While computer modeling of annular displacement efficiency is widely applied in cementing engineering,modeling the displacement flow inside a casing or drill string for cementing operations has received less attention.Although predicting displacement efficiency inside a full-length pipe is desired by cementing engineers,the attempt of developing a model with both efficiency and accuracy faces challenges.Access to computer simulators for this purpose is limited.Compared with annular flow,the displacement flow inside pipe,although within a simpler geometry and without eccentricity effect,is not simpler in physics,modelling strategy and predictability,because a variety of flow patterns and flow instabilities can develop to create complicated fluid interfaces.In this paper,we present an integrated numerical model developed to simulate displacement flows inside a full-length pipe,which connects an existing annulus model to enable complete displacement simulations of cementing jobs.The model uses three-dimensional grid to solve fluid concentrations with degrees of mixing,and incorporates flow instability detection and flow regime determination.Applied in cementing,the model accounts for effects of pumping rate,well inclination,pipe rotation,fluid densities,rheological parameters and more.This computationally efficient model does not rely on high-resolution mesh as often required by conventional Computational Fluid Dynamics models,thus it is suitable to be implemented in a cementing software for daily use by well cementing engineers.The methodology of the model is discussed in detail in this paper.To validate the model,we examine simulation results against experimental results obtained in our laboratory tests and CFD simulations;acceptable agreement is found under different testing conditions.We also presented two case studies of real cementing jobs with cement evaluation logs compared to simulation results,showing that the model can predict consistent displacement efficiency results.
Hu DaiAli EslamiJason SchneiderGefei LiuFred Schwering
Six degrees of freedom(6DoF)input interfaces are essential formanipulating virtual objects through translation or rotation in three-dimensional(3D)space.A traditional outside-in tracking controller requires the installation of expensive hardware in advance.While inside-out tracking controllers have been proposed,they often suffer from limitations such as interaction limited to the tracking range of the sensor(e.g.,a sensor on the head-mounted display(HMD))or the need for pose value modification to function as an input interface(e.g.,a sensor on the controller).This study investigates 6DoF pose estimation methods without restricting the tracking range,using a smartphone as a controller in augmented reality(AR)environments.Our approach involves proposing methods for estimating the initial pose of the controller and correcting the pose using an inside-out tracking approach.In addition,seven pose estimation algorithms were presented as candidates depending on the tracking range of the device sensor,the tracking method(e.g.,marker recognition,visual-inertial odometry(VIO)),and whether modification of the initial pose is necessary.Through two experiments(discrete and continuous data),the performance of the algorithms was evaluated.The results demonstrate enhanced final pose accuracy achieved by correcting the initial pose.Furthermore,the importance of selecting the tracking algorithm based on the tracking range of the devices and the actual input value of the 3D interaction was emphasized.
After a number of oficals were found guilty of accepting large bribes for costly cosmetic services,experts are calling out the toxic culture within China's officialdom that excessively values appearance and beauty.
China's Manufacturing Activity Expands in March Manufacturing in China expanded in March,following five consecutive months of contraction,as industrial activity rebounded following the Chinese New Year holiday.The official Purchasing Managers'Index(PMI),increased from 49.1 in February to 50.8 in March.The PMI operates on a scale of 0 to 100,with 50 marking the cutoff between contraction and expansion..
China Issues 50-year Ultra-long Special Treasury Bonds in Major Boost for Economy China issued the year's first batch of ultra-long special treasury bonds on June 14.The 50-year bonds,issued on the Beijing Stock Exchange were worth a total of RMB35 billion(USD4.82 billion)at an interest rate of 2.53%.The bonds received strong institutional demand as they were heavily oversubscribed,according to Global Times.
Fast-fashion Giant Shein Files for IPO Fast fashion company Shein has made a confidential filing to make a public listing in the United States.Reported by sources familiar with the matter,it would make Shein one of the most valuable Chinese-founded companies to list on the New York Stock Exchange.
Biggest Apple Store in Asia Opens in Shanghai.Apple CEO Tim Cook has demonstrated his commitment to the Chinese market by inaugurating the company's latest flagship store in Shanghai to an eager crowd on March 21,some of whom had camped out since the previous day.Situated across from the historic jing'an Temple,the new outlet is Apple's 57th in China and its eighth in Shanghai,securing its position as the second-largest Apple store globally,following the iconic Fifth Avenue store in New York city.Speaking with local media,Cook praised China's advanced manufacturing capabilities and well-trained workers while also promising increased investment in the country.
