METHOD OF WELL CONSOLIDATION AND DEVICE FOR METHOD EMBODIMENT Russian patent published in 2003 - IPC

FIELD: well drilling, particularly, methods and devices for well consolidation. SUBSTANCE: method includes determination of depth of cavern location by data of section gage logging; lowering of casing string carrying section with collar for covering cavern, and cementing device with one or several sections with collars of various shapes to ensure forced change of motion of cement mortar from well wall to casing string wall with overlapping entire annular space; injection of cement mortar into casing string and forcing it into annular space by displacing fluid to effect cementing of annular space. Device for method embodiment includes casing string and section with collar. It has additionally one or several sections with collars. Sections are installed one under another. Section has one collar cut in its lower part at casing string, and its diameter is equal to diameter of wellbore. The other collar has diameter smaller than that of wellbore. Each collar is secured in section on steel springs whose ends are fastened by upper and lower rings with the help of pins to casing string. Upper ends of springs are located in recesses of upper rings for motion through value ensuring their opening and touching of well wall, and in cavern as well. EFFECT: higher quality of well consolidation by increased degree of replacement of drilling mud with cement mortar, especially, in cavernous part of wellbore under different conditions of cement mortar flowing at all stages of cementing. 2 cl, 3 dwg