MULTI-STAGE WELL ISOLATION AND FRACTURING
In a first aspect, a frac valve tool is taught, said tool comprising one or more ports a sleeve movable between a closed position in which the sleeve prevents fluid flow through said one or more ports and an open position in which the sleeve allows fluid flow through said one or more ports and a ball receiving seat removably connected to the sleeve wherein receipt of a ball on the ball receiving seat moves said seat and said sleeve from closed to open positions. In a second aspect, a frac valve tool is taught, said tool comprising a ball receiving seat removably received within said tool, said seat comprising a seating profile for receiving a ball; wherein said seating profile matches a radius of said ball to nondeformably grip said ball.
1 . A frac valve tool, said tool comprising:
a. one or more ports;
b. a sleeve movable between a closed position in which the sleeve prevents fluid flow through said one or more ports and an open position in which the sleeve allows fluid flow through said one or more ports; and
c. a ball receiving seat removably connected to the sleeve;
wherein receipt of a ball on the ball receiving seat moves said seat and said sleeve from closed to open positions.
2 . A frac valve tool, said tool comprising a ball receiving seat removably received within said tool, said seat comprising a seating profile for receiving a ball; wherein said seating profile matches a radius of said ball to nondeformably grip said ball.
3 . The frac valve tool of claim 1 , wherein the seat further comprises a seating profile to receive and grip the ball.
4 . The frac valve tool of claim 3 , wherein the seating profile has a geometry that non-deformably grips the ball.
5 . The frac valve tool of claim 4 ; wherein the removable seat is changeable to accommodate more than one size of seat and more than one size of ball in the tool.
6 . The frac valve of claim 1 , further comprising one or more shear screws affixing the sleeve to the tool, said shear screws being shearable at a predetermined liner pressure accumulated in the tool when the ball lands on the seat, wherein shearing of said one or more shear screws allows the seat and sleeve to shift to the open position.
7 . The frac valve tool of claim 6 , further comprising a mandrel within which the sleeve is movably affixed via the shear screws and through the circumference of which the one or more ports are formed.
8 . The frac valve tool of claim 1 , wherein the total flow area through all of the one or more ports is greater than the flow area through the liner.
9 . The frac valve tool of claim 1 , wherein the seat is a drillable seat.
10 . The frac valve tool of claim 9 , wherein the drillable seat is made of a friable material that crumbles upon drilling.
11 . The frac valve tool of claim 10 , wherein then seat is composed of a cast iron.
12 . The frac valve tool of claim 11 , the seat is surface hardened
13 . The frac valve tool of claim 12 , wherein the seat has a Rockwell hardness rating of HRC 50 to HRC 55.
14 . The frac valve tool of claim 1 , further comprising a closable feature.
15 . The frac valve tool of claim 14 , wherein the frac valve tool is closable before the seat is drilled out.
16 . The frac valve tool of claim 14 , wherein the frac valve tool is closable after the seat is drilled out.
17 . The frac valve tool of claim 1 , further comprising one or more anti-rotation tabs inside the frac valve tool to stabilize the seat against rotation during drill out.
18 . The frac valve tool of claim 17 , wherein the seat is threadably affixed into the sleeve in a direction that serves to tighten against rotation during drill out.
19 . The frac valve tool of claim 18 , wherein the seat is left hand threaded into the sleeve and tend towards tightening when the seat is drilled.
20 . The frac valve tool of claim 1 , further comprising a quality control inspection fixture to inspect dimensional one or more characteristics of the frac valve tool.
21 . The frac valve tool of claim 20 , wherein the quality control inspection fixture inspects bore hole size through the seat, the bore hole of seating profile, concentricity of both bore hole through seat with bore hole through seating profile, geometry of the seat profile and distance from the seat to a top surface of the frac valve tool.
22 . The frac valve tool of claim 21 , wherein the quality control inspection fixture is attached to a seat installation tool to install a predetermined seat into the frac valve tool.