1. A system for conducting a seismic survey, comprising:
a plurality of devices;
a plurality of conductor pairs in electrical communication with the plurality of devices, each of the conductor pairs being configured to convey power and telemetry signals;
a power supply configured to supply the power signals to each of the plurality of devices over at least two of the plurality of conductor pairs; and
a data communication device configured to communicate with each of the plurality of devices over the at least two of the plurality of conductor pairs.
2. The system of claim 1, wherein the plurality of conductor pairs is configured to form at least one of a point-to-point network and a daisy chain network between the power supply and each of the plurality of devices, and the plurality of devices includes a plurality of seismic devices distributed across an earth surface at intervals, the system further comprising:
a plurality of seismic sensor units coupled to at least one seismic device through cabling, the seismic sensor units providing seismic signals to the at least one seismic device in response to detected reflections from acoustic energy waves directed into the earth surface;
a central recording system receiving telemetry data from one or more of the plurality of seismic devices through the data communication device; and
one or more center tapped transformers configured to superimpose telemetry signals on to the power signals;
wherein the power supply is configured to supply direct current voltage, and one or more seismic devices are configured to transmit telemetry data as telemetry signals superimposed on the power signals over one or more of the plurality of conductor pairs, the telemetry signals superimposed on the power signals through the one or more center tapped transformers.
3. The system of claim 1, wherein the plurality of devices includes at least one seismic device.
4. The system of claim 1, further comprising:
a center tapped transformer configured to superimpose the telemetry signal on to the power signal.
5. The system of claim 1, wherein the power supply is configured to supply direct current voltage.
6. The system of claim, wherein the plurality of conductor pairs is configured to form a point-to-point network between the power supply and each of the plurality of devices.
7. A method of conducting a seismic survey, comprising:
maintaining power distribution to each of a plurality of devices using at least one of a plurality of conductor pairs during a failure of at least one other of the plurality of conductor pairs connected to at least one of the plurality of devices, the conductor pairs being configured to supply power and telemetry signals.
8. The method of claim 7, wherein the plurality of devices are seismic devices, and wherein maintaining power distribution comprises supplying DC power signals over the at least one of the plurality of conductor pairs from a power supply, the method further comprising:
connecting the plurality of conductor pairs to form at least one of a point-to-point network and a daisy chain network between the power supply and the plurality of devices;
providing seismic signals to one or more of the plurality of seismic devices in response to detected reflections from acoustic energy waves directed into the earth surface;
acquiring telemetry data from the seismic signals;
transmitting telemetry data as telemetry signals superimposed on the power signals over the at least one of the plurality of conductor pairs by utilizing one or more center tapped transformers;
receiving the transmitted telemetry data at a central recording system.
9. The method of claim 7, wherein the plurality of devices includes at least one seismic device.
10. The method of claim 7, using a DC power supply to provide the power over the plurality of conductor pairs.
11. The method of claim 7, further comprising:
superimposing the telemetry signals on the power signals.
12. The method of claim 11, using a center tapped transformer to superimpose the telemetry signals on the power signals.
13. The method of claim 7, wherein each of the plurality of devices is connected to at least one power supply using the plurality of conductor pairs to form one of: (i) a point-to-point network and (ii) a daisy chain.
14. A method of conducting a seismic survey, comprising:
supplying power to each of a plurality of devices over a plurality of conductor pairs, the conductor pairs being configured to supply power and telemetry signals.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A packer comprising:
packer body having a corresponding throughbore;
an external packer sleeve, having an inner surface with a grooved section, positioned upon the packer body such that relative movement of the body with respect to the sleeve is restrained by a radially displaceable locking element comprising a shoe having a ridged outer surface adapted to interlock with the grooved section of the inner surface of the external packer sleeve; and
a retention spring for selectively moving the shoe with respect to the external packer sleeve to disengage the displaceable locking element and allow movement of the packer body within the external packer sleeve.
2. The packer of claim 1 wherein the packer body is axially movable with respect to the external packer sleeve in response to a pressure event.
3. The packer of claim 2 wherein the packer body includes a valve seat adapted to receive an obturator that is deliverable to the seat through a drill string with circulating fluid, the combination of the obturator and seat in use allowing a pressure change to be realized.
4. A method comprising:
providing a compression packer tool comprising a disengageable packer assembly wherein a packer sleeve is positioned upon a packer body such that relative movement of the packer body with respect to the packer sleeve is restrained by engagement of a selectively radially movable retaining element therebetween, and wherein the movable retaining element comprises a spring biased shoe having a ridged outer surface adapted to interlock with a grooved section of an inner surface of the packer sleeve;
moving the packer tool in a well bore until a shoulder on the packer sleeve of the packer tool co-operates with a formation within the well;
performing an inflow or negative test to test the integrity of the well bore; and
introducing an obturator to a valve seat of the packer body under gravity or by means of circulating fluid through the tool, and maintaining delivery of fluid to the tool to increase pressure upon the packer body to move the obturator within the throughbore from a first to a second position to cause movement of the shoe away from the grooved section of the inner surface of the packer sleeve and thereby effect disengagement of the packer body from the packer sleeve.
5. The method of claim 4 wherein the packer body is axially movable with respect to the external packer sleeve in response to a pressure event.
6. The method of claim 4 wherein the shoe is operably connected to a spring retention means configured to retract the shoe away from the grooved section of the inner surface of the packer sleeve.