Abstract: A pipe-in-pipe system, including: an outer pipe; an inner pipe disposed within the outer pipe; a mid line assembly configured to connect the outer pipe and the inner pipe to a current source; and an annulus region between an outer surface of the inner pipe and an inner surface of the outer pipe, wherein the annulus region includes a conductive or semiconductive electrical path configured to carry current between the inner pipe and the outer pipe.

Abstract: A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300° C.

Abstract: A heating system for a subsurface formation includes an elongated electrical conductor located in the subsurface formation. The electrical conductor extends between at least a first electrical contact and a second electrical contact. A ferromagnetic conductor at least partially surrounds and at least partially extends lengthwise around the electrical conductor. The electrical conductor, when energized with time-varying electrical current, induces sufficient electrical current flow in the ferromagnetic conductor such that the ferromagnetic conductor resistively heats to a temperature of at least about 300° C.

Abstract: Methods for determining electrical and thermal properties of a heated pipeline are provided. During commissioning or at any time thereafter, a base curve of impedance versus temperature of the pipeline is determined, so that impedance measurements can thereafter be used to measure temperature of the pipeline. Continuous monitoring of impedance is provided to detect changes in conditions of the pipeline. Start-up procedures that decrease risk of damage to the annulus from arcing are disclosed.

Abstract: An Electrical Insulating Joint (EIJ) for a pipe-in-pipe electrically heated pipeline is provided. A ceramic disk under compressive load and dielectrics in an annulus provide electrical isolation and mechanical strength. An insulative liner extends around the ceramic disk to provide electrical isolation when materials other than hydrocarbons pass through the EIJ. The insulative liner may be extended through a knee joint. Pressure ports may be used to monitor fluid leaks and a built-in transformer may be used to monitor electrical leakage current.

Abstract: A method and apparatus for electrically testing a pipe-in-pipe pipeline during the construction, installation, commissioning, operation, or dismantling phases of an electrically heated pipe-in-pipe subsea pipeline. One embodiment is directed to a high voltage qualification test of the electrical integrity of a segment of a pipe-in-pipe pipeline. Another embodiment is directed to a method and an apparatus for performing a high voltage pulse test of the electrical integrity of a pipe-in-pipe pipeline. Yet another embodiment of the present invention is directed to a method and an apparatus for performing a low voltage pulse test of the electrical integrity of a pipe-in-pipe pipeline, which may be performed during the operation phase of an electrically heated pipe-in-pipe pipeline.

Abstract: An Electrical Insulating Joint (EIJ) for a pipe-in-pipe electrically heated pipeline is provided. A ceramic disk under compressive load and dielectrics in an annulus provide electrical isolation and mechanical strength. An insulative liner extends around the ceramic disk to provide electrical isolation when materials other than hydrocarbons pass through the EIJ. The insulative liner may be extended through a knee joint. Pressure ports may be used to monitor fluid leaks and a built-in transformer may be used to monitor electrical leakage current.

Abstract: Methods for determining electrical and thermal properties of a heated pipeline are provided. During commissioning or at any time thereafter, a base curve of impedance versus temperature of the pipeline is determined, so that impedance measurements can thereafter be used to measure temperature of the pipeline. Continuous monitoring of impedance is provided to detect changes in conditions of the pipeline. Start-up procedures that decrease risk of damage to the annulus from arcing are disclosed.

Abstract: A method and apparatus for electrically testing a pipe-in-pipe pipeline during the construction, installation, commissioning, operation, or dismantling phases of an electrically heated pipe-in-pipe subsea pipeline. One embodiment is directed to a high voltage qualification test of the electrical integrity of a segment of a pipe-in-pipe pipeline. Another embodiment is directed to a method and an apparatus for performing a high voltage pulse test of the electrical integrity of a pipe-in-pipe pipeline. Yet another embodiment of the present invention is directed to a method and an apparatus for performing a low voltage pulse test of the electrical integrity of a pipe-in-pipe pipeline, which may be performed during the operation phase of an electrically heated pipe-in-pipe pipeline.

Abstract: Apparatus and method are provided for electrically heating subsea pipelines. An electrically insulating layer is placed over the pipe in the segment of the pipeline to be heated and electrical current is caused to flow axially through the steel wall of the pipe. In one embodiment (end fed), an insulating joint at the host end of the pipeline is used to apply voltage to the end of the segment. At the remote end an electrical connector is used to conduct the electrical current to a return cable or to a seawater electrode. A buffer zone of the pipeline beyond the remote end is provided. Separate electrical heating may also be applied in the buffer zone. Electrical chokes may be used in different arrangements to decrease leakage current in the pipeline outside the heated segment. In another embodiment (center fed), voltage is applied at or near the midpoint of the segment to be heated through an electrical connector and no insulating joint is used.

Abstract: Apparatus and method are provided for connecting electrical power for heating subsea pipelines after the pipeline is deployed. Electrical connections may be made subsea using wet-mateable connectors. The electrical power may be supplied from a boat or may be supplied from a host structure. A Remotely Operated Vehicle may be used to make the subsea electrical connections. Single Heated Insulated Pipes, Pipe-in-Pipe, heat tracing and other configurations for heating may be employed. The deployment of cables and other equipment for heating may be delayed until a need or potential need for heating or the probable locations of impediments to flow are identified in the subsea pipeline.

Abstract: Apparatus and method for electrically heating a segment of a subsea pipeline are provided. Electrical power may be supplied about midpoint between the ends of concentric pipes. The annulus between the pipes electrically isolates the pipes, but at the ends of the segment the concentric pipes are electrically connected. The pipes may be electrically connected by bulkheads or by an insulating joint. A toroidal transformer may be placed in the annulus for extracting power at a selected location along the pipeline. An insulating joint allows power to be extracted from the ends of the heated segment. Extracted power may be used for pumps, other devices or for heating jumpers or other short segments of the pipeline. Contiguous segments of a pipeline may be heated, each segment having an electrical connection to the inner and the outer pipe intermediate the ends of the segment. A riser or segment of a riser having a pipe-in-pipe configuration may also be heated.

Abstract: A method of repairing the insulation of a subsea insulated pipeline which includes the use of an induction heating coil placed around the insulated pipe in the vicinity of an insulation defect. An electric current is provided to the induction heating coil which heats the pipe and melts the surrounding thermoplastic insulation, and thereby repairs and seals the insulation defect.

Abstract: An subsea pipeline system having jumpers (short segments connecting equipment or wells and the main segments) that can be electrically heated is provided. The jumpers are heated by induction coils placed around the jumpers, either before placing the jumpers subsea or afterward. Electrical power may be supplied to the induction coils from current flow in the walls of the heated segment of pipeline or from an external source such as from a subsea transformer or ROV.

Abstract: A lightweight absorbent foam is produced using a high internal phase emulsion (HIPE), the production of which incorporates the use of capillary viscosity measurements as an in-line diagnostic for HIPE quality. The in-line diagnostics yield measurements of viscosity slope and amplitude. These measurements offer several advantages for monitoring emulsion quality, including stable high resolution measurement of hardware-independent parameters of the whole flow, without the need for sampling.

Abstract: In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties by first advancing one or more of the monomers. All or a portion of the monomers are advanced in the presence of an advancement initiator or a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid. Then, a water-in-oil high internal phase emulsion is formed with the advanced monomers and optionally additional monomers or the advanced monomers are added to a water-in-oil high internal phase emulsion containing other monomers. The emulsions containing the advanced monomers are cured. The process provides an improved method to incorporate volatile monomers in the porous polymeric material.

Abstract: A lightweight absorbent foam is produced using a high internal phase emulsion (HIPE), the production of which incorporates the use of capillary viscosity measurements as an in-line diagnostic for HIPE quality. The in-line diagnostics yield measurements of viscosity slope and amplitude. These measurements offer several advantages for monitoring emulsion quality, including stable high resolution measurement of hardware-independent parameters of the whole flow, without the need for sampling.

Abstract: In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties by first advancing one or more of the monomers. All or a portion of the monomers are advanced in the presence of an advancement initiator or a free-radical-producing radiation source for about 5% to about 95% of the time effective to form a solid. Then, a water-in-oil high internal phase emulsion is formed with the advanced monomers and optionally additional monomers or the advanced monomers are added to a water-in-oil high internal phase emulsion containing other monomers. The emulsions containing the advanced monomers are cured. The process provides an improved method to incorporate volatile monomers in the porous polymeric material.

Abstract: In a process for the preparation of a low density porous crosslinked polymeric material by polymerizing a water-in-oil high internal phase emulsion, curing time of the monomers in the emulsion can be reduced without adversely affecting polymer properties or substantially affecting the emulsion by carrying out the curing in multiple-stages. The emulsion is first pre-cured at a temperature less than about 65.degree. C. until the emulsion reaches a Rheometrics dynamic shear modulus of at least about 500 and subsequently curing at a temperature above about 70.degree. C.

Abstract: A process for the production of a stable curable water-in-oil high internal phase emulsion containing monomers as the continuous phase is provided by adding an initiator subsequent to formation of a water-in-oil high internal phase emulsion. The process forms uniform stable water-in-oil high internal phase emulsions in a continuous mixing process. These curable water-in-oil high internal phase emulsions are useful for the preparation of low density porous crosslinked polymeric materials.