US 12,624,865 B2 · Forming high-efficiency geothermal wellbores

Abstract

Wellbore synthesis techniques are disclosed suitable for use in geothermal applications. Embodiments are provided where open hole drilled wellbores are sealed while drilling in sequenced operations with utilization of phase change materials to form an impervious layer at the wellbore/formation interface in high temperature applications. The techniques may be chemical, thermal, mechanical, biological and are fully intended to irreversibly damage the formation in terms of the permeability thereof. With the permeability negated, the wellbore may be used to create a closed loop surface to surface geothermal well operable in the absence of well casing for heat transfer surfaces for maximizing thermal transfer to a circulating working fluid. Formulations for the working and drilling fluids are disclosed.

Claims20

Dependent claims

A method, comprising:

limiting, with an insulative drill string disposed in a wellbore and having a preselected thermal conductivity, thermal transfer between a drilling fluid introduced to a rock face and the drilling fluid returning to a terranean surface of said wellbore to maintain a temperature differential of at least 90° Celsius (C) between the rock face and the drilling fluid contacting the rock face;
drilling at a specified rate of penetration of said drill string into said a geothermal zone of a geological formation, the geothermal zone having a higher temperature than the drilling fluid contacting the rock face, while maintaining said temperature differential, the specified rate of penetration higher than a rate of penetration absent said maintaining said temperature differential;
and
sealing, by flowing a sealant downhole, pore spaces along at least a portion of the wellbore.

1 more element

Dependencies are inferred from the claim text.

Forming high-efficiency geothermal wellbores

Life of this patent

Forming high-efficiency geothermal wellbores

Life of this patent

Abstract

Claims20