Abstract: In an embodiment, a system may be used to heat a hydrocarbon containing formation. The system may include a conduit placed within an opening in the formation. A conductor may be placed within the conduit. The conductor may provide heat to a portion of the formation. In some embodiments, an electrically conductive material may be coupled to a portion of the conductor in the overburden. The electrically conductive material may lower the electrical resistance of the portion of the conductor in the overburden. Lowering the electrical resistance of the portion of the conductor in the overburden may reduce the heat output of the portion in the overburden. The system may allow heat to transfer from the conductor to a section of the formation.

Abstract: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke.

Abstract: The oil shale formation may be treated using an in situ thermal process. Heat may be provided to a section of the formation from one or more heat sources. A portion of a heat source may include conductive material. In some embodiments, the conductive portion may reduce heat loss to a non-hydrocarbon containing layer in the formation. Heat may be allowed to transfer from the heat sources to a section of the formation. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation.

Abstract: Apparatus and method for electrically heating a segment of a subsea pipeline are provided. The annulus between the pipes electrically isolates the pipes, but at the ends of the segment the concentric pipes are electrically connected. The inner pipe may be thermally insulated. Electrically insulating water stops are provided to act as flood control barriers in the event the outer pipe is breached. Collars on seals around the water stops may help avoid electrical shorts and packets of super-absorbent may be in place to further reduce the risk of electrical faults.

Abstract: The oil shale formation may be treated using an in situ thermal process. Heat may be provided to a section of the formation from one or more heat sources. A portion of a heat source may include conductive material. In some embodiments, the conductive portion may reduce heat loss to a non-hydrocarbon containing layer in the formation. Heat may be allowed to transfer from the heat sources to a section of the formation. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation.

Abstract: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke.

Abstract: Methods are provided for installing an electrically heated pipe-in-pipe pipeline on the seafloor. Inner and outer pipe segments are formed and the inner pipe is coated and insulated. Coating may include sprayed polyurethane foam and insulating half-shells that are placed around welds. Epoxy is preferably coated on the inner pipe before other coatings. The segments are loaded on a lay barge and water stops are preferably installed in the annulus as the pipeline is formed. Water stops may be formed by placing a liquid polymer in the annulus and allowing it to cure.

Abstract: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke.

Abstract: Apparatus and method for providing corrosion protection of subsea pipe-in-pipe electrically heated pipeline are provided. The exterior surface of the outer pipe is coated with a thick protective coating in and near the splash zone and near the bulkhead of the heated line. A discharge electrode is placed over the thick protective covering or bare pipe is created near the thick protective covering. Methods are provided for determining the area needed in the discharge electrode or bare pipe.

Abstract: Apparatus and method for electrically heating a segment of a subsea pipeline are provided. The annulus between the pipes electrically isolates the pipes, but at the ends of the segment the concentric pipes are electrically connected. The inner pipe may be thermally insulated. Electrically insulating water stops are provided to act as flood control barriers in the event the outer pipe is breached. Collars on seals around the water stops may help avoid electrical shorts and packets of super-absorbent may be in place to further reduce the risk of electrical faults.

Abstract: In an embodiment, a system may be used to heat a hydrocarbon containing formation. The system may include a conduit placed within an opening in the formation. A conductor may be placed within the conduit. The conductor may provide heat to a portion of the formation. In some embodiments, an electrically conductive material may be coupled to a portion of the conductor in the overburden. The electrically conductive material may lower the electrical resistance of the portion of the conductor in the overburden. Lowering the electrical resistance of the portion of the conductor in the overburden may reduce the heat output of the portion in the overburden. The system may allow heat to transfer from the conductor to a section of the formation.

Abstract: A current impedance device for routing a time-varying electrical current in a piping structure comprising an induction choke. The induction choke is generally concentric about a portion of the piping structure such that during operation a voltage potential forms between the piping structure and an electrical return when the time-varying electrical current is transmitted through and along the piping structure, and such that during operation part of the current can be routed through a device electrically connected to the piping structure due to the voltage potential formed. The induction choke may be unpowered and may comprise a ferromagnetic material. A system for defining an electrical circuit in a piping structure using at least one unpowered ferromagnetic induction choke, comprises an electrically conductive portion of the piping structure, a source of time-varying current, at least one induction choke, a device, and an electrical return.

Abstract: Methods are provided for installing an electrically heated pipe-in-pipe pipeline on the seafloor. Inner and outer pipe segments are formed and the inner pipe is coated and insulated. Coating may include sprayed polyurethane foam and insulating half-shells that are placed around welds. Epoxy is preferably coated on the inner pipe before other coatings. The segments are loaded on a lay barge and water stops are preferably installed in the annulus as the pipeline is formed. Water stops may be formed by placing a liquid polymer in the annulus and allowing it to cure.

Abstract: Apparatus and method for providing corrosion protection of subsea pipe-in-pipe electrically heated pipeline are provided. The exterior surface of the outer pipe is coated with a thick protective coating in and near the splash zone and near the bulkhead of the heated line. A discharge electrode is placed over the thick protective covering or bare pipe is created near the thick protective covering. Methods are provided for determining the area needed in the discharge electrode or bare pipe.

Abstract: A current impedance device for routing a time-varying electrical current in a piping structure comprising an induction choke. The induction choke is generally concentric about a portion of the piping structure such that during operation a voltage potential forms between the piping structure and an electrical return when the time-varying electrical current is transmitted through and along the piping structure, and such that during operation part of the current can be routed through a device electrically connected to the piping structure due to the voltage potential formed. The induction choke may be unpowered and may comprise a ferromagnetic material. A system for defining an electrical circuit in a piping structure using at least one unpowered ferromagnetic induction choke, comprises an electrically conductive portion of the piping structure, a source of time-varying current, at least one induction choke, a device, and an electrical return.

Abstract: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke.

Abstract: A heated flowline electrical isolation joint is disclosed for introducing current into a pipe-in-pipe system having an outer and an inner pipe. A hub presents a load flange having tension and compression load shoulders on its terminal end and connects to the inner pipe on its other end. An end flange presents an end flange load shoulder on one end and a high strength, highly electrically insulative first ring separates the compression load shoulder from the end flange load shoulder which engage therethrough in a load bearing relationship. A plurality of o-ring seals secure the compression load shoulder-to-first ring-to-end flange load shoulder interfaces. A retainer flange connects to the end flange on one end and to the outer piper on the other end, encircling the hub and presenting a retainer flange load shoulder.

Abstract: A method for enhancing the flow of heavy crude oil by heating a subsea pipeline is disclosed in which a pipe-in-pipe subsea pipeline is established having a flowline for transporting well fluids in the form of an electrically conductive inner pipe concentrically surrounded by an electrically conductive protective outer pipe and the inner pipe is electrically insulated from the outer pipe along the length of the subsea pipeline. The pipe-in-pipe subsea pipeline is electrically heated continuously along its length to maintain the temperature of crude oil at a level facilitating pipeline transportation, this heating comprising passing alternating electrical current along the exterior surface of the inner pipe and along the interior surface of the outer pipe. In this manner the crude oil can be maintained at a temperature at which viscosity does not prevent efficient and economical pipeline transport.

Abstract: A method for installing an offshore pipeline is disclosed in which the inner and outer pipes are structurally connected at a terminal end of a pipe-in-pipe flowline and centralizers are placed in the annulus to provide lateral support and maintain concentricity between the two pipes and to prevent buckling of the inner pipe. The working end of the pipeline is suspended under construction in a substantially vertical position within slips at the weld floor of a J-lay installation barge and sections of inner and outer pipe are added. Inner pipe is added by sections by grasping and orienting the section of inner pipe to a vertical position and the section is brought into abutting position with the inner pipe at the working end of the pipeline under construction, welded in place, and the weld is coated with an arc resistant material.

Abstract: A method is disclosed for pipeline leak detection in which a vacuum is maintained in the annulus of a pipe-in-pipe flowline with a vacuum pump having a discharge reservoir which is monitored for the appearance of water and hydrocarbon vapors. In another aspect of the invention pipeline leak detection is accomplished through maintaining a gas at a nominally constant pressure in an annulus of a pipe-in-pipe flowline and monitoring the annulus for pressure increase indicative of water or product intrusion into the annulus.