Continuous circulation drilling method

A system for connecting and disconnecting tubulars to a drill string while continuously circulating a drilling fluid through the drill string comprising:

• (a) chamber means for defining a pressure chamber;
• (b) multiple inlet and outlet passage means in said chamber for continuously circulating drilling fluid through said chamber and down said drill string;
• (c) an upper preventer positioned adjacent the upper portion of said chamber and a lower preventer positioned adjacent the lower portion of said chamber for sealing against the high pressure of the bore hole;
• (d) ram preventer means for dividing said chamber into upper and lower portions and for opening and closing fluid flow between said upper and lower chamber portions;
• and
• (e) separate upper and lower gripping means for moving radially and gripping said tubular and said drill string, respectively.

A coupler for connecting and disconnecting a plurality of tubulars having upsets to and from a drill string while continuously circulating drilling fluid comprising;

• (a) a high pressure chamber having an upper end for receiving a tubular with an upset and a lower end for receiving a drill string;
• (b) first high pressure sealing means for moving radially and sealing said upper chamber end about said tubular;
• (c) second high pressure sealing means for moving radially and sealing said lower chamber end about said drill string;
• (d) divider valve means in said chamber for dividing said chamber into upper and lower portions and for placing said upper and lower chamber portions into and out of fluid communication;
• and
• (e) wherein at least said first high pressure sealing means is a radially movable seal of a size and shape such as to not pass said upset therethrough when engaged about said tubular.

A coupler for adding and removing tubulars to and from a drill string comprising:

• (a) a fluid tight casing forming a chamber;
• (b) a divider in said chamber for dividing said chamber into upper and lower portions, and said divider including a valve;
• (c) first grips connected to said chamber for engaging said tubulars;
• (d) second grips connected to said chamber for engaging said drill string;
• and
• (e) rotary means connected to at least one of said grips for rotating said tubulars and said drill string relative to each other.

A method for changing tubulars of a drill string while continuously recirculating drilling fluid down the drill string comprising:

• (a) gripping the upper end of a drill string with lower grips;
• (b) gripping the lower end of a tubular with upper grips;
• (c) continuously flowing drilling fluid through a chamber surrounding said drill string and down said drill string;
• and
• (d) rotating said tubular and said drill stem relative to each other to make and break connections therebetween.

An apparatus for adding and removing tubulars to and from a drill string while continuing to flow drilling fluid down the string into a bore hole, comprising:

• (a) a casing forming a pressure chamber;
• (b) said chamber having a top and a bottom;
• (c) high pressure seals positioned at said top and bottom of said chamber capable of withstanding the pressure in said bore hole during drilling thereof;
• (d) radially movable grips connected to said chamber for gripping said drill string;
• (e) rotary means connected to said chamber for rotating said tubular into and out of threaded engagement with said drill string;
• and
• (f) radially movable slips connected to said chamber and positioned below said radially movable grips for positively locking said drill string against downward movement.

Apparatus for connecting or disconnecting tubulars to and from a drill string while continuously rotating the drill string in a bore hole comprising:

• (a) first means for positioning a tubular above a drill string in axial alignment;
• (b) rotary grip means for gripping said drill string;
• and
• (c) motorized means connected to said rotary grip means for rotating said drill string relative to said tubular and continuously rotating said drill string in the bore hole while simultaneously connecting or disconnecting said tubular to and from said drill string.

The apparatus of claim further comprising:

• (a) means forming a chamber
• (b) said chamber being such as to receive the lower end of said tubular and the upper end of said drill string;
• and
• (c) inlet and outlet passage means for circulating drilling fluid into said chamber and down said drill string while rotating said drill string and simultaneously connecting or disconnecting said tubular from said drill string.

Apparatus for connecting or disconnecting a tubular to or from a drill string extending into a bore hole while continuously flowing drilling fluid down the drill string into the bore hole comprising:

• (a) a coupler forming a pressure chamber;
• (b) a said coupler being of a size and shape such as to receive the lower end of the said tubular and the upper end of said drill string;
• (c) said coupler including high pressure seals for sealing said chamber against the pressure in the said bore hole;
• (d) a divider valve dividing said chamber into upper and lower portions when said divider valve is closed;
• (e) upper grips connected to said chamber and positioned above said divider valve;
• (f) lower grips positioned below said divider valve;
• and
• (g) inlet and outlet passage means in said chamber for continuously flowing drilling fluid into said chamber and down through said drill string while said tubular is connected or disconnected from said drill string by said upper and lower grips.