The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandston...The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandstone reservoirs because of their complex pore structure and large heterogeneity.Specifically,the method that is commonly used to characterize the reservoir pore structure is dependent on the nuclear magnetic resonance(NMR)transverse relaxation time(T2)distribution,which is closely related to the pore size distribution.Further,the pore structure parameters(displacement pressure,maximum pore-throat radius,and median pore-throat radius)can be determined and applied to reservoir classification based on the empirical linear or power function obtained from the NMR T2 distributions and the mercury intrusion capillary pressure ourves.However,the effective generalization of these empirical functions is difficult because they differ according to the region and are limited by the representative samples of different regions.A lognormal distribution is commonly used to describe the pore size and particle size distributions of the rock and quantitatively characterize the reservoir pore structure based on the volume,mean radius,and standard deviation of the small and large pores.In this study,we obtain six parameters(the volume,mean radius,and standard deviation of the small and large pores)that represent the characteristics of pore distribution and rock heterogeneity,calculate the total porosity via NMR logging,and classify the reservoirs via cluster analysis by adopting a bimodal lognormal distribution to fit the NMR T2 spectrum.Finally,based on the data obtained from the core tests and the NMR logs,the proposed method,which is readily applicable,can effectively classify the tight sandstone reservoirs.展开更多
In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper anal...In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper analyzes geomechanical parameters of sandstones of Dindifélo and basalt of Bafoundou belonging to the Proterozoic rocks domain of eastern Senegal. By Rock Mass Rating (RMR) and Geological Strength Index (GSI), sandstones of the Dindifello Cliff show fair to poor characteristics while basalts of the hills of Bafoundou are fair quality. In addition to the qualities of rock mass, Young moduli, uniaxial compressive strengths and tensile strength of rock mass are also defined using Rock Quality Designation (RQD) GSI, RMR. Hoek-Brown parameters m and a, depend both on the fracturation and the content fine in the rock. Values of mechanical parameters are different when deduced from RMR, GSI and from intact rock laboratory test. Those differences are due to variables taken account. The variation depends also on the quality of the rock. Statistical analysis shows possible unstabilities which depend on rock mass parameters but with acceptable probability of failure. Probability of failure is the highest when deducing from Mohr criterion than from Hoek-Brown criterion.展开更多
In this research,an integrated classification method based on principal component analysis-simulated annealing genetic algorithm-fuzzy cluster means(PCA-SAGA-FCM)was proposed for the unsupervised classification of tig...In this research,an integrated classification method based on principal component analysis-simulated annealing genetic algorithm-fuzzy cluster means(PCA-SAGA-FCM)was proposed for the unsupervised classification of tight sandstone reservoirs which lack the prior information and core experiments.A variety of evaluation parameters were selected,including lithology characteristic parameters,poro-permeability quality characteristic parameters,engineering quality characteristic parameters,and pore structure characteristic parameters.The PCA was used to reduce the dimension of the evaluation pa-rameters,and the low-dimensional data was used as input.The unsupervised reservoir classification of tight sandstone reservoir was carried out by the SAGA-FCM,the characteristics of reservoir at different categories were analyzed and compared with the lithological profiles.The analysis results of numerical simulation and actual logging data show that:1)compared with FCM algorithm,SAGA-FCM has stronger stability and higher accuracy;2)the proposed method can cluster the reservoir flexibly and effectively according to the degree of membership;3)the results of reservoir integrated classification match well with the lithologic profle,which demonstrates the reliability of the classification method.展开更多
目的:分析基于Triangle模型的分层分级延续护理在2型糖尿病(T2DM)病人中的应用效果。方法:纳入2021年11月—2022年11月在徐州医科大学附属宿迁医院接受治疗的120例T2DM病人,按随机数字表法分为观察组与对照组,各60例。对照组接受延续性...目的:分析基于Triangle模型的分层分级延续护理在2型糖尿病(T2DM)病人中的应用效果。方法:纳入2021年11月—2022年11月在徐州医科大学附属宿迁医院接受治疗的120例T2DM病人,按随机数字表法分为观察组与对照组,各60例。对照组接受延续性护理,观察组接受基于Triangle模型的分层分级延续性护理。于干预前、干预3个月时、干预6个月时评定病人血糖控制状况、自我管理能力、生活质量;并记录病人干预期间再住院次数。结果:干预3个月、6个月时,两组病人空腹血糖(FPG)、餐后2 h血糖(2 h PG)、糖化血红蛋白(HbA1c)水平明显低于干预前,糖尿病自我管理行为量表(SDSCA)得分高于干预前,中国糖尿病病人生存质量特异性量表(DSQL)得分低于干预前,且观察组病人各项指标改善优于对照组(P<0.05);但两组病人干预6个月时的各项指标与干预3个月时比较,差异无统计学意义(P>0.05);观察组病人再住院次数少于对照组(P<0.05)。结论:基于Triangle模型的分层分级延续性护理可提高T2DM病人的血糖控制水平、自我管理能力及生活质量,并减少再住院次数。展开更多
Background To investigate the classification and microsurgical treatment of foramen magnum meningioma(FMM).Methods We retrospectively analyzed 76 patients with FMM and classified them into two classifications,classifi...Background To investigate the classification and microsurgical treatment of foramen magnum meningioma(FMM).Methods We retrospectively analyzed 76 patients with FMM and classified them into two classifications,classification ABS according to the relationship between the FMM and the brainstem and classification SIM according to the relationship between the FMM and the vertebral artery(VA).All patients underwent either the far lateral approach(54 cases)or the suboccipital midline approach(22 cases).Results Of the 76 cases,47 cases were located ahead of the brainstem(A),16 cases at the back of the brainstem(B),and 13 cases were located laterally to the brainstem(S).There were 15 cases located superior to the VA(S),49 cases were inferior(I),and 12 cases were mixed type(M).Among 76 cases,71 cases were resected with Simpson grade 2(93.42%),3 with Simpson grade 3(3.95%),and 2 with Simpson grade 4(2.63%).We summarized four anatomical triangles:triangles SOT,VOT,JVV,and TVV.The mean postoperative Karnofsky performance score was improved in all patients(p<0.05).However,several complications occurred,including hoarseness and CSF leak.Conclusion ABS and SIM classifications are objective indices for choosing the surgical approach and predicting the difficulty of FMMs,and it is of great importance to master the content,position relationship with the tumor,and variable anatomical structures in the four"triangles"for the success of the operation.展开更多
基金supported by the by the National Science and Technology Major Project “Prediction Technique and Evaluation of Tight Oil Sweet Spot”(2016ZX05046-002)
文摘The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandstone reservoirs because of their complex pore structure and large heterogeneity.Specifically,the method that is commonly used to characterize the reservoir pore structure is dependent on the nuclear magnetic resonance(NMR)transverse relaxation time(T2)distribution,which is closely related to the pore size distribution.Further,the pore structure parameters(displacement pressure,maximum pore-throat radius,and median pore-throat radius)can be determined and applied to reservoir classification based on the empirical linear or power function obtained from the NMR T2 distributions and the mercury intrusion capillary pressure ourves.However,the effective generalization of these empirical functions is difficult because they differ according to the region and are limited by the representative samples of different regions.A lognormal distribution is commonly used to describe the pore size and particle size distributions of the rock and quantitatively characterize the reservoir pore structure based on the volume,mean radius,and standard deviation of the small and large pores.In this study,we obtain six parameters(the volume,mean radius,and standard deviation of the small and large pores)that represent the characteristics of pore distribution and rock heterogeneity,calculate the total porosity via NMR logging,and classify the reservoirs via cluster analysis by adopting a bimodal lognormal distribution to fit the NMR T2 spectrum.Finally,based on the data obtained from the core tests and the NMR logs,the proposed method,which is readily applicable,can effectively classify the tight sandstone reservoirs.
文摘In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper analyzes geomechanical parameters of sandstones of Dindifélo and basalt of Bafoundou belonging to the Proterozoic rocks domain of eastern Senegal. By Rock Mass Rating (RMR) and Geological Strength Index (GSI), sandstones of the Dindifello Cliff show fair to poor characteristics while basalts of the hills of Bafoundou are fair quality. In addition to the qualities of rock mass, Young moduli, uniaxial compressive strengths and tensile strength of rock mass are also defined using Rock Quality Designation (RQD) GSI, RMR. Hoek-Brown parameters m and a, depend both on the fracturation and the content fine in the rock. Values of mechanical parameters are different when deduced from RMR, GSI and from intact rock laboratory test. Those differences are due to variables taken account. The variation depends also on the quality of the rock. Statistical analysis shows possible unstabilities which depend on rock mass parameters but with acceptable probability of failure. Probability of failure is the highest when deducing from Mohr criterion than from Hoek-Brown criterion.
基金funded by the National Natural Science Foundation of China(42174131)the Strategic Cooperation Technology Projects of CNPC and CUPB(ZLZX2020-03).
文摘In this research,an integrated classification method based on principal component analysis-simulated annealing genetic algorithm-fuzzy cluster means(PCA-SAGA-FCM)was proposed for the unsupervised classification of tight sandstone reservoirs which lack the prior information and core experiments.A variety of evaluation parameters were selected,including lithology characteristic parameters,poro-permeability quality characteristic parameters,engineering quality characteristic parameters,and pore structure characteristic parameters.The PCA was used to reduce the dimension of the evaluation pa-rameters,and the low-dimensional data was used as input.The unsupervised reservoir classification of tight sandstone reservoir was carried out by the SAGA-FCM,the characteristics of reservoir at different categories were analyzed and compared with the lithological profiles.The analysis results of numerical simulation and actual logging data show that:1)compared with FCM algorithm,SAGA-FCM has stronger stability and higher accuracy;2)the proposed method can cluster the reservoir flexibly and effectively according to the degree of membership;3)the results of reservoir integrated classification match well with the lithologic profle,which demonstrates the reliability of the classification method.
文摘目的:分析基于Triangle模型的分层分级延续护理在2型糖尿病(T2DM)病人中的应用效果。方法:纳入2021年11月—2022年11月在徐州医科大学附属宿迁医院接受治疗的120例T2DM病人,按随机数字表法分为观察组与对照组,各60例。对照组接受延续性护理,观察组接受基于Triangle模型的分层分级延续性护理。于干预前、干预3个月时、干预6个月时评定病人血糖控制状况、自我管理能力、生活质量;并记录病人干预期间再住院次数。结果:干预3个月、6个月时,两组病人空腹血糖(FPG)、餐后2 h血糖(2 h PG)、糖化血红蛋白(HbA1c)水平明显低于干预前,糖尿病自我管理行为量表(SDSCA)得分高于干预前,中国糖尿病病人生存质量特异性量表(DSQL)得分低于干预前,且观察组病人各项指标改善优于对照组(P<0.05);但两组病人干预6个月时的各项指标与干预3个月时比较,差异无统计学意义(P>0.05);观察组病人再住院次数少于对照组(P<0.05)。结论:基于Triangle模型的分层分级延续性护理可提高T2DM病人的血糖控制水平、自我管理能力及生活质量,并减少再住院次数。
基金supported by the Scientific Research Fund of Liaoning Provincial Education Department(CN)(FWZR2020006)
文摘Background To investigate the classification and microsurgical treatment of foramen magnum meningioma(FMM).Methods We retrospectively analyzed 76 patients with FMM and classified them into two classifications,classification ABS according to the relationship between the FMM and the brainstem and classification SIM according to the relationship between the FMM and the vertebral artery(VA).All patients underwent either the far lateral approach(54 cases)or the suboccipital midline approach(22 cases).Results Of the 76 cases,47 cases were located ahead of the brainstem(A),16 cases at the back of the brainstem(B),and 13 cases were located laterally to the brainstem(S).There were 15 cases located superior to the VA(S),49 cases were inferior(I),and 12 cases were mixed type(M).Among 76 cases,71 cases were resected with Simpson grade 2(93.42%),3 with Simpson grade 3(3.95%),and 2 with Simpson grade 4(2.63%).We summarized four anatomical triangles:triangles SOT,VOT,JVV,and TVV.The mean postoperative Karnofsky performance score was improved in all patients(p<0.05).However,several complications occurred,including hoarseness and CSF leak.Conclusion ABS and SIM classifications are objective indices for choosing the surgical approach and predicting the difficulty of FMMs,and it is of great importance to master the content,position relationship with the tumor,and variable anatomical structures in the four"triangles"for the success of the operation.
