DRAIN HOLE CONNECTION WITH BENT BRANCHES OF THE MAIN DRAIN AND SIDE DRAIN, WELL SYSTEM WITH DRAIN HOLE CONNECTION AND METHOD FOR ITS FORMATION Russian patent published in 2023 - IPC E21B7/06 E21B17/18 E21B19/16 

FIELD: oil production.

SUBSTANCE: selective operations in a wellbore under pressure, namely to drain hole connections with bent branches of the main shaft and side drain. The drain hole connection consists of a y-shaped unit, a branch of the main wellbore and a branch of the side drain. The Y-shaped unit consists of a housing, a single first drain, second and third separate drains. The housing has a first end and a second opposite end. The single first drain extends into the housing from the first end. The single first drain defines the first centerline. The second and third separate drains extend into the housing and branch off from the single first drain. The second drain defines the second centerline, and the third drain defines the third centerline. The branch of the main wellbore has the first end of the branch of the main drain connected to the second drain, and the second opposite end of the branch of the main drain. The lateral drain branch has a first end of the lateral drain branch connected to the third drain and a second opposite end of the lateral drain branch in the lateral wellbore. The main drain branch and the side drain branch are curved relative to the second drain and the third drain in such a way that the first plane passing through the axial lines of the second opposite end of the main drain branch and the second opposite end of the side drain branch are located at an angle of at least 15° relative to the second plane passing through the second centerline and the third centerline. The downhole system comprises a main wellbore, a lateral wellbore extending from the main wellbore, and a drain hole connection. The drain hole connection is located in close proximity to the intersection of the main wellbore and the lateral wellbore. The method for forming a well system includes placing a drain hole connection in close proximity to the intersection of the main wellbore and the lateral wellbore.

EFFECT: creation of a tight drain hole connection for access to all side well bores is provided.

15 cl, 24 dwg