High-pressure multilateral junction with mainbore and lateral access and control

A multilateral junction, comprising:

• a y-block, the y-block including;
• a housing comprising a monolithic block of material, the housing having a first end and a second opposing end defining a length (L);
• a single first bore extending into the monolithic block of material from the first end, the single first bore defining a first centerline;
• and
• second and third separate bores extending into the monolithic block of material and branching off from the single first bore, the second bore defining a second centerline and the third bore defining a third centerline, wherein the second and third centerlines are angled relative to one another, wherein the second and third bores include a shared interior wall along at least a portion of the length (L), the shared interior wall extending to a downhole end of at least one of the second or third separate bores, wherein the second bore includes a pin joint at the second opposing end and the third bore includes a box joint at the second opposing end;
• a mainbore leg coupled to one of the second bore or the third bore for extending into a main wellbore;
• and
• a lateral bore leg coupled to an other of the third bore or the second bore for extending into a lateral wellbore.

A well system, comprising:

• a main wellbore;
• a tubing string located in the main wellbore
• a lateral wellbore extending from the main wellbore;
• and
• a multilateral junction positioned at an intersection of the main wellbore and the lateral wellbore, the multilateral junction including;
• a y-block located in the tubing string, the y-block including;
• a housing comprising a monolithic block of material, the housing having a first end and a second opposing end defining a length (L);
• a single first bore extending into the monolithic block of material from the first end, the single first bore defining a first centerline;
• and
• second and third separate bores extending into the monolithic block of material and branching off from the single first bore, the second bore defining a second centerline and the third bore defining a third centerline, wherein the second and third centerlines are angled relative to one another, wherein the second and third bores include a shared interior wall along at least a portion of the length (L), the shared interior wall extending to a downhole end of at least one of the second or third separate bores, wherein the second bore includes a pin joint at the second opposing end and the third bore includes a box joint at the second opposing end;
• a mainbore leg coupled to one of the second bore or the third bore and extending into the main wellbore;
• and
• a lateral bore leg coupled to an other of the third bore or the second bore and
• extending into the lateral wellbore.