The complex tool for well monitoring comprises a cylindrical housing and at least two lever centralizers aligning the tool along a well axis. Each centralizer has at least three levers, as well as at least one fluid flow temperature sensor, at least one phase composition sensor and at least one thermal flow velocity sensor, all sensors are located on an axis of the tool. The tool also comprises at least three groups of sensors distributed around a perimeter of the wellbore when the levers of at least one centralizer are being opened. Each group of the sensors comprises at least a fluid flow temperature sensor, a fluid phase composition sensor and a thermal flow velocity sensor, disposed on the same line parallel to the axis of the tool.

A system includes a cable and a toolstring. The toolstring may couple to the cable to enable the toolstring to be placed in a wellbore. The toolstring includes a sensor that can collect measurements relating to the wellbore. An electromagnetic or anchoring device may selectively hold the toolstring or the cable against a surface of the wellbore.

A method of optimizing the cross-sectional shape of a logging tool sensor includes the step of, for a given major axis dimension, selecting the minor axis dimension such that for a circular borehole geometry the cross-sectional area of the space between the sensor and a said circular borehole with which the sensor is pressed into contact is minimized. Logging tools optimized according to this technique exhibit beneficial sensor stand-off characteristics.

Method and device for performing vertical seismic profiling (VSP) in a borehole with a seismic device (10) comprising an elongated cable (20) with conductors (30) for transporting power and at least one communication line (40) for carrying signals. The device further comprises at least one connection point (50) placed along the elongated cable (20), where the connection point (50) comprises wireless power providing means (60) and communication means (65) that are connected to said conductors (30) and communication line (40) in the elongated cable (20), and at least one sealed seismic module (70) fixed to the at least one connection point (50), the seismic module (70) comprises a geophone (75), electronics (80) for detecting and transferring seismic signals, power receiving means (85) for wirelessly receiving power from the connection point (50) and means for wirelessly transmitting seismic signals to the communication line (40) via the communication means (65) comprised in the connection point (50).

Reservoir simulation for simulation models which include a large edge aquifer region is provided with a speed up in processing reducing computer processing time. Connected aquifer grid cells in a vertical column are amalgamated to reduce the total number of active cells in the solution phase. The fine grid property data is maintained for computing distributed 3D graph, and connection factors (transmissibilities), as well as pore volume and compressibility calculation of coarsened aquifer cells during nonlinear solution phase. Since the work load in the solution phase is proportional to the total number of active cells, a significant speedup in simulation time is provided. The aquifer fine grid pressures are computed using vertical equilibrium treatment of hydraulic potential inside an amalgamated aquifer coarse cell.

A method that includes deploying an acoustic caliper tool in a borehole, the tool having several axially-spaced acoustic transceivers; obtaining acoustic signal reflection measurements for the transceivers; estimating a distance-to-boundary value for the transceivers based on reflection measurements; calculating a tool inclination angle based on the distance-to-boundary values; and deriving a correction value based on the angle. A system that includes an acoustic caliper tool having several axially-spaced acoustic transceivers to obtain reflection measurements; at least one processor; and at least one memory in communication with the processor, the memory storing instructions that cause the processor to: receive the acoustic signal reflection measurements; estimate a distance-to-boundary value for the transceivers based on the reflection measurements; calculate a tool inclination angle based on the distance-to-boundary values; and derive a correction value based on the angle.

A method and apparatus for determining the relative orientation of objects downwell, and especially to determining perforator orientation, involves varying the orientation of an object, such as a perforator gun (302) in the wellbore (202) and activating at least one directional acoustic source (402a-c). Each directional acoustic source is fixed in a predetermined location to the object and transmits an acoustic signal preferentially in a known direction. The directional acoustic sources are activated so as to generate sound in a plurality of different orientations of said object. An optical fiber (104) is interrogated to provide distributed acoustic sensing in the vicinity of the object; and the acoustic signals detected by the optical fiber are analyzed to determine the orientation of the at least one directional acoustic source relative to the optical fiber, for instance by looking at the relative intensity in the different orientations.

A measurement vehicle includes a geophysical sensor. One or more operational sensors are configured to detect operational data related to operation of the measurement vehicle. A driving system is configured to move the measurement vehicle in a travel direction relative to a measurement point. A controller is configured to receive information from the geophysical sensor and the operational sensors, and to control the driving system based on the information.

A technique facilitates the accumulation and analysis of data related to a subterranean formation. An arrangement of different types of sensors is mounted on a collar utilized in accumulating data on the subterranean formation. The sensors are operable in combination to improve the image quality of data obtained with respect to the subterranean formation. Certain applications utilize an arrangement of sensors comprising at least one of each of an electromagnetic sensor and an ultrasonic pulse-echo transducer. A stabilizer or stabilizers may be used to precisely orient and position the sensors within a wellbore.

A probe is provided that contacts the inner surface of the casing or other production tubing and imparts energy to the surface at the contact point, for example as heat energy or mechanical energy. Energy is imparted around the circumference of the casing, and a fiber optic distributed sensor located on the outer surface of the casing is used to measure and record the energy that it receives whilst the probe is moved to impart energy around the circumference. A record of energy versus position of the probe around the circumference can be obtained, from which maxima in the detected energy measurements can then be found. The position around the circumference which gave the maximum measurement should be the position at which the optical fiber of the fiber optic distributed sensor is located. In addition, an ultrasonic arrangement is also described, that relies on ultrasonic sound to provide detection.