Mobile drilling rig with telescoping substructure boxes

A drilling rig mast erection system, comprising:

• a mast support shoe fixedly attached to a drilling rig substructure, said mast support shoe comprising a first pinned connection;
• a bottom mast section of a drilling rig mast, said bottom mast section comprising a second pinned connection that is adapted to be pivotably connected to said first pinned connection of said mast support shoe;
• and
• a mast positioning apparatus attached to said drilling rig substructure and pivotably attached to said bottom mast section, said mast positioning apparatus comprising a mast erection apparatus having a first end that is pivotably attached to said drilling rig substructure and a bottom mast support spreader having a first end that is pivotably attached to said bottom mast section, wherein said mast positioning apparatus is adapted to pivotably position said bottom mast section so that said second pinned connection of said bottom mast section is positioned adjacent to said first pinned connection of said mast support shoe, wherein said mast erection apparatus is adapted to be retracted so as to pivotably rotate said bottom mast support spreader, and wherein said pivotably rotating bottom mast support spreader is adapted to raise at least a lower end of said bottom mast section and pivotably position said second pinned connection of said bottom mast section adjacent to said first pinned connection of said mast support shoe.

A telescoping substructure, comprising:

• a first telescoping substructure box;
• and
• a second telescoping substructure box that is laterally spaced apart from said first telescoping substructure box, wherein each of said first and second telescoping substructure boxes comprises:
• an upper substructure box comprising a plurality of structural members that are assembled to define a substantially open interior space and a substantially open bottom frame;
• a lower substructure box, wherein at least a portion of said lower substructure box is sized to pass through said substantially open bottom frame of said upper substructure box and to nest inside of said substantially open interior space of said upper substructure box when said upper substructure box is telescopically raised and lowered relative to said lower substructure box;
• and
• raising means for telescopically raising and lowering said upper substructure box relative to said lower substructure box.

A telescoping substructure, comprising:

• a first telescoping substructure box;
• and
• a second telescoping substructure box that is laterally spaced apart from said first telescoping substructure box, wherein each of said first and second telescoping substructure boxes comprise:
• a lower substructure box comprising a plurality of structural members that are assembled to define a substantially open interior space and a substantially open upper frame;
• an upper substructure box, wherein at least a portion of said upper substructure box is sized to pass through said substantially open upper frame of said lower substructure box and to nest inside of said substantially open interior space of said lower substructure box when said upper substructure box is telescopically raised and lowered relative to said lower substructure box;
• and
• raising means for telescopically raising and lowering said upper substructure box relative to said lower substructure box.

A telescoping substructure box, comprising:

• an upper substructure box comprising a plurality of upper structural members;
• a lower substructure box comprising a plurality of lower structural members that are assembled to define a substantially open interior space and a substantially open upper frame, wherein said substantially open interior space of said lower substructure box is sized to receive at least a portion of said upper substructure box through said substantially open upper frame of said lower substructure box when said upper substructure box is telescopically raised and lowered relative to said lower substructure box between a raised drilling position and a lowered transportation position;
• and
• raising means for telescopically raising and lowering said upper substructure box relative to said lower substructure box.