US 5,287,879 A · Hydraulically energized wireline blowout preventer

Abstract

A single ram wireline BOP mechanism is disclosed which incorporates opposed rams having elastomeric packing capsules and outer elastomeric seals for accomplishing sealing about a wireline extending through the BOP body. The packing capsules cooperate to define a centrally oriented grease chamber into which is injected grease from an externally accessible grease fitting so as to establish grease sealing about the wireline. Grease pressure from the grease chamber is ducted through the BOP rams and into inner cylinders where it acts upon the pressure responsive area of a free piston contained therein. The grease pressure develops a force on the free piston which acts against the ram to enhance the closing force of the ram. The free piston has a pressure responsive area significantly greater than the pressure responsive area of the packing capsule portion of the ram so that grease pressure acting upon both of these components develops a significant resultant force that enhances the closing force and thus sealing capability of the rams. The rams are also operated in the closing and opening directions by hydraulic fluid which is introduced through fittings into an outer hydraulic cylinder. The BOP mechanism is also provided with a non-rising stem type lock out device which drives a lock nut for securing the ram energizing piston in its closed position when desired. The apparatus also incorporates a position indicator stem which is coupled with the ram energizing piston so that the position of the piston and rams may be visually inspected.

Claims30

Dependent claims

A wireline BOP mechanism having sealing capability with respect to a wireline that is movable therethrough and which forms interstices between armor strands thereof, comprising:

(a) a BOP body having a vertical flow passage and forming a pair of opposed horizontal ram passages;
(b) a pair of rams being movably disposed within said ram passages, each of said rams having elastomeric sealing elements adapted for sealing engagement with the wireline, said rams adapted to cooperatively form a grease chamber therebetween and being movable to an open position wherein said elastomeric sealing elements are positioned away from said wireline and a closed position where said elastomeric sealing elements establish sealing engagement with said wireline;
(c) means for imparting opening and closing forces to said rams and causing movement of said rams to said open and closed positions;
(d) means for injecting grease into said grease chamber at sufficiently high pressure to establish hydraulic sealing with said wireline in said grease chamber to prevent leakage of fluid pressure through said interstices of said wireline;
and
(e) means for enhancing said closing force of said rams in response to the pressure of grease within said grease chamber.

3 more elements

A method for establishing a grease pressure enhanced seal between the opposed rams of a wireline BOP mechanism having upper and lower internal sealing elements for establishing spaced sealing with a wireline forming interstices between the armor strands thereof, said opposed rams when in sealing relation with said wireline, establishing a grease chamber therebetween, said method comprising:

(a) imparting closing movement to said rams thus bringing said upper and lower internal sealing elements of said rams into sealing engagement with one another and sealing engagement with said wireline;
(b) injecting a quantity of grease through said BOP body into said grease chamber for establishment of interstitial sealing with said wireline to prevent leakage of fluid pressure through said interstices;
and
(c) utilizing the pressure of said injected grease for enhancing the closing force and thus the sealing capability of said rams with said wireline.

1 more element

A wireline BOP mechanism having sealing capability with a wireline and having injected grease pressure closing force enhancement for enhancing the sealing capability thereof, comprising:

(a) a BOP body having a vertical flow passage and forming a pair of tubular housings defining opposed horizontal ram passages;
(b) a pair of rams being movably disposed within said ram passages, each of said rams having a pair of vertically spaced elastomeric face sealing elements adapted for mechanical sealing engagement with a wireline, said rams being adapted to cooperatively define a grease chamber therebetween through which said wireline extends when said rams are closed, said rams being movable to an open position wherein said face sealing elements of said rams are positioned away from said wireline and a closed position where said face sealing elements of said rams establish sealing engagement with said wireline;
(c) primary operating means for imparting controlled movement of said rams to said open and closed positions;
(d) means for injecting grease into said grease chamber at sufficiently high pressure to establish sealing with said wireline in said grease chamber to prevent interstitial leakage of fluid pressure through said interstices of said wireline;
(e) secondary operating means for enhancing the closing force of said rams;
and
(f) means causing pressure induced actuation of said secondary operating means for enhancing the closing force of said rams responsive to injected grease pressure.

4 more elements

Dependencies are inferred from the claim text.

Hydraulically energized wireline blowout preventer

Life of this patent

Hydraulically energized wireline blowout preventer

Life of this patent

Abstract

Claims30