Abstract: A method for reducing a skin effect in a downhole environment is provided, including the step of radiating vibrational waves at a wellbore wall such that the vibrational waves have at least one direction of greatest vibrational energy transfer directed toward the wall, thereby reducing the skin effect. An apparatus for reducing a skin effect in a downhole environment is also provided. The apparatus includes at least one vibrational wave source having at least one direction of greatest vibrational energy transfer, and a means for positioning the vibrational wave source proximate a wellbore wall.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may include exciting a plurality of signal source pairs having a substantially equal and non-zero acoustic signature amplitude difference in a frequency domain to provide acoustic signal data, and acquiring the acoustic signal data along a selected azimuth. The plurality of signal source pairs may comprise acoustic bender plates, perhaps included in the outer wall of a downhole tool.

Abstract: An apparatus for generating acoustic waves, the apparatus having: a support structure; two tines extending from the support structure so that proximal ends of the two tines are attached to the support structure so that distal ends of the two tines are positioned with standoffs relative to a dimension of the support structure and the distal ends of the two tines are uninhibited, wherein the two tines each comprise a moment arm; and an oscillator in mechanical communication with the two tines.

Abstract: A method for generating acoustic waves, the method having the steps of: extending a tine from a support structure so that a proximal end of the tine is attached to the support structure and a distal end of the tine is uninhibited; positioning an oscillator so as to be supported by the support structure and to mechanically communicate with the tine; and oscillating the tine with the oscillator.

Abstract: A system and method for determining blockage in a wellbore containing fluid and/or in a formation adjacent the wellbore, according to which energy is generated in the fluid and variables associated with the energy are measured.

Abstract: A system and method for stimulating a formation surrounding a well and vibrating a device for supporting a gravel pack in the well, according to which a build up of scale on the device is sensed and a corresponding signal is output. A driver is provided for driving a transducer coupled to the device for vibrating the device and removing scale from the device.

Abstract: An apparatus and system are disclosed for in situ measurement of downhole fluid flow using Doppler techniques. First, a baseline speed of sound is established as close to the desired measurement point as possible. This speed of sound measurement is then used in Doppler calculations for determining flow velocities based from induced Doppler shift resulting from fluid flow. A heterodyne receiver arrangement is preferably used for processing so that the flow direction can be determined and the detection sensitivity for low flow velocities can be enhanced. From in situ measurements, well kicks may be spotted and dealt with in real-time. In addition, current theoretical models of rheological properties may be verified and expounded upon using in situ downhole measurement techniques. Furthermore, the velocity measurements described herein can be used to recognize downhole lost circulation and/or gas/water/oil influxes as early as possible, even when the mud recirculation pumps are turned off.