Abstract: An assembly for use in a wellbore can include a plurality of sensors positioned external to a casing string. The plurality of sensors can be positioned for detecting an amount of a hydrocarbon that is present in a fluid in the wellbore and a pH of the fluid in the wellbore. The plurality of sensors can be positioned for wirelessly transmitting signals representing the amount of the hydrocarbon that is present in the fluid and the pH of the fluid to a receiving device.

Abstract: Methods and systems are presented in this disclosure for determining information (e.g., visual information) about locations of different fluids flowing along a casing in a wellbore. A plurality of radio frequency (RF) micro-electro-mechanical system (MEMS) tags is placed in a plurality of fluids flowing through an annulus region between a casing string in the wellbore and a reservoir formation. At a plurality of sensing nodes located along the casing string, information about the fluids is gathered by communicating with the RF MEMS tags placed in the fluids. The information about fluid locations along the casing gathered by the sensing nodes is communicated to a receiving device, and appropriate operation in relation to the wellbore is performed based on the communicated information.

Abstract: A communication unit is situated in or on a casing collar. The casing collar has two threaded ends for joining casing joints to construct a well casing, and a communication unit is disposed in or on a central region of the tube between the two threaded ends. In an example, the communication unit has a transmitter for transmitting sensor data uphole from a sensor sensing a well bore condition. For example, the communication unit has a receiver for receiving sensor data from Micro-Electro-Mechanical Systems (MEMS) sensors, a transceiver for interrogating RFID tags, an acoustic transceiver for sensing wellbore conditions, a pressure sensor, a temperature sensor, and batteries for powering the communication unit.

Abstract: Disclosed are telemetry systems and methods that employ a plurality of electromagnetic transceivers disposed outside a well casing string at a corresponding plurality of depths along the casing string. Each transceiver includes one or more toroidal inductors circumferentially surrounding the casing string and inductively coupled thereto to allow signal transmission between transceivers via currents induced in the casing. In some embodiments, signals are relayed via a chain of transceivers to facilitate indirect communication between a surface facility and other transceivers located too deep for direct communication to the surface.

Abstract: A well casing is cemented in a well bore in a subterranean formation by pumping cement slurry down into the well casing so that the cement slurry flows up into an annulus surrounding the well casing. While pumping the cement slurry, the position of the top of the cement slurry in the annulus is sensed, and the rise of the sensed position of the top of the cement slurry in the annulus is recorded as a function of time. The recording is analyzed to evaluate the cement job. For example, the analysis may indicate a problem addressed by adjusting a cement plan for a future cement job, and the analysis may indicate a need to repair a location of the set cement by perforating the well casing at the location to be repaired, and pumping cement slurry down the well casing to fill the location to be repaired.

Abstract: Radio frequency Micro-Electro-Mechanical System (“MEMS”) tags are geometrically shaped using protective structures. The MEMS tags may be added to wellbore cement, and pumped downhole. In addition to protecting the MEMS tags from the harsh downhole environment, the protective structures produce a more rounded shape which, in turns, increases the flow efficiency of the MEMS tags. An interrogation tool may be deployed downhole to interrogate the MEMS tags, to thereby perform a variety of wellbore operations such as assessing the integrity of the cement seal.

Abstract: A communication system that is positionable in a wellbore can include a first transceiver positioned externally to a casing string. The first transceiver can be operable to detect a presence or an absence of a surface wave; determine a location of a fluid in the wellbore based on the presence or the absence of the surface wave; and transmit data indicative of the location to a second transceiver. The surface wave can include an electromagnetic wave that has a magnetic field or an electric field that is non-transverse to a direction of propagation of the surface wave. The communication system can also include the second transceiver, which can be positioned externally the casing string and operable to receive the data.

Abstract: A communication assembly is described that when placed around a string casing in a wellbore transmits data along a pipe string from the wellbore to, for example, the surface of the well. The assembly includes a high magnetic permeability substrate to eliminate signal loss to the casing string thereby enhancing the signal and improving data transmission.

Abstract: An assembly for use in a wellbore can include a plurality of sensors positioned external to a casing string. The plurality of sensors can be positioned for detecting an amount of a hydrocarbon that is present in a fluid in the wellbore and a pH of the fluid in the wellbore. The plurality of sensors can be positioned for wirelessly transmitting signals representing the amount of the hydrocarbon that is present in the fluid and the pH of the fluid to a receiving device.

Abstract: An assembly for use in a wellbore can include a plurality of sensors positioned external to a casing string. The plurality of sensors can be positioned for detecting an amount of a hydrocarbon that is present in a fluid in the wellbore and a pH of the fluid in the wellbore. The plurality of sensors can be positioned for wirelessly transmitting signals representing the amount of the hydrocarbon that is present in the fluid and the pH of the fluid to a receiving device.

Abstract: A magnetic signally assembly is described that when placed around a string casing in a wellbore can ascertain properties of the fluid in the annulus surrounding the string casing. Further, methods of using the magnetic signaling assembly to ascertain fluid properties and to indicate the condition of the well are also described.

Abstract: A communication assembly including at least one sensor assembly made up of interrogation circuitry and one or more antennae is described. The interrogation circuitry comprises at least one inductor comprising at least two sensing coils for reception of signals from the MEMS data sensors.

Abstract: A system that is positionable in a wellbore can include a transceiver that is positionable external to a casing string and programmable to vary a number of data packets that are wirelessly transmitted by the transceiver. The number of data packets can correspond to an amount of data wirelessly transmitted by the transceiver about an environment in the wellbore.

Abstract: Micro-Electro-Mechanical System (“MEMS”) tags having high and low resonant frequencies are used to detect the cured or uncured state of wellbore cement. The MEMS tags may be added to wellbore cement, and pumped downhole. An interrogation tool emits a signal at one or both of the resonant frequencies which, in turn, interacts with the MEMS tags to produce a response signal. Since uncured cement has a high attenuation, only the lower resonant frequency response signal is sensed by an interrogation device, thus indicating the cement remains uncured. When the cement cures, its conductivity drops and the attenuation of the higher resonant frequency response signal drops also, thus allowing that signal to be detected by the interrogation device and indicating the cement has cured.

Abstract: A communication assembly including at least one sensor assembly made up of interrogation circuitry and one or more antennae. The interrogation circuitry comprises at least one inductor coil sensor including a single turn coil inductor for reception of signals from the MEMS data sensors.

Abstract: A system that is positionable in a wellbore can include a transceiver that is positionable external to a casing string. The transceiver can be remotely programmable while in the wellbore to set an internal clock using a timing signal wirelessly transmitted from a source and a position of the transceiver in the wellbore relative to the source. The transceiver can use the internal clock for controlling a timing of the transceiver for transmitting a wireless signal.

Abstract: Sensor assemblies are deployed in a borehole for a well, such as an oil well or other hydrocarbon recovery well. The sensor assemblies may be coupled to a casing string (e.g., the exterior of the casing), and detect RFID tags or other properties of material (e.g., fluids) in an annulus surrounding the casing string. During cementing or other operations, RFID tags may be used to track fluids. RFID detection circuits may be used to scan at different frequencies, and corresponding results may be compared by various means and processes to determine the presence of RFID tags.

Abstract: A repeater system provided in a wellbore including a plurality of communication units spaced at intervals along a length of a wellbore, the communication units being communicatively coupled via a transmission medium. The communication units are configured to relay data from one communication unit to another communication unit selected from the plurality of communication units along the transmission medium, wherein at least one of the communication units is hopped over as data is relayed across the plurality of communication units along the length of the wellbore.

Abstract: A system that is positionable in a wellbore in a subterranean formation can include a first transceiver that is positionable external to a casing string in the wellbore. The first transceiver can wirelessly transmit data via a signal within a frequency band that is selected based on a fluid property of a fluid in the wellbore and a property of the subterranean formation.

Abstract: A communication system that is positionable in a wellbore can include a first transceiver for coupling externally to a casing string. The first transceiver can be for wirelessly transmitting data by generating and modulating a surface wave that propagates along an interface surface. The surface wave can include an electromagnetic wave that has a magnetic field or an electric field that is at an acute angle to a direction of propagation of the surface wave. The communication system can also include a second transceiver for coupling to the casing string and for wirelessly receiving the surface wave and detecting the data.