Blowout preventer protector and method of using same

An apparatus for protecting a blowout preventer from exposure to fluid pressures, abrasives and corrosive fluids used in a well treatment to stimulate production and for supporting a tubing string in a wellbore so that the tubing string is accessible during the well treatment, comprising:

• a mandrel adapted to be inserted down through the blowout preventer to an operative position, the mandrel having a mandrel top end and a mandrel bottom end, the mandrel bottom end including an annular sealing body for sealing engagement with a bit guide at a top of a casing of the well when the mandrel is in the operative position;
• a mandrel head affixed to a top end of the mandrel, the mandrel head including a top flange;
• a base member adapted for connection to a wellhead above the blowout preventer, the base member including fluid seals through which the mandrel is reciprocally movable;
• a fracturing head mounted to the mandrel head, the fracturing head including a central passage and at least one radial passage in fluid communication with the central passage;
• a tubing adapter mounted to a top end of the fracturing head, the tubing adapter supporting the tubing string while permitting fluid communication with the tubing string;
• and
• a lock mechanism for locking the mandrel head in a fixed position above the base member to inhibit upward movement of the mandrel induced by fluid pressures in the wellbore and downward movement of the mandrel head induced by a weight of the tubing string supported by the tubing adapter.

A method of providing access to a tubing string while protecting a blowout preventer on a wellhead from exposure to fluid pressure as well as to abrasive and corrosive fluids during a well treatment to stimulate production, comprising steps of:

• suspending, above the wellhead an apparatus for protecting the blowout preventer from exposure to fluid pressure as well as to abrasive and corrosive fluids during the well treatment to stimulate production, the apparatus comprising a mandrel having a mandrel top end and a mandrel bottom end that includes an annular sealing body, a fracturing head mounted to the mandrel top end, the fracturing head having an axial passage in fluid communication with the mandrel and at least one radial passage in fluid communication with the axial passage and a base member for detachably securing the mandrel to the wellhead;
• aligning the apparatus with a tubing string supported on the wellhead and extending above the wellhead, and lowering the apparatus until a top end of the tubing string extends through the axial passage above the fracturing head;
• connecting the top end of the tubing string to a top end of the fracturing head, lowering the tubing string and the apparatus until the apparatus rests on the wellhead, and mounting the base member to the wellhead;
• opening the blowout preventer;
• lowering the tubing string and the fracturing head to stroke the mandrel bottom end down through the blowout preventer, and adjusting a lock mechanism until the mandrel is in an operative position in which the annular scaling body is in fluid sealing engagement with a bit guide mounted to a top of a casing of the well;
• adjusting the lock mechanism to lock the mandrel in the operative position and to transfer weight of the tubing string and the apparatus to the wellhead so that the sealing body is not compressed against the bit guide by a full weight of the tubing string.

A method of running a tubing string into or out of a well while protecting a first blowout preventer on a wellhead of the well from exposure to fluid pressure as well as to abrasive and corrosive fluids during a well treatment to stimulate production, comprising steps of:

• mounting to the wellhead a base member of an apparatus for protecting the blowout preventer from exposure to fluid pressure as well as to abrasive and corrosive fluids during the well treatment to stimulate production, the apparatus comprising a mandrel having a mandrel top end and a mandrel bottom end that includes an annular sealing body, a fracturing head mounted to the mandrel top end, the fracturing head having an axial passage in fluid communication with the mandrel and at least one radial passage in fluid communication with the axial passage and the base member for detachably securing the mandrel to the wellhead;
• closing at least one second blowout preventer which is mounted to an adapter flange mounted to a top of the fracturing head;
• opening the first blowout preventer;
• lowering the fracturing head to stroke the mandrel bottom end down through the blowout preventer, and adjusting a lock mechanism until the mandrel is in an operative position in which the annular sealing body is in fluid sealing engagement with a bit guide mounted to a top of a casing of the well;
• adjusting the lock mechanism to lock the mandrel in the operative position and to transfer weight of the tubing string and the apparatus to the wellhead so that the sealing body will not be compressed against the bit guide by a full weight of the tubing string;
• and
• running the tubing string into or out of the well through the at least one second blowout preventer.