Based on the study of <sup>29</sup>Si,<sup>27</sup>Al NMR spectra for some orthoclases determined byX-ray powder diffraction method,Zhou et al.found that there are three maxima for the<sup&g...Based on the study of <sup>29</sup>Si,<sup>27</sup>Al NMR spectra for some orthoclases determined byX-ray powder diffraction method,Zhou et al.found that there are three maxima for the<sup>29</sup>Si NMR spectra of these orthoclases.In order to explain the three maxima the authorsexamined the <sup>29</sup>Si NMR spectrum and microstructure of Taiping orthoclase occurring ingranitic dyke.展开更多
The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being ...The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being effective in their applications to unconventional reservoirs.This study employed nuclear magnetic resonance(NMR)spectrum decomposition to dissect the NMR T_(2)spectrum into multiple subspectra.Furthermore,it employed laboratory NMR experiments to ascertain the fluid properties of these sub-spectra,aiming to enhance identification accuracy.The findings indicate that fluids of distinct properties overlap in the T_(2)spectra,with bound water,movable water,bound oil,and movable oil appearing sequentially from the low-value zone to the high-value zone.Consequently,an oil layer classification scheme was proposed,which considers the physical properties of reservoirs,oil-bearing capacity,and the characteristics of both mobility and the oil-water two-phase flow.When applied to tight oil layer identification,the scheme's outcomes align closely with actual test results.A horizontal well,deployed based on these findings,has produced high-yield industrial oil flow,underscoring the precision and dependability of this new approach.展开更多
CO_(2) storage capacity is significantly influenced by the saturation levels of reservoir rocks,with underground fluid saturation typically evaluated using resistivity data.The conductive pathways of fluids in various...CO_(2) storage capacity is significantly influenced by the saturation levels of reservoir rocks,with underground fluid saturation typically evaluated using resistivity data.The conductive pathways of fluids in various states within rock pores differ,alongside variations in conductive mechanisms.To clarify the conductivity of water in rocks across different states,this study employed a three-pore segment saturation model,which corrected for the additional conductivity of clay by categorizing water into large-pore segment,medium-pore segment,and small-pore segment types.Addressing the heterogeneity of tight sandstone reservoirs,we classified distinct pore structures and inverted Archie equation parameters from NMR logging data using a segmented characterization approach,yielding dynamic Archie parameters that vary with depth.Ultimately,we established an improved saturation parameter method based on joint inversion of NMR and resistivity data,which was validated through laboratory experiments and practical downhole applications.The results indicate that this saturation parameter inversion method has been effectively applied in both settings.Furthermore,we discussed the varying conductive behaviors of fluids in large and medium pore segment under saturated and drained states.Lastly,we proposed a workflow for inverting saturation based on downhole data,providing a robust foundation for CO_(2) storage and predicting underground fluid saturation.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘Based on the study of <sup>29</sup>Si,<sup>27</sup>Al NMR spectra for some orthoclases determined byX-ray powder diffraction method,Zhou et al.found that there are three maxima for the<sup>29</sup>Si NMR spectra of these orthoclases.In order to explain the three maxima the authorsexamined the <sup>29</sup>Si NMR spectrum and microstructure of Taiping orthoclase occurring ingranitic dyke.
基金funded by a major special project of PetroChina Company Limited(No.2021DJ1003No.2023ZZ2).
文摘The intricate distribution of oil and water in tight rocks makes pinpointing oil layers challenging.While conventional identification methods offer potential solutions,their limited accuracy precludes them from being effective in their applications to unconventional reservoirs.This study employed nuclear magnetic resonance(NMR)spectrum decomposition to dissect the NMR T_(2)spectrum into multiple subspectra.Furthermore,it employed laboratory NMR experiments to ascertain the fluid properties of these sub-spectra,aiming to enhance identification accuracy.The findings indicate that fluids of distinct properties overlap in the T_(2)spectra,with bound water,movable water,bound oil,and movable oil appearing sequentially from the low-value zone to the high-value zone.Consequently,an oil layer classification scheme was proposed,which considers the physical properties of reservoirs,oil-bearing capacity,and the characteristics of both mobility and the oil-water two-phase flow.When applied to tight oil layer identification,the scheme's outcomes align closely with actual test results.A horizontal well,deployed based on these findings,has produced high-yield industrial oil flow,underscoring the precision and dependability of this new approach.
基金supported in part by the Key National Research Project of China under Grant 2023YFC3707900in part by the National Natural Science Foundation of China under Grant 42204122 and Grant 42072323。
文摘CO_(2) storage capacity is significantly influenced by the saturation levels of reservoir rocks,with underground fluid saturation typically evaluated using resistivity data.The conductive pathways of fluids in various states within rock pores differ,alongside variations in conductive mechanisms.To clarify the conductivity of water in rocks across different states,this study employed a three-pore segment saturation model,which corrected for the additional conductivity of clay by categorizing water into large-pore segment,medium-pore segment,and small-pore segment types.Addressing the heterogeneity of tight sandstone reservoirs,we classified distinct pore structures and inverted Archie equation parameters from NMR logging data using a segmented characterization approach,yielding dynamic Archie parameters that vary with depth.Ultimately,we established an improved saturation parameter method based on joint inversion of NMR and resistivity data,which was validated through laboratory experiments and practical downhole applications.The results indicate that this saturation parameter inversion method has been effectively applied in both settings.Furthermore,we discussed the varying conductive behaviors of fluids in large and medium pore segment under saturated and drained states.Lastly,we proposed a workflow for inverting saturation based on downhole data,providing a robust foundation for CO_(2) storage and predicting underground fluid saturation.
