DOWNHOLE HYDRAULIC JETTING ASSEMBLY, AND METHOD FOR STIMULATING A PRODUCTION WELLBORE

摘要

A method for forming multiple lateral boreholes from an existing wellbore is provided. The wellbore has been completed with a string of production casing. The wellbore may have a slimhole region having an inner diameter that is less than the inner diameter of the production casing. The method generally comprises providing a downhole apparatus having a whipstock. The whipstock may be a single piece tool that rotates into position below the slimhole region, or it may be a two piece tool comprising a top whipstock member and a separate bottom whipstock member. The whipstock has a curved face. The method also includes running the apparatus down into the parent wellbore. A force is applied to the apparatus to cause the whipstock to rotate within the wellbore into an operating position. In this position, the curved face of the whipstock forms a bend-radius that allows the jetting hose to bend across the entire inner diameter of the production casing. A jetting hose is run into the wellbore. Upon contact with the curved face of the whipstock, the jetting hose is re-directed through a window in the production casing. Hydraulic fluid is injected under pressure through the hose to provide hydraulic jetting. The hose is directed through the window and into the formation to create a lateral borehole extending many feet outwardly into a subsurface formation. A downhole jetting assembly for forming multiple lateral boreholes from a parent wellbore is also provided herein. The assembly utilizes substantially the entire inner diameter of the casing as the bend radius for a hydraulic jetting hose, thus providing for the maximum hydraulic horsepower at the jetting nozzle.