Making drilling operations visible: the role of articulation work for organisational safety

In the petroleum industry, new technologies and work processes are currently being developed as an innovation strategy for better, faster and safer drilling. In this article, some features of today’s work processes that contribute to successful operations are presented and discussed. The articulation work involved in handling the transient complexity of operations involves making black-boxed and invisible work processes visible and transparent. It is argued that this articulation work contributes to the organisation’s understanding and knowledge of the drilling processes and the dependencies that exist between different actors. In addition to contributing to ongoing problem solving, the articulation work also contributes to the awareness of possible future events. Following this insight, it is argued that efforts to improve operational efficiency and safety by introducing new tools and work processes should focus not only on the capability of new tools to support decisions and actions by instrumentation and automation, but attention should also be paid to the existing articulation work and its role in the accomplishment of work. In that way, the contributions of today’s articulation work can be strengthened instead of lost, and the outcome of the change processes can be even better than anticipated.     

Using artificial intelligence to predict surface roughness in deep drilling of steel components

A predictive model is presented to optimize deep drilling operations under high speed conditions for the manufacture of steel components such as moulds and dies. The input data include cutting parameters and axial cutting forces measured by sensors on the milling centres where the tests are performed. The novelty of the paper lies in the use of Bayesian Networks that consider the cooling system as an input variable for the optimization of roughness quality in deep drilling operations. Two different coolant strategies are tested: traditional working fluid and MQL (Minimum Quantity Lubrication). The model is based on a machine learning classification method known as Bayesian networks. Various measures used to assess the model demonstrate its suitability to control this type of industrial task. Its ease of interpretation is a further advantage in comparison with other artificial intelligence tools, which makes it a user-friendly application for machine operators.     

A Non-Forced-Write Atomic Commit Protocol for Cluster File Systems

Distributed metadata consistency is one of the critical issues of metadata clusters in distributed file systems. Existing methods to maintain metadata consistency generally need several log forced write operations. Since synchronous disk IO is very inefficient, the average response time of metadata operations is greatly increased. In this paper, an asynchronous atomic commit protocol （ACP） named Dual-Log （DL） is presented. It does not need any log forced write operations. Optimizing for distributed metadata operations involving only two metadata servers, DL mutually records the redo log in counterpart metadata servers by transferring through the low latency network. A crashed metadata server can redo the metadata operation with the redundant redo log. Since the latency of the network is much lower than the latency of disk IO, DL can improve the performance of distributed metadata service significantly. The prototype of DL is implemented based on local journal. The performance is tested by comparing with two widely used protocols, EP and S2PC-MP, and the results show that the average response time of distributed metadata operations is reduced by about 40%-60%, and the recovery time is only I second under 10 thousands uncompleted distributed metadata operations.     

Boolean operations for 3D simulation of CNC machining of drilling tools

This paper addresses the simulation of drilling tools CNC machining. It describes a novel approach for the computation of the boundary representation of the machined tools. Machining consists of a sequence of boolean operations of difference between the tool and the grinding wheels through time. The proposed method performs the dynamic boolean operations on cross sections of the tool and it reconstructs the 3Dmodel by tiling between the cross sections. The method is based on classical computational geometry algorithms such as intersection tests, hull computations, 2D boolean operations and surface tiling. This approach is efficient and it provides user control on the resolution of the operations.     

基于路径覆盖插桩的可执行代码测试工具实现

为解决传统程序插桩技术存在代码膨胀和运行时间较长的问题,提出对可执行代码进行控制流路径覆盖消除冗余的插桩策略。依据该策略设计一种针对Java可执行代码的单元测试工具,完成程序执行路径跟踪和覆盖率分析。对测试工具进行功能验证和性能分析,结果表明,该策略能够有效减少插桩点数量,降低插桩对被测程序时间特性的影响。     

A Philosophy of Information Technology and Systems (IT & S) as Tools: Tool Development Context, Associated Skills and the Global Technology Transfer (GTT) Process

It is the intent of this paper to discuss a philosophy of Information Technology and Systems (IT & S) as tools and the impact of this philosophy on the Global Technical Transfer (GTT) process of IT & S.It is argued that IT & S by definition, are artefacts, tools that have been made, used, inherited and studied within a cultural context which encompasses economic, historical, technical and social values and assumptions which are focussed in particular skill sets. It is assumed that these skill sets are mostly in evidence in any culture that receives the IT & S tool for use in a technical transfer process. It is argued, therefore, if we understand the cultural context in which a tool is made then we will understand the skills to transfer and use such tools in an effective manner. The issue we must face as makers, users, inheritors and scholars of IT & S tools, however, is that the tool context and inherent in-built values and skill sets, may not be in evidence across all cultures. This would make the effective use of IT & S, in a global sense, a difficult and complex (if not impossible) undertaking.From this position it is argued that IT & S tools reflect the IT & S discipline, as it is these tools which embody the assumptions of the discipline and hence, its paradigm. The Bunker and Dean (Bunker DJ, Dean RG. Philosophical Traditions in Information Systems: Challenger of an Interdisciplinary View, Faculty of Commerce Workshop, University of Wollongong, July 10--11, 1997) disciplinary model is highlighted as a means of understanding how tools are made within a cultural context and how they reflect the discipline in which they are created. This paper then goes on to explain the ramifications of IT & S as a discipline on the GTT process and proposes a skill-focussed approach, within a culture, to determining what IT & S may be appropriate for that particular cultural context.     

定向钻具姿态的双线性补偿控制策略

在地质钻进过程中,钻具运动具有复杂非线性特性,因而很难有效实现钻具姿态的控制.对此,提出一种面向定向钻具姿态的双线性补偿控制策略,以实现对非线性钻具运动的准确控制.首先,通过分析定向钻具运动特性,建立定向钻具的运动模型,针对运动模型存在非线性和耦合特性,利用泰勒展开法和双线性逼近变换技术对钻具运动模型进行变换;然后,运用双线性补偿控制思想扩展局部线性控制范围和优化控制效果.仿真结果表明,所提出的控制策略能够简化定向钻具控制过程,提高定向钻具控制的准确性,具有较好的稳定性.     

基于S7-1200 与SmartLink远程IO 的ProfiNet 通信控制的实现

西门子S7-1200 PLC通过五类双绞网线与SmartLink 的适配器相连,从而以通信的方式实现远程IO模块的控 制,在同一ProfiNet 工业以太网总线下实现数据交换。本文对控制系统的框架做了介绍,对SmartLink 远程智能IO的拓扑结构 做了说明,并介绍了如何在西门子TIA博途软件中进行硬件组态及参数设定及数据传递工程,最后以FB块的方式对多分布式 IO的执行机构做管理控制。     

一种基于APGD方法的随钻核磁共振测井快速反演算法

随钻核磁测井仪器受限于遥传带宽限制和测井时序要求,必须在井下测井仪器中快速实现回波T₂谱反演功能。根据实时性要求并结合原始回波串数据特点,设计一种基于加速投影梯度下降APGD(Accelerated Projected Gradient Descend)方法的回波T₂谱快速反演算法,充分利用FPGA硬件资源,采用分布式算法将矩阵乘法运算转换为查找表和累加移位操作,并对算法中开方、开根号等运算化简,提高算法执行效率。在自主研发的随钻核磁共振测井仪实验室刻度实验中的运行结果显示,实验结果与理论分析和数值计算相符合,实时性能满足随钻核磁测井仪器快速反演的需求,并且为随钻测井仪器井下数据处理技术领域的研究工作提供了有益的参考。     

Static analysis of a parallel logic language based on the blackboard model

Shared Prolog is a parallel logic language based on the blackboard interpretation of logic programming. In such an interpretation a logic program is seen as a set of rules executed by a set of agents cooperating via a shared working memory called the blackboard. A distributed interpreter for Shared Prolog was implemented and described in another paper, where the blackboard was a centralized data structure. In this paper we show how the blackboard can be distributed using some static analysis techniques. The basic idea is to perform an abstract interpretation starting from the Shared Prolog operational semantics to generate data structures which represent possible interactions and links among agents. The resulting data structures are used to reduce the number of run time communication operations in an implementation distributed over a network of workstations.     

The behavioral sciences in the computer age

This article proposes that computers are likely to have a major impact on our society in general, and on psychology, psychiatry, sociology and related behavioral sciences in particular. It is argued that the continuing technological improvements being made on computers and their increasingly widespread use in society is likely to affect behavioral scientists in two ways. First, they themselves will become users of computers. Second, they will be called upon to evaluate and help control how computers impact human behavior. Ways of proactively shaping such future developments are discussed.     

Application of sensitivity analysis to the optimization of petroleum drilling operations

Optimized drilling models which are concerned with determining the mimimum drilling costs of petroleum operations are analyzed from the point of view of sensitivity of the optimal solution to changes in model parameters. These models are nonlinear and the parameters are typically derived from field or laboratory data. The sensitivity analysis procedures of geometric programming are used to study the impact of parameter changes such as rock hardness and abrasiveness, rate of drill wear and bearing wear among others. The procedures are illustrated with a numerical example which is used to determine an optimal drilling rig configuration as well as determine the impact on that configuration of changing drilling parameters.     

高性能计算平台的IO性能测试与分析

在高性能计算平台上测试NFS和Lustre文件系统在大规模并行计算环境下的IO速率,根据测试结果分析该实验平台的IO瓶颈并提出改进方案;之后测试本地Cache、并行应用进行IO时的TransferSize和并行程序存取文件的FileSize等因素对分布式文件系统性能的影响,并根据实验结果提出如何合理地部署并行软件以有效地利用本地Cache,以及提出在编写并行程序时设置合适的TransferSize和FileSize以提高IO性能的建议。     

未来智能钻井系统

展望了未来智能钻井技术的系统组成、功能及其运行方式.智能钻井新技术是钻井技术、新材料技术、检测控制、微电子技术、通信和计算机、机器人和超微加工技术等的集成.未来的智能钻井将采用轻便车载连续油管全自动钻机,钻井作业中,安置在钻头上的智能机器人将观测和检测到的所有井下参数上传到地面,在钻井的同时完成测井工作;地面人员通过控制钻头运动轨迹和转速,实现遥控智能钻井;起下钻等钻井作业均由地面机器人按指令自动完成;通过通信网络技术,实现全球钻井协同工作.因此,智能钻井将大幅度降低钻井成本,大大提高钻井速度,减少钻井事故的产生,实现井眼轨迹的精确控制,进一步提高石油天然气勘探开发技术水平.     

基于PROFIBUS-DP的智能远程IO通信设备的设计和实现

基于PROFIBUS-DP的智能远程IO通信设备是符合PROFIBUS-DP协议的从站设备,是模块化分布式的I/O系统,具有卡件扫描功能,能够实现过程输入和输出数据从现场到控制室的远距离、全数字、双向传输,能够弥补常规分散控制系统(DCS)将过程的输入、输出集中集成在自动化系统中的不足,是DCS系统实现分布式自动化应用的理想解决方案。详细介绍了基于ProfiBus-DP的智能远程IO通信设备的设计和实现方法。     

Uniform scheduling of interruptible garbage collection and request IO to improve performance and wear-leveling of SSDs

In the past ten years, solid-state drive (SSD) has become one of the mainstream storage devices due to its performance advantages. However, how to reduce the impact of garbage collection operations on host-side IO is still a challenging issue in SSD firmware design. To solve this problem, this paper proposes a uniform scheduling of interruptible garbage collection and host IO (USIGC). The main contributions of USIGC include: First, USIGC sets up an interruptible garbage collection sub-request queue, and then uniformly schedules this sub-request queue with the host IO queue. In this way, the idle time of each channel is fully utilized to complete valid page migration and erase operation of interrupt garbage collection. Second, USIGC predicts the probability that the erase operation can be completed in the current idle time based on the historical idle interval and then makes the erase operation decision to reduce the probability of blocking the host IO. Third, by converting the amount of data that can be written in future to the present and taking the number of invalid pages of the current block as the selection basis of the victim block, the garbage collection and wear-leveling can be unified. Experimental results show that, compared with existing works, USIGC can reduce the average response time and max wait time and achieve the best wear-leveling performance.

     

Voice Loops as Coordination Aids in Space Shuttle Mission Control

Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.     

Simulation-based Testing of Communication Protocols for Dependable Embedded Systems

We present a novel approach to testing fault-tolerant and real-time protocol implementations. Cesium, our testing environment, executes the protocols in a centralized simulator of the distributed system. It simulates the occurrence of inputs and the failure scenarios the protocols are designed to tolerate, while automatically verifying that the required safety and timeliness properties hold at all times during test experiments. Within this framework, the human tester can define failure operations that simulate every failure class studied in the literature. We apply our approach to two fault-tolerant protocols typical in embedded systems. The results show that Cesium can pinpoint implementation errors that would be very difficult to identify in a real system, and can also compute accurate performance predictions that would be problematic to measure in the real embedded platform without ad hoc hardware instrumentation.     

Performance analysis of a distributed processing system — a case study

A cost-effective computer-aided methodology is established for the performance analysis of distributed processing systems. Software tools (based on probabilistic and simulation models) to support this methodology are briefly described. The methodology and software tools are illustrated by applying them to the analysis of a local area network. An instrumentation system is used to monitor a prototype network and to assess the accuracy of the models. The models are shown to be good approximations. Although the case study considers the analysis of a file-server system, the software tools are quite general and may be used for other types of distributed processing system.     

基于HLA和Vega的空空对抗演练仿真系统

根据基于高层体系结构和Vega的虚拟战场空空对抗演练分布式仿真系统的设计需求,在扩展的PRPFOM基础上,使用VR—Link的API工具开发系统联邦和联邦成员。采用VR—Link技术设计并实现联邦成员间的同步和仿真进程控制方法。设计Vega导航器,完成导弹目标跟踪仿真演示并验证系统性能。