Subsea wellhead connection assembly and methods of installation

A subsea wellhead connection assembly for establishing fluid communication and production capability between a subsea wellhead and an adjacent subsea manifold system, comprising:

• conduit means for fluidly connecting the wellhead and the manifold system, the conduit means having one end extending substantially horizontally and the other end extending downwardly;
• wellhead connector means fluidly connected to the downwardly directed end of the conduit means for releasably connecting the conduit means to the wellhead upon downward movement of the assembly to establish fluid communication therebetween;
• manifold system connector means fluidly connected to the horizontal end of the conduit means for releasably connecting the conduit means to the manifold system upon lateral movement of the manifold system connector means to establish fluid communication therebetween;
• a guide frame rigidly secured to the wellhead connector means for supporting the manifold system connector means and the conduit means, and for vertically aligning the wellhead connector means over the wellhead and horizontally aligning the manifold system connector means with the manifold system;
• and
• mechanical linkage means supported by the guide frame and having a lever arm having one end attached to the manifold system connector means for laterally moving the manifold system connector means into operative connection with the manifold system and for reversing such operation to disconnect.

A subsea wellhead connection assembly for establishing fluid communication and production capability between a subsea wellhead supported on the peripheral portion of a circular marine floor base template and an adjacent subsea atmospheric manifold system supported on the central portion of the template, the wellhead being situated within a well bay defined by vertical dividers rigidly mounted on the template and extending inwardly toward said central portion from said peripheral portion along radially aligned planes, said assembly comprising:

• conduit means for fluidly connecting the wellhead and the manifold system, the conduit means having one end extending substantially horizontally toward the central portion of the template and the other end extending downwardly;
• wellhead connector means fluidly connected to the downwardly directed end of the conduit means and releasably connected to the wellhead so as to establish fluid communication between the wellhead and the conduit means;
• manifold system connector means fluidly connected to the horizontal end of the conduit means and releasably connected to the manifold system so as to establish fluid communication between the conduit means and the wellhead;
• and
• a guide frame rigidly secured to the wellhead connector means for supporting the manifold system connector means and the conduit means, and for vertically aligning the wellhead connector means over the wellhead and horizontally aligning the manifold system connector means with the manifold system, the guide frame being mounted in the well bay on the marine floor base template.

A subsea wellhead connection assembly for establishing fluid communication and production capability between a subsea wellhead and an adjacent subsea atmospheric manifold system and for establishing fluid communication between the wellhead and a connector mandrel, comprising:

• first conduit means curved in a loop traversing at least about one full turn for fluidly connecting the wellhead and the manifold system, the first conduit means having one end extending substantially horizontally and the other end situated below the horizontal end;
• wellhead connector means fluidly connected to said other end of the first conduit means for releasably connecting the first conduit means to the wellhead upon downward movement of the assembly to establish fluid communication therebetween;
• manifold system connector means fluidly connected to the horizontal end of the first conduit means for releasably connecting the first conduit means to the manifold system upon lateral movement of the manifold system connector means to establish fluid communication therebetween, the manifold system connector means having a pair of guide pins extending substantially horizontally from opposing sides of the connector means to permit alignment during horizontal movement of said manifold system connector means;
• substantially vertically extending second conduit means having a downwardly directed end fluidly connected to the wellhead connector means and an upwardly directed end fluidly connected to the connector mandrel for establishing fluid communication between the wellhead and the mandrel independent of the manifold system connector means;
• a protective guide frame comprised of rigid structural piping for supporting and surrounding the manifold system connector means and the first and second conduit means, and for vertically aligning the wellhead connector means over the wellhead and horizontally aligning the manifold system connector means with the manifold system, the guide frame comprising upper and lower support members having substantially identical outer peripheries, when viewed from above, and vertical tubular members rigidly connected between the upper and lower support members, the lower support member being rigidly attached to the wellhead connector means and the upper support member being rigidly attached to the upwardly directed end of the second conduit means;
• mechanical linkage means supported by the guide frame and having a lever arm having one end attached to the manifold system connector means for laterally moving the manifold system connector means into operative connection with the manifold system, and for reversing such operation to disconnect, the mechanical linkage means further having an actuating member pivotally connected to the lever arm, the actuating member having its free end extending substantially vertically upward;
• and
• a pair of substantially oppositely facing guide plates rigidly attached to at least one of the vertical members of the guide frame, each guide plate having a slot for supporting and guiding the respective manifold system connector guide pins during lateral movement of the manifold system connector means, the guide pins, guide plates and slots being relatively situated so as to align the manifold system connector means with the manifold system.

A subsea wellhead connection assembly for establishing fluid communication and production capability between a subsea wellhead and an adjacent subsea hull penetrator and for establishing fluid communication between the wellhead and a connector mandrel, comprising:

• a plurality of flexible loop flowlines for fluidly connecting the wellhead and the penetrator, at least one of the flowlines being curved in a substantially vertically extending loop traversing about one full turn and on a radius of at least 1.52 meters for permitting passage of well pump-down tools therethrough, the flowlines each having one end extending substantially horizontally and the other end extending downwardly;
• wellhead connector means fluidly connected to the downwardly directed ends of the flowlines for releasably connecting the flowlines to the wellhead upon downward movement of the assembly to establish fluid communication therebetween;
• penetrator connector means fluidly connected to the horizontal ends of the flowlines for releasably connecting the flowlines to the penetrator upon lateral movement of the penetrator connector means to establish fluid communication therebetween;
• substantially vertically extending conduit means having a downwardly directed end fluidly connected to the wellhead connector means and an upwardly directed end fluidly connected to the connector mandrel for establishing fluid communication between the wellhead and the mandrel independent of the penetrator, the conduit means including swab valve means and a vertical wye spool having diverter valve means disposed therein;
• a protective guide frame including rigid structural piping for supporting and surrounding the penetrator connector means, the conduit means, and the flowlines, and for vertically aligning the wellhead connector means over the wellhead and horizontally aligning the penetrator connector means with the penetrator, the guide frame comprising upper and lower support members having substantially identical outer peripheries, when viewed from above and vertical members rigidly connected between the upper and lower support members, the lower support member being rigidly attched to the wellhead connector means and the upper support member being rigidly attached to the conduit means;
• and
• mechanical linkage means supported by the guide frame and having a lever arm having one end attached to the penetrator connector means for laterally moving the penetrator connector means into operative connection with the penetrator, and for reversing such operation to disconnect, the mechanical linkage means further having an actuating member pivotally connected to the lever arm, the actuating member having its free end extending substantially vertically upward.

A method of establishing fluid communication and production capability between a marine floor wellhead and an adjacent subsea manifold system, comprising:

• providing a wellhead connection assembly comprising conduit means for fluidly connecting the wellhead and the manifold system, the conduit means having one end extending substantially horizontally and the other end situated below the horizontal end, wellhead connector means fluidly connected to said other end of the conduit means, manifold system connector means fluidly connected to the horizontal end of the conduit means, and a guide frame rigidly secured to the wellhead connector means for supporting the manifold system connector means and the conduit means;
• laterally moving the wellhead connection assembly into a generally wedge-shaped well bay defined by vertical dividers, wherein two opposing sides of the guide frame are similarly wedge-shaped and the assembly is guided into position above the wellhead by the vertical dividers;
• releasably connecting the wellhead connector means to the wellhead, thereby establishing fluid communication between the wellhead and the conduit means;
• and
• then horizontally moving the manifold system connector into operative connection with the manifold system, thereby establishing fluid communication between the conduit means and the manifold system.

A method of establishing fluid communication and production capability between a marine floor wellhead and an adjacent subsea manifold system, comprising:

• providing a wellhead connection assembly comprising conduit means for fluidly connecting the wellhead and the manifold system, the conduit means having one end extending substantially horizontally and the other end situated below the horizontal end, wellhead connector means fluidly connected to said other end of the conduit means, manifold system connector means fluidly connected to the horizontal end of the conduit means, and a guide frame rigidly secured to the wellhead connector means for supporting the manifold system connector means and the conduit means;
• lowering the wellhead connection assembly;
• providing a circular guide ring extending from the upper periphery of the wellhead, providing the wellhead connection assembly with a downwardly-directed alignment funnel means rigidly attached to the wellhead connector means and extending from the lower periphery of the guide frame, and contacting the guide ring with the inner periphery of the alignment funnel as the assembly is lowered during its installation on the wellhead, thereby vertically aligning the wellhead connector means directly over the wellhead;
• providing the wellhead connection assembly with mechanical linkage means supported by the guide frame and having a lever arm having one end attached to the manifold system connector means, and exerting a force on the lever arm so as to laterally move the manifold system connector means into operative connection with the manifold system;
• releasably connecting the wellhead connector means to the wellhead, thereby establishing fluid communication between the wellhead and the conduit means;
• and
• then horizontally moving the manifold system connector into operative connection with the manifold system, thereby establishing fluid communication between the conduit means and the manifold system.