Patent ID: 7681645

Claim:
A method for selectively stimulating a plurality of producing zones in an oil and gas well comprising: positioning an assembly in the well, the assembly comprising a plurality of modules connected to a string, wherein each module is positioned adjacent a zone to be stimulated and each module includes a housing having a central passageway, one or more passageways extending radially through the housing, and a shiftable sleeve slidably mounted within the housing, wherein the shiftable sleeve is adapted to receive an actuating ball for shifting the shiftable sleeve from a closed position over the radial passageways to an open position whereby the radial passageways are in communication with the central passageway of the housing; pumping cement down the string and into an annulus between the string and the wellbore; pumping a wiper plug down the string; pumping an acid solution down the string, wherein the acid solution is pumped down the string prior to the curing of the cement; allowing the cement in the annulus to cure; selectively breaking down the cured cement and stimulating each of the producing zones in succession from the lowermost zone to the uppermost zone from the module adjacent each zone by successively moving the shiftable sleeve to the open position in each of the modules beginning with the lowermost module and finishing with the uppermost module by using a progressively larger actuating ball for each of the successive modules.