Prediction of Flooding in Packed Liquid-Liquid and High-Pressure Extraction Columns Using a Gaussian Process

Reliable prediction of flooding conditions is needed for sizing and operating packed extraction columns. Due to the complex interplay of physicochemical properties, operational parameters and the packing-specific properties, it is challenging to develop accurate semi-empirical or rigorous models with a high validity range. State of the art models may therefore fail to predict flooding accurately. To overcome this problem, a data-driven model based on Gaussian processes is developed to predict flooding for packed liquid-liquid and high-pressure extraction columns. The optimized Gaussian process for the liquid-liquid extraction column results in an average absolute relative error (AARE) of 15.23 %, whereas the algorithm for the high-pressure extraction column results in an AARE of 13.68 %. Both algorithms can predict flooding curves for different packing geometries and chemical systems precisely.     

碱法造纸黑液驱油研究

在玻璃细珠充填柱人造岩心模型上进行了碱法造纸黑液驱替稠油的实验研究，考察了稠油酸值、盐、温度、岩心渗透率、注入量和注入方式的影响。在实验条件下碱法造纸黑液驱稠油的采收率较水驱提高２５％     

A VERSATILE CORRELATION OF LIQUID HOLD-UP IN TWO-PHASE COUNTER-CURRENT TRICKLE BED COLUMN

A new definition of the flooding point in a two-phase counter-current trickle bed column has been proposed. Based on this point a versatile correlation of liquid hold-up has been formulated. The coefficients of this correlation are invariant to the change of physical properties of liquid, type and size of the packing forming the bed and gas velocity. This conclusion has been reached from the analysis of experiments with four different liquids irrigating the bed and three types of packing of various size. The versatile correlation can be used also re-currently to calculate flooding hold-up and flooding liquid rate from two known values of liquid hold-up for a given gas rate.     

多冗余点到点链路下OSPF扩散算法的一种改进方案

文章讨论了OSPF路由协议的扩散算法在多冗余点到点链路情况下存在的缺陷,提出了一种基于扩散接口选举的改进方案。     

注高温热水管线缓蚀,阻垢实验研究

针对辽河油田高凝油区块注高温热水(85—95℃)引起的腐蚀、结垢,开展了室内和现场缓蚀、阻垢试验;分析了不同温度下注水的腐蚀情况,对比、考察了不同的缓蚀剂、阻垢剂及其复配物,得出了如下认识:在注高温热水条件下直接采用常温下使用的防腐蚀、防垢方法是不可行的,必须有针对性地进行高温条件下防腐蚀、防垢的实验研究工作。     

高渗透稠油油藏氮气泡沫驱现场实践与认识

八面河油田面14区沙河街组沙三上段属于高孔高渗透普通稠油油藏,受储层非均质性,注水、边水推进等原因,在油田开发过程中表现出含水上升快,产量自然递减快,采出程度低的开发特点。针对高渗透稠油油藏特高含水开发初期稳油控水,2007年开展了整体氮气泡沫驱现场试验,取得了显著的控水增油效果,投入产出比为1∶7.0。研究结果对于同类油田氮气驱提高采收率具有一定的借鉴意义。     

压力监测资料在注水开发油田的应用

合理的压力驱替系统对低渗透油藏的高效开发至关重要,而影响此因素的注水参数、注水方式及注采综合调控措施的选取则与注水开发过程中各项压力监测资料息息相关。王窑区是安塞油田最早注水开发的区块,在长达20多年的开发过程中,逐步形成了以压力监测资料为主,结合开发动态资料确定调整措施的经验和方法,对安塞油田开发具有十分重要的指导意义,也为低渗透同类油藏提供借鉴经验。     

八面河油田近年注水开发工作的实践与认识

八面河油田油藏类型多样,开发方式多样,其中注水开发储量占全油田动用储量的61%。近年来,为改善注水开发油藏开采效果,保持产量稳定,油田针对各区块注水开发中存在的问题,在面4区面5块、广北8块、面14区沙三上采取了完善注采井网,注水井注氮调剖,水井动态调水以及改善水质等方面的工作,初步取得了较好的效果。     

Utilizing bloom filters for detecting flooding attacks against SIP based services

Any application or service utilizing the Internet is exposed to both general Internet attacks and other specific ones. Most of the times the latter are exploiting a vulnerability or misconfiguration in the provided service and/or in the utilized protocol itself. Consequently, the employment of critical services, like Voice over IP (VoIP) services, over the Internet is vulnerable to such attacks and, on top of that, they offer a field for new attacks or variations of existing ones. Among the various threats–attacks that a service provider should consider are the flooding attacks, at the signaling level, which are very similar to those against TCP servers but have emerged at the application level of the Internet architecture. This paper examines flooding attacks against VoIP architectures that employ the Session Initiation Protocol (SIP) as their signaling protocol. The focus is on the design and implementation of the appropriate detection method. Specifically, a bloom filter based monitor is presented and a new metric, named session distance, is introduced in order to provide an effective protection scheme against flooding attacks. The proposed scheme is evaluated through experimental test bed architecture under different scenarios. The results of the evaluation demonstrate that the required time to detect such an attack is negligible and also that the number of false alarms is close to zero.     

A P2P strategy for QoS discovery and SLA negotiation in Grid environment

In recent years, Grid systems and Peer to Peer networks are the most commonly-used solutions to achieve the same goal: the sharing of resources and services in heterogeneous, dynamic, distributed environments. Many studies have proposed hybrid approaches that try to conjugate the advantages of the two models. This paper proposes an architecture that integrates the P2P interaction model in Grid environments, so as to build an open cooperative model wherein Grid entities are composed in a decentralized way. In particular, this paper focuses on a QoS aware discovery algorithm for P2P Grid systems, analyzing protocol and explaining techniques used to improve its performance.