A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale ...A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed.The dynamic seepage process of fracking-soaking-backflow-production integration was simulated,which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery(EOR).The seepage of tight/shale reservoirs can be divided into three stages:strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures,weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores,and weak displacement and weak imbibition at dynamic equilibrium.The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery.However,if the displacement pressure is too high,the injected water is easy to break through the front and reduce the recovery degree.The higher the permeability,the greater the imbibition and displacement recovery,the shorter the time of imbibition balance,and the higher the final recovery.The fractures can effectively increase the imbibition contact area between matrix and water,reduce the oil-water seepage resistance,promote the oil-water displacement between matrix and fracture,and improve the oil displacement rate and recovery of the matrix.The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid;also,the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.展开更多
目的:探讨结肠癌诊断中应用低剂量CT结肠成像结合增强扫描的价值。方法:选择我院2016年1月—2017年6月门诊接待的诊查疑似结肠癌患者100例作为研究对象,纳入对象愿意配合本研究,有完整资料,按照随机数表法分组,每组50例,对照组接受常规...目的:探讨结肠癌诊断中应用低剂量CT结肠成像结合增强扫描的价值。方法:选择我院2016年1月—2017年6月门诊接待的诊查疑似结肠癌患者100例作为研究对象,纳入对象愿意配合本研究,有完整资料,按照随机数表法分组,每组50例,对照组接受常规剂量CT结肠成像诊断,研究组接受低剂量CT结肠成像诊断,并根据情况结合增强扫描,将病理结果作为金标准,观察与统计两组诊断的特异性、敏感性及约登指数,并记录两组的辐射剂量情况,利用统计学软件S P S S20.0处理。结果:对照组诊断敏感性、特异性、约登指数依次为96.88%、94.44%、0.92,研究组则依次为100.00%、88.89%、0.85,两组比较差异无统计学意义(P>0.05);研究组CT扫描有效辐射剂量为15.18±4.22msv,对照组则为22.38±5.27msv,同时研究组放射剂量长度乘积明显低于对照组,两组比较差异有统计学意义(P<0.05)。结论:低剂量CT结肠成像结合增强扫描诊断结肠癌在特异性、敏感性及约登指数上可取得与常规剂量CT扫描相似的效果,但可以更好地减少受检者的辐射剂量,安全性更好,值得借鉴。展开更多
基金Supported by the PetroChina Science and Technology Major Project(2021-117)PetroChina CCUS Major Science and Technology Project(2021ZZ01-03)。
文摘A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance(NMR)and CT scanning.The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed.The dynamic seepage process of fracking-soaking-backflow-production integration was simulated,which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery(EOR).The seepage of tight/shale reservoirs can be divided into three stages:strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures,weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores,and weak displacement and weak imbibition at dynamic equilibrium.The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery.However,if the displacement pressure is too high,the injected water is easy to break through the front and reduce the recovery degree.The higher the permeability,the greater the imbibition and displacement recovery,the shorter the time of imbibition balance,and the higher the final recovery.The fractures can effectively increase the imbibition contact area between matrix and water,reduce the oil-water seepage resistance,promote the oil-water displacement between matrix and fracture,and improve the oil displacement rate and recovery of the matrix.The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid;also,the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.
文摘目的:探讨结肠癌诊断中应用低剂量CT结肠成像结合增强扫描的价值。方法:选择我院2016年1月—2017年6月门诊接待的诊查疑似结肠癌患者100例作为研究对象,纳入对象愿意配合本研究,有完整资料,按照随机数表法分组,每组50例,对照组接受常规剂量CT结肠成像诊断,研究组接受低剂量CT结肠成像诊断,并根据情况结合增强扫描,将病理结果作为金标准,观察与统计两组诊断的特异性、敏感性及约登指数,并记录两组的辐射剂量情况,利用统计学软件S P S S20.0处理。结果:对照组诊断敏感性、特异性、约登指数依次为96.88%、94.44%、0.92,研究组则依次为100.00%、88.89%、0.85,两组比较差异无统计学意义(P>0.05);研究组CT扫描有效辐射剂量为15.18±4.22msv,对照组则为22.38±5.27msv,同时研究组放射剂量长度乘积明显低于对照组,两组比较差异有统计学意义(P<0.05)。结论:低剂量CT结肠成像结合增强扫描诊断结肠癌在特异性、敏感性及约登指数上可取得与常规剂量CT扫描相似的效果,但可以更好地减少受检者的辐射剂量,安全性更好,值得借鉴。
