Abstract: A transducer assembly includes a piezoelectric transducer and a support member encasing the transducer. The transducer and the support member may have commonly disposed openings. The support member has a progressively increasing thickness at progressive positions from the opening to distribute equally the stresses at the different positions on the piezoelectric transducer. A plurality of such transducer assemblies may be disposed at spaced positions in an oil well with the support members supported on a support rail extending through the well. The support rail serves as an electrical ground. A bus bar extends through the well at positions corresponding substantially to the centers of the transducer assemblies. The bus bar is supported by electrically insulating spacer members extending from the support rail. A ring is supported at one end by the support rail and is coupled at the other end to a tubing. The tubing envelopes, the transducer assemblies, the support rail, the bus bar and the spacer members.