Method and apparatus for conducting wireline operations during blowout conditions in oil and gas wells
AssigneeSchlumberger Technology Corporation
InventorC. P. Lanmon, II
Life of this patent
Estimating the term…
Abstract
A method and apparatus for conducting wireline operations in oil and gas wells under blowout conditions is disclosed, wherein a releasable annular wireline blowout preventer is provided, whereby wireline operations may be conducted under normal operating conditions by only using a short riser and a releasable annular wireline blowout preventer. Under blowout conditions, a second riser may be attached to the releasable annular wireline blowout preventer to quickly enable a wireline suspended tool to be safely removed from the well, along with the releasable wireline seal assembly means of the blowout preventer.
Claims12
A releasable annular wireline blowout preventer for use with oil and gas wells during wireline operations comprising:
- an annular body having upper and lower ends and an inner diameter capable of allowing the through passage of a wireline suspended tool;
- first means for attaching the annular body to a well-head cut-off valve, said first attachment means associated with the lower end of the annular body;
- second means for attaching the annular body to a length of pressure containing pipe, said second attachment means associated with the upper end of the annular body;
- a wireline seal assembly means for preventing well fluid leakage about the wireline, said wireline seal assembly means having an annular rib, said annular body having selective engaging means for securing the seal assembly means within the annular body during normal wireline operations, said selective engaging means having at least one bolt threaded in said annular body, which, upon rotation, extends into the interior of the annular body above said rib on the wireline seal assembly means whereby said wireline seal assembly means is selectively prevented from moving in the upward direction due to well pressures;
- and
- means for releasing said selective engaging means to allow the removal of the seal assembly means upwardly through the annular body.
A method for conducting wireline operations in an oil and gas well under the possibility of blowout conditions in the well, said well being provided with a wellhead cut-off valve, comprising the steps of:
- (a) fixedly securing an annular body to the cut-off valve, said body having an inner diameter capable of allowing the through passage of a wireline suspended tool;
- said annular body having means associated with its upper end with means for attaching the annular body to a length of pressure containing pipe;
- (b) lowering a wireline suspended tool through said annular body and cut-off valve, said wireline suspended tool having a wireline seal assembly means disposed about the wireline;
- (c) securing the wireline seal assembly means within the annular body;
- (d) lowering the wireline suspended tool in the well;
- and
- (e) readying a length of pressure containing pipe for attachment to said upper end of said annular body in preparation of emergency blowout conditions in the well.
A method for conducting wireline operations in an oil and gas well and for removal of wireline suspended tools during blowout conditions in the well, said well being provided with a main cut-off valve, comprising the steps of:
- (a) fixedly securing an annular body to the top of a first riser associated with the cut-off valve, said body having an inner diameter capable of allowing the through passage of a wireline suspended tool;
- (b) opening the cut-off valve;
- (c) lowering a wireline suspended tool through said annular body, first riser, and cut-off valve, said wireline suspended tool having a wireline seal assembly means disposed about the wireline;
- (d) securing the wireline seal assembly means within the annular body;
- (e) lowering the wireline suspended tool into the well;
- (f) sealing the wireline seal assembly means about the wireline upon encountering blowout conditions in the well;
- (g) passing a portion of the wireline, which is disposed outside the well and wireline seal assembly means through a second riser, having a stuffing box disposed in the upper end of the second riser;
- (h) attaching the lower end of the second riser to the top of the annular body and sealing the stuffing box about the wireline;
- (i) equalizing the pressure between the first and second risers;
- (j) releasing the wireline seal assembly means from the annular body;
- (k) raising the wireline suspended tool and wireline seal assembly means into the second riser and past the cut-off valve;
- and,
- (l) closing the cut-off valve to seal the well.
A releasable annular wireline blowout preventer for use with oil and gas wells during wireline operations comprising:
- an annular body having upper and lower ends and an inner diameter capable of allowing the through passage of a wireline suspended tool;
- first means for attaching the annular body to a wellhead cut-off valve, said first attachment means associated with the lower end of the annular body;
- second means for attaching the annular body to a length of pressure containing pipe, said second attachment means associated with the upper end of the annular body;
- a wireline seal assembly means for preventing well fluid leakage about the wireline, said annular body having selective engaging means for securing the seal assembly means within the annular body during normal wireline operations, said selective engaging means having one or more slotted portions on the outer annular surface of the wireline assembly means, said slotted portions selectively adapted to mate with corresponding end portions of one or more bolts in said annular body extending into the interior of said annular body by downward and radial movement of the sealing assembly means with respect to the annular body;
- and
- means for releasing said selective engaging means to allow the removal of the seal assembly means upwardly through the annular body.
A releasable annular wireline blowout preventer for use with oil and gas wells during wireline operations comprising:
- an annular body having upper and lower ends and an inner diameter capable of allowing the through passage of a wireline suspended tool;
- first means for attaching the annular body to a wellhead cut-off valve, said first attachment means associated with the lower end of the annular body;
- second means for attaching the annular body to a length of pressure containing pipe, said second attachment means associated with the upper end of the annular body;
- a wireline seal assembly means for preventing well fluid leakage about the wireline, said wireline seal assembly having an annular rib, said annular body having selective engaging means for securing the seal assembly means within the annular body during normal wireline operations, said selective engaging means having one or more hydraulically operated piston members having end portions extending into the interior of the annular body above said rib on the wireline seal assembly means whereby said wireline seal assembly means is selectively prevented from moving in the upward direction due to well pressures;
- and
- means for releasing said selective engaging means to allow the removal of the seal assembly means upwardly through the annular body.
Dependencies are inferred from the claim text.