reverse redistribution pattern is defined as decreased activity in the myocardium in the rest phase of the myocardial perfusion scan in comparison with the stress images. there are many studies concerning the etiology and clinical significant of this phenomenon in nuclear medicine literature. the dominant idea about etiology of reverse redistribution is early wash out of the radiotracer from th...

The complex formation pressure system and diverse fluid components during deepwater deep drilling make it easy for gas intrusion accidents to occur. dissolution suspension of the intruded in difference between gas–liquid phase distribution characteristics gas–water two-phase flow wellbore lead errors calculation overflow assessment after intrusion. In this article, a multiphase model, consideri...

A transient fully coupled model is proposed to investigate the two-phase flow of CO2 and water-based fluid in a wellbore, considering complex mass heat transfer different patterns dynamic coupling between wellbore reservoir. Based on conservation, momentum, energy balance, employs state-of-the-art equation state transport models analyze variations multiphase behaviors properties wellbore. Appli...

This paper describes a combined field, laboratory, and numerical study of electromagnetic borehole flowmeter measurements acquired without the use of a packer or skirt to block bypass flow around the flowmeter. The most significant finding is that inflow through the wellbore screen changes the ratio of flow through the flowmeter to wellbore flow. Experiments reveal up to a factor of two differe...

We investigate the initiation and early-stage propagation of an axi-symmetric hydraulic fracture from a wellbore drilled in the direction of the minimum principal stress in an elastic and impermeable formation. Such a configuration is akin to the case of a horizontal well and a hydraulic fracture transverse to the well axis in an open hole completion. In addition to the effect of the wellbore o...

Stress state analysis to casing-cement sheathformation system (CCSFS) is the foundation of the wellbore integrity design and examination. Many elastic mechanic models have been established to calculate the stresses and displacements of CCFS, but all analytical models and most finite element models took no account of the initial loaded state, and ignored the initial stresses and displacements on...

Understanding and quantification of wellbore skin improves our ability to accurately measure or estimate hydrologic parameters with tests at wells such as pumping tests, flowmeter tests, and slug tests. This paper presents observations and results from a series of field, laboratory, and modeling tests which, together, explain the source of wellbore skin at wells at a research wellfield and whic...

An Offshore China/South China Sea operator wanted to optimize the use of rotary steerable drilling assembly, simplify and reduce operational steps, and provide a larger reservoir wellbore. The operator elected to drill a single 8.5” wellbore and, in order to address a variety of issues and potential problems, change from a Cloud Point Glycol Drilling Fluid to a DrillIn Fluid (DIF) at the reserv...

The formation pressure plays a very important role in drilling engineering. So it is of great significance to predict formation pressure before drilling. In order to solve the problem, the concept of formation matrix and wellbore matrixwere put forward. Also the method of epitaxial transplantation for the regional formation pressurewas proposed. With the concept of wellbore pressure matrix, the...