Method and Apparatus for Drilling a Multilateral Well

Abstract

The method and device for forming multilateral wells includes drilling a first lateral well bore and a second lateral well bore; sidetracking on the low side of the first. Subsequently a first production casing string along with the device is run in the well so that the device is positioned adjacent to the first lateral well bore. A second production casing string is run into the well and the device directs the second production casing string into the first lateral well bore.

What is claimed is: 
     
         1 . A method of forming multilateral wells comprising:
 a) drilling a first well bore of sufficient diameter to accommodate two or more production casings,   b) drilling a first lateral well bore to a given depth,   c) drilling a second well bore sidetracking on the low side of the first lateral well bore,   d) providing a multilateral device on a producing casing string and positioning the production casing in the well such that the multilateral device is positioned to guide a second production casing string into the first well bore, and   e) running in said second production casing string into the well so that the multilateral device directs the second production casing into the first lateral well.   
     
     
         2 . The method of  claim 1  further including the step of cementing in place the two production strings. 
     
     
         3 . The method of  claims 1  further including the step of placing an intermediate casing in the first well bore. 
     
     
         4 . A multilateral well tool comprising;
 a) a solid body having a first end and a second end,   b) at least one collar having a first bore adapted to accommodate a first production casing string,   c) a groove formed in an exterior surface of the tool for receiving and guiding a second production casing string.   
     
     
         5 . The multilateral well tool as claimed in  claim 4  further including a ramp positioned adjacent to the groove for guiding the second production casing string laterally. 
     
     
         6 . The multilateral tool as claimed in  claim 4  wherein there are two collars, one located at said first end and one positioned at said second end, each collar having a bore. 
     
     
         7 . The method of  claim 1  further including the step of placing a plurality of guides on the first production casing string, the guides having a through bore adapted to receive the second production casing string as it is run into the well. 
     
     
         8 . The method of  claim 7  wherein the guides include rollers to facilitate running in and rotational positioning of the first producing casing string.