In- Well Piezoelectric Devices to Transmit Signals

BACKGROUND

The environment within a well is both wet and at high pressure. Thus, instances where power or electrical communications must be transferred through the wall of a well tool require a well-sealed, robust pass-through or penetrator. The pass-through can be a source of leaks and can limit the pressure holding capacity of the well tool. Additionally, there are instances where electrical communications must be transferred between well tools of concentric tubing strings or between a well tool of a tubing string and the casing. A pass-through or penetrator is not applicable to this type of communication.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic side cross-sectional view of an example well.

FIG. 2 is a schematic detail, side cross-sectional view of an example well tool.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0001] Referring first to FIG. 1, a well 100 includes a substantially cylindrical wellbore 110 that extends from a wellhead 112 at the surface 114 downward into the Earth into one or more subterranean zones 116. A portion of the wellbore 110 extending from the wellhead 112 to the subterranean zone 116 is lined with lengths of tubing, called casing 118. In other instances, the casing 118 can be omitted or the casing can extend to the termination of the wellbore 110. The depicted well 100 is a horizontal well, having a substantially vertical wellbore portion that extends from the surface 114 to the subterranean zone 116, and a substantially horizontal wellbore portion in the subterranean zone 116. The concepts herein, however, are applicable to many other different configurations of wells, including vertical wells, slanted or otherwise deviated wells, and multilateral wells.

[0002] A tubing string 120 is shown as having been lowered from the surface 114 into the wellbore 110. Depending on whether the well 100 has been completed or, if in construction, the phase of construction, the tubing string 120 can take different forms. 17604-0061WO1 / 2008-IP-013448 PCT

For example, in certain instances, the tubing string 120 is a drill string for drilling the wellbore 110 including a drill bit, a motor (e.g., mud motor and/or other type of motor), logging-while-drilling (LWD) tools, measurement-while-drilling (MWD) tools and/or other components. In certain instances, the tubing string 120 is a working string for performing operations on the well, such as chemical treatments (e.g. acidizing and/or other chemical treatments), stimulation treatments (e.g., fracture stimulation and/or other stimulation treatments), perforating, depositing equipment and tools in the well, and/or performing other operations. In certain instances, the tubing string 120 is a completion or production string for producing from the subterranean zone 116. Yet other examples exist. The tubing string 120 can be a series of jointed tubing coupled together and/or a continuous (i.e., not jointed) coiled tubing, and can include one or more well tools (e.g., one shown, well tool 122). In still other instances, the tubing string 120 can be arranged such that it does not extend from the surface 114, but rather depends into the well on a wire, such as a slickline, wireline, e-line and/or other wire.

[0003] Referring to FIG. 2A, an example well tool 122 is depicted having an arrangement for communicating signals, such as information signals (e.g., data and/or actuation signals) and/or power, through a wall of the well tool 122 without the need for a pass- through to accommodate a wire (e.g., electrical, fiber optic and/or other type of wire). The example well tool 122 includes a housing 202. A first piezoelectric device 204 is exterior of the housing 202. Although the device 204 is shown mounted on the exterior of the housing 202, in the annulus of the wellbore 110, it could be otherwise arranged. For example, in certain instances, the device 204 could be embedded in the wall 208 of the housing 202 on its exterior, included in a sealed sub-housing on the exterior of the housing 202, and/or otherwise exterior the housing 202. A second piezoelectric device 206 is interior the housing 202, spaced apart from the first piezoelectric device 204 by the wall 208 of the housing 202. Although the device 206 is shown embedded in the interior of the wall 208, it could be otherwise arranged. For example, in certain instances, the device 204 could be mounted on the wall 208 (e.g., in the central bore), included in a sealed sub-housing in the interior of the housing 202, and/or otherwise interior the 17604-0061WO1 / 2008-IP-013448 PCT housing 202. The interior of the housing 202 containing the second piezoelectric device is fluidically sealed from the from the first piezoelectric device 204.

[0004] The first piezoelectric device 204 and second piezoelectric device 206 are arranged on the wall 208 to communicate a mechanical signal (e.g., vibration) with each other and between the interior and exterior of the housing 202. In certain instances, the first piezoelectric device 204 can be operated as a transmitter that receives an input electric signal from exterior the housing 202 and generates and transmits a mechanical signal into the wall 208 to the second piezoelectric device 206. FIG. 2 A shows an electric signal conductor 218, such as a wire or other conductor, attached to the exterior of the tubing string 120 for communicating electric signals with the first piezoelectric device 204, but electric signals could be communicated to the first piezoelectric device 204 in other manners. When the first piezoelectric device 204 is operated as a transmitter, the second piezoelectric device 206 can then be operated as a receiver that receives the mechanical signal from the wall 208 and generates, interior the housing 202, an output electrical signal from the mechanical signal. In other instances, the second piezoelectric device 206 can be operated as a transmitter and the first piezoelectric device 204 operated as the receiver.

[0005] In certain instances, the well tool 122 includes one or more an actuated elements 210 (one shown) that can be actuated between one state and another and/or adjusted to intermediate states. For example, the actuated element 210 can be a valve or a choke that can be actuated between open and closed and can be adjusted between differing degrees of part open and part closed. The valve or choke can control flow and pressure through the interior central bore of the tubing string 120 and/or be arranged to control flow and pressure in another flow path, such as a hydraulic signal path used in operating or signaling another component, a fluid communication path with the annulus between the well tool 120 and the wellbore 110, and/or another flow path. In another example, the actuated element 210 can be a release mechanism (e.g., dog, collet and/or other mechanism) actuated to release, for example, a spring, a piston and/or another component involved in the operation of the well tool 122. In yet another example, the actuated element 210 can be gripping mechanism (e.g., slips, dog, collet and/or other mechanism) 17604-0061WO1 / 2008-IP-013448 PCT actuated to secure components together or secure the well tool 120 to the casing or wellbore wall. In still another example, the actuated element can be a sealing mechanism actuated to seal components together or to seal the well tool 120 to the casing or wall of the wellbore.

[0006] The actuated element 210 is operated by an electromechanical actuator 212, such as a motor, servo, and/or other actuator, that responds to an electric signal with mechanical movement that, in turns, moves the actuated element 210. The actuator 212 is in electric communication with the output of the second piezoelectric device 206 to receive electric signals from the second piezoelectric device 206. Thus, in operation, an input electric signal to actuate the actuated element 210 is communicated to the first piezoelectric device 204, for example, via the electric signal conductor 218 or in another manner. The first piezoelectric device 204 generates a mechanical signal based on the input electric signal and transmits the mechanical signal into the wall 208 of the housing 202. The second piezoelectric device 206 receives the mechanical signal, and generates an output electric signal based on the mechanical signal that is representative of the input electric signal received at the first piezoelectric device 204. The second piezoelectric device 206 outputs the electric signal to the actuator 212, and the actuator 212 operates the actuated element 210.

[0007] In one example, the actuated element 210 can be a valve of an electrically operated safety valve. An electric signal to operate the safety valve is transmitted along the electric conductor 218, and through the wall 208 by the piezoelectric devices 204, 206 to the actuator 212 interior the safety valve. When the electric signal is ceased, for example if the conductor 218 is severed in connection with severing or separating a tubing string associated with the conductor 218, the actuated element 210 (i.e., valve) is operated to close off flow through the central bore of the tubing string 120.

[0008] In another example, the actuated element 210 can be a valve, choke, inflow control device or other element of a "smart" or "intelligent" well. A smart well is a well with permanent monitoring systems including distributed sensors and zonal and interval controls that enable more precise control over the operation of the well. Smart wells typically have an electrical communication line for communicating with the monitoring 17604-0061WO1 / 2008-IP-013448 PCT systems and controls, and electric conductor 218 could be part of that electric

communication line.

[0009] The electric signal sent to the first piezoelectric device 204 can include both power and an actuation signal. Thus, the actuator 212 can be powered by electric signals from the second piezoelectric device 206 and/or the actuator 212 can be powered by another power source 214, such as a battery. In instances where a battery is provided, the battery can be in electric communication with the second piezoelectric device 206 to receive electric signals from the second piezoelectric device 206, so that the second piezoelectric device 206 can supply electricity to charge the battery.

[0010] In certain instances, the power source 214 can include a generator, for example, that generates power based fluid flow, temperature differential and/or in another manner. In addition to or as an alternative to powering the actuator 212, the generator can supply an input electric signal to the second piezoelectric device 206. The second piezoelectric device 206 then, in turn, generates a mechanical signal based on the input electric signal and transmits the mechanical signal into the wall 208 of the housing 202. The first piezoelectric device 206 receives the mechanical signal, and generates an output electric signal based on the mechanical signal and outputs the electric signal on the conductor 218 for example to supply power over the conductor 218 elsewhere in the wellbore 110 such as to another tool.

[0011] In certain instances, the well tool 122 can include one or more sensors 216 (one shown) in electric communication with the second piezoelectric device 206 to

communicate electric signals output from the sensor 216 to the second piezoelectric device 206. For example, the sensor 216 can include one or more of a pressure sensor, temperature sensor, flow rate sensor, actuated element position sensor and/or other sensors. Upon receiving the signals output by the sensor 216, the second piezoelectric device 206 generates a mechanical signal based on the electric signal and transmits the mechanical signal into the wall 208 of the housing 202. The first piezoelectric device 206 receives the mechanical signal, and generates an electric signal based on the mechanical signal that is representative of the electric signal received at the second piezoelectric device 204. The electric signal output by the first piezoelectric device 206 17604-0061WO1 / 2008-IP-013448 PCT can be communicated elsewhere in the wellbore 110, such as to another tool or data storage device, and/or to the surface by the electric signal conductor 218 or in another manner.

[0012] Multiple pairs of piezoelectric devices 204, 206 can be provided spaced along the tubing string 120, for example, to allow communication of signals between multiple components interior the tubing string 120. For example, an electric signal from a first device interior the tubing string 120 (e.g., power source 214, sensor 216, and/or another device) can be communicated onto the electric conductor 218 via a first pair of piezoelectric devices. The electric signal can then be communicated over the electric conductor 218 to a second pair of piezoelectric devices, which in turn communicate the electric signal to a second device interior the tubing string 120 (e.g., power source, an actuator, sensor and/or other device). Power and information signals can be

communicated simultaneously. For example, pairs of piezoelectric devices can be used to form a daisy chain communication system having a self powered repeater. The repeater receives the information signal and the power, and the power is used to retransmit the information signal and power to the next repeater.

[0013] Although in FIG. 2Athe first piezoelectric device 204 and second piezoelectric device 206 are shown as being carried on opposing sides of the same wall 208 of the same well tool 122, the devices 204, 206 can be carried on separate, unconnected elements, such as on two separate strings (FIG. 2B), on a casing 118 and tubing string 120 (FIG. 2C) and/or in another manner. In FIG. 2B the first piezoelectric device 204 is carried on a well tool 300 of one tubing string that is concentrically received within and movable relative to the well tool 122 of another tubing string. In FIG. 2C, the well tool 122 and its associated tubing string 120 is concentrically received within and movable relative to the casing 118. Either system, FIG. 2B or 2C, operates similarly to that described with respect to FIG. 2A above. However, in the configurations of FIGS. 2B and 2C, the proximity of the piezoelectric devices 204, 206 is changeable, and the distance between the piezoelectric devices 204, 206 can affect whether the mechanical signal is effectively transmitted between the devices 204, 206. Notably, as above, one or 17604-0061WO1 / 2008-IP-013448 PCT both of the well tools 122, 300 and/or casing 118 can include sensors 216, power sources 214 and/or actuators and actuated elements.

[0014] In some examples, the first and second piezoelectric devices 204, 206 can be operated as a depth (i.e., position) sensing system. For example, the second piezoelectric device 206 can be supplied an electric signal to generate a mechanical signal. When the first piezoelectric device 204 passes near with the second piezoelectric device 206, it receives the mechanical signal and generates an electric signal indicating the devices 204, 206 are proximate one another and aligned. Alternately, the first piezoelectric device 204 can be supplied an electric signal and the second piezoelectric device 206 generates an electric signal when the devices 204, 206 are proximate one another and aligned. Thus, as in FIG. 2B, the configuration can be used to indicate when the well tools 122, 300 are at the same depth by looking for an indication that the mechanical signal is being transmitted between the devices 204, 206. As in FIG. 2C, the configuration can be used to indicate when the well tool 122 is at a specified depth in the casing 118 (i.e., the depth at which the piezoelectric device 206 is placed) in the same manner.

[0015] In certain instances, multiple piezoelectric devices 204, 206 can be provided to enable determining depth at multiple locations in the well. For example, if multiple second piezoelectric devices 206 are provided, each time the first piezoelectric device 204 passes a second piezoelectric device 206 it will generate an electric signal, much in the same way a casing collar locator generates a signal each time it passes a casing collar.

[0016] If multiple piezoelectric devices 204, 206 are provided, some or all can be supplied the same or different electric signals. In certain instances, the different electric signals can be selected to generate unique mechanical signals at one or more or each of the piezoelectric devices. Thus, the unique mechanical signals enable identification of which of the piezoelectric devices are in proximity. Furthermore, generating multiple mechanical signals enables triangulation between the unique signals to enable

determining position between (rather than proximate) piezoelectric devices.

[0017] In some examples, the position or depth information can be used to actuate an aspect of the well tool 122, 300. For example, the well tool 300 can be configured with an actuator and valve actuated element that can be actuated to close off the central bore of 17604-0061WO1 / 2008-IP-013448 PCT the well tool 300. The first piezoelectric device 204 can be supplied with an electric signal that, when the corresponding mechanical signal is received at the second piezoelectric device 206, it signals the actuator to operate the valve element. In certain instances, the configuration can be used as a formation isolation valve that closes in response to the first piezoelectric device 204 passing the second piezoelectric device 206 as the well tool 300 is withdrawn from the well tool 122.

[0018] In some examples, the piezoelectric device of one element can be used to charge the power source of another element. For example, in the context of FIG. 2B, the first piezoelectric device 204 of well tool 300 can be lowered into proximity with the second well tool 122, and power supplied to the first well tool 300 in the form of an electric signal over the conductor 218 of the well tool 300. The power supplied to the well tool 300 can then be transmitted to the well tool 122 via the piezoelectric devices 204, 206. Alternately, power can be supplied over the conductor 218 of the well tool 122 and transmitted to well tool 300. Similarly, in the context of FIG. 2C, the first piezoelectric device 204 of well tool 122 can be lowered into proximity of the casing 118 including the second piezoelectric device 206, and power supplied in the form on an electric signal over conductor 218 of well tool 122 and transmitted to the casing 118. Alternately, power can be supplied over the electric conductor 218 of the casing 118 and transmitted to the well tool 122. In certain instances, the well tool 122 can be suspended on a wire, such as an e-line, and the electric conductor 218 can be the electric conductor of the e-line. Thus, the well tool 122 can be lowered into position, pause to supply power to casing 118, and subsequently moved to a different location or retrieved to the surface.

A number of embodiments of have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other embodiments are within the scope of the following claims.