Well packer

#1. Field of the Invention

#The present invention relates to well packer apparatus and methods for sealing tubing strings in wells as customarily used in the production of petroleum effluents from wells. The packer is used to seal the annulus between the well casing and the production tubing string through which the well effluents flow to the surface. Such packers are sometimes employed to provide seals for injecting fluids into the well and for a variety of other purposes.

#2. Description of the Prior Art

#FIGS. 1A and 1B together constitute a view partially in vertical section and partially in elevation illustrating the packer of the present invention in unset condition as it would appear while being lowered into position within a well casing, with FIG. 1A showing the mandrel extending above the packer body, and FIG. 1B showing the components of the packer body;

#FIGS. 2A and 2B together constitute a view similar to FIGS. 1A and 1B together, illustrating the packer in set condition with the bypass closed, FIG. 2A including the packer body, and FIG. 2B showing the mandrel extending below the packer body;

#FIGS. 3A and 3B together constitute a view similar to FIGS. 1A, 1B, and 2A, 2B, illustrating the packer in set condition with the bypass opened, FIG. 3A showing the packer body, and FIG. 3B showing the mandrel extending below the packer body;

#The well packer of the present invention, indicated generally at 10, is illustrated in the drawings within a well casing, or conduit, C. The packer is suspended within the casing C by a tubing string T which is threadedly engaged to the upper end of a mandrel assembly indicated generally at 12. The mandrel assembly 12 extends centrally through the packer body, which is indicated generally at 14. The mandrel assembly 12, which provides a tubular conduit through the packer body 14, includes an upper seal section 16 is threadedly engaged to a lower connector section 18. A tubular mandrel body 20 extends from the lower connector section 18. As shown in FIGS. 1A and 1B, the packer body 14 is connected to the mandrel assembly 12 through the combined operation of a J-slot section 22 threadedly engaged, or otherwise rigidly secured, to the tubular mandrel body 20, and an array of J-slot pins 24 carried at the lower end of the packer body 14. While one such pin and slot combination may suffice, the embodiment of the invention illustrated herein utilizes three pins and three slots, though only two of each are visible. In a conventional manner, each pin 24 extends into one of the J-slots 26 (best seen in FIGS. 2B and 3B) formed in the J-slot 22. Each slot 26 includes a closed vertical leg 26a with upper and lower stops 26b and 26c, respectively, a slanted cam portion 26d, a vertical passage 26e, and a diverging mouth 26f. A continuation of the tubing string T' extends downwardly, as needed, from the J-slot section 22.

#A friction drag assembly 28 employs a plurality of spring loaded friction blocks 30 to hold the packer body 14 in frictional engagement with the internal wall of the casing C for a purpose to be described hereinafter. Each friction block 30 is allowed limited radial movement within an annular bay 28a of the friction drag assembly 28, and is urged outwardly by springs 32. A friction block retainer ring 34, welded to the friction drag assembly 28, further defines the top of the bay 28a to limit motion by the friction blocks 30.

#The packer body 14 includes resilient packer seals 36a, 36b, and 36c, and metal anchoring slip segments 38. When the packer 10 is set, as illustrated in FIG. 2A, the seals 36 function to form a fluid seal with the surrounding casing wall C, and the slip segments 38 are extended radially outwardly into firm gripping engagement with the surrounding casing wall. When the packer 10 is being moved relative to the casing C, the seals 36 and the slip segments 38 are radially retracted away from such engagement with the wall caing, as illustrated in FIG. 1B.