The present paper investigates the application of high resolution magnetic survey to detecting igneous bodies. The slight difference in magnetism between igneous bodies and their surrounding rocks is measured first an...The present paper investigates the application of high resolution magnetic survey to detecting igneous bodies. The slight difference in magnetism between igneous bodies and their surrounding rocks is measured first and then the magnetic survey data are processed to determine whether there exist igneous bodies by analog among several measuring lines, and finally the modified Marquart inversion was used to determine the occurrence and distribution of the igneous bodies.展开更多
A considerable effort has been made in the literature for quality assurance (QA) and quality checking (QC) of the petrophysical log data for computation of reservoir rock property parameters. Well log data plays an in...A considerable effort has been made in the literature for quality assurance (QA) and quality checking (QC) of the petrophysical log data for computation of reservoir rock property parameters. Well log data plays an integral role in building a rock physics model for quantitative interpretation (QI) work. A poor-quality rock physics model may lead to significant financial and HSSE implications by drilling wells in undesired locations. Historically, a variety of techniques have been used including histograms and cross plots for reviewing the feasibility of petrophysical logs for QI work. However, no attempt has ever been made to introduce a simplified workflow. This paper serves two-fold. It provides a simplified step by step approach for building a petrophysics/rock physics model. A case study has been presented to compare the synthetic seismogram generated from the simplified workflow with the actual seismic trace at well locations. Secondly, the paper shows how a few key cross plots and rock property parameters provide adequate information to validate petrophysical data, distinguish overburden and reservoir sections, and to help identify fluids and saturation trends within the reservoir sands. In the mentioned case study, the robustness of the simplified rock physics model has helped seismic data to successfully distinguish hydrocarbon bearing reservoir sands from non-reservoir shales.展开更多
With the popularization and application of fast drilling technology in Sichuan-Chongqing gas provinces,the returned cuttings are fine and even powdered,so the traditional cutting lithology identification methods are n...With the popularization and application of fast drilling technology in Sichuan-Chongqing gas provinces,the returned cuttings are fine and even powdered,so the traditional cutting lithology identification methods are not applicable any longer.In this paper,qualitative lithology identification and quantitative interpretation based on element logging were conducted on the key oil and gas bearing layers in this area according to the principle of elemental geochemistry.The study results show that:(1)different lithologies can be identified easily because of their different element logging characteristics.For example,basalts have the element characteristics of 0.35<Fe/Si<0.55 and Ca/(Na+K)<4.00,while sedimentary rocks have Fe/Si<0.35 or>0.55.(2)Clastic rocks,carbonate rocks,sulphate and transition rocks in the category of sedimentary rocks can be identified based on the element combination of(Al+Si+Fe)and(Ca+Mg+S).Among them,clastic rocks have(Al+Si+Fe)>31%,carbonate rocks have(Al+Si+Fe)<8%and(Ca+Mg+S)<36%,and sulphate rocks have(Al+Si+Fe)<5%and(Ca+Mg+S)>36%.(3)Then,based on the element combination of(Si+K+Ca)tSi/Al and(Al+Si+Fe+K)t(Ca+S)/Mg,sandstone,mudstone(shale),gypsum,dolomite,limestone and transition rocks can be identified.Finally,a qualitative identification chart and a set of quantitative interpretation software of element logging on key horizons in Sichuan-Chongqing gas provinces were developed to make this method convenient for field application.This method was applied on site in ten wells(such as Well MX207)in Sichuan-Chongqing gas provinces.It is indicated that the coincidence rate of lithology identification is in the range of 88.75-95.22%(averaging 92.42%).Obviously,it can satisfy the requirements of fast lithology identification while drilling of key oil and gas horizons in Sichuan-Chongqing gas provinces.展开更多
This paper presents an automatic techruque of suitable reference potential selection for quantitative EEG interpretation.The 16-channels EEG recording under mono-polar derivation is analyzed.There are two prejudgments...This paper presents an automatic techruque of suitable reference potential selection for quantitative EEG interpretation.The 16-channels EEG recording under mono-polar derivation is analyzed.There are two prejudgments defined for checking the amplitude distribution and ear lobe activation.After prejudgments,the EEG is classified into several cases in cluding diffused case,non-diffused case,and artifact contami nation case.Due to the cases,an automatic reference selection method is applied in order to find out suitable reference potential.Finally,the referential derivation constructed according to the obtained reference potential,is evaluated for further EEG rhythm analysis.The presented technique can high light the EEG rhythm of interest,which is useful for quantitative EEG interpretation by both visual inspection and automatic evaluation.展开更多
This paper proposes a new neural algorithm to perform the segmentation of an observed scene into regions corresponding to different moving objects byanalyzing a time-varying images sequence. The method consists of a c...This paper proposes a new neural algorithm to perform the segmentation of an observed scene into regions corresponding to different moving objects byanalyzing a time-varying images sequence. The method consists of a classificationstep, where the motion of small patches is characterized through an optimizationapproach, and a segmentation step merging neighboring patches characterized bythe same motion. Classification of motion is performed without optical flow computation, but considering only the spatial and temporal image gradients into anappropriate energy function minimized with a Hopfield-like neural network givingas output directly the 3D motion parameter estimates. Network convergence is accelerated by integrating the quantitative estimation of motion parameters with aqualitative estimate of dominant motion using the geometric theory of differentialequations.展开更多
文摘The present paper investigates the application of high resolution magnetic survey to detecting igneous bodies. The slight difference in magnetism between igneous bodies and their surrounding rocks is measured first and then the magnetic survey data are processed to determine whether there exist igneous bodies by analog among several measuring lines, and finally the modified Marquart inversion was used to determine the occurrence and distribution of the igneous bodies.
文摘A considerable effort has been made in the literature for quality assurance (QA) and quality checking (QC) of the petrophysical log data for computation of reservoir rock property parameters. Well log data plays an integral role in building a rock physics model for quantitative interpretation (QI) work. A poor-quality rock physics model may lead to significant financial and HSSE implications by drilling wells in undesired locations. Historically, a variety of techniques have been used including histograms and cross plots for reviewing the feasibility of petrophysical logs for QI work. However, no attempt has ever been made to introduce a simplified workflow. This paper serves two-fold. It provides a simplified step by step approach for building a petrophysics/rock physics model. A case study has been presented to compare the synthetic seismogram generated from the simplified workflow with the actual seismic trace at well locations. Secondly, the paper shows how a few key cross plots and rock property parameters provide adequate information to validate petrophysical data, distinguish overburden and reservoir sections, and to help identify fluids and saturation trends within the reservoir sands. In the mentioned case study, the robustness of the simplified rock physics model has helped seismic data to successfully distinguish hydrocarbon bearing reservoir sands from non-reservoir shales.
基金Project supported by the Science and Technology Project of CNPC Chuanqing Drilling Engineering Co.,Ltd“Element logging features of key horizons and application in SichuaneChongqing gas provinces”(No.:CQ2014B-14-1-1).
文摘With the popularization and application of fast drilling technology in Sichuan-Chongqing gas provinces,the returned cuttings are fine and even powdered,so the traditional cutting lithology identification methods are not applicable any longer.In this paper,qualitative lithology identification and quantitative interpretation based on element logging were conducted on the key oil and gas bearing layers in this area according to the principle of elemental geochemistry.The study results show that:(1)different lithologies can be identified easily because of their different element logging characteristics.For example,basalts have the element characteristics of 0.35<Fe/Si<0.55 and Ca/(Na+K)<4.00,while sedimentary rocks have Fe/Si<0.35 or>0.55.(2)Clastic rocks,carbonate rocks,sulphate and transition rocks in the category of sedimentary rocks can be identified based on the element combination of(Al+Si+Fe)and(Ca+Mg+S).Among them,clastic rocks have(Al+Si+Fe)>31%,carbonate rocks have(Al+Si+Fe)<8%and(Ca+Mg+S)<36%,and sulphate rocks have(Al+Si+Fe)<5%and(Ca+Mg+S)>36%.(3)Then,based on the element combination of(Si+K+Ca)tSi/Al and(Al+Si+Fe+K)t(Ca+S)/Mg,sandstone,mudstone(shale),gypsum,dolomite,limestone and transition rocks can be identified.Finally,a qualitative identification chart and a set of quantitative interpretation software of element logging on key horizons in Sichuan-Chongqing gas provinces were developed to make this method convenient for field application.This method was applied on site in ten wells(such as Well MX207)in Sichuan-Chongqing gas provinces.It is indicated that the coincidence rate of lithology identification is in the range of 88.75-95.22%(averaging 92.42%).Obviously,it can satisfy the requirements of fast lithology identification while drilling of key oil and gas horizons in Sichuan-Chongqing gas provinces.
基金Grant sponsor:National Natural Science Foundation of China,grant number:61074113grant sponsor:Shanghai Leading Academic Discipline Project,grant number:B504grant sponsor:Fundamental Research Funds for the Central Universities,grant number:WH0914028
文摘This paper presents an automatic techruque of suitable reference potential selection for quantitative EEG interpretation.The 16-channels EEG recording under mono-polar derivation is analyzed.There are two prejudgments defined for checking the amplitude distribution and ear lobe activation.After prejudgments,the EEG is classified into several cases in cluding diffused case,non-diffused case,and artifact contami nation case.Due to the cases,an automatic reference selection method is applied in order to find out suitable reference potential.Finally,the referential derivation constructed according to the obtained reference potential,is evaluated for further EEG rhythm analysis.The presented technique can high light the EEG rhythm of interest,which is useful for quantitative EEG interpretation by both visual inspection and automatic evaluation.
文摘This paper proposes a new neural algorithm to perform the segmentation of an observed scene into regions corresponding to different moving objects byanalyzing a time-varying images sequence. The method consists of a classificationstep, where the motion of small patches is characterized through an optimizationapproach, and a segmentation step merging neighboring patches characterized bythe same motion. Classification of motion is performed without optical flow computation, but considering only the spatial and temporal image gradients into anappropriate energy function minimized with a Hopfield-like neural network givingas output directly the 3D motion parameter estimates. Network convergence is accelerated by integrating the quantitative estimation of motion parameters with aqualitative estimate of dominant motion using the geometric theory of differentialequations.
