| It is inevitable that sand-carrying often appears on the process of oil and gas exploration and gathering, which will accelerate erosion of pipe fittings such as elbow and valve, even causing perforation and tube explosion, and has posed a great threat to the security of management staff the normal production of hydrocarbon as well as surrounding environment. However, it is still a main problem that how to dectect sand production accurately and determine operation parameters of pipeline containing sand to decrease the damage of particle wearing erosion, which restrict the development of oil and gas fields.Although there are many mature products monitoring sand production and erosion based on electric resistance (ER) techniqe in overseas, these products protected by foreign intellectual property are expensive and inconvenient to maintain, and so far domestic industrial product with similar functions has not been developed out. Therefore, it is quite necessary to develop the sand probe for our intellectual property, which will provide theory and technic supporting for further industrialization.In this research, an eroding wear testing device made by ourself was designed and built up. and the thoretical model of monitoring sand production as well as erosion based on balanced electric bridge was put forward. The maximum impact angle of a square bend of 304 SS steel was studied by SiO2 sand blast, and a mathematical model of predicting the maximal erosion rate of bend was established according to the erosive amount of sand probe. By comparing and selecting, constantan alloy 6J40 and 304 SS steel were used as probe element and probe body, respectively. In addition, the structure design, circuit design and relative development of software of sand probe were completed, and the insulation mode, power supply mode and voltage stabilizing mode were analyzed to determine successfully, then accomplished the system debugging for sand probe step by step.Afterwards, the effect of temperature, gas velocity and electrolyte solution on output signal of sensor were analyzed through laboratory experiment, and the principle model of sand monitoring was verified by a series of experiment to evaluate the performance of sand probe. Investigating the influence of sand production, particle velocity and particle size on the monitoring error of sand probe combined with orthonormal design of experiments.The results show that the maximum impact angle of a square bend of 304 SS steel is about 55° and the prediction error of the mathematical model predicting the maximal erosion rate of square bend is -2.35%?0.488%; in order to detect the sand production and erosion reliably, the power supply of sand probe is using constant voltage pulse mode and voltage stabilizer MIC29502 is adopted to regulate voltage, moreover, double polyimide films assisted by high temperature glue is a better insulation of sensing element, and from testing and analysis the possible interferences of sand probe, we find that temperature, gas velocity and electrolyte solution have relatively little influence for output signal, that is to say physical factors or environmental factors basically have no impacts on the sand probe.The correctness of the thoretical model for monitoring sand production and erosion based on balanced electric bridge was verified by experimental test, the sand probe could relative accurately monitor sand production and erosion no matter which working face we use, and the monitoring error of sand production is -8.9%?7.5% as well as the monitoring accuracy of erosion is ±7.14 nm. The performance of sand probe tested through the orthonormal experiment is roughly the same as the verification stage, and the effects on the monitoring error for sand probe are particle velocity> sand production> particle size, and the lower detective limit of sand production is 0.08 g/s. |
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