Study On Remote Measurement And Control System Of Oilfield Pumping Unit

In some oil fields, for its long history of exploitation, its equipments is obsolete and is lack of real time monitoring of pumping units state. Furthermore, oil producing station is always situated in remote field, pumping units is always destroyed by people in the night. If we fail to cope with the fault in time, not only can make a loss of oil production and equipments but also endanger the life of people around there.Also pumping units are always in remote field, it is so remote and is difficult for staffs to detect timely, so real time monitoring is poor, working efficiency is very low. At present, in the domestic the detection of pumping units operating state is regular inspection personally. But actually, for its big error, complexity of working process, long monitor cycle, high costs etc, it is cannot meet with the automation and information of oil fields in economy and technology.The paper based on the control of pumping units , research on the remote inspect of oil units running state, according to the control of large-tonnage mechanical produce before, using wireless data communication method to remote control the pumping units state, alarming when accidents happened.In the paper we draw a comparison between the scheme of wireless data transceiver (module), digital cellular grouping data technology CDPD, GSM-SMS module wireless data transmission, analysis the application scope, advantages and disadvantages respectively. Select wireless data transceiver as the main communication means.In the wireless communication, if we choose only one collection site transmit data to base station, unable to meet with efficiency. But efficiency is the premise of safety. If accident cannot feed back timely to control center, safe production is inhibited. Therefore remote wireless communication needs multi-hop routing mechanism in multi-node to full display its own resource, aim to attain rationally allocation. In the paper comprehensively consider many kinds of routing protocols, including AODV, DSDV, DSR etc. According to practical situation, select one routing protocols, conduct simulation of based on it.Hardware circuit select the wireless data transmission module chip HAC-LM, 51 single-chip computer AT89S52 produced by ATMEL, A/D conversion chip ADC0804 produced by NS, wireless data transmission chip connect with single-chip computer by RS-232 interface. Key switch instead of the input of digital signal. Make and break of light emitting diodes represent the output. The input of analog signal is achieved by adjustment of potentiometer, the brightness and darkness of light emitting diodes instead of output, real time displayed by serial port communication interface compiled by VC++.Error control protocol stop-wait protocol and FEC. Using C51 single-chip computer accomplish the wireless sending and receiving of switch signal and analog.Conduct receiving and sending experiment with hardware. Switch signal can receive and send well, while analog signal appears hysteresis phenomenon during A/D conversion for the single-chip computer is small, but it does not affect theoretical research.Background program corresponding to alarming mechanism. If network voltage appeared big fluctuate or phase deficiency, lower than the setting threshold, alarm siren resounds, accident appeared.In the paper, using NS2 network simulation software conduct simulation according to group network routing protocol mentioned before. For N2 is an open source simulation software, run in Linux system platform, therefore the exploitation of many kinds of protocol have big flexibility, because it is free, therefore it does not need to bear the large cost. NS2 is a kind of object oriented network simulator, in essence it is a discrete time simulator. It has a virtual clock. All analog is driving by discrete event. At present it can be used to simulate many kinds of IP network, among which network transmission protocol, such as TCP and UDP, business source flow generator, such as FTP, Telnet, Web CBR and VBR, routing queue management mechanism, such as DropTail,RED and CBQ, routing algorithm, such as Dijkstra etc. NS2 also achieve MAC sub-layer protocol for conducting local area network simulation.The paper uses several kinds of mainstream routing protocol to conduct simulation, analysis the parameter packet loss rate and draw the following conclusion: comparing with network load simulation conducted in fixed network scale, when network load is lower, packet loss rate of DSR routing protocol is lower than AODV and DSDV, and when load increase, AODV is the lowest among three protocols. Comparing with network scale simulation conducted by fixed network load, when network scale is small, packet loss rate producing by the three routing protocols are all not large, but when network scale is big enough, AODV is better than DSR and DSDV obviously.There are still a few shortages in this paper and need further improved, such as when conducting hardware experiment, for the limit of node quantity, we cannot realize multi-node networking. Because of being short of detection of practical field interference, it exists unpredictable noise interference, therefore when conducting experiment we have not taken unpredictable information into consideration. This needs to be improved in the further, and finished product according with industry require.