Abstract: An apparatus and method may operate to position an electrode assembly within a fluid. The electrode assembly may include an injection electrode and a receiving electrode in spaced relation to one another. The method may include providing a series of excitation signals at a plurality of frequencies to the injection electrode to inject a series of injection signals into the fluid. The method can further include receiving signals in response to the series of injection signals through the receiving electrode. The received signals can be representative of an impedance spectrum including impedance values representative of the fluid. The method can further include generating a phase angle fingerprint based on the impedance spectrum to characterize the fluid according to the phase angle fingerprint. Additional apparatus, systems, and methods are disclosed.

Abstract: An apparatus and method may operate to mount an electrode assembly with the exterior of a casing string to be placed in a borehole in a subterranean formation. The electrode assembly may include electrodes in spaced relation to one another. After the casing string and associated electrode assembly are in the borehole, the method may include providing a series of excitation signals at a plurality of frequencies to at least one electrode to inject a series of injection signals into fluid in the annulus. The method can further include receiving signals in response to the series of injection signals through at least one other electrode. The received signals can be representative of an impedance spectrum including impedance values representative of the fluid in the borehole annulus. The method can further include identifying the fluid in reference to the impedance spectrum. Additional apparatus, systems, and methods are disclosed.

Abstract: A variety of methods and compositions, including, in one embodiment, a method that comprises providing a treatment fluid comprising a carrier fluid and temperature-activated polymeric particulates. The temperature-activated polymeric particulates may include a compressible gas trapped in the temperature-activated polymeric particulates. The method may further comprise introducing the treatment fluid into a well bore annulus.

Abstract: A radio frequency identification (RFID) tag can include a die attached to an inductive-capacitive (LC) circuit including a capacitive element coupled to an inductive element. The LC circuit can have a resonant frequency that varies according to properties of fluid proximate the RFID tag. The RFID tag can further include a coating material disposed around the die to form an outer surface of the RFID tag. The coating material may have a thickness over a portion of the LC circuit, to permit a conductivity property of a fluid proximate the outer surface to affect the resonant frequency of the LC circuit such that the resonant frequency shifts to a second resonant frequency. Additional apparatus, systems, and methods are disclosed.

Abstract: A method of cementing in a subterranean formation comprises: introducing a cement composition into a wellbore penetrating the subterranean formation, wherein at least a portion of the subterranean formation has a temperature less than or equal to the freezing point of an aqueous liquid, and wherein the cement composition comprises: (A) cement; (B) water; and (C) a pozzolan, wherein the cement composition has a heat of hydration of less than 50 BTU per pound; and causing or allowing the cement composition to set in the wellbore after the step of introducing. The pozzolan can have a calcium oxide concentration of less than 15% by weight of the pozzolan, and the pozzolan can have a concentration of at least 15% by weight of the cement. Gas hydrates can be present in or adjacent to a portion of the well.

Abstract: An apparatus and method may operate to mount one or more communication assemblies relative to the exterior of a casing being placed in a borehole. Two communication assemblies can be placed in longitudinally spaced relation to one another along the casing, wherein each communication assembly is configured to obtain data from RFID tags in one or more azimuthally oriented regions of the annulus surrounding the casing, and to interrogate RFID tags in a first fluid in the borehole. Additional apparatus, systems, and methods are disclosed.

Abstract: Sensor assemblies are deployed in a borehole for a well, such as an oil well or other hydrocarbon recovery well. The sensor assemblies are coupled to a casing string (e.g., the exterior of the casing), and may detect RFID tags or other properties of material (e.g., fluids) in an annulus surrounding the casing string. Limited battery power for the sensor assemblies and for assemblies for communicating sensed data may be a concern, and the sensor assemblies and communication assemblies may therefore operate in different modes of varying power consumption. In certain modes, sensing operations are curtailed (or expanded) depending on particular requirements. In one case, sensor operation is expanded during active portions of a cementing operation, and curtailed prior to and thereafter. Different triggering events may cause the sensor assembly to operate in different modes at different sensing frequencies.

Abstract: A hydrocarbon well (e.g., oil well) may be monitored during to determine whether a fault exists during an operation such as injecting sealant (e.g., cement) into the borehole. RFID tags may be mixed in a wellbore fluid (e.g., drilling mud, cement, etc.), placed into a borehole, and then tracked within the borehole by communication assemblies with RFID sensors. Data may be obtained by interrogating RFID tags in one or more azimuthally oriented regions of an annulus surrounding a casing of the borehole. Fluid distribution in the annulus will be evaluated with respect to azimuthally offset regions of the annulus.

Abstract: A method for measuring parameters related to wellsite operations comprises mixing Micro-Electro-Mechanical System (MEMS) sensors with a wellbore servicing composition in surface wellbore operating equipment. The MEMS sensors are assigned a unique identified that may be used to track individual MEMS sensor as the MEMS sensors travel through the wellbore and may be used to correlate sensor measurements taken by the MEMS sensors with particular locations in the wellbore. The MEMS sensors may be active and transmit their respective identifiers and sensor data to the surface. Transmitting identifier and sensor data from a MEMS sensor to the surface wellbore operating equipment may be via one or more other MEMS sensors, downhole devices, and surface devices.

Abstract: According to an embodiment, a drilling fluid comprises: water and a set accelerator, wherein the drilling fluid has a 10 minute gel strength of less than 20 lb*ft/100 sq ft, wherein the drilling fluid has a density in the range of about 9 to about 14 pounds per gallon, wherein the drilling fluid remains pourable for at least 5 days, and wherein when at least one part of the drilling fluid mixes with three parts of a cement composition consisting of water and cement, the drilling fluid cement composition mixture develops a compressive strength of at least 1,200 psi. According to another embodiment, a method of using the drilling fluid comprises the steps of: introducing the drilling fluid into at least a portion of a subterranean formation, wherein at least a portion of the drilling fluid is capable of mixing with a cement composition.

Abstract: A variety of methods and compositions are disclosed, including, in one embodiment, a method that comprises providing a treatment fluid comprising a carrier fluid and temperature-activated polymeric particulates, wherein a compressible gas is trapped in the polymeric particulates; and introducing the treatment fluid into a well bore annulus.

Abstract: An apparatus and method may operate to mount one or more communication assemblies relative to the exterior of a casing being placed in a borehole. Two communication assemblies can be placed in longitudinally spaced relation to one another along the casing, wherein each communication assembly is configured to obtain excitation responses from electrodes of a fluid sensing component, where the excitation responses vary based on properties of fluids in one or more regions of the annulus surrounding the casing. Additional apparatus, systems, and methods are disclosed.

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 method of cementing in a subterranean formation comprises: introducing a cement composition into a wellbore penetrating the subterranean formation, wherein at least a portion of the subterranean formation has a temperature less than or equal to the freezing point of an aqueous liquid, and wherein the cement composition comprises: (A) cement; (B) water; and (C) a pozzolan, wherein the cement composition has a heat of hydration of less than 50 BTU per pound; and causing or allowing the cement composition to set in the wellbore after the step of introducing. The pozzolan can have a calcium oxide concentration of less than 15% by weight of the pozzolan, and the pozzolan can have a concentration of at least 15% by weight of the cement. Gas hydrates can be present in or adjacent to a portion of the well.

Abstract: Methods and compositions for treating a subterranean formation with salt-tolerant cement slurries including treating a salt-containing subterranean formation having sodium salts, potassium salts, magnesium salts, calcium salts, or any combination thereof comprising: providing a salt-tolerant cement slurry comprising: a base fluid, a cementitious material, a pozzolanic material, a salt-tolerant fluid loss additive, a salt additive, and optionally, an elastomer, a weight additive, a fluid loss intensifier, a strengthening agent, a dispersant, or any combination thereof; introducing the salt-tolerant cement slurry into the subterranean formation; and allowing the salt-tolerant cement slurry to set.

Abstract: Sensor assemblies are deployed in a borehole for a well, such as an oil well or other hydrocarbon recovery well. The sensor assemblies are coupled to a casing string (e.g., the exterior of the casing), and may detect RFID tags or other properties of material (e.g., fluids) in an annulus surrounding the casing string. Limited battery power for the sensor assemblies and for assemblies for communicating sensed data may be a concern, and the sensor assemblies and communication assemblies may therefore operate in different modes of varying power consumption. In certain modes, sensing operations are curtailed (or expanded) depending on particular requirements. In one case, sensor operation is expanded during active portions of a cementing operation, and curtailed prior to and thereafter. Different triggering events may cause the sensor assembly to operate in different modes at different sensing frequencies.

Abstract: A hydrocarbon well (e.g., oil well) may be monitored during to determine whether a fault exists during an operation such as injecting sealant (e.g., cement) into the borehole. RFID tags may be mixed in a wellbore fluid (e.g., drilling mud, cement, etc.), placed into a borehole, and then tracked within the borehole by communication assemblies with RFID sensors. Data may be obtained by interrogating RFID tags in one or more azimuthally oriented regions of an annulus surrounding a casing of the borehole. Fluid distribution in the annulus will be evaluated with respect to azimuthally offset regions of the annulus.

Abstract: An apparatus and method may operate to mount one or more communication assemblies relative to the exterior of a casing being placed in a borehole. Two communication assemblies can be placed in longitudinally spaced relation to one another along the casing, wherein each communication assembly is configured to obtain data from RFID tags in one or more azimuthally oriented regions of the annulus surrounding the casing, and to interrogate RFID tags in a first fluid in the borehole. Additional apparatus, systems, and methods are disclosed.

Abstract: A radio frequency identification (RFID) tag can include a die attached to an inductive-capacitive (LC) circuit including a capacitive element coupled to an inductive element. The LC circuit can have a resonant frequency that varies according to properties of fluid proximate the RFID tag. The RFID tag can further include a coating material disposed around the die to form an outer surface of the RFID tag. The coating material may have a thickness over a portion of the LC circuit, to permit a conductivity property of a fluid proximate the outer surface to affect the resonant frequency of the LC circuit such that the resonant frequency shifts to a second resonant frequency. Additional apparatus, systems, and methods are disclosed.

Abstract: Of the many methods and compositions provided herein, one method includes a method comprising introducing a sealant composition into a well bore that penetrates a subterranean formation, wherein the sealant composition comprises a base fluid, a binder material, and a filler material; and allowing the sealant composition to form a cohesive sealant. One composition provided herein includes a sealant composition comprising a base fluid, a binder material, and a filler material, wherein the sealant composition will form a cohesive sealant.