A system for providing a local response to a condition in an oil well, including: a sensor (210,310,732,1132,1220) to detect a parameter indicative of a local boundary condition of a section of a drill string having at least two sections, wherein the local boundary condition comprises a condition which locally limits the free motion of the section of the drill string; a controllable element (205,305,505,520,605,1315,1320,1500,1605,1700) in at least one section of the drill string to modulate energy in the at least one section of the drill string; and a controller in at least one section of the drill string coupled to the sensor (210,310,732,1132,1220) and to the controllable element (205,305,505,520,605,1315,1320,1500,1605,1700), the controller to: receive a signal from the sensor (210,310,732,1132,1220), the signal indicating the presence of said local boundary condition associated with the section of the drill string; and process the signal to determine an energy modulation in the at least one section of the drill string having a characteristic for affecting the local boundary condition associated with the section of the drill string, wherein the characteristic affects the local boundary condition of at least one of an annulus drilling fluid, a borehole mud cake, a borehole wall, and a near-borehole invaded zone of the oil well associated with the section of the drill string to modify the local boundary condition associated with the section of the drill string; and send a signal to the controllable element (205,305,505,520,605,1315,1320,1500,1605,1700) in the at least one section of the drill string to cause the determined energy modulation in the at least one section of the drill string without causing the determined energy modulation in at least one other section of the drill string. a sensor (210,310,732,1132,1220) to detect a parameter indicative of a local boundary condition of a section of a drill string having at least two sections, wherein the local boundary condition comprises a condition which locally limits the free motion of the section of the drill string; a controllable element (205,305,505,520,605,1315,1320,1500,1605,1700) in at least one section of the drill string to modulate energy in the at least one section of the drill string; and a controller in at least one section of the drill string coupled to the sensor (210,310,732,1132,1220) and to the controllable element (205,305,505,520,605,1315,1320,1500,1605,1700), the controller to: receive a signal from the sensor (210,310,732,1132,1220), the signal indicating the presence of said local boundary condition associated with the section of the drill string; and process the signal to determine an energy modulation in the at least one section of the drill string having a characteristic for affecting the local boundary condition associated with the section of the drill string, wherein the characteristic affects the local boundary condition of at least one of an annulus drilling fluid, a borehole mud cake, a borehole wall, and a near-borehole invaded zone of the oil well associated with the section of the drill string to modify the local boundary condition associated with the section of the drill string; and send a signal to the controllable element (205,305,505,520,605,1315,1320,1500,1605,1700) in the at least one section of the drill string to cause the determined energy modulation in the at least one section of the drill string without causing the determined energy modulation in at least one other section of the drill string. receive a signal from the sensor (210,310,732,1132,1220), the signal indicating the presence of said local boundary condition associated with the section of the drill string; and process the signal to determine an energy modulation in the at least one section of the drill string having a characteristic for affecting the local boundary condition associated with the section of the drill string, wherein the characteristic affects the local boundary condition of at least one of an annulus drilling fluid, a borehole mud cake, a borehole wall, and a near-borehole invaded zone of the oil well associated with the section of the drill string to modify the local boundary condition associated with the section of the drill string; and send a signal to the controllable element (205,305,505,520,605,1315,1320,1500,1605,1700) in the at least one section of the drill string to cause the determined energy modulation in the at least one section of the drill string without causing the determined energy modulation in at least one other section of the drill string.