Well Performance Visualization and Analysis

Abstract

Abstract A system has been developed based on a powerful portable microcomputer and an integrated data acquisition instrumentation package which allows real-time visualization of pumping well performance.The system integrates all the necessary elements to obtain a complete analysis of the performance of the pumping system which includes the pumping unit (beam or submersible), the wellbore, and the reservoir. The data acquisition package consists of the necessary analog and digital input channels to process data from standard transducers such as pressure, temperature, rod load, displacement, etc. so that detailed surface unit performance curves such as dynamometer, speed, acceleration, power etc. can be obtained and analyzed. When the instrument is used in conjunction with an acoustic pulse generator and receiver, it digitizes and records the reflected acoustic signals which are digitally filtered and automatically processed to determine the liquid level. This is undertaken under program control so that a recording of fluid level vs, time is obtained concurrently with the pumping performance parameters. Fluid level data is processed by the software to calculate bottom-hole pressure as well as flow into and out of the well bore. Changing the well from flowing to shut in conditions allows recording of pressure buildup data which is then interpreted in terms of reservoir parameters. Alternatively, pump start-up after shutting in the well in for stabilization, provides draw-down testing capability. The analog/digital electronics system contains outputs of a 12 volts relay driver and also normally open/closed contacts for external control of gas-gun valves, motors, variable speed drives, casing vent valves, etc. These outputs are computer controlled and can be actuated depending upon input data, operator keyboard entry and/or time. Graphic display of the various diagnostic parameters allows complete visualization of the performance of the whole pumping system including the reservoir, wellbore and pumping unit. The system can be used as a diagnostic tool to optimize pumping well performance on a periodic basis. The present performance of the well is compared to the performance recorded previously and in the case where significant changes are noted a more detailed analysis is undertaken. In critical well applications, the system can function as a stand-alone dedicated controller.