【作者】 张建国；

【导师】 赵志钦； 王健；

【作者基本信息】 电子科技大学 ， 软件工程（专业学位）， 2014， 硕士

【摘要】 远程测控终端(RTU:Remote Terminal Unit)也叫远程终端单元或远程终端控制系统。依据RTU设计公司的不同,实现的功能及实现的方法并不相同。目前,应用于油田的RTU有的只具有数据传输功能,有的兼有测量功能,有的兼有控制功能。这些RTU多数为通用RTU改造而来,并不能很好的满足油田的需要。通过广泛调研,针对油田上现存问题、关注点及实际需求,本RTU的设计重点集中在通讯、数据采集、远程控制、设备保护、间抽及工图诊断五个方面。在通讯方面,早期油田使用的设备,不具备通讯功能(目前,油田上的油井、注水井、水源井、计量间乃至联合站使用的多数仪表仍然不具备通讯功能),所有仪表数据均需工作人员巡检抄读,数据获取不及时,很难获得预警数据,无法及时获取数据,也就谈不上故障的预判与阻止事故的产生。后期,油田出现了有线通讯方式(该方式通讯多采用RS485接口),但这种通讯方式,需要布线,对设备分布极广的油田来说,远程通讯成本高昂,维护不便,因此使用不广泛,通常仅作为井场局部通讯使用。随着互联网技术的发展,尤其是无线互联网技术的发展,这为油田数字化建设提供了可能。本RTU的通讯设计就是基于互联网技术实现的。RTU与主站之间,采用IPv4与IPv6双协议栈,以满足不同用户环境的需要。RTU之间采用的是IPv4协议,方便应用者的配置使用。与仪表通讯则采用了微功率无线通讯技术,目的是延长野外电池供电设备的电池更换周期。油田需要采集的物理量主要是开关状态、压力、温度、载荷、位移、流量以及交流模拟量。其特点是精度要求不是很高,但采集的数量较多,比如油井需要采集油压、套压、回压、井口油温、油井的冲程、冲次、载荷以及电机的工作电压、电流、功率等几十个物理量。对于计量间,采集的数据就更多了,仅温度一项通常就高达几十个之多。因此,RTU的设计必须要能够采集多路物理量,且具有扩展性。远程控制方面是出现了远程通讯之后出现的新的操作方法。为了及时解决设备出现的故障,避免损失的扩大,设备的控制多数为自动进行的。因此,需要远程控制的操作并不多,比如油井,其控制主要有三个,一是远程启停井控制;二是语音报警控制;三是灯光报警控制。设备保护,即设备出现的故障或某些数据超出正常值后,为避免损失的扩大或产生故障,RTU进行自动控制的行为。考虑到油田设备对数据采集、远程控制、设备保护的实时性的严苛要求,本RTU采用uC/OS-II实时操作系统,取代传统的非实时的linux操作系统。使RTU采集、处理、响应速度达到了毫秒级。通用RTU没有间抽控制功能,本RTU为节能及减少设备损耗,设计了两种间抽功能。在采用复费率的地区,可用节能抽控制,通过综合考虑油井产油量及当地电价波动,把油井抽油时间放在电价低的时段进行抽油,可大大降低油田运营成本。在没有采用复费率的地区,则只需要考虑油泵的充满系数,用操作简单的间抽控制功能即可实现节能降耗。示功图对于油田来说异常重要,目前油田应用的RTU多数仅能实现载荷、位移的同步采集,而对电流、功率却无法达到同步采集的要求。即使个别公司做了电流、功率图的采集,但由于电能量采集使用的是电表模块或就是一块485串行接口的电能表。通过串口通讯采集,导致两个问题:1、采集时间点不能真实的同步;2、电表模块对功率的处理是根据DL645规约对正向和反向功率分别显示的,而RTU生产商仅采集了正向有功功率,导致抽油机下冲程放电过程中,功率始终为0,不能真实反映抽油机的实际工作情况,这在高原机上体现尤为明显。本RTU直接搭建了电能量采集电路,示功图应用程序,同时采集载荷、位移、电流、功率,确保了采样时间的一致性。这使得工图诊断从理论分析走向了实际应用层面。更多还原

【Abstract】 The Remote Terminal Unit(RTU) is also called a Remote Measurement and Control Terminal or Remote Terminal Control System. Based on RTU design differences of each company, the functions and realization methods are not same. Today, among the RTUs which are applied to oil fields, some only have the functions of data transmission, and some have measurement functions, and some have control functions at same time. The most of these RTUs are transformed from general RTUs and cannot meet the need of oil fields.Through extensive investigation and research, in view of existing problems, concerns, and the actual demand on oil fields, the designs of the RTU of this paper are focused on the following five aspects: communication, data acquisition, remote control, equipment protection, intermittent pumping and Engineering drawing diagnose.In communications, the early oil field equipment does not have the communication function(now, most oil wells, water injection wells, water wells, metering room and united stations do not have the communication function yet). All instruments are required to inspect and read by staff, data acquisition is not timely, it is difficult to obtain early warning data. Say nothing of fault pre judgment and prevention of accidents. Later, wired communication mode appeared in oil field(the way of communication with RS485 interface), but because the wiring is required, this method of remote communication has high cost and is not convenient in maintenance for a wide range of equipment of oil fields, therefore it is not widely used, and is used usually only in well local communication. With the development of Internet technology, especially the development of wireless Internet technology, wireless Internet technology provides the possibility for the construction of digital oil field. Communication design of this RTU of the paper is based on Internet technology. Between the RTU and the master station, IPv4 and IPv6 dual protocol stack are used in order to meet the different environment needs of every user. The Communication between RTUs is based on IPv4 protocol, for convenient of configuration of user application. The Communication between RTU and instrument make use of the micro power wireless communication technology, for the aim of prolonging the replacement cycle of powered battery in open country.The main quantity which oil fields need to collect include switch state, flow, pressure, temperature, load, displacement, flow rate and the AC analog. The characteristic is that the precision requirement is not very high, but the numbers of collected data are large, such as oil pressure, casing pressure, wellhead back pressure, oil temperature, oil wells stroke, speed, load, and the working voltage, current, power of the motor and so on, and other dozens of physical quantities. For measurement room, the collection numbers of data are much more, for only one temperature is often as more as dozens. Therefore, the design of the RTU quantities must be able to capture more multiple physical quantities, and has scalability.Remote control is a new remote operation method of communication. In order to solve the fault of equipment, avoid expansive losses, most of the equipment controls are run automatically. Therefore, remote controlled operation needed is not much. For example, the controls of an oil well include 3 points: one is the remote start and stop well control; two is the voice alarm control; three is the light alarm control.Equipment protection namely means the auto control actions of the RTUs in order to avoid further loss or failure when there is fault equipment or some data beyond the normal value. Taking into account the stringent real-time requirements in oilfield equipment for data acquisition, remote control, equipment protection, the RTU of this paper uses the u C/OS-II real-time operation system, instead of non-real-time traditional Linux operating system. The speed of the RTU acquisition, processing, response gets to millisecond.General RTU has no intermittent pumping control function. The RTU of this paper designs two kinds of intermittent pumping function for energy saving and reducing the loss of equipment. In the multi-rate area, energy saving pumping control can be used. By considering the well production and local electricity price fluctuations, the oil pumping time can be arranged at a lower price time, and it can greatly reduce the operation cost of the oil field. In the non-multi-rate area, only the pump full coefficient is needed to consider, and simple operation of the intermittent pumping control function can be used to realizing energy saving.Indicator diagram is very important for the oil field. At present, the most of RTUs in oilfield can only realize the load and displacement synchronization acquisition, but the acquisition of current and power cannot meet the requirements of synchronization. Individual companies do the collection of current and power figure. And electric energy data acquisition only uses a meter module or a 485 serial interface electric energy meter. The serial port communication acquisition leads to two problems: 1, the acquisition time cannot be true synchronization; 2, power meter module is based on the DL645 protocol to display on the forward and reverse power respectively, while the RTU producers only collect the positive active power, resulting in power always displaying 0 during pumping unit stroke discharge, not reflecting the actual working conditions of pumping unit, and this is obvious in the plateau machine. The RTU of this paper build directly the electric energy acquisition circuit and indicator diagram application, collect load, displacement, current, power. Thus the RTU ensures the consistency of the sampling time. This makes the diagram diagnosis develops from theoretical analysis to practical application level.更多还原