Thermal Response Modeling and Thermodynamic Analysis of Horizontal Wellbore Fluids

Open Access
Author:
Dong, Ting
Graduate Program:
Petroleum and Natural Gas Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 04, 2014
Committee Members:
  • Luis F Ayala H, Thesis Advisor
Keywords:
  • Horizontal Wellbore
  • Temperature Prediction
  • Single Phase flow
  • Two Phase Flow
Abstract:
Wellbore models are required for integrated reservoir management studies as well as the optimization of production operations. Distributed Temperature Sensing (DTS) is a smart well technology deployed for permanent downhole monitoring. Temperature is measured via fiber optic sensors installed along horizontal wellbores. Correct interpretation of DTS surveys has thus become of utmost importance and analytical models for analysis of temperature distribution behavior are critical. This study conducted a comprehensive thermodynamic analysis to interpret thermal response of horizontal wellbore fluids. A generalized wellbore thermal response model (η_s-driven model) is derived starting from 1-D conservative mass, momentum and energy balance equations. Steady-state velocity, pressure and temperature profiles are presented along with its single-phase and two-phase solution procedures. Steady-state applications are conducted and discussed. In steady state, both single-phase and two-phase flows are considered in both openhole and perforated wellbore conditions. Both the homogeneous and drift-flux models are implemented in two-phase flow, together with the comparison of results between the two models. Results show that for single-phase flow, oil and water are heated, while gas is cooled along the horizontal wellbore; thermal behavior of wellbore fluid is driven by wellbore inclination, flowrate, roughness, radius and completion type. When two-phase flow appears, a temperature derivation compared with single-phase case can be detected from temperature profiles. The effects of each thermal factor on overall thermal response are also discussed in the study for both horizontal and inclined wellbores. Rather than only utilizing the common accepted tool value of Joule Thomson Coefficient to predict heating or cooling effect in wellbore, this study show cases on the importance of Isentropic Thermal Coefficient, which always contributes to cooling.