To resolve the issue of design for multi-stage and multi-cluster fracturing in multi-zone reservoirs, a new efficient algorithm for the planar 3 D multi-fracture propagation model was proposed. The model considers flu...To resolve the issue of design for multi-stage and multi-cluster fracturing in multi-zone reservoirs, a new efficient algorithm for the planar 3 D multi-fracture propagation model was proposed. The model considers fluid flow in the wellbore-perforation-fracture system and fluid leak-off into the rock matrix, and uses a 3 D boundary integral equation to describe the solid deformation. The solid-fluid coupling equation is solved by an explicit integration algorithm, and the fracture front is determined by the uniform tip asymptotic solutions and shortest path algorithm. The accuracy of the algorithm is verified by the analytical solution of radial fracture, results of the implicit level set algorithm, and results of organic glass fracturing experiment. Compared with the implicit level set algorithm(ILSA), the new algorithm is much higher in computation speed. The numerical case study is conducted based on a horizontal well in shale gas formation of Zhejiang oilfield. The impact of stress heterogeneity among multiple clusters and perforation number distribution on multi-fracture growth and fluid distribution among multiple fractures are analyzed by numerical simulation. The results show that reducing perforation number in each cluster can counteract the effect of stress contrast among perforation clusters. Adjusting perforation number in each cluster can promote uniform flux among clusters, and the perforation number difference should better be 1-2 among clusters. Increasing perforation number in the cluster with high in situ stress is conducive to uniform fluid partitioning. However, uniform fluid partitioning is not equivalent to uniform fracture geometry. The fracture geometry is controlled by the stress interference and horizontal principal stress profile jointly.展开更多
目的:探讨三维可变反转角快速自旋回波(3D sampling perfection with application optimized contrasts using different flip angle evolution,3D-SPACE)序列在直肠癌术前T分期中的临床应用价值。方法:回顾性分析复旦大学附属肿瘤医院2...目的:探讨三维可变反转角快速自旋回波(3D sampling perfection with application optimized contrasts using different flip angle evolution,3D-SPACE)序列在直肠癌术前T分期中的临床应用价值。方法:回顾性分析复旦大学附属肿瘤医院2015年12月—2016年11月经肠镜活检确诊为直肠癌的患者,其术前未接受放化疗,但行直肠MRI检查。共收集178例,其中107例肿瘤轴位T2WI使用薄层小视野(field of view,FOV)T2WI序列(以下简称高分辨率T2WI序列),71例使用3D SPACE的T2WI序列(以下简称3D SPACE序列),并于2周内进行手术。将MRI所得T分期结果与病理结果进行对照分析,比较两种MRI技术评估直肠癌T分期的灵敏度、特异度、准确率。结果:高分辨率T2WI序列诊断T分期的总准确率为75.7%,3D SPACE序列诊断总准确率为83.0%。对早期T1、T2期的诊断准确率(T1:98.6%vs.88.8%;T2:87.3%vs.75.7%),3D SPACE序列均高于高分辨率T2WI序列;对T3期的诊断准确率,两者相当(85.9%vs.86.0%);而对T4期的诊断,3D SPACE序列优势不明显(95.8%vs.99.1%)。结论:3D SPACE序列可获得高信号比、高分辨率图像,提高直肠癌T分期的准确率,尤其对早期直肠癌的诊断有优势。展开更多
目的:探讨并分析MRI弥散加权成像(DWI)联合3D-VIBE序列动态增强扫描在卵巢癌分期中的应用。方法:回顾性分析2013年1月—2017年5月期间我院38例术前均行M R I弥散加权成像及3D-V I B E序列动态增强扫描且术后病理结果证实为卵巢癌患者的...目的:探讨并分析MRI弥散加权成像(DWI)联合3D-VIBE序列动态增强扫描在卵巢癌分期中的应用。方法:回顾性分析2013年1月—2017年5月期间我院38例术前均行M R I弥散加权成像及3D-V I B E序列动态增强扫描且术后病理结果证实为卵巢癌患者的临床资料,比较分析A组(MRI平扫+弥散加权成像)及B组(MRI平扫+弥散加权成像+3D-VIBE序列动态增强扫描)两组对诊断及分期的符合率。结果:A组对卵巢癌的诊断符合率为86.8%(33/38),B组为92.1%(35/38),B组优于A组(χ~2=2.2027,P<0.05)。A组分期诊断准确性为84.2%(32/38),B组分期诊断准确性为92.1(35/38),B组优于A组(χ~2=3.0964,P<0.05);B组对子宫、输卵管、其它盆腔组织、腹膜及网膜种植、淋巴结转移病灶数目的诊断敏感度高于A组;A组对卵巢癌转移病灶数目的诊断总符合率为86.6%(232/268)明显低于B组的92.2%(247/268)(χ~2=15.1440,P<0.05)。结论:MRI对卵巢癌的诊断有较高的临床价值,与平扫+DWI序列相比,MRI平扫+DWI+3D-VIBE序列动态增强扫描对卵巢癌的定性及分期的诊断符合率更高。展开更多
基金China National Science and Technology Major Project(2016ZX05023).
文摘To resolve the issue of design for multi-stage and multi-cluster fracturing in multi-zone reservoirs, a new efficient algorithm for the planar 3 D multi-fracture propagation model was proposed. The model considers fluid flow in the wellbore-perforation-fracture system and fluid leak-off into the rock matrix, and uses a 3 D boundary integral equation to describe the solid deformation. The solid-fluid coupling equation is solved by an explicit integration algorithm, and the fracture front is determined by the uniform tip asymptotic solutions and shortest path algorithm. The accuracy of the algorithm is verified by the analytical solution of radial fracture, results of the implicit level set algorithm, and results of organic glass fracturing experiment. Compared with the implicit level set algorithm(ILSA), the new algorithm is much higher in computation speed. The numerical case study is conducted based on a horizontal well in shale gas formation of Zhejiang oilfield. The impact of stress heterogeneity among multiple clusters and perforation number distribution on multi-fracture growth and fluid distribution among multiple fractures are analyzed by numerical simulation. The results show that reducing perforation number in each cluster can counteract the effect of stress contrast among perforation clusters. Adjusting perforation number in each cluster can promote uniform flux among clusters, and the perforation number difference should better be 1-2 among clusters. Increasing perforation number in the cluster with high in situ stress is conducive to uniform fluid partitioning. However, uniform fluid partitioning is not equivalent to uniform fracture geometry. The fracture geometry is controlled by the stress interference and horizontal principal stress profile jointly.
文摘目的:探讨三维可变反转角快速自旋回波(3D sampling perfection with application optimized contrasts using different flip angle evolution,3D-SPACE)序列在直肠癌术前T分期中的临床应用价值。方法:回顾性分析复旦大学附属肿瘤医院2015年12月—2016年11月经肠镜活检确诊为直肠癌的患者,其术前未接受放化疗,但行直肠MRI检查。共收集178例,其中107例肿瘤轴位T2WI使用薄层小视野(field of view,FOV)T2WI序列(以下简称高分辨率T2WI序列),71例使用3D SPACE的T2WI序列(以下简称3D SPACE序列),并于2周内进行手术。将MRI所得T分期结果与病理结果进行对照分析,比较两种MRI技术评估直肠癌T分期的灵敏度、特异度、准确率。结果:高分辨率T2WI序列诊断T分期的总准确率为75.7%,3D SPACE序列诊断总准确率为83.0%。对早期T1、T2期的诊断准确率(T1:98.6%vs.88.8%;T2:87.3%vs.75.7%),3D SPACE序列均高于高分辨率T2WI序列;对T3期的诊断准确率,两者相当(85.9%vs.86.0%);而对T4期的诊断,3D SPACE序列优势不明显(95.8%vs.99.1%)。结论:3D SPACE序列可获得高信号比、高分辨率图像,提高直肠癌T分期的准确率,尤其对早期直肠癌的诊断有优势。
文摘目的:探讨并分析MRI弥散加权成像(DWI)联合3D-VIBE序列动态增强扫描在卵巢癌分期中的应用。方法:回顾性分析2013年1月—2017年5月期间我院38例术前均行M R I弥散加权成像及3D-V I B E序列动态增强扫描且术后病理结果证实为卵巢癌患者的临床资料,比较分析A组(MRI平扫+弥散加权成像)及B组(MRI平扫+弥散加权成像+3D-VIBE序列动态增强扫描)两组对诊断及分期的符合率。结果:A组对卵巢癌的诊断符合率为86.8%(33/38),B组为92.1%(35/38),B组优于A组(χ~2=2.2027,P<0.05)。A组分期诊断准确性为84.2%(32/38),B组分期诊断准确性为92.1(35/38),B组优于A组(χ~2=3.0964,P<0.05);B组对子宫、输卵管、其它盆腔组织、腹膜及网膜种植、淋巴结转移病灶数目的诊断敏感度高于A组;A组对卵巢癌转移病灶数目的诊断总符合率为86.6%(232/268)明显低于B组的92.2%(247/268)(χ~2=15.1440,P<0.05)。结论:MRI对卵巢癌的诊断有较高的临床价值,与平扫+DWI序列相比,MRI平扫+DWI+3D-VIBE序列动态增强扫描对卵巢癌的定性及分期的诊断符合率更高。
