Abstract: A predetermined condition in a fluid-filled wellbore system can be detected by generating at least one sound in the wellbore system in response to the condition, such that a detectable change is created in some characteristic of the emitted sound, and detecting the at least one sound and the change, the detection being indicative that the predetermined condition has occurred. Equipment for facilitating detection of the condition can include a trigger operable in response to the condition; a generator operable to emit sound in the borehole and to create a detectable change in some characteristic of the emitted sound in response to the trigger; and at least one sensor operable to monitor the sound and detect the change, the detection being indicative that the predetermined condition has occurred. It is also possible to estimate a value of a property of a fluid-filled wellbore system.

Abstract: A value of a property of a fluid-filled wellbore system can be detected. This can be accomplished by recording data including at least one of pressure and rate of flow at one or more locations in the wellbore system, and then estimating the value of the property by employing a model for predicting at least one of pressure and rate of flow dependent upon characteristics and locations of disturbances to pressure and flow in the wellbore system, in order to determine a best prediction of some attribute of the recorded data.

Abstract: Disclosed herein are implementations of various technologies for a method for seismic data processing. The method may receive seismic data for a region of interest. The seismic data may be acquired in a seismic survey. The method may determine an exclusion criterion. The exclusion criterion may provide rules for selecting shot points in the acquired seismic data. The method may determine sparse seismic data using statistical sampling based on the exclusion criterion and the acquired seismic data. The method may determine simulated seismic data based on the earth model and shot points corresponding to the sparse seismic data. The method may determine an objective function that represents a mismatch between the sparse seismic data and the simulated seismic data. The method may update the earth model using the objective function.

Abstract: Methods and related systems are described for measuring and analyzing refracted acoustic energy. A plurality of receivers mounted are on a downhole tool, and are arranged and adapted to receive refracted acoustic energy from a downhole formation. Measurements of refracted acoustic energy is analyzed such that information relating to an azimuthal direction relative to the downhole tool of an interface within the downhole formation can be estimated. The receivers can be mounted on a drill collar as part of a LWD tool and steering of the drilling trajectory can be based in part on the estimated formation information.

Abstract: Methods and related systems are described for processing surface seismic data. Surface seismic data representing seismic signals detected at a plurality of surface locations is wavefield deconvolved using a combination of direct wave travel times estimated from borehole seismic data, and wavefield energy estimated from the surface seismic data.

Abstract: Tubewaves are used to transmit an indication of the depth at which a condition is detected in a well. In particular, the depth is calculated based on the difference in arrival time at the surface of a first tubewave which propagates directly upward in the borehole and a second tubewave which initially travels downward and is then reflected upward. The tubewaves may be generated by a canister designed to implode at a certain pressure. The canister is carried downhole by gravity and the fluid being pumped. At a depth at which its pressure tolerance is exceeded, it implodes and generates the tubewaves. An analyzer at the surface detects the tubewaves and generates a pressure versus depth profile of the well. Canisters may be acoustically tagged in order to generate tubewaves having particular frequency and amplitude characteristics. Canisters may also be configured to produce multiple implosions.

Abstract: Elastodynamic waves are generated by a tool having a hammer rotatably connected with a housing by a first hinge and an actuator arm rotatably connected with the hammer by a second hinge. An axial force applied to the actuator arm by a drive shaft and spring is translated and amplified to a radial impact force by rotation of the hammer around the first hinge. The tool may also include a stabilizer arm connected to the actuator arm by a third hinge, and connected to the housing by a fourth hinge. The housing may be an acoustic wireline tool cylinder having an opening that permits the hammer mass to extend outside the housing when rotated in a first direction. The housing may also include a second opening that permits the hammer mass to extend outside the housing when rotated in a second direction, and a third opening that permits the hammer mass to extend outside the housing when rotated between the first and second openings.

Abstract: Methods and related systems are described for measuring and analyzing refracted acoustic energy. A plurality of receivers mounted are on a downhole tool, and are arranged and adapted to receive refracted acoustic energy from a downhole formation. Measurements of refracted acoustic energy is analyzed such that information relating to an azimuthal direction relative to the downhole tool of an interface within the downhole formation can be estimated. The receivers can be mounted on a drill collar as part of a LWD tool and steering of the drilling trajectory can be based in part on the estimated formation information.

Abstract: Methods and related systems are described for processing surface seismic data. Surface seismic data representing seismic signals detected at a plurality of surface locations is wavefield deconvolved using a combination of direct wave travel times estimated from borehole seismic data, and wavefield energy estimated from the surface seismic data.

Abstract: Tubewaves are used to transmit an indication of the depth at which a condition is detected in a well. In particular, the depth is calculated based on the difference in arrival time at the surface of a first tubewave which propagates directly upward in the borehole and a second tubewave which initially travels downward and is then reflected upward. The tubewaves may be generated by a canister designed to implode at a certain pressure. After being introduced into the flowline at an above ground inlet, the canister is carried downhole by gravity and the fluid being pumped. When the canister reaches a depth at which its pressure tolerance is exceeded, it implodes and generates the tubewaves. An analyzer at the surface detects the tubewaves with a hydrophone array and generates a pressure versus depth profile of the well, i.e., one data point for each implosion.

Abstract: A predetermined condition in a fluid-filled wellbore system can be detected by generating at least one sound in the wellbore system in response to the condition, such that a detectable change is created in some characteristic of the emitted sound, and detecting the at least one sound and the change, the detection being indicative that the predetermined condition has occurred. Equipment for facilitating detection of the condition can include a trigger operable in response to the condition; a generator operable to emit sound in the borehole and to create a detectable change in some characteristic of the emitted sound in response to the trigger; and at least one sensor operable to monitor the sound and detect the change, the detection being indicative that the predetermined condition has occurred. It is also possible to estimate a value of a property of a fluid-filled wellbore system.

Abstract: Elastodynamic waves are generated by a tool having a hammer rotatably connected with a housing by a first hinge and an actuator arm rotatably connected with the hammer by a second hinge. An axial force applied to the actuator arm by a drive shaft and spring is translated and amplified to a radial impact force by rotation of the hammer around the first hinge. The tool may also include a stabilizer arm connected to the actuator arm by a third hinge, and connected to the housing by a fourth hinge. The housing may be an acoustic wireline tool cylinder having an opening that permits the hammer mass to extend outside the housing when rotated in a first direction. The housing may also include a second opening that permits the hammer mass to extend outside the housing when rotated in a second direction, and a third opening that permits the hammer mass to extend outside the housing when rotated between the first and second openings.

Abstract: The present invention provides methods and systems for making measurements associated with a rock formation including a main borehole, a microborehole extending from the main borehole into the rock formation, and one or more sensing devices positioned and arranged to make a measurement at measurement zones being located in the microborehole. A packer can also be installed in the microborehole dimensioned and arranged to hydraulically isolate the measurement zones from conditions present in other parts of the microborehole and/or main borehole. Methods and systems are also provided for taking fluid samples and injecting fluid tracers in a microborehole.

Abstract: Methods and systems are disclosed for making measurements associated with a rock formation including a main borehole, a microborehole extending from the main borehole into the rock formation, and one or more sensing devices positioned and arranged to make a measurement at measurement zones being located in the microborehole. A packer can also be installed in the microborehole dimensioned and arranged to hydraulically isolate the measurement zones from conditions present in other parts of the microborehole and/or main borehole. Methods and systems are also disclosed for taking fluid samples and injecting fluid tracers in a mircoborehole.

Abstract: Methods and apparatus are described for the seismic exploration of strata adjacent to a borehole, wherein an arrangement of geophones is lowered into the borehole and clamped to the wall. The geophones are clamped at essentially equal angular distances along the circumference of the borehole. A plurality of such arrangements can be positioned along the longitudinal axis of the borehole. By combining the outputs of the geophones noise signals generated by symmetric guided waves are attenuated. The arrangement can be used for cross-well seismic acquisition and in combination with seismic sources and/or attenuator so as to form an single-unit exploration tool for borehole seismics.