Solution and Analysis of Wellbore Temperature and Pressure Field Coupling Model under Lost Circulation

Area of Science:

• Petroleum Engineering
• Fluid Dynamics
• Geothermal Energy Transfer

Background:

• Lost circulation significantly impacts wellbore pressure and heat transfer.
• Accurate modeling is crucial for understanding drilling fluid behavior under these conditions.

Purpose of the Study:

• To establish a coupled model for transient wellbore temperature and pressure under lost circulation.
• To analyze the influence of drilling fluid properties and lost circulation parameters on wellbore conditions.

Main Methods:

• Developed a coupled model based on hydrodynamics and energy conservation.
• Incorporated casing programs, bottom hole assembly, and drilling heat sources.
• Validated the model against field data and previous research.

Main Results:

• Drilling fluid density, viscosity, and bottom hole pressure increase with circulation time.
• Annular temperature stabilizes after 8 hours, decreasing with higher loss rates and closer loss zones.
• Loss zone location can be identified by inflection points on annular temperature difference curves.

Conclusions:

• The developed model accurately predicts wellbore conditions during lost circulation.
• Understanding fluid property variations is key to managing drilling operations.
• The model provides a method for locating lost circulation zones.