Patent ID: 9371694
Filing Date: 2016-06-21
CPC Classification: E21B

Claim Text:
1. A process for drilling a sidetrack wellbore from a tailpipe through a liner pipe and into a desired formation, wherein the process comprises: a. incorporating a permanent bypass whipstock assembly into a section of a length of a tailpipe, wherein said permanent bypass whipstock assembly has an elongated generally cylindrical body, and within a middle section of said permanent bypass whipstock assembly, a primary path and a deviating sidetrack path, wherein said primary path extends from a first end and a second end and allowing complete access to production below the permanent bypass whipstock assembly; wherein said deviating sidetrack path has a downhole end along a peripheral side of said permanent bypass whipstock assembly and a uphole end closer to the first end of and open to said primary path of said permanent bypass whipstock assembly, wherein said tailpipe is releasably connected to the first and second ends of the primary path; wherein said permanent bypass whipstock assembly has a larger diameter than said tailpipe; b. installing said permanent bypass whipstock and tailpipe into a production assembly; c. introducing said production assembly inside a liner in a wellbore wherein said permanent bypass whipstock assembly is in proximity to said liner eliminating the need for cement, wherein said primary path of said permanent bypass whipstock assembly is slightly offset from an axis of said liner to create the larger diameter of the permanent bypass whipstock assembly as compared to the tailpipe, wherein said deviating sidetrack path diverges from said primary path at an incline to ultimately form the sidetrack wellbore, wherein the permanent bypass whipstock assembly reduces the clearance to no more than is necessary to run an additional permanent bypass whipstock assembly, a packer assembly or combinations thereof into the liner; d. positioning said production assembly into a wellbore with the deviating sidetrack path of the permanent bypass whipstock assembly aligned in a predetermined direction for forming the sidetrack well which may later be drilled; e. sealing said wellbore with said production assembly; f. installing a diverter, wherein the diverter closes said primary path below the desired location of said sidetrack well, wherein the diverter is installed independent of the permanent bypass whipstock assembly, wherein said diverter directs tools from the primary path to said deviating sidetrack path, wherein the diverter is retrievable; g. installing a milling system, wherein the milling system includes a milling bit at the downhole end of a drill string whereby when the milling system reaches the diverter the milling system is deflected onto said deviating sidetrack path and continues along the deviating sidetrack path whereby the milling system forms a window in the liner; h. removing the milling system; i. installing a drill system, wherein the drill system includes a drillbit located at the downhole end of a drill string, wherein the drill system runs through the primary path and through the permanent bypass whipstock assembly whereby the drill system is diverted onto the deviating sidetrack path by the diverter whereby the drill system reaches the window formed in the liner by the milling system; j. drilling a sidetrack wellbore with the drill system; k. removing the drill system; and l. installing a liner pipe casing into the sidetrack wellbore, wherein the liner pipe is run down said primary path and through said permanent bypass whipstock assembly whereby said liner pipe is diverted onto the deviating sidetrack path by the diverter, wherein the liner pipe casing substantially supports the formation exposed by the window, wherein said permanent bypass whipstock assembly is permanently installed in said wellbore.