Guidelineless system for riser entry/reentry that permits quick release of a riser column from a subsea installation

A guidelineless system for use in positioning a riser column on a subsea installation at a well site, the system permitting quick attachment to or release of the riser column from the subsea installation, comprising:

• two telescopic guideposts affixed to the lower end of the riser column one each on opposite sides thereof and in substantially parallel relationship therewith, said guideposts movable between a retracted position and an extended position;
• two guide funnels mounted on the upper end of the subsea installation one each on opposite sides thereof, the larger opening of said funnels positioned upwardly in relation to the subsea installation and the neck portion of said funnels extending axially downwardly therefrom for engaging the lower end of said guideposts;
• means for locating the subsea installation;
• means for moving the riser column toward the subsea installation wherein each of said guideposts are in their extended position so that the lower ends thereof engage a respective one of said funnels to operatively position riser column at the subsea installation;
• and
• means for disconnectably connecting the riser column to the subsea installation when the riser column is positioned and orientated with respect thereto, said guideposts when in their retracted position not contacting the guide funnels.

A guidelineless system for use in positioning a riser column at a subsea installation at a subsea well site and for permitting quick release of the riser column from the subsea installation, comprising:

• two probes affixed at the lower end of the riser column one each on opposite sides thereof and in substantially parallel relationship therewith, each of said probes including a housing affixed at the lower end of the riser column, an arm arranged in said housing to be slidably movable therein, the lower portion of said arm having a generally downwardly-tapered shape, and means in said housing to move said arm between an extended position and a retracted position;
• two guide funnels connected at the upper end of the subsea installation one each on opposite sides thereof, each of said funnels having their larger openings positioned upwardly in relation to the subsea installation for receiving the lower portion of said arms of said probes to position and orientate the riser column at the subsea installation;
• means for locating the subsea installation;
• means for moving the riser column toward the subsea installation to locate each of said arms of said probes in a respective one of said funnels, said arms of said probes in their extended position;
• and
• means for disconnectably connecting the riser column to the subsea installation when the riser column is operatively positioned thereon, said arms of said probes in their retracted position.

A guidelineless system for use in positioning a riser column at a subsea installation at a well site, the system permitting quick attachment or release of the riser column from the subsea installation, comprising:

• at least two probes affixed to the lower end of the riser column one each on opposite sides thereof, said probes including a substantially cylindrical-shaped housing affixed to the lower end of the riser, a substantially cylindrical-shaped arm concentrically arranged and slidably movable within said housing, the lower portion of said arm having a generally tapered configuration, and means for moving said arm between a retracted position where the major part of said arm along its longitudinal axis is located within said housing and an extended position where the lower portion of said arm is located substantially below the lower end of the riser column;
• at least two funnel guide means affixed to the upper end of the subsea installation one each on opposite sides thereof for receiving said arms of probes when said arms are in their extended position to position and orientate the riser with respect to the subsea installation for connection thereto, each of said funnel guide means including a wide mouth portion positioned upwardly in relation to the subsea installation and a neck portion extending axially downwardly from said mouth portion;
• means for locating the subsea installation;
• means for moving the riser column toward the subsea installation to locate a respective one of said arms of said probes in the wide mouth portion of a respective funnel means to orientate the riser at the subsea installation, said arms of said probes being in their extended position;
• and
• means for disconnectably connecting the riser column to the subsea installation after said arms of said probes have been positioned in the neck portion of said funnel means, said riser column being operatively connected to the subsea installation and said arms of said probes being in their retracted position.

A guidelineless system for making a remote connection between a subsea installation and a riser column extending from a floating vessel on the surface of a body of water, the system allowing quick release of the riser column from the subsea installation, comprising:

• a probe assembly connected to the lower end of the riser column, said probe assembly including a first housing affixed to the lower end of the riser column in substantially parallel relation therewith, a second housing affixed to the lower end of the riser column on a side thereof opposite from the side where said first housing is affixed, an arm arranged in each of said housings to be movable therein along an axis substantially parallel to that of the riser column, the lower portions of said arms having a generally downwardly-tapered shape, and means in each of said housings for moving said arms between a retracted position where said arms are substantially located within said housings and an extended position where the lower portions of said arms extend substantially beyond the lower end of the riser column;
• means for locating the subsea installation;
• means for moving the riser column toward the subsea installation;
• a receiver assembly affixed to the upper end of the subsea installation for receiving said probe assembly to position the riser on the subsea installation for connection thereto, said receiver assembly including two funnel guide means one each affixed on opposite sides of the subsea installation for engaging said arms of said probe assembly when said arms are in their extended position so that the riser column may be operatively positioned on the subsea installation;
• and
• means for disconnectably connecting the riser column to the subsea installation so that the riser column may thereafter be removed, said arms of said probe assembly in their retracted position when the riser column is connected to the subsea installation.

A method for positioning a riser column at a subsea installation at a well site, comprising:

• affixing at least two telescopic guideposts to the lower end of the riser column one each on opposite sides thereof, said guideposts movable between a retracted and an extended position;
• mounting at least two guide funnel means at the upper end of the subsea installation one each on opposite sides thereof for receiving said guideposts;
• locating the subsea installation;
• moving the riser column toward the subsea installation;
• positioning the riser column on the subsea installation by maneuvering the riser column so that said guideposts in their extended position are engaged by said guide funnel means;
• disconnectably connecting the riser column to the subsea installation;
• and
• moving said guideposts into their retracted position after the riser column is operatively connected to the subsea installation so as to permit quick release of the riser column from the subsea installation.

A method for positioning a riser column at a subsea installation where the riser column extends from a floating platform on the surface of a body of water, comprising:

• affixing two housings to the lower end of the riser column, one each on opposite sides of the riser column and in substantially parallel relationship therewith;
• arranging an arm in each of said housings to be slidably movable therein in parallel relationship with the riser column wherein said arm is movable between an extended position where the lower part of said arm extends substantially below the lower end of the riser column and a retracted position where said arm is located substantially within said housing;
• mounting a first guide funnel to the upper end of the subsea installation with the larger opening of said first funnel positioned upwardly in relation to the subsea installation with the neck portion extending axially downwardly therefrom;
• mounting a second guide funnel to the upper end of the subsea installation on a side thereof diametrically opposite from said first funnel, the larger opening of said second funnel positioned upwardly in relation to the subsea installation with the neck portion extending axially downwardly therefrom;
• locating the subsea installation;
• moving the riser column toward the subsea installation;
• moving said arms into their extended position;
• maneuvering the riser column so as to locate said one of said arms in each of the larger openings of said funnels so that the riser column is appropriately orientated on the subsea installation;
• lowering said riser column onto the subsea installation for connection thereto wherein the lower part of said arms are extended into the neck portion of said funnels;
• disconnectably connecting the riser column into operative association with the subsea installation;
• and
• moving said arms into their retracted position to permit quick release of the riser column from the subsea installation.