areas based on rock resistivity. The data processing using wavelet transform, three point smoothing, RES2 DINV and Maxwell processing software to obtain 2D resistivity structure. The results showed that the layers with maximum resistivity values（30e33 U m on Line 1, 30e31 U m on Line 2, 32e40 U m on Line3） are founded at station 1e7, and 14e20 on Line 1,13e18 on Line 2, and 8e13 and 16e20 on Line 3 which is predicted as goaf layer, and the minimum resistivity values（20e26 U m of TEM, 45e75 U m of HDRM） at the other layers. This resistivity difference was caused by the geology and characteristics of the study area which is located close by the cleugh with rich coal, so the goaf area distinguishable with aquifer layer and coal seam. The results were also significant accidents and serious destruction of ecological environment.
文摘The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.
文摘High-density resistivity method is a new, efficient electrical prospecting method, which can complete a two-dimensional （vertical and horizontal） prospecting process, possesses certain imaging functions for the geo-electric structure, and integrates electric profiling method with electric sounding method together. In this paper, the basic principle, data processing, and result explanation and inference of high- density resistivity method are introduced by taking the application of high-density resistivity method to the prospecting project in the slope of Gongchangling Open Pit, Liaoyang. The result of the prospecting result map analysis showed that the prospecting result was basically in line with the actual situation and proved the great significance of high-density resistivity method to the evaluation on the slope stability of Gongchangling open pit.
文摘Based on the relationship between the diameter and buried depth of goal, the authors establish the forward modeling by Res2dmod and inverse the model by Res2dinv. Thus, three kinds of models are obtained ： the model of single resistivity anomalous body, model of double different distance resistivity anomalous body, and model of layered resistivity anomalous body. Using forward and inversion, the image of detection is simulated, and the reliability is proved by comparing with the engineering examples.
文摘As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequently occurred in the graph of apparent resistivity pseudo-section or inverted geoelectrical section obtained from high-density electrical technique,and are difficult to remove.In this study,the authors explain the mechanism of the false anomalies and put forward the horizontal differential field method to identify the false anomalies.Based on the analysis of modeling results,this method is applied in the surveying data in Xinlei Quarry of Jiuquan,and the results confirm the effectiveness of the horizontal differential field method.
文摘The Jiaoshiba shale gasfield is located in the Fuling area of the Sichuan Basin,with the Upper Ordovician Wufeng-Lower Silurian Longmaxi Fm as the pay zone.At the bottom of the pay zone,a high-quality shale gas reservoir about 20 m thick is generally developed with high organic contents and gas abundance,but its resistivity is relatively low.Accordingly,the gas saturation calculated by formulas(e.g.Archie)using electric logging data is often much lower than the experiment-derived value.In this paper,a new method was presented for calculating gas saturation more accurately based on non-electric logging data.Firstly,the causes for the low resistivity of shale gas reservoirs in this area were analyzed.Then,the limitation of traditional methods for calculating gas saturation based on electric logging data was diagnosed,and the feasibility of the neutronedensity porosity overlay method was illustrated.According to the response characteristics of neutron,density and other porosity logging in shale gas reservoirs,a model for calculating gas saturation of shale gas was established by core experimental calibration based on the density logging value,the density porosity and the difference between density porosity and neutron porosity,by means of multiple methods(e.g.the dual-porosity overlay method by optimizing the best overlay coefficient).This new method avoids the effect of low resistivity,and thus can provide normal calculated gas saturation of high-quality shale gas reservoirs.It works well in practical application.This new method provides a technical support for the calculation of shale gas reserves in this area.
