Abstract:
Electrical current flow is induced in a ferromagnetic conductor providing time-varying electrical current at a first frequency to an electrical conductor located in a formation. The ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The ferromagnetic conductor resistively heats up to a first temperature of at most about 300° C. Water in the formation is vaporized with heat at the first temperature. Subsequently, time-varying electrical current at a second frequency is provided to the elongated electrical conductor to induce electrical current flow at the second frequency such that the ferromagnetic conductor resistively heats up to a second temperature above about 300° C. Heat transfers from the ferromagnetic conductor at the second temperature to at least a part of the formation to mobilize at least some hydrocarbons in the part of the formation.
Abstract:
A method of treating a subsurface formation includes circulating at least one molten salt through at least one conduit of a conduit-in-conduit heater located in the formation to heat hydrocarbons in the formation to at least a mobilization temperature of the hydrocarbons. At least some of the hydrocarbons are produced from the formation. An electrical resistance of at least one of the conduits of the conduit-in-conduit heater is assessed to assess a presence of a leak in at least one of the conduits.
Abstract:
A method for heating a subsurface formation includes applying heat from a plurality of heaters to at least a portion of the subsurface formation. A portion of one or more of the heaters are allowed to move relative to the heaters respective wellhead using sliding seals to accommodate thermal expansion of the heaters.
Abstract:
Methods for assessing a temperature in an opening in a subsurface formation are described herein. A method may include assessing one or more dielectric properties along a length of an insulated conductor located in the opening and assessing one or more temperatures along the length of the insulated conductor based on the one or more assessed dielectric properties.
Abstract:
A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.
Abstract:
Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.