A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

A generator of acoustic waves for submarine environments has a hollow body that extends along an axis delimited by a first closed end and by a second end that is provided with an acoustic diffuser member. The hollow body has a first cylindrical portion delimited by the first end that houses a first piston and a second cylindrical portion delimited by the second end that houses a second piston in a freely axially sliding manner. The second piston is mechanically free from the first piston and has a face that faces the acoustic diffuser member. An impulsive actuator is configured together with the first piston to move the first piston towards the second piston. An adjustor for a longitudinal motion of the second piston is arranged between the first piston and the second piston.

A generator of acoustic waves for submarine environments has a hollow body that extends along an axis delimited by a first closed end and by a second end that is provided with an acoustic diffuser member. The hollow body has a first cylindrical portion delimited by the first end that houses a first piston and a second cylindrical portion delimited by the second end that houses a second piston in a freely axially sliding manner. The second piston is mechanically free from the first piston and has a face that faces the acoustic diffuser member. An impulsive actuator is configured together with the first piston to move the first piston towards the second piston. An adjustor for a longitudinal motion of the second piston is arranged between the first piston and the second piston.

A method for treating a well includes hydraulically isolating an interval in a first well having a plurality of intervals along the first well, each interval having been fracture treated. A tube wave is induced in the first well in the isolated interval. Reflections are detected from the induced tube wave. Hydraulic boundary condition and hydraulic conductivity of a fracture connected to the first well in the isolated interval are determined using the detected reflections. A refracture treatment is performed in the isolated interval when the hydraulic boundary condition and the hydraulic conductivity are within a predetermine range.

A method for treating a well includes hydraulically isolating an interval in a first well having a plurality of intervals along the first well, each interval having been fracture treated. A tube wave is induced in the first well in the isolated interval. Reflections are detected from the induced tube wave. Hydraulic boundary condition and hydraulic conductivity of a fracture connected to the first well in the isolated interval are determined using the detected reflections. A refracture treatment is performed in the isolated interval when the hydraulic boundary condition and the hydraulic conductivity are within a predetermine range.

A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

A system includes a first instrumented bridge plug positionable in a downhole wellbore environment. The first instrumented bridge plug includes an acoustic source for transmitting an acoustic signal. The system also includes a second instrumented bridge plug positionable in the downhole wellbore environment. The second instrumented bridge plug includes an acoustic sensor for receiving a reflected acoustic signal originating from the acoustic signal. The reflected acoustic signal being usable to interpret wellbore formation characteristics of the downhole wellbore environment.

A sound source including a first gas filled underwater resonator, a second gas filled underwater resonator connected to the first resonator, where the second resonator comprises a Helmholtz resonator, and at least one excitation member configured to excite the first resonator and the second resonator is disclosed. The first resonator is permanently tuned to produce a first resonant frequency upon excitation by the at least one excitation member and the second resonator is permanently tuned to produce a second resonant frequency upon excitation by the at least one excitation member. The first resonant frequency is different from the second resonant frequency.

Embodiments herein describe a seismic source that includes a reservoir configured to hold compressed gas, a first firing head coupled to the reservoir where the first firing head configured to generate seismic energy by releasing a first portion of the compressed air from the reservoir to form a first gas bubble in a seismic medium, and a second firing head coupled to the reservoir where the second firing head configured to generate seismic energy by releasing a second portion of the compressed gas from the reservoir to form a second gas bubble in the seismic medium. Moreover, at least one first fill line is coupled directly to the reservoir.