| Title | Theoretical study of conditions for generation of periodic wellbore flow: Dependence on two-phase flow models |
|---|---|
| Authors | M. Matsumoto, N. Yoshida |
| Year | 2025 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | cycling wells, two-phase flow model, slip, transient wellbore flow, numerical simulation |
| Abstract | The periodic flow generated in a wellbore intersecting two reservoirs was theoretically investigated by performing numerical experiments of 200 runs in total. In particular, the condition for generating periodicity, established by one of the authors using the homogeneous flow model, was validated using the slip model, which considers the slip between the liquid and vapor phases. This condition is described based on the mean specific enthalpy of the shallow and deep reservoirs weighted by their productivity indices. The inflow of the low-enthalpy fluid at the shallow feed zone triggers periodic wellbore flow. The slip limits the upflow of the liquid phase in the wellbore and significantly affects the appearance of constant, periodic, and unstable flow patterns. Nevertheless, the results of the numerical experiments supported the generality of the condition for generating periodicity, regardless of the two-phase flow models, and its applicability to actual wells. This finding will facilitate sustaining the output of geothermal power plants by developing effective measures to stabilize the wellbore flow. |