Through-tubing recirculating tool assembly for well completions

For use in conjunction with a subterranean well completion having obstructed production fluid inlet perforations in its production tubing portion, a method of restoring production fluid inflow into the production tubing, said method comprising the steps of:

• forming additional production fluid inlet perforations in the production tubing;
• providing a recirculating tool assembly including an upper recirculating tool portion releasably locked to a hollow, lower sealing and tubing extension structure having external annular sealing means thereon and a perforated tube area circumscribed by a sand screen structure;
• connecting said upper recirculating tool portion to an end of tubing means having an outer diameter less than the inner diameter of the production tubing;
• lowering said recirculating tool assembly into the production tubing, on said tubing means, to a position therein in which said lower sealing and tubing extension structure is supported on a portion of the production tubing, said sealing means are in sealing engagement with the interior surface of the production tubing, and said sand screen structure is vertically adjacent said additional production fluid inlet perforations;
• forming a gravel pack between said additional production fluid inlet perforations and said sand screen structure by flowing a fluid/gravel packing material slurry downwardly through said tubing means and a first portion of said recirculating tool assembly into the production tubing and flowing a recirculated fluid portion of said slurry upwardly through a second portion of said recirculating tool assembly;
• unlocking said upper recirculating tool portion from said lower sealing and tubing extension structure;
• pulling the unlocked upper recirculating tool portion out of the production tubing on said tubing means and leaving said lower sealing and tubing extension structure in place within the production tubing;
• and
• permitting production fluid to flow sequentially through said additional production fluid inlet perforations, said gravel pack structure, said sand screen structure, said perforated tube area of said lower sealing and tubing extension structure, and upwardly through said lower sealing and tubing extension structure into the production tubing for delivery to the surface of the well completion.

A recirculating tool assembly for use in restoring production fluid flow into a subterranean well completion production tubing structure having obstructed production fluid inlet perforations, said recirculating tool assembly being lowerable into the production tubing structure, on an end of tubing means having an outer diameter less than the inner diameter of the production tubing structure, to a predetermined position therein relative to the obstructed inlet perforations, said recirculating tool assembly comprising:

• a hollow upper recirculating tool portion securable to said end of said tubing means;
• a hollow lower sealing and tubing extension structure having support means thereon for engaging an interior portion of the production tubing and supporting said sealing and tubing extension structure at said predetermined position, and seal means for engaging the interior surface of the production tubing structure and forming an annular seal around said sealing and tubing extension structure;
• latch means for releasably locking said upper recirculating tool portion to said lower sealing and tubing extension structure;
• first wall means for defining a first flow path through which a fluid within said tubing means may be flowed downwardly through said recirculating tool assembly and discharged therefrom;
• second wall means for defining a second flow path, isolated from said first flow path, through which a portion of the discharged fluid may be returned upwardly through said recirculating tool assembly and discharged therefrom;
• and
• fluid pressure operable means, disposed in said first flow path, for unlocking said latch means and freeing said upper recirculating tool portion from said lower sealing and tubing extension structure.

A recirculating tool assembly for use in restoring production fluid flow into a subterranean well completion production tubing structure having obstructed production fluid inlet perforations, said recirculating tool assembly being lowerable into the production tubing structure, on an end of tubing means having an outer diameter less than the inner diameter of the production tubing structure, to a predetermined position therein relative to the obstructed inlet perforations, said recirculating tool assembly comprising:

• a hollow upper recirculating tool portion securable to said end of said tubing means;
• a hollow lower sealing and tubing extension structure having support means thereon for engaging an interior portion of the production tubing and supporting said sealing and tubing extension structure at said predetermined position, and seal means for engaging the interior surface of the production tubing structure and forming an annular seal around said sealing and tubing extension structure, a lower portion of said recirculating tool portion being telescopingly received in an upper portion of said sealing and tubing extension structure;
• latch means for releasably interlocking the telescoped portions of said upper recirculating tool portion and said lower sealing and tubing extension structure;
• first wall means for defining a first flow path through which a fluid within said tubing means may be flowed downwardly through said recirculating tool assembly and discharged therefrom;
• second wall means for defining a second flow path, isolated from said first flow path, through which a portion of the discharged fluid may be returned upwardly through said recirculating tool assembly and discharged therefrom;
• and
• fluid pressure operable means, disposed in said first flow path, for unlocking said latch means and freeing said upper recirculating tool portion from said lower sealing and tubing extension structure, said fluid pressure operable means including hollow tubular piston means slidably received in said upper recirculating tool portion and releasably locked to said upper recirculating tool portion by frangible means,
• said piston means, in response to a downward fluid pressure force exerted thereon, being operative to break said frangible means, move downwardly in said first flow path, and responsively cooperate with said latch means in a manner causing said latch means to release said upper recirculating tool portion from said lower sealing and tubing extension structure.