Method for drilling multilateral wells with reduced under-reaming and related device

A method of forming a junction between a first wellbore and one or more lateral wells which branch from said first wellbore, said method comprising:

• enlarging a portion of said first wellbore to form an enlarged section of said first wellbore;
• installing an arcuate drillable guide within said enlarged section;
• pumping material into said enlarge section, said material hardening within said enlarged section to form hardened material;
• positioning a packer within said enlarged section;
• and
• inflating said packer during said step of pumping by pumping said material into said packer.

A method for drilling a second wellbore that branches laterally from a first wellbore, the method comprising the steps of:

• filling a section of said first wellbore with a fluid material which hardens to form a solid material;
• drilling an arcuate passageway through said solid material for reestablishing said first wellbore;
• forming said second wellbore by drilling out a lateral path through said hardened material;
• and
• installing an arcuate drillable guide within said section.

A method for drilling a second wellbore that branches laterally from a first wellbore, the method comprising the steps of:

• filling a section of said first wellbore with a fluid material which hardens to form a solid material;
• drilling an arcuate passageway through said solid material for reestablishing said first wellbore;
• forming said second wellbore by drilling out a lateral path through said hardened material,
• wherein said step of filling further comprises plugging said first wellbore with an inflatable packer by pumping said fluid material into said packer.

A method for drilling a second wellbore that branches laterally from a first wellbore, the method comprising the steps of:

• filling a section of said first wellbore with a fluid material which hardens to form a solid material;
• drilling an arcuate passageway through said solid material for reestablishing said first wellbore;
• forming said second wellbore by drilling out a lateral path through said hardened material;
• under-reaming said section prior to said step of filling.

A method for drilling a second wellbore that branches laterally from a first wellbore, the method comprising the steps of:

• pumping a fluid material into a section of said first wellbore whereupon said fluid material hardens to form a solid material;
• drilling an arcuate passageway within said solid material which connects to said first wellbore;
• mounting a deflection assembly within said arcuate passageway;
• and
• drilling said second wellbore through said solid material to thereby form a junction of said first wellbore and said second wellbore within said solid material.