Method and apparatus for remote installation and servicing of underwater well apparatus

The method for installing multiple strings of tubing in an underwater well installation of the type comprising wellhead structure including an upwardly exposed support for a tubing hanger, a wellhead body member above and adjacent to the support and presenting a rotational orientation reference, and blowout preventer means mounted on the wellhead body member, comprising

• providing a composite handling joint which presents a cylindrical outer surface longer than the effective height of the blowout preventer means, the handling joint defining
• a plurality of larger diameter longitudinal passages equal in number to the strings of tubing to be installed, and
• at least one small longitudinal pressure fluid passage;
• providing a handling tool comprising
• a handling tool body,
• fluid pressure operated connector means carried by the handling tool body,
• pressure fluid passage means arranged to supply pressure fluid to operate the connector means,
• a plurality of larger diameter passages equal in number to the strings of tubing to be installed, and
• locator means constructed and arranged to cooperate with the rotational orientation reference of the wellhead body means;
• securing the handling tool rigidly to the composite handling joint with the pressure fluid passage means of the tool communicating with the at least one pressure fluid passage of the composite joint and with the larger diameter passages of the handling tool communicating each with a different one of the larger diameter passages of the composite handling joint;
• securing the last joints of the tubing strings to a multiple string tubing hanger having a body,
• a support member presenting a downwardly facing shoulder adapted to be landed on the upwardly exposed support of a wellhead structure,
• rotary bearing means between the support member and the tubing hanger body, and
• weight-set means constructed and arranged to maintain the tubing hanger initially in condition for rotation of the tubing hanger body relative to the support member when the support member of the hanger has been landed on the upwardly exposed support of the wellhead structure;
• releasably securing the body of the tubing hanger to the handling tool by the fluid pressure operated connector means of the handling tool;
• lowering the combination of the composite handling joint, handling tool and tubing hanger from the operational base with the aid of guidance means until the support member of the tubing hanger lands upon the upwardly exposed support of the wellhead structure, the handling tool is within the wellhead body member, and the composite handling joint extends through the blowout preventer means;
• rotating the combination of the composite handling joint, handling tool and tubing hanger body until the locator means of the handling tool cooperates with the orientation reference of the wellhead body member to establish a predetermined rotational position for the tubing hanger,
• the step of rotating the composite handling joint, handling tool and tubing hanger being carried out while supporting a predominant portion of the weight of the tubing strings, hanger, handling tool and composite handling joint from the operational base;
• then reducing the support from the operational base to allow the weight of the tubing strings, hanger, handling tool and composite joint to actuate the weight-set means of the tubing hanger and thus complete landing of the tubing hanger in its predetermined rotational position;
• releasing the connector means of the handling tool by pressure fluid supplied via the at least one pressure fluid passage of the composite handling joint and thereby disconnecting the handling tool from the tubing hanger;
• and
• recovering the composite handling joint and handling tool.

In an underwater well apparatus, the combination of

• underwater wellhead means including
• upright body means defining an upright through bore,
• an upwardly exposed tubing hanger support disposed in the through bore,
• rotational orientation reference means exposed to the through bore and located above the tubing hanger support, and
• blowout preventer means mounted on the body means and located above the orientation reference means;
• handling string means capable of extending from an operational base at the surface of the water downwardly to the wellhead means and including a composite lowermost joint defining
• a plurality of larger diameter longitudinal passages, and
• at least one small longitudinal pressure fluid passage;
• a handling tool comprising
• body means rigidly secured to the lower end of the composite lowermost joint of the handling string means and having
• a plurality of larger diameter through passages each communicating with a different one of the larger diameter longitudinal passages of the composite lowermost joint, and
• at least one pressure fluid passage communicating with the corresponding pressure fluid passage of the composite lowermost joint,
• locator means carried by the body means and constructed and arranged to cooperate with the rotational orientation reference means of the wellhead means, and
• fluid pressure operated connector means;
• a multiple string tubing hanger comprising
• a body having a plurality of through passages to cooperate with tubing strings,
• an annular support member presenting a downwardly facing shoulder adapted to be landed on the upwardly exposed tubing hanger support of the wellhead means,
• rotary bearing means operatively disposed between the annular support member and the tubing hanger body, and
• weight-set means constructed and arranged to maintain the tubing hanger in initial freedom for rotation relative to the annular support member when the annular support member has been landed on the upwardly exposed tubing hanger support of the wellhead means and a major portion of the weight of the tubing strings is still supported by the handling string means,
• the weight-set means allowing the tubing hanger body to descend relative to the annular support member into fully landed position when support via the handling string means ceases;
• and
• a plurality of well tubing strings secured to and depending from the tubing hanger;
• the effective lengths of the composite lowermost joint of the handling string means, the handling tool and the tubing hanger being such that, when the annular support member of the tubing hanger is initially landed on the upwardly exposed tubing hanger support of the wellhead means, the handling tool is disposed in the wellhead body means in a location such that the locator means of the handling tool will cooperate with the orientation reference means of the wellhead means upon rotation of the handling tool, and the composite lowermost joint of the handling string means extends through the blowout preventer means;
• the composite lowermost joint of the handling string means having a rigid cylindrical outer surface of a length to extend through the blowout preventer means, the blowout preventer means being constructed and arranged to seal against said outer surface of the composite lowermost joint;
• the combination of the composite lowermost joint of the handling string means, the handling tool and the body of the tubing hanger being rigid and capable of accepting loads in compression and in tension as well as rotational loads.

In an underwater well apparatus, the combination of

• underwater wellhead means including
• upright body means defining an upright through bore, and
• blowout preventer means mounted on the upright body means;
• handling string means capable of extending from an operational base at the surface of the water downwardly to the wellhead means and including a composite lowermost joint defining
• at least one larger diameter longutidinal passage, and
• a plurality of small longitudinal pressure fluid passages;
• a handling tool comprising
• body means having at least one larger diameter longitudinal through passage and a plurality of small pressure fluid passages, the body having a lower end portion including a transverse annular outwardly opening groove,
• a tubular member surrounding the handling tool body means and coacting therewith to define an annular cylinder,
• a first annular piston slidably disposed in said annular cylinder and including a dependent skirt extending downwardly from said annular cylinder,
• a first duct in the handling tool body means communicating between a first one of the pressure fluid passages of the handling tool and said annular cylinder in a location above said first annular piston, and
• a second duct in the handling tool body means communicating between a second one of the pressure fluid passages of the handling tool and said annular cylinder in a location below said first annular piston;
• means securing the handling tool to the lower end of the composite lowermost joint of the handling string means with the at least one larger diameter passage of the handling tool communicating with the at least one larger diameter passage of the composite lowermost joint and with the pressure fluid passages of the handling tool communicating respectively with the pressure fluid passages of the composite lowermost joint;
• a well tool having
• a body, and
• a tubular sleeve projecting upwardly from the body and having a transverse annular inwardly opening groove;
• the tubular sleeve of the well tool embracing the lower end portion of the body means of the handling tool and being so disposed that the inwardly opening groove of the sleeve opposes the outwardly opening groove of the lower end portion of the body means of the handling tool;
• and
• generally annular lock means disposed in one of said outwardly opening groove and said inwardly opening groove and resiliently biased for locking engagement in the others of said grooves,
• said lock means presenting upwardly directed cam surface means of generally frustoconical form aligned below the dependent skirt of said first annular piston and so oriented that downward movement of the piston causes the skirt to engage the cam surface means and cam the lock means to a disengaged position to disconnect the well tool from the handling tool, supply of pressure fluid via said first duct thus being effective to drive said first piston downwardly to cam the lock means to disengaged position,
• supply of pressure fluid via said second duct being effective to drive said first piston upwardly to disengage said skirt from the cam surface means of the lock means.