Abstract: An arrangement for extraction of hydrocarbons includes a flow conduit that leads from a subsurface region to an above-surface region. A normally-closed shut-in valve is located in the subsurface region of the flow conduit. A hydraulic system is arranged to cause the shut-in valve to open when the hydraulic system is pressurized. A release valve releases pressure in the hydraulic system. A wireless interface having a unique identifier is adapted to open the release valve on receipt of a wireless communication from a remote device. A plurality of remote devices each include a wireless transmitter that is compatible with the wireless interface and able to transmit control instructions to the wireless interface. At least one control instruction in any sequence of control instructions is issued by the remote device including the unique identifier. The wireless interface is adapted to ignore control instructions containing an identifier differing from the unique identifier.

Abstract: An arrangement for extraction of hydrocarbons includes a flow conduit that leads from a subsurface region to an above-surface region. A normally-closed shut-in valve is located in the subsurface region of the flow conduit. A hydraulic system is arranged to cause the shut-in valve to open when the hydraulic system is pressurised. A release valve releases pressure in the hydraulic system. A wireless interface having a unique identifier is adapted to open the release valve on receipt of a wireless communication from a remote device. A plurality of remote devices each include a wireless transmitter that is compatible with the wireless interface and able to transmit control instructions to the wireless interface. At least one control instruction in any sequence of control instructions is issued by the remote device including the unique identifier. The wireless interface is adapted to ignore control instructions containing an identifier differing from the unique identifier.

Abstract: A communications system comprises a primary wireless network and at least one secondary wireless networks, the primary and secondary wireless networks differing in at least one characteristic, at least one sensor unit comprising a means for sensing a parameter and a node of that secondary network adapted to transmit data relating to the parameter via that secondary network, at least one local data gathering point associated with the at least one secondary wireless network, incorporating a node of that secondary wireless network, a node of the primary network, and a control unit adapted to receive data signals from the at least one sensor unit via the secondary network, construct an outgoing data signal incorporating information from the received data signal, and transmit the outgoing data signal via the primary network, the primary wireless network being a multipoint radio network.

Abstract: A communications system comprises a primary wireless network and at least one secondary wireless networks, the primary and secondary wireless networks differing in at least one characteristic, at least one sensor unit comprising a means for sensing a parameter and a node of that secondary network adapted to transmit data relating to the parameter via that secondary network, at least one local data gathering point associated with the at least one secondary wireless network, incorporating a node of that secondary wireless network, a node of the primary network, and a control unit adapted to receive data signals from the at least one sensor unit via the secondary network, construct an outgoing data signal incorporating information from the received data signal, and transmit the outgoing data signal via the primary network, the primary wireless network being a multipoint radio network.