Well installations

A well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up electrical signals from the downhole metallic structure and transmitting the signals onwards by applying electrical signals to the downhole metallic structure, wherein

• the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe and the first run of downhole metallic pipe extending further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends and
• the installation further comprises an insulating centraliser provided in the annulus towards the lower end of the second run of downhole metallic pipe for holding the second run of downhole metallic pipe away from the first run of downhole metallic pipe and the repeater apparatus is disposed in the annulus and arranged for at least one of picking up signals from the downhole metallic structure in the region of the insulating centraliser and applying signals to the downhole metallic structure in the region of the insulating centraliser.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure,

• wherein the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure,
• wherein the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end,
• wherein the remote power arrangement comprises an electrical power source connected to the repeater via an electrical cable;
• the well installation further comprises a communication unit at a location spaced from the repeater apparatus which communication unit is arranged for sensing voltage and/or current in a signal circuit including said cable;
• and
• wherein the repeater apparatus comprises variable impedance means for varying the impedance introduced into the signal circuit including said cable to encode data, and the communication unit is arranged to extract said data by monitoring variations in the voltage and/or current caused by the variable impedance means.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure,

• wherein the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure,
• wherein the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end,
• wherein the installation further comprises an insulating centraliser provided in the annulus towards the lower end of the second run of downhole metallic pipe for holding the second run of downhole metallic pipe away from the first run of downhole metallic pipe and the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure in the region of the insulating centraliser and applying signals to the downhole metallic structure in the region of the insulating centraliser, and
• the repeater apparatus is disposed in the annulus.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure,

• wherein the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure,
• wherein the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end,
• wherein the repeater apparatus comprises spaced contacts mechanically and electrically contacting with one of the runs of downhole metallic pipe at spaced locations on the run of downhole metallic pipe for at least one of picking up signals from and applying signals to said one of the runs of downhole metallic pipe.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure, wherein

• the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure, wherein
• the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end, wherein
• the remote power arrangement comprises a battery pack disposed at a shallower location in the borehole than a location at which the repeater apparatus at least one of picks up signals from and applies signals to the downhole metallic structure;
• and
• the well installation comprises an annular sealing plug or device in said annulus at a level above the location at which the repeater apparatus at least one of picks up signals from and applies signals to the downhole metallic structure and the battery pack is disposed in the annulus above the level of the sealing plug or device.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure, wherein

• the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure, wherein
• the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end, wherein
• the repeater apparatus comprises a harvesting device for harvesting electrical power from the downhole metallic structure,
• the harvesting device is electrically connected to the metallic structure at a first location and to the metallic structure at a second location spaced from the first location, the first and second locations being chosen such that, in use, there is a potential difference therebetween due to the electric current flowing in the structure;
• the harvesting module is arranged to harvest electrical energy from the electric current, and
• the spaced locations are axially spaced with contact being made to the same run of downhole metallic pipe and the spacing between the locations is 100 m or more.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure, wherein

• the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure, wherein
• the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end, wherein
• the repeater apparatus comprises at least one of a transmitter, receiver or transceiver which is controllable under the control of a control unit for selective use of a modulation scheme selected from at least two available modulation schemes with which the at least one of a transmitter, receiver or transceiver can function.

A wireless communication enabled well installation comprising downhole metallic structure and downhole repeater apparatus for receiving signals and in response transmitting signals onwards, the repeater apparatus being arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure, wherein

• the downhole metallic structure comprises first and second runs of downhole metallic pipe provided in a borehole, the first run of downhole metallic pipe being provided within the second run of downhole metallic pipe so as to define an annulus between the first and second runs of downhole metallic pipe;
• and
• the well installation comprises a remote power arrangement comprising a remote power source for powering the repeater apparatus, said remote power source being provided at a location which is spaced from the region where the repeater apparatus is arranged for at least one of picking up signals from the downhole metallic structure and applying signals to the downhole metallic structure, wherein
• the first run of downhole metallic pipe extends further into the borehole than the second run of downhole metallic pipe, such that the second run of downhole metallic pipe has a lower end past which the first run of downhole metallic pipe extends;
• and
• the repeater apparatus is disposed in the region of the lower end of the second run of downhole metallic pipe and arranged for at least one of picking up signals from the downhole metallic structure in the region of said lower end and applying signals to the downhole metallic structure in the region of said lower end, wherein
• the repeater apparatus comprises a sleeve electrode arrangement comprising a conductive sleeve disposed around the first run of downhole metallic pipe arranged for electrical contact with the surroundings and an insulating layer disposed between the conductive sleeve and the first run of downhole metallic pipe for insulating the conductive sleeve therefrom.