Method for performing well performance diagnostics

An automated method for well performance management of a well system in a hydrocarbon reservoir and detecting performance degradation events in a well in the well system, comprising the steps of:

• a) inputting well test production data into a well performance model, the well performance model comprised of model parameters, the model parameters comprising one or more reservoir properties, the well performance model further comprising
• an inflow component modeling a pressure drop for hydrocarbon fluids flowing from a reservoir to the well, and
• an outflow component modeling a pressure drop for hydrocarbon fluids flowing in and along tubing in the well to a surface;
• b) calculating a downhole model pressure based on the well performance model;
• c) continuously comparing the calculated downhole model pressure with a real-time measured downhole pressure;
• d) determining if there is a deviation between the calculated downhole model pressure and the real-time measured downhole pressure, and if there is a deviation, performing an analysis, by the well performance model, on the model parameters to determine one or more potential attributing causes for the deviation, wherein the analysis is formulated using one or more inverse optimization formulations that minimize a deviation in values for the model parameters based on the well performance model and well test production data of down-hole gauge pressures, and wherein one of the inverse optimization formulations minimizes the squared error between the down-hole gauge pressures of the outflow component based on the well performance model and the well test production data using the following equation:
• min
• x
• ∈
• 𝒳
• (
• f
• ⁡
• (
• x
• )
• -
• P
• g
• )
• 2
• ;
• e) inferring from the analysis on the plurality of parameters one or more causes of the deviation to improve hydrocarbon resources recovery;
• and
• f) changing a reservoir pressure by increasing an injection fluid rate of an injection well or decreasing the injection fluid rate of the injection well responsive to the inferring one or more causes of deviation.