Balanced geothermal energy transfer loop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional geothermal wells face challenges such as inaccessible hot aquifers and induced seismicity due to formation fracturing, while closed-loop designs have had marginal success due to unbalanced downhole loop configurations, leading to inefficient thermal energy extraction.
Innovation Solution
A balanced flow design for geothermal wells, where multiple open hole circuits connecting two wellbores form a sealed loop with equal circuit velocities, pressures, lengths, and volumes, facilitating efficient thermal energy transfer through a thermosiphon effect and reducing pumping penalties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional geothermal wells tap into hot aquifers, then thermal energy extraction is achieved, but hot aquifers are not readily accessible
Solution Approach 1:
The system divides the geothermal energy extraction process into multiple separate wellbores (injection wellbore and production wellbore) with lateral sections, rather than relying on a single wellbore configuration. This segmentation allows access to thermal energy in formations that would otherwise be inaccessible through conventional single-well approaches.
2Productivity
If formation fracturing is used to enhance permeability, then flow rates within aquifer are enhanced, but induced seismicity and water losses occur
Solution Approach 1:
The invention extracts the harmful fracturing process from the system by using a closed-loop circulation system that does not require formation fracturing. Instead of injecting fluid into fractured formations to enhance permeability, the system circulates working fluid through sealed lateral wellbore sections, achieving thermal energy transfer without the harmful seismic effects of fracturing.
3Reliability
If unbalanced downhole loop configurations are used, then closed-loop design is implemented, but thermal energy extraction efficiency is reduced
Solution Approach 1:
The system achieves balanced flow conditions by designing the lateral wellbore sections to have equal lengths and equivalent hydraulic resistances. This equipotential design ensures that fluid circulation through the closed-loop system occurs with balanced pressure gradients, maximizing thermal energy extraction efficiency while maintaining the reliability of the closed-loop configuration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The balanced flow design significantly increases thermal energy extraction from the geothermal formation to the surface, enhancing thermal transfer capabilities and reducing operational costs by minimizing pumping penalties and seismic risks.
Implementation Method 1
facilitating efficient thermal energy transfer through a thermosiphon effect
Data Source
AI summary
A system and method for geothermal heat production. A balanced geothermal energy transfer loop includes a first wellbore and a second wellbore extending from surface to a subterranean geothermal formation and a plurality of balanced open hole circuits extending between the first wellbore and the second wellbore through the geothermal formation, forming a substantially sealed closed loop. Each of the plurality of circuits is designed or modified to have a substantially equal circuit parameter. The circuit parameter may include one or more of circuit fluid velocity, circuit pressure drop, circuit volume and/or circuit length. The circuit parameter may include circuit length and volume, and the circuits connect the supply/return wells in a first out/last in configuration.