Abstract: A drilling assembly (2) comprises upper (4) and lower (6) drill strings with a fluid passage (80) therethrough for distributing fluid to a bottom hole assembly (10). The upper drill string (4) has an upper end (11) connectable to a drilling apparatus (13) and fluid source (16) and a lower end (18) with an attached casing expander unit (20) that communicates the fluid passage (80) of the upper (4) and lower (6) drill strings. An upper end (22) of the lower drill string (6) is formed from a casing string (24) telescoped over the casing expander unit. A constriction (31) connects the casing string (24) with the rest of the lower drill string (6). A flow restriction device (35) in the lower drill string acts to control fluid flow through the fluid passage.

Abstract: An apparatus for providing heat energy to a fluid, including a housing adapted for connection into a working string and for inserting into a borehole, a flow path for the fluid extending within the housing, a pressure drop device positioned within the flow path, and an actuator for actuating the apparatus between a minimum pressure drop position and a maximum pressure drop position. A method for providing heat energy to a fluid, including the steps of providing an apparatus in a borehole, actuating the apparatus to a maximum pressure drop position, and circulating the fluid through a pressure drop device which is positioned within a flow path in the apparatus.

Abstract: A multi-layered wellbore junction. In a described embodiment, a method of forming an expanded chamber in a subterranean well includes the steps of: positioning multiple chamber sidewall layers in the well; and expanding the layers in the well to form the expanded chamber.