The Study Of Automatism Measure And Monitoring Technique By Dynamometer Card Of Oil Wells

The measurement of well production is an important part in the management of oilfield production. The measure technique of dynamometer card is a low-cost, high reliability, easy maintenance and new technology in the well measurement. However, special cases existed in low oil penetration area and hyper-low penetration area of HUA QING oil field such as low liquid yield, intermittent flow of oil, high gas-oil ratio, which made the measure technique of dynamometer card have large errors in practice. In order to solve this problem, the follow work was done in this paper:Taking the oil-producing characteristics in low oil penetration area into account, the dynamometer card measure principle was studied. The mathematic model of rod pumping system and wave equation were established. Based on the ground dynamometer card, the underground pump diagram was predicted, and a method of five point average curvature was used to compute the available pump stroke length and get the ideal underground liquid yield. Furthermore, it can compute surface liquid yield through analyzing the physical parameters of underground multiphase liquid.The automatic measurement soft system of oil well dynamometer card has been designed by Visual Basic The soft includes modules of data entry, well productivity prediction, intermediate data output, which make the software interface and operation more convenient, and meet the user requirements. It improved the calculation efficiency of dynamometer card through taking the method of more quickly calculation wave equation.To be suitable for the low oil penetration oilfield, the portable-type surface separation metering device has been developed, whose advantages are small size, easy to install and high accuracy.The computation result of dynamometer card was compared with that achieved by high degree portable-type surface separation metering device. Some results of yield measurement using dynamometer card were properly modified, which could improve the accuracy of calculation.The contrast validation experiments were taken in well295-51, well301-521and well296-50of HUA QING oil field, and the result shows that the average relative error of calculation should be controlled within5%used the automatic measurement soft system of dynamometer card, which verifies this method could satisfy the production measurement of low oil penetration well in HUA QING oil field.