One of the main types of repair operations in wells at hydrocarbon fields and in underground gas storages is usually sand-clay and proppant plugs washing operation. The use of coiled tubing in such well operations is one of the perspective directions of well workover technologies development. In order to increase the efficiency of wells bottomhole normalization process, authors of the paper developed and introduced the design of hydraulic hammer unit, which operates in a complex with coiled tubing string. Application of this unit is useful for dense sand-clay and proppant plugs washing, as well as for cement bridgings destruction. one of the advantages of this unit is the use of operating fluid jet, which is tangentially directed to wellbore periphery, and its impulse effect on the drillable surface of casing wall.