Testing of ram and annular blowout preventers

Claim 1

For testing the sealing and holding characteristics of an annular blowout preventer with a radially expansible-contractile bag and a casing rams-equipped blowout preventer, which are arranged one above the other in a blowout preventer stack, in turn mounted on a wellhead, comprising: a test sub having casing-simulating section with an outer diameter equal to that of the string of casing against which the two preventers are designed to operate, said casing-simulating section of the test sub having a length at least equal to the distance between the top of the bag of the annular blowout preventer and the bottom of the casing rams of the casing rams-equipped blowout preventer, said test sub being provided at its upper and lower ends with respective threaded connectors for threadable connection with respective joints of drill pipe, a joint of drill pipe having its upper end threaded to the lower threaded connector of the test sub; a test plug, the lower end of said joint of drill pipe being threaded into the test plug; a string of drill pipe having its lower end threaded to the upper threaded connector of the test sub, to complete a testing device constituted by the string of drill pipe, test sub, joint of drill pipe and test plug, whereby the testing device may be run into a well to a level at which the test plug seats in the wellhead and the casing-simulating section of the test sub is positioned to be circumferentially engaged, in turn, by the casing rams and the bag of the annular blowout preventer.

Claim 5

A method for testing the sealing and holding characteristics of an annular blowout preventer with a radially expansible-contractile bag and a casing rams-equipped blowout preventer, which are arranged one above the other in a blowout preventer stack, in turn mounted on a wellhead, comprising: making up and running into the well until it seats a string of drill pipe having a test plug at the lower end thereof and incorporating a larger diameter section, of the diameter of the casing which the casing rams are designed to seal against, said section being of such length and placement in the string of drill pipe, that when the test plug seats in the wellhead the section is in position to be alternately circumferentially gripped by the casing rams and the bag of the annular preventer; opening the annular preventer, closing the casing rams on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the casing rams and the test plug, and monitoring for leakage from the annulus, of pressurized fluid; opening the casing rams, closing the annular preventer on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the annular preventer and the test plug, and monitoring for leakage of pressurized fluid from the annulus; opening the annular preventer and pulling the string of drill pipe, test plug and incorporated larger diameter section from the well.

Claim 6

A method for testing the sealing and holding characteristics of an annular blowout preventer with a radially expansible-contractile bag and a casing rams-equipped blowout preventer, which are arranged one above the other in a blowout preventer stack, in turn mounted on a wellhead, comprising: making up and running into the well until it seats a string of drill pipe having a test plug at the lower end thereof and incorporating a larger diameter section, of the diameter of the casing which the casing rams are designed to seal against, said section being of such length and placement in the string of drill pipe, that when the test plug seats in the wellhead the section is in position to be alternately circumferentially gripped by the casing rams and the bag of the annular preventer; opening the annular preventer, closing the casing rams on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the casing rams and the test plug, and monitoring for leakage from the annulus, of pressurized fluid; opening the casing rams, closing the annular preventer on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the annular preventer and the test plug, and monitoring for leakage of pressurized fluid from the annulus; opening the annular preventer and pulling the string of drill pipe, test plug and incorporated larger diameter section from the well.

Claim 7

A method for testing the sealing and holding characteristics of an annular blowout preventer with a radially expansible-contractile bag and a casing rams-equipped blowout preventer, which are arranged one above the other in a blowout preventer stack, in turn mounted on a wellhead, comprising: making up and running into the well until it seats a string of drill pipe having a test plug at the lower end thereof and incorporating a larger diameter section, of the diameter of the casing which the casing rams are designed to seal against, said section being of such length and placement in the string of drill pipe, that when the test plug seats in the wellhead the section is in position to be alternately circumferentially gripped by the casing rams and the bag of the annular preventer; opening the annular preventer, closing the casing rams on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the casing rams and the test plug, and monitoring for leakage from the annulus, of pressurized fluid; by monitoring pressure within the drill pipe; opening the casing rams, closing the annular preventer on said larger diameter section, introducing pressurized fluid from within the drill pipe into the annulus outside said string between the annular preventer and the test plug, and monitoring for leakage from the annulus, of pressurized fluid by monitoring pressure within the drill pipe; opening the annular preventer and pulling the string of drill pipe, test plug and incorporated larger diameter section from the well.

Claim 8

A method for testing the sealing and holding characteristics of an annular blowout preventer with a radially expansible-contractile bag and a casing rams-equipped blowout preventer, which are arranged one above the other in a blowout preventer stack, in turn mounted on a wellhead, comprising: making up and running into the well until it seats a string of drill pipe having a test plug at the lower end thereof and incorporating a larger diameter section, of the diameter of the casing which the casing rams are designed to seal against, said section being of such length and placement in the string of drill pipe, that when the test plug seats in the wellhead the section is in position to be alternately circumferentially gripped by the casing rams and the bag of the annular preventer; opening the annular preventer, closing the casing rams on said larger diameter section, introducing pressurized fluid into the annulus outside said string between the casing rams and the test plug, and monitoring for leakage from the annulus, of pressurized fluid; by monitoring pressure within the drill pipe; opening the casing rams, closing the annular preventer on said larger diameter section, introducing pressurized fluid from within the drill pipe into the annulus outside said string between the annular preventer and the test plug, and monitoring for leakage from the annulus, of pressurized fluid by monitoring pressure within the drill pipe; opening the annular preventer and pulling the string of drill pipe, test plug and incorporated larger diameter section from the well.