Transient well flow modelling and modern estimation techniques for accurate production allocation

Rate allocation is the procedure of identifying the origin of the produced fluids (oil, water, gas) in a production system comprising multiple wells and/or producing zones. This information is essential for the daily management of the production, as well as for the long term planning. The ultimate scenario would obviously be continuous direct measurement of all relevant flow rates, both downhole and at surface. However, permanent multiphase metering is expensive and therefore other approaches for better r ate allocation need to be approached. The current project aims for a more accurate and efficient rate allocation process by combining advanced transient well models, state of the art estimation techniques and readily available measurements, in particula r of temperature and pressure. Exploiting this, a continuously updated model (including uncertainty estimates) that incorporates both consecutive pressure and temperature measurements, as well as infrequent test separator and other measurements will be ma intained. In this project the implementation of a robust and efficient estimator will be a crucial issue. This will be done utilizing modern estimation techniques developed for use in large scale systems. For proper use of the estimator, representation o f likely inflow profiles need to be developed. Testing on production data from wells in operation is planned at an early stage in the project in cooperation with supporting oil companies. Based on the results of these test the further focus will be on rem oving any potential bottlenecks towards implementing the developed tools in an industrial workflow.