Abstract: Various triaxial antenna designs having are provided. Some embodiments include a split-z coil that can include two axial coils with saddle coils in the x- and y-directions located therebetween. The split z-coils can function by having a combined magnetic moment similar to that of a single axial coil located between the two parts of the split z-coil. In some examples, the antenna assemblies can include a protrusion or other non-planar structure.

Abstract: A NMR logging tool is provided and disposed in a wellbore at some desired depth. Packers are provided and actuated to hydraulically isolate a section of the wellbore and form a cavity between the NMR logging tool and the wall of the isolated section of the wellbore. The cavity is evacuated until a first desired pressure within the cavity is attained. Fluid is injected into the cavity until a second desired pressure within the cavity is attained. A plurality of NMR measurements is made on the region of the formation, each of the plurality of measurements being made at different times. Formation properties are inferred using the measurements. A baseline NMR measurement may be made when a first desired pressure is attained. A time-zero NMR measurement may be made when a second desired pressure is attained. Similar measurements may be made in a laboratory on a sample.

Abstract: A NMR logging tool is provided and disposed at some desired depth in a wellbore penetrating a subsurface formation. A first set of NMR measurements is made over a desired depth range and depth of investigation, wherein the first set of NMR measurements includes a first NMR signal intensity. Supercritical carbon dioxide is injected into the formation and a second set of NMR measurements is made over the desired depth range and depth of investigation, wherein the second set of NMR measurements includes a second NMR signal intensity. The first NMR signal intensity is compared to the second NMR signal intensity and one or more properties of the formation are inferred using the compared NMR measurements. A magnetic field gradient that varies a static magnetic field along a desired spatial dimension of a region of investigation may be provided to map a rate of fluid movement.

Abstract: A NMR logging tool is provided and disposed at some desired depth in a wellbore penetrating a subsurface formation. A first set of NMR measurements is made over a desired depth range and depth of investigation, wherein the first set of NMR measurements includes a first NMR signal intensity. Supercritical carbon dioxide is injected into the formation and a second set of NMR measurements is made over the desired depth range and depth of investigation, wherein the second set of NMR measurements includes a second NMR signal intensity. The first NMR signal intensity is compared to the second NMR signal intensity and one or more properties of the formation are inferred using the compared NMR measurements. A magnetic field gradient that varies a static magnetic field along a desired spatial dimension of a region of investigation may be provided to map a rate of fluid movement.

Abstract: An acoustic logging tool is disposed in a wellbore during an acidizing operation. Measurements are made using the acoustic logging tool on a region of a formation penetrated by the wellbore and being subjected to the acidizing operation. An acoustic anisotropic property of the formation is inferred at one or more depths of investigation within the region using the measurements, and a wormhole porosity and/or an orientation of one or more wormholes resulting from the acidizing operation is determined. Acidizing operation management decisions may be made based on the determined wormhole porosity and/or orientations of the wormholes. An acidizing operation management decision may be to maintain, increase, or decrease an acid injection rate. Measurements made may include the velocity of an acoustic wave propagating through the formation and the acoustic anisotropic properties of fast waves and slow waves. The acoustic anisotropic properties of the formation generally depend on rock stiffness.

Abstract: A wireline configurable well logging instrument is connected to a drill pipe carrier and movable from a retracted position to an extended position. The drill pipe carrier is positioned on a pipe string that may comprise a portion of wired pipes communicatively coupled at each joint. Communication between the drill pipe carrier and the well logging instrument includes the use of inductive couplers, wires and combinations thereof.

Abstract: A downhole tool to make one or more downhole measurements of laser-induced vaporization and/or pyrolysis of hydrocarbons is provided and disposed at a desired location within a wellbore. A tool head of the downhole tool is brought into sealing engagement with the wellbore wall. The fluid within an interior region enclosed by the tool head and the wellbore wall is evacuated and a measurement spot is irradiated with a laser to generate volatile hydrocarbons and/or pyrolytic hydrocarbons. Measurements are made on the volatile hydrocarbons and/or pyrolytic hydrocarbons and one or more formation properties are inferred based on the measurements. A low level of laser radiation intensity, irradiating some or all of the wellbore wall enclosing the interior region, may be used to prevent measurement contamination, and both medium power and high power levels of laser radiation may be used to first vaporize and then pyrolyze the hydrocarbons.

Abstract: A method comprising using a first mass analyzer of a downhole tool to isolate specific ions within a sample received in the downhole tool, using a second mass analyzer of the downhole tool to stabilize the ions isolated by the first mass analyzer, and using a third mass analyzer of the downhole tool to catalog the stabilized ions.

Abstract: A logging tool is disposed in a wellbore during an acidizing operation. The logging tool may be an acoustic tool, a resistivity tool, or a neutron tool. Measurements are made using the logging tool on a region of a formation penetrated by the wellbore and being subjected to the acidizing operation. A formation property is inferred at one or more depths of investigation within the region using the measurements, and acidizing operation management decisions are made based on the determined inferred property. The inferred property may also be simulated. A minimized difference between the inferred formation property and the corresponding simulated formation property is determined, and acidizing operation management decisions are made based on the determined difference. The inferred property may be acoustic velocity, conductivity peak observation time, near-to-far detector count ratio, or porosity. An acidizing operation management decision may be to maintain, increase, or decrease an acid injection rate.

Abstract: Sealing particles are used to stop or reduce undesired fluid loss. The sealing particles may be swellable or have effective cross-sectional areas greater than five square millimeters or are both swellable and have effective cross-sectional areas greater than five square millimeters. The sealing particles are disposed in one or more locations in which there is undesired fluid flow and, once lodged therein, stop or at least reduce the undesired fluid loss. A tubular having a bypass flow path may be used to deploy the sealing particles. The bypass flow path may use a biased or unbiased sleeve that is selectably movable to expose or block exit ports in the tubular. A retrievable sealing disk may be deployed to move the sleeve. The sealing particles may be made of a bi-stable material with extenders and may be actuated using swellable material. The sealing particles may extend in multiple dimensions.

Abstract: According to some embodiments, a borehole deployable apparatus is described that can be used to generate strong vibrations in a subterranean rock formation. In some embodiments, the apparatus accelerates a mass using mechanisms built into the tool and causes the mass to strike the borehole wall. The mechanisms can control the mass acceleration, and the frequency of strikes. In some embodiments, the apparatus is designed for use in the field of petroleum recovery where the vibrations are used to create or re-establish a flow rate for the fluids in the formation.

Abstract: Wireless communication and electromagnetic telemetry between various surface or downhole devices may be provided using two or more dipole antennas. The dipole antennas may be formed, for example, by electrically isolating, for each electric dipole antenna, two electrically conductive portions. The two electrically conductive portions are part of a downhole casing, a downhole liner, a completion, a production tube, or a downhole tool. The two or more electric dipole antennas are disposed in different sections of a completed well, in one or more lateral wells, in different completed wells, or in any combination of those. An electromagnetic signal is transmitting from at least one of the two or more dipole antennas and received at any other of the two or more dipole antennas, thereby providing telemetry or wireless communication between the dipole antennas of the petrophysical devices.

Abstract: Systems and methods are described for controlling the location where a fracture initiates and the fracture direction at the initiation point. A mechanical device is positioned in a main wellbore or partially or fully in a side hole off of the main wellbore. The mechanical device is actuated so as to contact the formation walls and induce stress in the formation. According to some embodiments, fractures are also initiated using the mechanical device. A hydraulic fracturing process is then carried out to fracture and/or propagate fractures in locations and/or directions according to the actuation of the mechanical device.

Abstract: The present disclosure relates to a method to determine the phase of a signal when transmitter and receiver circuits use separate clocks. A discrepancy between the separate clocks is determined, as is a correction factor between the separate clocks. The phase is determined using a measured time of arrival of the signal, the determined discrepancy, and the determined correction factor. A drift factor and an expected start time of a pulse sequence may be used to determine the discrepancy. A start time of a pulse within the pulse sequence is determined and used to determine the correction factor. The method works by either absolute synchronization of the separate clocks, or by making the measurements independent of clock synchronization.

Abstract: A surface seismic survey is generated or obtained from Earth's surface and is based on time in which acoustic waves are reflected to Earth's surface. One or more tools measure density and sonic velocity of a subsurface formation. An estimate of acoustic impedance is obtained from the density and the sonic velocity to generate a synthetic seismic survey. The synthetic seismic survey and the surface seismic survey are compared and/or correlated. The acoustic impedance can be iteratively estimated until the synthetic seismic survey matches the surface seismic survey. Matching the surface seismic survey with the synthetic seismic survey may ensure that the surface seismic survey may be calibrated in actual depth.

Abstract: A chemical stimulation system and a resistivity tool are disposed in a wellbore. Chemical stimulation operations are performed in the wellbore using the chemical stimulation system. Resistivity measurements are made with the resistivity tool before, during, and/or after the chemical stimulation operations. The resistivity measurements may be used to determine the porosity of a formation penetrated by the wellbore. A wormhole distribution and/or penetration in the formation is determined based on the resistivity measurements. Decisions regarding stimulation operations are made based on the determined wormhole distribution and/or penetration. The resistivity tool may be modular and have various arrays allowing various depths of investigation. The depths of penetration of the wormholes into the formation may be determined using the measurements from the multiple depths of investigation. The volume of the formation that is dissolved by the chemical stimulation operations may also be estimated.

Abstract: An anchor is placed in a wellbore to convey loads into a wellbore. The anchor is placed at some desired location in a wellbore and installed at that location using, for example, arms that penetrate into the formation surrounding the anchor. A line extends from the surface, wraps around a pulley in the anchor and attaches to the downhole end of the load. Tension is applied at the surface to the line to pull the load to a desired location in the wellbore. Optionally, the same or a second line can be attached to the uphole end of the load to reposition or retrieve the load. Alternatively, a powered anchor has a line drive device and a spool. A portion of a line extends from the anchor to the load. The line is spooled onto the spool by the line drive device, thereby pulling the load into the wellbore.

Abstract: A drill bit assembly having an electrically isolated gap joint for electromagnetic telemetry comprises a drill bit, a pin body, an electrically insulating gap joint therebetween, and an electrical conductor extending across the gap joint. The bit head has a cutting end and an opposite connecting end with an engagement section. The pin body has a tubular body with an axial bore therethrough, and comprises a connecting end with an engagement section. The pin body connecting end is connected to the bit head connecting end such that the engagement sections overlap. The electrically insulating gap joint fills an annular gap between the bit head and pin body engagement sections such that the bit head and pin body are mechanically connected together at the connecting ends but are electrically separated. The electrical conductor has one end electrically contacting one of the bit head and pin body, and the other end communicable with electronics equipment.

Abstract: Systems, methods, and devices for two-way communication with a downhole tool string are provided. In one example, a method may include placing a downhole tool string into a pressure riser of a well while at least one component of the downhole tool string is not activated. Thereafter, a wireless control signal may be issued through the pressure riser to the downhole tool to cause the downhole tool string to activate the component. The wireless control signal may involve an acoustic signal, an optical signal, and/or an electromagnetic signal such as electrical dipole coupling or magnetic dipole coupling.

Abstract: Methods are provided for separating oil and water signals in multidimensional nuclear magnetic resonance (NMR) maps. In one embodiment, separate multidimensional NMR maps are provided for oil and water content. In another embodiment, an oil-water boundary and a water-gas boundary are generated on a D-T2 map. The boundaries may be curved boundaries or lines.