Apparatus and method for detecting fracture geometry using acoustic telemetry
First Claim
1. An electro-acoustic telemetry system for evaluating fracture geometry in a subsurface formation, comprising:
- a casing string disposed in a wellbore, the casing string being comprised of pipe joints connected end-to-end;
at least two sensors disposed along the wellbore and configured to detect elastic waves within the subsurface formation;
a series of communications nodes placed along the wellbore, the communications nodes being configured to relay acoustic signals indicative of elastic waves caused by movement of rock within the subsurface formation as detected by the sensors;
a receiver at the surface configured to receive signals from an uppermost of the communications nodes;
wherein each of the communications nodes comprises;
a sealed housing;
an electro-acoustic transducer and associated transceiver also residing within the housing designed to relay acoustic signals from node-to-node up the wellbore and to the receiver during a wellbore operation; and
an independent power source residing within the housing providing power to the transceiver.
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Accused Products
Abstract
An electro-acoustic system for downhole telemetry employs a series of communications nodes spaced along a string of casing within a wellbore. The nodes allow wireless communication between transceivers residing within the communications nodes and a receiver at the surface. The transceivers provide node-to-node communication of data indicating elastic waves generated as a result of the formation of subsurface fractures. The data is processed which generates a map of fracture geometry. A method of evaluating fracture geometry in a subsurface formation uses a plurality of data transmission nodes situated along the casing string which send signals to a receiver at the surface. The signals are analyzed which generates a subsurface map.
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Citations
41 Claims
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1. An electro-acoustic telemetry system for evaluating fracture geometry in a subsurface formation, comprising:
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a casing string disposed in a wellbore, the casing string being comprised of pipe joints connected end-to-end; at least two sensors disposed along the wellbore and configured to detect elastic waves within the subsurface formation; a series of communications nodes placed along the wellbore, the communications nodes being configured to relay acoustic signals indicative of elastic waves caused by movement of rock within the subsurface formation as detected by the sensors; a receiver at the surface configured to receive signals from an uppermost of the communications nodes; wherein each of the communications nodes comprises; a sealed housing; an electro-acoustic transducer and associated transceiver also residing within the housing designed to relay acoustic signals from node-to-node up the wellbore and to the receiver during a wellbore operation; and an independent power source residing within the housing providing power to the transceiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of evaluating fracture geometry in a subsurface formation, comprising:
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running joints of casing into the wellbore, the joints of casing being connected by threaded couplings to form a casing string; attaching a series of communications nodes to the joints of casing according to a pre-designated spacing, wherein adjacent communications nodes are configured to communicate by acoustic signals transmitted through the joints of casing, and wherein each of the communications nodes comprises; a sealed housing; an electro-acoustic transducer and associated transceiver residing within the housing configured to relay signals, with each signal representing a packet of information that comprises (i) an identifier for the subsurface communications node originally transmitting the signal, and (ii) an acoustic waveform indicative of elastic waves caused by movement of rock within the subsurface formation during a wellbore operation; and an independent power source also residing within the housing for providing power to the transceiver; sending signals from the communications nodes to a receiver at a surface via the series of communications nodes; processing the signals to determine the geographical origin of the elastic waves; and generating a map of subsurface fractures from the processed signals. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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Specification