Study Of Prodcution Profile Of Oil Reservoir Monitoring Technology Based On Optical Fiber Sensing

The dynamic monitoring of the production profiles is significant to developoil-water wells. It can not only reflect the real-time oil production capacity ofunderground reservoir, but also provides reliable basis for proper determination of thedevelopment plans at later time of injection oilfield. The parameters have significantmeaning to oilfield’s sustainable development. In recent years, the produced profileslogging has been well developed. However, as the downhole behavior is complicated,the traditional monitoring methods are difficult to implement of quasi-distributedmeasurement in real time, the logging methods is a serious pollutant to wells. So thedistributed monitoring of the downhole production profiles is need urgently.Based on the Raman fiber temperature sensor principle, a monitoring system ofproduction profiles is designed independently in this paper. As self-temperature-limiting heating tapes heats the flowing wellbore fluid, the temperature of the tapes isdifferent as the flow rate is different, in this way, the measurement of productionprofiles can be translate to the measurement of the tapes’ temperature. Main researchworks are as follows.First, based on the heat transfer principle and the principle of engineering fluidmechanics, this paper analyses the flow pattern of fluid within the wellbore, and the heattransfer process during the monitoring. The pattern of laminar and turbulent flow isstudied in this paper. The calculation model of the monitoring process is established, themodel includes the radial steady heat transfer process and the axialconvection heat transfer process.Secondly, the monitoring system is designed with the Raman optical fibertemperature sensor as the core sensing element. The mechanical character and the heattransfer performance of the fiber sensor and the heating tape package technology areanalyzed and the result meets the demand of the monitoring process. The key programof the sets of optical sensor networks is completed.Finally, the finite element analysis model and laboratory experiment is used tovalidate the correctness of the calculation model. The comparison results show thatdifferences exist between the results of fea method and of theoretical method. Thesensitivity of the experimental system meets the calculation sensitivity at low flow rate.In this paper, the distributed monitoring system of oilfield production profiles isbuilt based on the compound of optical fiber sensor and heating tape. The calculationmodel of flow rate monitoring process is established, the package technology of monitoring system is designed and analyzed. The finite element analysis and thelaboratory experiment is completed to validate the theoretical model.