In the exploration for oil and gas, a main well bore is drilled and cased. The well bore may be a vertical or horizontal well. It is often necessary to drill one or more lateral wells off of the main well bore. These lateral wells are usually drilled to increase production from the producing zone or enter new zones which may contain a hydrocarbon reservoir. To drill a lateral well, a whip stock is run into the main well bore on a work string and anchored at a location where the lateral well is to be drilled. The upper end of the whip stock has an inclined face. A milling bit on a tubular is diverted by the whip stock's inclined face into the casing wall where a window or opening in the casing is made for a lateral exit from the main well bore. The whip stock may be removed from the well bore after the lateral has been completed.
After removal of the whip stock, the need may arise to reenter a lateral well to clean it out or conduct remedial work. The present invention provides a reliable, cost-effective means to locate and reenter a lateral well bore after the whip stock has been removed from the main well bore.
USPTO Backgrounds
USPTO Backgrounds