US 4,540,053 AGranted

Breech block hanger support well completion method

AssigneeSmith International, Inc.

InventorsBenton F. Baugh, Herman O. Henderson, Jr., John H. Fowler

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Abstract

Method for completing an underwater well includes locating drilling apparatus at the well site, and installing conductor casing in the floor of the body of water with a wellhead, blowout preventer stack, and riser attached thereto at a point near the floor, with the riser extending upwardly to the drilling means. A drill string and standard 171/2 inch drill bit is then run through the wellhead and conductor casing, and a hole is drilled for suspending 16 inch casing within the wellhead and conductor casing. A hanger-support member having a casing string attached thereto is lowered into the well until it lands in the wellhead, and it is then rotated less than 360.degree. to connect it within the wellhead. The hanger-support member is then latched within the wellhead. A hole is then drilled for suspending another casing within the wellhead, and a casing hanger with casing string is run through the riser and into the wellhead, and the casing hanger is landed on the hanger-support member.

Claims10

Dependent claims

A method for completing an underwater well having a weak formation extending below the conductor casing, which formation cannot otherwise withstand the pressure of the drilling mud required to contain the downhole pressure of the well, comprising the steps of:

(a) locating drilling means at an underwater well site above the weak formation;
(b) installing conductor casing in the floor of a body of water with a wellhead, blowout preventer stack, and riser attached thereto at a point near the floor, the riser extending upwardly to the drilling means;
(c) running a drill string and standard drill bit through the wellhead and conductor casing;
(d) drilling a hole for suspending an intermediate-sized formation support casing within said wellhead and conductor casing;
(e) lowering a hanger-support member having the intermediate-sized formation support casing string attached thereto into the well until the hanger-support member lands in the wellhead, said intermediate-sized formation support casing string extending below the conductor casing and through the weak formation;
(f) rotating the hanger-support member less than 360.degree. to connect the hanger-support member within the wellhead;
(g) latching the hanger-support member within the wellhead;
(h) drilling a hole for suspending the outermost surface casing within the wellhead and conductor casing and the intermediate-sized formation support casing;
(i) running a casing hanger with such outermost surface casing string attached thereto through the riser and into the wellhead;
and
(j) landing the casing hanger with such outermost surface casing string attached thereto on the hanger-support member.

8 more elements

A method for completing an underwater oil or gas well having a working pressure in the 15,000 psi range and extending through a weak subsurface formation below the conductor casing of the well, the borehole through which is otherwise unable to support, without rupturing, the pressure of the weight of the drilling mud used to contain the bottom hole pressure, comprising the steps of:

(a) locating drilling means at an underwater well site above the weak subsurface formation;
(b) installing and cementing a 20 inch conductor casing in the floor of a body of water with a wellhead, blowout preventer stack, and riser attached thereto at a point near the floor, the riser extending upwardly to the drilling means;
(c) running a drill string and standard 171/2 inch drill bit through the wellhead and 20 inch conductor casing;
(d) drilling a hole for suspending a 16 inch casing within said wellhead and 20 inch conductor casing;
(e) lowering a hanger-support member having an upwardly facing support shoulder on its upper end and a 16 inch casing string attached to its lower end into the well until the hanger-support member lands in the wellhead, said 16 inch casing string extending below the 20 inch conductor casing and through the weak formation;
(f) rotating the hanger-support member less than 360.degree. to connect the hanger-support member within the wellhead;
(g) latching the hanger-support member within the wellhead;
(h) cementing the 16 inch casing string in place below the 20 inch conductor casing through passageways along the exterior surface of the hanger-support member;
(i) installing a packoff ring having an upwardly facing support shoulder on its upper end on the support shoulder of the hanger-support member for sealing between the packoff ring and the bore wall of the wellhead and between the packoff ring and the interior bore of the hanger-support member to seal off the upper annulus of the well;
(j) drilling a hole for suspending another casing string within the wellhead;
(k) running a casing hanger with such other casing string attached thereto through the riser and into the wellhead;
and
(l) landing the casing hanger on the support shoulder of the packoff ring.

10 more elements

Dependencies are inferred from the claim text.