Apparatus and Method for Relieving Annular Pressure in a Wellbore Using a Wireless Sensor Network

摘要

An electro-acoustic system for downhole telemetry is provided herein. The system employs a series of communications nodes spaced along a string of casing within a wellbore. The nodes are placed within the annular region surrounding the joints of casing within the well-bore. The nodes allow for wireless communication between transceivers residing within the communications nodes and a topside communications node at the wellhead. More specifically, the transceivers provide for node-to-node communication up a wellbore at high data transmission rates for data indicative of a parameter within an annular region behind the string of casing. A method of evaluating a parameter within an annular region along a cased-hole wellbore is also provided herein. The method uses a plurality of data transmission nodes situated along the casing string which send signals to a receiver at the surface. The signals are then analyzed.

主权项

1. An acoustic telemetry system for monitoring a parameter along an annular region in a cased-hole wellbore, comprising:
a casing string disposed in a wellbore, with a cement sheath residing at least partially within an annular region formed between the casing string and a surrounding subsurface rock matrix along the casing string; a topside communications node placed proximate a well head of the wellbore; a plurality of subsurface communications nodes spaced along the wellbore and attached to a wall of the casing string, the subsurface communications nodes configured to transmit acoustic waves from node-to-node up the wellbore and to the topside communications node; one or more sensors for sensing a parameter within the annular region, with each sensor being in electrical communication with an associated subsurface communications node; and a receiver at the surface configured to receive signals from the topside communications node; wherein each of the subsurface communications nodes comprises:
a sealed housing;an electro-acoustic transducer and associated transceiver also residing within the housing, with the transceiver being designed to relay signals from node-to-node up the wellbore, with each signal representing a packet of information that comprises an identifier for the subsurface communications node that originally transmitted the signal, and an acoustic waveform having an amplitude indicative of the parameter; andan independent power source residing within the housing providing power to the transceiver.