Abstract: Methods, systems, and computer-readable medium to perform operations including: determining, based on at least one dimension of an annulus of a wellbore, a respective downhole position at which to position at least one of an upper sensor and a lower sensor of a downhole pumping tool that includes a pump; positioning the downhole pumping tool in the wellbore such that at least one of the upper sensor and the lower sensor are positioned at the respective downhole position; in response to the upper sensor detecting a first fluid level in the annulus, activating the pump so that the pump pumps fluid from the annulus into a tubing of the wellbore, where the tubing carries the fluid to the surface; and in response to the lower sensor detecting a second fluid level in the annulus, deactivating the pump, where the second fluid level is below the first fluid level.

Abstract: A shoe for use with a casing string in a borehole. The shoe may include a first screen positioned within a bore of the shoe or of the casing string near the shoe. The first screen may include orifices sized to prevent the passage of lost circulation material or a material with properties similar to the lost circulation material from outside the shoe through the first screen.

Abstract: Well installations and methods for constructing wireless ready well installations. The installations comprise downhole metallic structure (2) and downhole repeater apparatus (5) for receiving signals and in response transmitting signals onwards. The repeater apparatus (5) are arranged for at least one of receiving the signals by picking up at least one of electrical and acoustic signals from the downhole metallic structure and transmitting the signals onwards by applying at least one of electrical and acoustic signals to the downhole metallic structure. Various arrangement and methods are described to allow provision of well installations ready for wireless communications.

Abstract: Described are tools, systems, and methods for dielectric logging using transient waveforms. In some embodiments, one or more microstrip antennas are employed for the measurements. In various embodiments, the waveforms are processed in the time-domain to determine the dielectric properties of a formation, from which geophysical formation properties can then be derived. Further embodiments are disclosed.

Abstract: Methods of using capture gamma-ray spectroscopy for analyzing gravel-packs, frac-packs, and cement are disclosed herein. The methods can include distinguishing particles placed in a borehole region from particles placed in a subterranean formation outside of the borehole region, by utilizing a slurry comprising a liquid, particles, and a thermal neutron absorbing material to place the particles into the borehole region. The methods can also include obtaining first and second data sets by lowering into a borehole traversing the borehole region a pulsed neutron logging tool comprising a pulsed neutron source and a detector, emitting pulses of neutrons from the pulsed neutron source into the borehole region at intervals of one pulse per about 1,000 ?sec for the first data set and about one pulse per about 100 ?sec for the second data set, and detecting capture gamma rays resulting from nuclear reactions in the borehole and the subterranean formation.

Abstract: A method and system for completing cementing operations in a subterranean well with a wiper plug assembly includes delivering the wiper plug assembly into a casing, the wiper plug assembly having a wiper plug body with a circular cross section and a resilient wiper element that engages an inner diameter of the casing string. An inclination of the wiper plug assembly is measured in three dimensions with an accelerometer assembly and an azimuth of the wiper plug assembly is measured in three dimensions with a magnetometer. The inclination and the azimuth of the wiper plug assembly are delivered to a control unit in real time. An inclination of the wiper plug assembly is determined in real time. The inclination of the wiper plug assembly is delivered to an earth's surface in real time with a transmitter of the electronics package.

Abstract: A method of monitoring a substance in a well can include disposing at least one optical electromagnetic sensor and at least one electromagnetic transmitter in the well, and inducing strain in the sensor, the strain being indicative of an electromagnetic parameter of the substance in an annulus between a casing and a wellbore of the well. A system for monitoring a substance in a well can include at least one electromagnetic transmitter, and at least one optical electromagnetic sensor with an optical waveguide extending along a wellbore to a remote location, the sensor being positioned external to a casing in the wellbore.

Abstract: Systems and methods are provided for determining a cure state of cement in a wellbore. A drill device can be used to drill cement in a wellbore. Contact between the drill device and the cement can cause friction or heat, which can produce a gas. A gas detector can be positioned near a wellbore for detecting an amount of gas and a type of gas produced by contact between the drill device and the cement in the wellbore. The cure state of cement in the wellbore can be determined based on the amount of gas and the type of gas detected.

Abstract: Methods including taking a gamma spectrum from a wellbore at a target depth, wherein the wellbore penetrates a subterranean formation and has a completion profile comprising a pipe and an annulus between the pipe and the subterranean formation; determining a cement volumetric void space in the wellbore at the target depth; establishing a cement-void-spatial calibration curve based on obtained gamma spectra representing cement spatial void space locations in the annulus of the completion profile, wherein each cement volumetric void space amount in the wellbore has a characteristic cement-void-spatial calibration curve; comparing the wellbore gamma spectrum and the cement-void-spatial calibration curve; and determining a location of the cement volumetric void space in the wellbore at the target depth.

Abstract: In an embodiment, a method is performed by a computer system. The method includes integrating a series of data inputs related to a well. The series of data inputs includes at least one real-time data input and at least one non-real-time data input. The method further includes based, at least in part, on a result of the integrating, facilitating a real-time display of performance data for the well. The real-time display includes information related to at least one of hydraulic surveillance and torque-and-drag surveillance.

Abstract: Sonic data, ultrasonic data, density data, cased-hole neutron data, and open-hole neutron data of the wellbore are obtained. The sonic and ultrasonic data provides the amplitude, frequency, and phase of the altered sonic and ultrasonic waves. The far counts, near counts, and energy spectrum are obtained from density data, cased-hole (CH) neutron data, and open-hole (OH) neutron data. The amplitude, frequency, and phase provide the interface densities of the first, second, and third interfaces. The hydrogen index (HI) of the formation and the cased wellbore are obtained from the CH and OH neutron data. The widths of the second and third interfaces are obtained from the HI's and the densities of the second and third interfaces.

Abstract: Sonic data, ultrasonic data, and density data of the annulus are obtained using a sonic tool, an ultrasonic tool, and a density tool, respectively, included in a tool string. A first deconvolution operation is performed to obtain an amplitude, a frequency, and a phase of the modified sonic wave. A first inverse modeling operation results in a first density value of the annular media. A second deconvolution operation is performed to obtain an amplitude, a frequency, and a phase of the modified ultrasonic wave. A second inverse modeling operation results in a second density value of the annular media. A third deconvolution operation is performed to obtain far counts, near counts, and an energy spectrum of gamma rays. A third inverse modeling operation results in a third density value of the annular media.

Abstract: Compositions useful as wellbore fluids are generally disclosed. In some embodiments, the compositions include polymerizable olefinic surfactant compositions, which, under certain conditions, can polymerize via free-radical polymerization to form surfactant polymers. In some embodiments, the compositions are introduced to an oil well as part of the drilling or extraction process, e.g., to assist in flushing hydrocarbon material out of subterranean formations.

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: In one aspect, a wellbore system is disclosed that in one non-limiting embodiment includes a cement section in the wellbore formed to prevent flow of fluids including hydrocarbons through the cement section, a plug disposed uphole of the cement section to provide a space between the cement section and the plug and a sensor in the space for providing measurements relating to a parameter of interest. In one aspect, the parameter of interest may include one or more of presence and extent of a hydrocarbon, presence of moisture; pressure; and temperature. The system may further include a transmitter that transmits measurements from the sensor via a communication line or wirelessly to a receiver for processing the sensor measurements.

Abstract: Micro-electro-mechanical systems lost circulation materials (MEMS-LCMs) of various sizes, shapes, and specific gravities may be used in a drilling fluid to determine the preferred LCMs for use in wellbore strengthening of the wellbore. For example, a method may include drilling at least a portion of a wellbore penetrating a subterranean formation with a drilling fluid that comprises a base fluid, a plurality of MEMS-LCMs, and a plurality of LCMs, wherein the MEMS-LCMs and the LCMs are substantially similar in size, shape, and specific gravity; measuring a first concentration of the MEMS-LCMs in the drilling fluid before circulating the drilling fluid through the wellbore; measuring a second concentration of the MEMS-LCMs in the drilling fluid after circulating the drilling fluid through the wellbore; performing a comparison of the first and second concentrations of the MEMS-LCMs; and changing a composition of the drilling fluid based on the comparison.

Abstract: A method of opening a conduit cemented in a subterranean well can include flowing a fluid through a passage in the well after the conduit is cemented in the well, and the conduit opening in response to the flow of the fluid through the passage. A well system can include a flow control device cemented in a wellbore, and a conduit positioned adjacent a passage of the flow control device, whereby the conduit opens in response to the passage being opened.

Abstract: A method of completing a subsea wellbore includes providing one or more conductor anchoring assemblies on an outer surface of a conductor; forming the subsea wellbore; positioning the conductor in the subsea wellbore; and energizing the one or more conductor anchoring assemblies into contact with the subsea wellbore, thereby stabilizing the conductor in the subsea wellbore. In yet another embodiment, the method further includes extending the subsea wellbore; positioning a casing inside the conductor, wherein the casing includes a casing anchoring assembly; and energizing the casing anchoring assembly into contact with the conductor.

Abstract: Various systems and methods for cementing plug tracking using distributed strain sensing include a downhole cementing apparatus that includes a distributed strain sensor with an optical cable and a first downhole cementing plug coupled to a fixed point on the optical cable. The apparatus further includes a second downhole cementing plug slidably coupled to the optical cable between the first downhole cementing plug and a sensing end of the optical cable. The second downhole cementing plug causes a detectable feature in a strain profile along the optical cable's length that indicates a position of the second downhole cementing plug.

Abstract: A method for determining along relatively uniformly spaced apart parallel first and second wellbores situated in an underground hydrocarbon-containing formation, regions within the formation, including in particular regions between such wellbores, where injection of a fluid at a pressure above formation dilation pressure may be advantageous in stimulating production of oil into the second of the two wellbores, and subsequently injecting fluid at pressures above formation dilation pressures at the discrete regions along such wellbores determined to be in need. An initial information-gathering procedure is conducted, wherein fluid is supplied under a pressure less than formation dilation or fracture pressure, to discrete intervals along a first wellbore, and sensors in the second wellbore measure and data is recorded regarding the ease of penetration of such fluid into the various regions of the formation intermediate the two wellbores.

Abstract: Disclosed herein is a method of servicing a wellbore comprising the steps of preparing a dry cement blend comprising a base cement and a crystalline component wherein the dry cement blend is based on an initial dry cement blend formulation, obtaining a diffraction pattern of a sample of the dry cement blend, generating a model diffraction pattern, refining the model diffraction pattern using a structural refinement method, determining the type and amount crystalline components present in the dry cement blend, generating a final dry cement blend formulation, and comparing the initial dry cement blend formulation to the final dry cement blend formulation.

Abstract: The present invention is directed to methods and systems for obtaining log data on a cased wellbore concurrently with wellbore cleanout operations. In some such embodiments, a combination of at least one cleaning means and at least one logging tool are integrated or otherwise affixed to a common workstring, such that both wellbore cleanout and logging operations can be accomplished without having to remove the workstring from the well between such operations. In some such embodiments, the one or more logging tool(s) transmit information about the cased wellbore to the surface wirelessly. In some or other such embodiments, such information is transmitted via cable, in real-time or in batch mode. In some or still other such embodiments, such information is stored in memory and accessed subsequent to the workstring being extracted from the wellbore.

Abstract: A method for identifying fluid migration or inflow associated with a wellbore tubular, comprises measuring strain of the wellbore tubular with a system comprising at least one string of interconnected sensors that is arranged such that the sensors are distributed along a length and the circumference of the wellbore tubular; establishing a baseline that is a function of steady state strain measurements within a first time period; and identifying fluid migration or inflow where strain measurements substantially deviate from the baseline within a second time period.

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: Optical analysis systems, methods, and apparatuses for analyzing fluids may be useful for in situ monitoring fluids that relate to cementing operations. For example, a method may include containing a cement fluid composition in a flow path comprising a wellbore; and optically interacting the cement fluid composition with an integrated computational element, thereby generating an output signal corresponding to a characteristic of the cement fluid composition, the integrated computational element being coupled to a tool.

Abstract: Various disclosed cement slurry monitoring methods include monitoring one or more parameter of the cement slurry at various positions along the borehole during the curing process and responsively identifying a span over which the slurry extends and whether there are any gaps or voids in that span. At least some system embodiments include a distributed sensing arrangement to provide parameter measurements as a function of position and time during the curing process. A computer analyzes the measurements to determine the span of the cement slurry and whether any gaps exist. Contemplated measurement parameters include temperature, pressure, strain, acoustic spectrum, acoustic coupling, and chemical concentration. Individually or in combination, these measurements can reveal in real time the state of the cement slurry and can enable remedial actions to be taken during or after the curing process if needed to address deficiencies in the annular seal being provided by the cement.

Abstract: A method for cement bond logging and targeted intervention, including lowering a cylindrical n×m array of ultrasound (US) transducers into a well, firing the US transducers to transmit US signals into a well casing, converting reflected US signals received by the transducers into electronic form and transmit the converted signals to a control unit, analyzing the converted signals to detect holidays, if a holiday is detected, determining a position and angle of the holiday with respect to the transducers, and applying a high intensity focused ultrasound (HIFU) signal to the well casing to fill the holiday.

Abstract: An apparatus for use in a wellbore, made of a casing and an annulus with a fluid within, comprises a reel or wound optic fiber line fixed to an object within the casing, and a light transmitter/receiver device that is able to generate a signal through the optic fiber line and to measure a change of said signal. The optic fiber line is (a) on a first position fixed to a reference point linked to the light transmitter/receiver device, and is (b) on a second position unwound from the reel. The light transmitter/receiver device is able to measure the change of said signal when occurring at the second position, and the apparatus has a system able to measure the flow rate of the fluid exiting the annulus at the surface.

Abstract: A method of controlling a well operation can include monitoring at least one parameter of cement lining a wellbore, the monitoring being performed via at least one optical waveguide, and modifying the well operation in response to the parameter being outside of a predetermined acceptable range. A well monitoring system can include at least one optical waveguide which is used to sense at least one parameter of cement lining a wellbore, an optical interrogation system optically connected to the at least one optical waveguide, and a control system which controls operation of at least one item of well equipment in response to information received from the optical interrogation system.

Abstract: An apparatus for verifying cement arrival at a target location includes a liner. A sensory structure radially outwardly disposed of the liner at a target arrival location of cement from a cementing operation. The sensory structure configured to sense arrival of cement. A seal configuration automatically responsive to the sensed arrival of cement. Also included is a method for addressing micro annulus formation in a down hole cementing operation.

Abstract: A method of servicing a wellbore, comprising placing a wellbore composition comprising a plurality of Micro-Electro-Mechanical System (MEMS) sensors in the wellbore, placing a plurality of acoustic sensors in the wellbore, obtaining data from the MEMS sensors and data from the acoustic sensors using a plurality of data interrogation units spaced along a length of the wellbore, and transmitting the data obtained from the MEMS sensors and the acoustic sensors from an interior of the wellbore to an exterior of the wellbore. A method of servicing a wellbore, comprising placing a wellbore composition comprising a plurality of Micro-Electro-Mechanical System (MEMS) sensors in the wellbore, and obtaining data from the MEMS sensors using a plurality of data interrogation units spaced along a length of the wellbore, wherein one or more of the data interrogation units is powered by a turbo generator or a thermoelectric generator located in the wellbore.

Abstract: The invention relates to a device for examining a tubular channel, the device comprising a three-way valve, buoyancy means, pressure means, a vent line, at least one sensor and computation means; wherein the three-way valve controls the fluid flow between the pressure means and the buoyancy means and between the buoyancy means and the vent line; the computation means is communicatively coupled to the at least one sensor and adapted to generate a control signal based on data received from the at least one sensor; and wherein the pressure means is fluidly coupled to the buoyancy means via the three-way valve such that a fluid may flow from the pressure means to the buoyancy means or from the buoyancy means to the surroundings of the device via the vent line; and wherein the computation means is communicatively coupled to the three-way valve and controls said three-way valve via the control signal. Thereby, the invention is able to examine e.g.

Abstract: A well logging fluid, and methods of using the same, include a base fluid selected from water, water-based mud, or oil-based mud, and an additive material selected from silica or cork or alike. The fluid has an impedance substantially different from that of the base fluid. Such a modified impedance helps improve the measurement accuracy.

Abstract: A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore at a flow rate, determining velocities of the MEMS sensors along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the velocities of the MEMS sensors and the fluid flow rate. A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore, determining positions of the MEMS sensors relative to one or more known positions along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the determined positions of the MEMS sensors.

Abstract: An apparatus for verifying cement arrival at a target location includes a liner. A sensory structure radially outwardly disposed of the liner at a target arrival location of cement from a cementing operation. The sensory structure configured to sense arrival of cement. A seal configuration automatically responsive to the sensed arrival of cement. Also included is a method for addressing micro annulus formation in a downhole cementing operation.

Abstract: A method of preparing a wellbore for production includes running a wellbore clean-out string, including a cement evaluation tool and a wellbore cleaning tool, into a wellbore, acquiring data relating to at least one property of a cement bond of the wellbore, using the cement evaluation tool, and simultaneously cleaning the wellbore, using the wellbore cleaning tool, as the clean-out string is run into the wellbore in order to acquire first and second sets of data while running the string into the wellbore. The first and second sets are combined to form first and second logs of cement bond, which are used to produce an enhanced log of the cement bond.

Abstract: A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore at a flow rate, determining velocities of the MEMS sensors along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the velocities of the MEMS sensors and the fluid flow rate. A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, pumping the wellbore composition into the wellbore, determining positions of the MEMS sensors relative to one or more known positions along a length of the wellbore, and determining an approximate cross-sectional area profile of the wellbore along the length of the wellbore from at least the determined positions of the MEMS sensors.

Abstract: A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in at least a portion of a sealant composition, placing the sealant composition in an annular space formed between a casing and the wellbore wall, and monitoring, via the MEMS sensors, the sealant composition and/or the annular space for a presence of gas, water, or both. A method of servicing a wellbore, comprising placing a plurality of Micro-Electro-Mechanical System (MEMS) sensors in a wellbore composition, placing the wellbore composition in the wellbore, and monitoring, via the MEMS sensors, the wellbore and/or the surrounding formation for movement.

Abstract: A method of servicing a wellbore, comprising placing a wellbore composition comprising a plurality of Micro-Electro-Mechanical System (MEMS) sensors in the wellbore, placing a plurality of acoustic sensors in the wellbore, obtaining data from the MEMS sensors and data from the acoustic sensors using a plurality of data interrogation units spaced along a length of the wellbore, and transmitting the data obtained from the MEMS sensors and the acoustic sensors from an interior of the wellbore to an exterior of the wellbore. A method of servicing a wellbore, comprising placing a wellbore composition comprising a plurality of Micro-Electro-Mechanical System (MEMS) sensors in the wellbore, and obtaining data from the MEMS sensors using a plurality of data interrogation units spaced along a length of the wellbore, wherein one or more of the data interrogation units is powered by a turbo generator or a thermoelectric generator located in the wellbore.

Abstract: A system for optimizing gravel deposition in a completion interval of a well. The system includes a pumping system that is operable to deliver a gravel pack slurry to the completion interval, an actuator system that is operable to control properties of the gravel pack slurry and a sensor system that is operable to monitor parameters representative of gravel deposition in the completion interval. A dynamic gravel pack model defined in a computer is operable to receive data from the sensor system and provides estimates of gravel deposition in the completion interval. A control system is operable to control the pumping system and the actuator system in relation to a gravel pack deposition plan and the dynamic gravel pack model, wherein the estimates of the dynamic gravel pack model are input into the control system to automatically modify the gravel pack deposition plan.

Abstract: A system and method for releasing a marker within a wellbore is provided. The system and method includes a sensor that detects movement or a position of the marker within the wellbore. The marker may be released in drilling fluid, for example, and may travel from the surface to the drill bit and return to the surface with cuttings. As an example, the markers are used to determine the flow of cuttings within the wellbore.

Abstract: An intelligent well system may include a first main bore transmission assembly disposed in a main bore and a first lateral bore transmission assembly disposed in a lateral bore. The first main bore transmission assembly may include a first main bore transmission unit, and the first lateral bore transmission assembly may include a first lateral bore transmission unit. The first main bore transmission unit and the first lateral bore transmission unit may be configured to establish a wireless connection there between, such that at least one of power or telemetry can be wirelessly transmitted. The first main bore transmission assembly may be configured to be communicatively connected to a surface communication device.

Abstract: Many reservoirs of interest include heavy oil. In such reservoirs, partly at normal temperatures, many instruments commonly used for formation evaluation may not be able to distinguish between heavy oil and bound water in the formation. Passive or active heating is used to elevate the temperature of the fluids in the formation. At elevated temperatures, distinguishing between heavy oil and bound water is easier. Of particular interest is the increase in the resolvability of the transverse relaxation time T2 of NMR spin echo measurements. Additionally, the dielectric constant and the loss tangents of water and heavy oil show different temperature and frequency dependence.

Abstract: The invention relates to a cement evaluation method and tool. In particular, the invention relates to a method of producing a wellbore cement bond log for evaluating a condition of cement in cased or lined portions of wellbores, and to a corresponding cement bond logging assembly. In an embodiment of the invention, a method of producing a wellbore cement bond log is disclosed which comprises the steps of running a cement evaluation tool (210) and a wellbore cleaning tool (222) into a wellbore (202); acquiring data relating to at least one property of a cement bond (212) of the wellbore using the cement evaluation tool; and generating a log of the acquired data.

Abstract: Downhole systems and methods including tags configured to provide distinguishable identifiers are set for selective release to a subsurface location. Sources/sensors in the wellbore are activated to detect the tags at a subsurface location, and signal data associated with the detected tags is conveyed to the surface.

Abstract: An apparatus for verifying cement arrival at a target location including a liner and a sensory structure radially outwardly disposed of the liner at a target arrival location of cement from a cementing operation; the sensory structure capable of sensing arrival of cement. A method for verifying completion of a cementing operation.

Abstract: A system and method for estimating an occurrence of a water breakthrough in a production well is provided that includes estimating, at least periodically, a measure of water in the fluid produced from one or more production zones and estimating the occurrence of the water breakthrough utilizing at least in part a trend of the estimated measures of the produced fluid. A controller determines one or more actions to be taken to mitigate an effect of the water breakthrough and may automatically initiate one or more such actions. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Methods and systems for reverse-circulation cementing in subterranean formations are provided. An example of a method is a method of cementing casing in a subterranean well bore, comprising inserting a casing into the well bore, the casing comprising a casing shoe; equipping the casing with a well head, and a casing inner diameter pressure indicator; flowing an equilibrium fluid into the well bore; flowing a cement composition into the well bore after the equilibrium fluid; determining from the well-bore pressure indicator when the well bore pressure has reached a desired value; discontinuing the flow of cement composition into the well bore upon determining that the well bore pressure has reached a desired value; and permitting the cement composition to set in the subterranean formation. Examples of systems include systems for cementing casing in a well bore.

Abstract: Methods and systems for reverse-circulation cementing in subterranean formations are provided. An example of a method is a method of cementing casing in a subterranean well bore, comprising inserting a casing into the well bore, the casing comprising a casing shoe; equipping the casing with a well head, and a casing inner diameter pressure indicator; flowing an equilibrium fluid into the well bore; flowing a cement composition into the well bore after the equilibrium fluid; determining from the well-bore pressure indicator when the well bore pressure has reached a desired value; discontinuing the flow of cement composition into the well bore upon determining that the well bore pressure has reached a desired value; and permitting the cement composition to set in the subterranean formation. Examples of systems include systems for cementing casing in a well bore.

Abstract: The disclosure concerns a method and a system for monitoring the composition of a cement slurry or wellbore service fluid, the method and system including one or more feeder units for solid particulate material; one or more mixing or blending units adapted to receive material from the feeder units; one or more outlet tubes to direct the cement slurry or wellbore service fluid to a storage facility or into a wellbore; and a control unit connected to at least one densitometer to monitor the density of the cement slurry or wellbore service fluid; wherein the densitometer comprises a generator free of radioactive material and capable of generating high-energy photons based on accelerating or decelerating electrons.