Abstract: An immersible ultrasonic transmitter consists of an end element of a first type, an end element of a second type and at least one transmitting member. The end element of the first type comprises a first cylindrical transmitter, a stack of piezoelectric elements, a second cylindrical transmitter and a coupling element with a threaded connection for coupling together the two cylindrical transmitters. The transmitting member contains a stack of piezoelectric elements, a cylindrical transmitter of a transmitting member, and an element with a threaded connection for coupling together the cylindrical transmitter of a transmitting member and the cylindrical transmitter of an adjacent transmitting member, or the second cylindrical transmitter of the end element of the first type.

Abstract: An acoustic waveguide includes a body defining a resonance chamber. The body has a tubular section defining a cylindrical central portion of the chamber along a longitudinal axis. First and second end sections extend from opposite ends of the tubular section. Each end section includes an end wall tapering away from the tubular section and towards the longitudinal axis, thus defining a conoidal end portion of the chamber.

Abstract: An immersible ultrasonic transmitter consists of an end element of a first type, an end element of a second type and at least one transmitting member. The end element of the first type comprises a first cylindrical transmitter, a stack of piezoelectric elements, a second cylindrical transmitter and a coupling element with a threaded connection for coupling together the two cylindrical transmitters. The transmitting member contains a stack of piezoelectric elements, a cylindrical transmitter of a transmitting member, and an element with a threaded connection for coupling together the cylindrical transmitter of a transmitting member and the cylindrical transmitter of an adjacent transmitting member, or the second cylindrical transmitter of the end element of the first type.

Abstract: A method includes simultaneously injecting a chemical agent, through an injector, into a perforated wellbore section of a well in a hydrocarbon reservoir, and generating an acoustic wave with an acoustic tool in the wellbore section. The injector and acoustic tool are moved to and fro in synchronization. The acoustic tool includes at least one of a sonotrode and a shock wave tool. A downhole tool assembly comprises the injector, the acoustic tool, and a movable cable hose connected to the injector and the acoustic tool for moving the injector and acoustic tool to and fro in synchronization. The cable hose comprises a wire for supplying power to the acoustic tool and having a conduit for supplying the chemical agent to the injector.

Abstract: A method includes simultaneously injecting a chemical agent, through an injector, into a perforated wellbore section of a well in a hydrocarbon reservoir, and generating an acoustic wave with an acoustic tool in the wellbore section. The injector and acoustic tool are moved to and fro in synchronization. The acoustic tool includes at least one of a sonotrode and a shock wave tool. A down-hole tool assembly comprises the injector, the acoustic tool, and a movable cable hose connected to the injector and the acoustic tool for moving the injector and acoustic tool to and fro in synchronization. The cable hose comprises a wire for supplying power to the acoustic tool and having a conduit for supplying the chemical agent to the injector.