A Model Approach to Analytically Identify Stuck Pipe and Its Mechanism in Wellbore

Stuck pipe incidents translate to non-productive time. There is a need to mitigate stuck pipe incidents which can be achieved by conforming to recommended practices. Also, quick diagnosis is necessary in order to free a stuck pipe. Trial-and-error method can further complicate the situation. This work aims at diagnosing stuck pipe mechanisms and recommend practices to free a stuck pipe. spANALYZE also estimates the axial force and torque needed to free a stuck pipe caused by differential sticking. spANALYZE is a thick desktop client application developed in C# using the Microsoft Visual Studio 2019 development environment. It is an object-oriented .NET application that utilizes the Windows Presentation Foundation (WPF) architecture for its user interface. Each of the analyzers within spANALYZE were implemented generically as a list of nodes, representing the concept of a flow chart. New analyzers can easily be added simply by programmatically defining each node in the flow chart. Each node has a node identifier, a node type, node text, and the node identifiers of each answer – yes, no and restricted. spANALYZE presents the following benefits: quick and early detection of stuck pipe mechanisms, propose recommended action steps to free pipe, calculate stuck pipe depth, compute the torque and axial force needed to free a stuck string.

Topology Optimization for Heterogeneous DHT-Based Multicast

Since the deployment of IP multicast remains restricted due to many practical and political issues, researchers have shifted focus to exploiting application-layer multicast for multicast data delivery. Recently there has been considerable interest in applying DHT routing algorithms to application-level multicast. However, early DHT-based multicast protocols are insufficient in addressing a number of technical issues such as heterogeneous capacity of nodes or node churn. In this chapter, the author describes a solution called BAM-Chord (i.e., Bandwidth Adaptive Multicast over Chord) that optimizes the topology of a multicast tree based on node bandwidth. In the proposed solution, node position (i.e., node identifier) on a BAM-Chord ring will be decided based on node bandwidth capacity such that it can build a wide and balanced multicast tree rooted at the source node. As a result, BAM-Chord protocol can utilize network resources of every node to reduce the depth of the multicast tree and take advantages of DHTs in maintaining the multicast tree.

Sensor Node Identifier Resolution of IP-Based and Non-IP-Based WSN

Traditional wireless sensor network(WSN) technology has localization limitations due to the data-centric characteristic.Therefore, it’s very important to introduce identifier resolution technology and the kernel of using identifier resolution technology is to trace sensor node and get the application information and real time data in WSN.This paper designed a sensor node identifier resolution method of IP-based and non-IP-based WSN,and it gets the sensor node production property information through Internet-based sensor node identifier resolution,while the real-time data and application property of sensor node in practical environment are obtained by WSN-internal sensor node identifier resolution.The process of sensor node identifier resolution is validated to be effective with being applied in the smart home system.

BAM-Chord

In recent years, there has been considerable interest in applying Distributed Hash Tables (DHTs) to application-level multicast since DHTs have many advantages that are good for multicast applications: decentralization, scalability, fault tolerance, load balancing, and good routing performances. However, an effective bandwidth utilization method is required for DHT-based multicast systems because of a number of technical issues such as heterogeneous node capacity and dynamic membership. In this paper, the authors propose their BAM-Chord (i.e., Bandwidth Adaptive Multicast over Chord), a DHT-based multicast system that focuses on host heterogeneity, network scalability and effective bandwidth utilization. In the authors’ system, when a node joins into the system, it will find out an appropriate position (i.e., node identifier) on a BAM-Chord ring and create links to neighbor nodes based on node’s bandwidth capacity such that the multicast tree can be built efficiently and balanced. Therefore, their system can utilize bandwidth of every node efficiently to reduce the depth of the multicast tree, increase network scalability and take advantages of DHTs in maintaining the multicast tree.