| dc.description.abstract | The development and production of underground hydrocarbon resources are affected by heat transfer between the fluid, downhole tubulars, and the surrounding formation. Understanding heat transfer becomes increasingly more critical in environmentally challenging reservoirs. The “rule-of-thumb” practice and complicated numerical simulations are neither reliable nor practical.
This thesis addresses analytical models for computing the wellbore or formation temperature profiles during drilling, completion, and production periods. It includes four parts: (1) the temperature profile in the counter-current flow system, (2) near-wellbore cooling effect due to drilling circulation, (3) fluid behavior identification during the clean-up period, and (4) non-isothermal fluid behavior during production.
The counter-current heat transfer model provides the temperature profiles in tubing and annulus at a minimal computational cost, a feature not available with numerical simulations. It is particularly advantageous in heavy oil wells where viscosity control is essential for flow assurance issues.
The near-wellbore cooling effect during drilling circulation may impair the reliability of applications using the measured formation temperature. This quantitative analysis provides information on the magnitude and duration of the cooling effect, reducing the uncertainty of the measured temperature.
Advanced temperature measuring device provides the ability to estimate the economic feasibility of a reservoir by using the temperature profile. Identifying the fluid behavior, interfaces, and properties - applications that were not available with the current measuring standards are introduced.
Contrary to the common assumption, the flowing fluid temperature in the reservoir is not isothermal due to several heat generation/transfer effects. A steady-state reservoir heat transfer model leads to better estimates of well productivity index, one of the key parameters in production optimization. All analytical models in this study with realistic assumptions allow engineers to estimate the temperature at a competitive computational cost. | en |
