Methods and systems for enhanced delivery of thermal energy for horizontal wellbores

摘要

Systems and methods for delivery of thermal energy to horizontal wellbores are disclosed. In one embodiment, a method comprises heating a heat transfer fluid; circulating the heat transfer fluid into a vertical bore to a heat exchanger; advancing feedwater into the vertical bore to the heat exchanger, wherein the heat exchanger is configured to transfer heat from the heat transfer fluid to the feedwater to generate steam; transmitting the steam from the heat exchanger into a horizontal wellbore to cause heating of a subterranean region; and returning the heat transfer fluid from the heat exchanger to the surface. The method may further comprise collecting liquefied formation in a second horizontal wellbore; and transmitting the liquefied formation to the surface through a production line.

主权项

1. A downhole heating system for delivery of thermal energy to a horizontal wellbore located in a subterranean formation via a connected vertical wellbore that provides a heated heat transfer fluid from a thermal fluid heater positioned above ground on the surface, said system comprising:
a steam chamber separated by a thermal packer assembly and positioned at a downhole position of the vertical wellbore, said steam chamber having at least one heat exchanger and perforations to direct steam from the steam chamber into the horizontal wellbore; and a heat transfer fluid closed loop system which comprises concentric strings for flow of the heated heat transfer fluid, cooled transfer fluid and hot feedwater, wherein an innermost first string and a second string of the concentric strings connect the heater to heat exchanger to supply the heated heat transfer fluid through the vertical wellbore to the heat exchanger and return the cooled transfer fluid from the heat exchanger to the surface thermal fluid heater for reheating, and a third string of the concentric strings to provide the hot feedwater to the steam chamber, wherein the heat exchanger has tubing which transfers heat from the heated heat transfer fluid to the hot feedwater to generate steam in the steam chamber and cause heating of a subterranean region via the thermal energy added by the steam from the steam chamber being directed into the horizontal wellbore through the perforations.