Abstract: A carrier rod having at least one recess extending along at least part of the length of the rod, in which recess a optical fiber assembly for monitoring strain, temperature and/or other physical parameters is arranged, which optical fiber assembly is along at least part of its length bonded within the recess. The carrier rod can be used in a system or a method of monitoring deformation and other characteristics of a casing or other tubular or cylindrical well equipment in a well traversing an underground formation.

Abstract: A carrier rod having at least one recess extending along at least part of the length of the rod, in which recess a optical fiber assembly for monitoring strain, temperature and/or other physical parameters is arranged, which optical fiber assembly is along at least part of its length bonded within the recess. The carrier rod can be used in a system or a method of monitoring deformation and other characteristics of a casing or other tubular or cylindrical well equipment in a well traversing an underground formation.

Abstract: A method of monitoring deformation and other characteristics of a casing or other tubular or cylindrical well equipment in a well traversing an underground formation. The method includes providing a carrier rod having at least one recess extending along at least part of the length of the rod, in which recess an optical fiber assembly for monitoring strain, temperature and/or other physical parameters is arranged, which assembly is along at least part of the assembly's length bonded within the recess; lowering the carrier rod and well equipment simultaneously into the well such that the rod is arranged in an annular space between the well equipment and the wellbore; securing the rod at a plurality of locations distributed along the rod's length to the well equipment; and connecting the optical fiber assembly to an optical signal transmission and reception assembly for monitoring physical parameters of the well equipment.

Abstract: A method of monitoring deformation and other characteristics of a casing or other tubular or cylindrical well equipment in a well traversing an underground formation. The method includes providing a carrier rod having at least one recess extending along at least part of the length of the rod, in which recess an optical fiber assembly for monitoring strain, temperature and/or other physical parameters is arranged, which assembly is along at least part of the assembly's length bonded within the recess; lowering the carrier rod and well equipment simultaneously into the well such that the rod is arranged in an annular space between the well equipment and the wellbore; securing the rod at a plurality of locations distributed along the rod's length to the well equipment; and connecting the optical fiber assembly to an optical signal transmission and reception assembly for monitoring physical parameters of the well equipment.

Abstract: A system for monitoring subsidence and/or rising of a waterbottom has string of pressure sensors along the interior of a sealed -protective tube(q?) that rests on the waterbottom and is filled with a low pressure liquid, so that any subsidence and/or rising of the can be deduced from subsidence and/or rising of a section of the tube and associated pressure variations measured by the sensors due to variation of the hydrostatic fluid pressure of the liquid in the of the tube. The tube interior is divided into segments by valves during descent to protect the sensors against hydrostatic pressure of the liquid within the tube during installation. The use of a low pressure liquid in the tube allows the use of sensitive pressure sensors which are able to monitor pressure variations of ?0.001 Bar associated with a waterbottom subsidence of ?1 cm, at a water depth of >km where the ambient water pressure may be >100 Bar.

Abstract: A pressure sensor assembly comprises a sensor housing having a flexible wall that is configured to deform in response to a pressure difference between the interior and exterior of the sensor housing; -a first fiber optical cable section that is bonded to the flexible wall of the sensor housing such that the length of the first fiber optical cable section changes in response to deformation of the wall in response to the said pressure difference; a second fiber optical cable section which is bonded to a thermal reference body, which body is connected to the sensor housing by a strain decoupled connection mechanism, such as a tack weld or flexible glue, and is configured to deform substantially solely in response to thermal deformation, such that the length of the second fiber optical cable section solely changes in response to thermal deformation of the thermal reference body.

Abstract: A method of monitoring deformation and other characteristics of a casing or other tubular or cylindrical well equipment in a well traversing an underground formation, comprises:—providing a carrier rod having at least one recess extending along at least part of the length of the rod, in which recess an optical fiber assembly for monitoring strain, temperature and/or other physical parameters is arranged, which assembly is along at least part of its length bonded within the recess;—lowering the carrier rod and well equipment simultaneously into the well such that the rod is arranged in an annular space between the well equipment and the wellbore;—securing the rod at a plurality of locations distributed along its length to the well equipment; and—connecting the optical fiber assembly to an optical signal transmission and reception assembly for monitoring the physical parameters of the well equipment.

Abstract: A pressure sensor assembly comprises a sensor housing having a flexible wall that is configured to deform in response to a pressure difference between the interior and exterior of the sensor housing; —a first fiber optical cable section that is bonded to the flexible wall of the sensor housing such that the length of the first fiber optical cable section changes in response to deformation of the wall in response to the said pressure difference; a second fiber optical cable section which is bonded to a thermal reference body, which body is connected to the sensor housing by a strain decoupled connection mechanism, such as a tack weld or flexible glue, and is configured to deform substantially solely in response to thermal deformation, such that the length of the second fiber optical cable section solely changes in response to thermal deformation of the thermal reference body.

Abstract: A fiber optical sensing cable is inserted into an underwater well by: connecting a housing (12A) comprising a coiled or spooled U-shaped fiber optical sensing cable (21) to the wellhead (2) of the well (1) such that an opening (14) in the wall of the housing (12A) is connected to a guide tube (15) extending into the underwater well (1); —inserting the U-shaped nose section (21A) of the fiber optical sensing cable (21) via the opening (14) into the guide tube (15), thereby uncoiling at least part of a pair of substantially parallel sections of the fiber optical sensing cable of which the lower ends are interconnected by the U-shaped nose section; and connecting the upper ends (21B) of the substantially parallel sections of the fiber optical sensing cable to an optical signal transmission and/or receiving unit via e.g. a pair of wet mateable connectors that are connected to a pair of underwater fiber optical transmission cables (14).

Abstract: A U-shaped fiber optical cable assembly (11, 21) is arranged in a heated well (1) such that a nose section (13, 23) comprising the bent U-shaped cable section (11C, 21C) is located near the toe (1 A) of the well where the ambient well temperature is lower than the temperature of an intermediate section of the well which is heated by steam injection, electrical heating and/or influx of heated hydrocarbon fluids from a heated section of the surrounding formation to a temperature above 200 degrees Celsius, thereby inhibiting the risk of hydrogen darkening of the bent U-shaped cable section. It is preferred to make the nose section of a glass solder, to arrange the U-shaped fiber optical cable assembly in an aluminium guide tube (22) sealed at its lower end with end cap (31), and to use a heat resistant fiber optical cable to further inhibit the risk of hydrogen darkening of the assembly.

Abstract: A method is disclosed for amplifying a light pulse (S) in an optical fiber (1), wherein a Raman pump signal (RPS) having a lower wavelength than the light pulse (S) is transmitted at a selected interval of time after the light pulse (S) into an end (IA) of an optical fiber(1), with dispersion such that the Raman pump signal (RPS) travels faster through the fiber(1) than the light pulse(S) and reaches and enhances the light pulse (S) after the light pulse has travelled along a selected distance (d1) through the fiber, wherein the Raman pump signal (RPS) is ramped in a substantially linear manner such that the amplification increases with the distance along which the light pulse has travelled along the length of the fiber from A1=S1+RPSmin at a distance d1 to A2=S+RPSmax at a distance d2>d1 from said end (IA) of the fiber 1 and such that the Raman gain increase is substantially similar to the fiber losses of the amplified signal.