Reverse circulating tool

In a combination for the drilling of a gas, oil, water and/or steam well comprised of a well hole, which is being drilled, well casing, which extends at least part of the way down the well hole, rotatable drill pipe, which extends down the well hole to the bottom thereof and which contains a passageway through the center thereof, a drill bit attached to the bottom of the drill pipe, means for rotating the drill pipe and the drill bit, and means for forcing a fluid down the passageway of the drill pipe to and through the drill bit, an annulus being formed by the region between the well casing and side of the well and the drill pipe, the fluid exiting out the annulus, the improvement which comprises a device located in the casing, the device comprising (i) a cylindrical body, (ii) four passageways lengthwise through the cylindrical body, (iii) a bottom member which is generally Y-shaped, which contains a Y-shaped passageway therethrough, which is affixed on the ends of its two upper arm members to the bottom surface of the cylindrical body so as to have each ot its upper arms communicate with one of two generally oppositely located passageways in the cylindrical body, the central axis of the bottom Y-shaped member generally lying on the central axis of the cylindrical body, the bottom member being attached to the bottom portion of the drill pipe, the Y-shaped passageway communicating with the bottom portion of the drill pipe, (iv) a top stem which has a passageway extending longitudinally through a portion thereof, and which has four side ports located in the side thereof that communicate with the passageway therein, the central axis of the top stem generally lying on the central axis of the cylindrical body, the passageway in the top stem communicating with the top portion of the drill pipe, (v) a collar which is rotatably positioned around the region of the top stem where the four ports therein are located, which is slidably removable from the top stem, which contains two side L-shaped arms, each having an L-shaped passageway therethrough which communicates with one of the ports in the top stem and with the top end of one of the passageways in the cylindrical body, and (vi) retainer means which is detachably positioned around the top region of the top stem and which retains the collar in position around the four ports in the top stem and the two side L-shaped arms of the collar in communication with the appropriate two passageways of the cylindrical body, the retainer means being attached to the top portion of the drill pipe, the cylindrical body tightly and rotatably fitting within the well casing.