Multiple-seal underwater pipe-riser connector
AssigneeShell Oil Company
InventorsJames D. Smith, Stewart A. Fox, William T. Asbill
Life of this patent
Estimating the term…
Abstract
A rugged screw-threaded pipe connector for handling corrosive or contaminating fluids under high pressure in a pipeline or pipe riser surrounded by a body of water and subject to high static or dynamic stresses and bending forces. The connector is provided with coarse threads having stabbing flanks and with load flanks adapted to support high loads. The connector is provided with multiple sealing means arranged within the body of the connector that isolate the threads from fluids outside the connector or within the bore of the connector.
Claims14
A multiple-seal threaded pipe-riser connector having a smooth bore therethrough of a diameter equal to the inner diameter of an elongated pipe made up of a plurality of pipe sections, said connector in its operational mode comprising:
- a tapered pin member having a thread formed thereon over a central portion of said tapered surface, a sealing lip extending axially from a small-diameter end of the threaded portion of the pin member, an interference shoulder extending radially at the large-diameter end of the threaded portion of the pin member, and a base;
- a circumferentially recessed thread-load redirection groove in the outer surface of the pin member and being of a depth greater than the depth of the threads and adjacent to the large-diameter end of the thread portion thereof;
- a box member adapted to threadedly receive said pin member and having a body, an end face, and having an extending sealing lip for engaging the sealing surface means at the base of said tapered pin member;
- recessed sealing surface means inside of the sealing surface means at the base of said tapered pin member, said recessed sealing surface means formed circumferentially in the body of said pin member adjacent said redirection groove, said sealing surface means including an axial interference shoulder;
- a portion of said box member having formed therein a surface tapered inwardly away from the sealing lip for a portion of the body of the box member, a thread formed on said tapered portion of the box member of a size to operationally engage the threaded portion of the pin member;
- a circumferentially recessed thread-load redirection groove formed in the wall of the box member adjacent the small diameter end of the thread portion thereof and being of a depth greater than the threads;
- recessed sealing surface means formed circumferentially in the inner wall of said box member adjacent and axially displaced from said redirection groove thereof, said recessed sealing surface means being of a size to receive the sealing lip of the pin member;
- and
- sealing surface means on the end face of the sealing lip of said box member for engaging the interference shoulder of said pin member.
A multiple-seal threaded pipe-riser connector for use in deep water oil production operations, said connector having a smooth bore of a diameter equal to that of the internal diameter of adjacent sections of a pipe-riser to which they are to be attached, said threaded connector comprising:
- a tubular pin member having first and second ends and a body, said first end adapted to be welded to one end of a pipe riser section, a portion of said pin member having a tapered central portion adapted to be threaded, a thread formed on said central portion of said pin member which tapers radially inwardly, a thin-walled sealing lip formed at the second end of said pin member and extending axially from the end of the threaded portion, and being provided with first sealing surface means;
- a circumferential thread-load redirection groove formed in the surface of the pin member adjacent the largest diameter threads on the pin member;
- second sealing surface means formed in the body of said pin member adjacent to and axially displaced from said thread-load redirection groove, comprising a circumferential groove and a O-ring seated therein;
- an axially extending recessed shoulder formed in the pin member adjacent to and axially displaced from said second sealing surface means;
- a tubular box member having first and second ends, said first end adapted to be welded to one end of a pipe riser section and adapted to be connected to a pin member of another pipe riser section;
- a thin-walled sealing lip formed at the second end of the box member and being of a size, when coupled to the pin member, to extend over the thread-load redirection groove and second box member sealing surface means and to seat on the recessed shoulder formed in the pin member;
- third sealing surface means formed on the inner wall of the lip of the box member to engage the axially extending recessed shoulder of the pin member;
- a portion of the box member adjacent the lip having a bore formed to taper radially outwardly toward the lip;
- a thread formed on the tapered bore section, said thread being of a size to threadedly engage the thread formed on the pin member;
- a thread-load redirection groove formed in the inner surface of the bore of the box member adjacent the box thread;
- and
- fourth sealing surface means formed on the inner surface of the bore of the box member adjacent the redirection groove axially positioned to engage the first sealing surface means of the pin member.
Dependencies are inferred from the claim text.