Evaluation of pressure-transient behavior of wells

A computing system, comprising:

• one or more processors;
• and
• a memory system comprising one or more non-transitory computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computer system to perform operations, the operations comprising:
• receiving data related to a composite reservoir, wherein the composite reservoir comprises an uninvaded oil zone, a water-invaded transition zone, and an aquifer;
• generating a model using the data;
• updating the model in response to movement of a fluid interface between the water-invaded transition zone and the uninvaded oil zone in the composite reservoir, the updating the model in response to the movement of the fluid interface further comprises:
• discerning an onset of a fluid front movement based on evaluating a second derivative function of a pressure change in a wellbore with respect to time;
• updating the model in response to movement of water from the aquifer toward the wellbore before the fluid interface reaches the wellbore formed in the composite reservoir;
• and
• determining a remedial action to take in the wellbore in response to the movement of the fluid interface, the movement of the water, or both.

A non-transitory computer-readable media storing instructions that, when executed by one or more processors of a computer system, cause the computer system to perform operations, the operations comprising:

• receiving data related to a composite reservoir, wherein the composite reservoir comprises an uninvaded oil zone, a water-invaded transition zone, and an aquifer;
• generating a model using the data;
• updating the model in response to movement of a fluid interface between the water-invaded transition zone and the uninvaded oil zone in the composite reservoir, the updating the model in response to the movement of the fluid interface further comprises:
• discerning an onset of a fluid front movement based on evaluating a second derivative function of a pressure change in a wellbore with respect to time;
• updating the model in response to movement of water from the aquifer toward the wellbore before the fluid interface reaches the wellbore formed in the composite reservoir;
• and
• determining a remedial action to take in the wellbore in response to the movement of the fluid interface, the movement of the water, or both.