The invention provides drill bits and methods of drilling curved boreholes.

Another aspect of the invention provides a method for drilling a curved borehole.

Drilling pipe for making a drill string, in particular adapted for deviation drilling.

The casing being disposed in a below ground deviated wellbore.

A system and method for facilitating the drilling of a deviated borehole.

A submersible pumping assembly for a deviated wellbore is disclosed.

Sidetrack drilling: allows drilling of several targets from the same drilling site.

An apparatus and method for removing cuttings in a deviated borehole using drilling fluids.

An impactor (11) for use with a directional boring machine (12) for replacement of underground pipes (16) includes a bursting head (23) having a rearwardly opening recess (27) and a front end opening that communicates with the recess.

Intervals are selected along a deviated wellbore, and a well test and treatment string is deployed in the wellbore.

Designing a drillstring in for use in a wellbore, such as a deviated or horizontal wellbore, particularly with application to extended reach wellbores.

Pressure is dissipated and fluid velocity is reduced as the diverted drilling fluid flows between a high fluid pressure within the drilling assembly to a lower pressure in the wellbore annulus.

The flow rate of the diverted drilling fluid is controlled to establish a fixed flow rate, or alternatively, a variable flow rate.

A method of increasing the penetration rate of a drill string (2) within a deviated well bore is disclosed.

The method includes providing a drill string with a drilling bottom hole assembly (7), and rotating the bit (6) in order to create the deviated well bore as well as a filter cake on the walls of the well bore.