Methods and systems for subterranean multilateral well drilling and completion

A system for creating a multilateral well, comprising:

• a diverter set at a prescribed position and a prescribed orientation in a main well flow conductor located within a main wellbore;
• a tool for creating a window having a particular shape into a sidewall of the main well flow conductor and boring into a material surrounding the main well flow conductor, the orientation of the diverter determining a lateral position of the window in the main well flow conductor, a lateral wellbore thereby being formed in the material and extending from the main wellbore;
• a liner, cooperable with the diverter, for lining the lateral wellbore, the liner having a portion extending into the main well flow conductor;
• and
• a pressure-bearing seal between the periphery of the window and the liner, the liner cemented in place within the lateral wellbore.

A subterranean multilateral well structure, comprising:

• a main well flow conductor located within a main wellbore, a sidewall of the main well flow conductor including a plurality of windows having a particular shape distributed along a length of the main well flow conductor, the windows having lateral orientations;
• a plurality of lateral wellbores formed in material surrounding the main wellbore, the lateral wellbores extending from respective ones of the plurality of windows;
• liners cemented within each of the lateral wellbores, a portion of each liner extending into the main well flow conductor;
• and,
• pressure-bearing seals between the peripheries of the windows and the liners to thereby provide for (a) connectivity among the main wellbore and the lateral wellbores, (b) pressure-bearing sealing of joints to allow selective isolation of a portion of the lateral wellbores and (c) subsequent selective access to the lateral wellbores.