In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method （WFEM）, because of its strong anti-interference capability, high resolution, ability to conduct expl...In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method （WFEM）, because of its strong anti-interference capability, high resolution, ability to conduct exploration at large depths, and high efficiency, to the Bayan Syncline in the South Huayuan block, Hunan Province. We collected rock samples and analyzed their resistivity and induced polarization （IP） and built A series of two-dimensional models for geological conditions to investigate the applicability of WFEM to different geological structures. We also analyzed the correlation between TOC of shale and the resistivity and IP ratio to determine the threshold for identifying target formations. We used WFEM to identify the underground structures and determine the distribution, depth, and thickness of the target strata. Resistivity, IP, and total organic carbon were used to evaluate the shale gas prospects and select favorable areas （sweet spots） for exploration and development. Subsequently, drilling in these areas proved the applicability of WFEM in shale gas exploration.展开更多
The time-frequency domain electromagnetic(TFEM)sounding technique can directly detect oil and gas characteristics through anomalies in resistivity and polarizability.In recent years,it has made some breakthroughs in h...The time-frequency domain electromagnetic(TFEM)sounding technique can directly detect oil and gas characteristics through anomalies in resistivity and polarizability.In recent years,it has made some breakthroughs in hydrocarbon detection.TFEM was applied to predict the petroliferous property of the Ili Basin.In accordance with the geological structure characteristics of the study area,a two-dimensional layered medium model was constructed and forward modeling was performed.We used the forward-modeling results to guide fi eld construction and ensure the quality of the fi eld data collection.We used the model inversion results to identify and distinguish the resolution of the geoelectric information and provide a reliable basis for data processing.On the basis of our results,key technologies such as 2D resistivity tomography imaging inversion and polarimetric constrained inversion were developed,and we obtained abundant geological and geophysical information.The characteristics of the TFEM anomalies of the hydrocarbon reservoirs in the Ili Basin were summarized through an analysis of the electrical logging data in the study area.Moreover,the oil-gas properties of the Permian and Triassic layers were predicted,and the next favorable exploration targets were optimized.展开更多
基金financially supported by the Thirteenth Five-Year-Plan Major Project "Marine Shale Gas Exploration and Evaluation over Laifengxianfeng and Hefeng Block"(No.2016ZX05034004-004)China Huadian Engineering Co.,LTD(No.CHEC-KJ-2014-Z10)
文摘In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method （WFEM）, because of its strong anti-interference capability, high resolution, ability to conduct exploration at large depths, and high efficiency, to the Bayan Syncline in the South Huayuan block, Hunan Province. We collected rock samples and analyzed their resistivity and induced polarization （IP） and built A series of two-dimensional models for geological conditions to investigate the applicability of WFEM to different geological structures. We also analyzed the correlation between TOC of shale and the resistivity and IP ratio to determine the threshold for identifying target formations. We used WFEM to identify the underground structures and determine the distribution, depth, and thickness of the target strata. Resistivity, IP, and total organic carbon were used to evaluate the shale gas prospects and select favorable areas （sweet spots） for exploration and development. Subsequently, drilling in these areas proved the applicability of WFEM in shale gas exploration.
基金This work was supported by the Geology and Mineral Resources Investigation and Evaluation Program(No.12120115006601 and No.DD20160181)the National key Research and Development projects(No.2016YFC060110204 and No.2016YFC060110305).
文摘The time-frequency domain electromagnetic(TFEM)sounding technique can directly detect oil and gas characteristics through anomalies in resistivity and polarizability.In recent years,it has made some breakthroughs in hydrocarbon detection.TFEM was applied to predict the petroliferous property of the Ili Basin.In accordance with the geological structure characteristics of the study area,a two-dimensional layered medium model was constructed and forward modeling was performed.We used the forward-modeling results to guide fi eld construction and ensure the quality of the fi eld data collection.We used the model inversion results to identify and distinguish the resolution of the geoelectric information and provide a reliable basis for data processing.On the basis of our results,key technologies such as 2D resistivity tomography imaging inversion and polarimetric constrained inversion were developed,and we obtained abundant geological and geophysical information.The characteristics of the TFEM anomalies of the hydrocarbon reservoirs in the Ili Basin were summarized through an analysis of the electrical logging data in the study area.Moreover,the oil-gas properties of the Permian and Triassic layers were predicted,and the next favorable exploration targets were optimized.
