Development And Trial Of Microwave Techniques For Measurement Of Multiphase Flow Of Oil, Water And Gas

Abstract

Abstract A prototype microwave and gamma-ray MFM has been developed for measurement of oil, water and gas flowrates on production pipelines and has been successfully trialed at the Thevenard Island oil production facility. The microwave and gamma-ray MFM determined the oil and water flow rates with errors of 5.4 and 5.9% relative respectively for the wide range of wells and flow conditions during the trial period. A prototype non-intrusive microwave MFM is being developed for measurement of oil, water and gas flow rates on production pipelines. The microwave MFM will be trialed on the West Kingfish platform in Bass Strait in late 1994. Introduction Crude oil extracted from geological reservoirs is normally accompanied by gaseous hydrocarbons and water. These three components are piped from the oil well as a multiphase mixture. The flow rate measurement of the oil, water and gas from individual wells is important for better reservoir management and optimisation of the total oil production over the field life. The current practice for the measurement of the flow rate of the oil, water and gas components of the multiphase mixture is to periodically physically divert the well output to a test separator. After separation, the flow rate of each component is measured with conventional devices such as orifice plates or turbine flow meters. There are a number of inherent disadvantages with this approach. Firstly, due to cost, a single test separator usually monitors a large number of wells, and therefore it is not possible to continuously monitor the output of each well. In addition the time to monitor a single well can be quite long due to the need to obtain stabilised flow during the test. These factors combined result in infrequent testing of component flows from wells, and potentially less than optimum management of the oil reservoir. Further, the test separator and its associated equipment may contribute significantly to the cost of an off-shore platform. For the purposes of reservoir management, the oil industry requires a multiphase flow meter which is compact and capable of measuring the flow rates continuously to within about 5-10% relative. P. 681^