Method and apparatus for wellbore fluid treatment
A tubing string assembly for fluid treatment of a wellbore includes substantially pressure holding closures spaced along the tubing string, which each close at least one port through the tubing string wall. The closures are openable by a sleeve drivable through the tubing string inner bore.
1. An apparatus for fluid treatment of a borehole, the apparatus comprising a tubing string having a long axis and a wall defining an inner bore, a plurality of closures accessible from the inner bore of the tubing string, each closure closing a port extending through the wall of the tubing string and preventing fluid flow through its port, but being openable to permit fluid flow through its port and each closure openable independently from each other closure, a port-opening sleeve positioned in the tubing string and driveable through the tubing string to actuate the plurality of closures to open the ports, the port-opening sleeve being driveable by plugging the sleeve with a sealing device and applying fluid pressure to move the sleeve and a second port-opening sleeve for opening a second plurality of closures.
2. The apparatus of claim 1 wherein at least one of the plurality of closures includes a cap extending into the tubing string inner bore, the cap being openable by movement therepast of the port-opening sleeve.
3. The apparatus of claim 2 wherein the cap is opened by engagement thereagainst by the port-opening sleeve.
4. The apparatus of claim 3 wherein cap is shearable by the port-opening sleeve.
5. The apparatus of claim 1 wherein at least one of the plurality of closures includes a port-closure sleeve covering its port, the port-closure sleeve being moveable to expose its port by engagement of the port-opening sleeve to move the port-closure sleeve along the tubing string.
6. The apparatus of claim 5 wherein the port-closure sleeve includes a profile and the port-opening sleeve includes a locking dog biased outwardly therefrom and selected to lock into the profile on the port-closure sleeve.
7. The apparatus of claim 1 wherein the sealing device can seal against fluid passage past the port-opening sleeve.
8. The apparatus of claim 1 wherein the port-opening sleeve has formed thereon a seat and the sealing device is a plug.
9. The apparatus of claim 1 wherein the port-opening sleeve has formed thereon a seat and the sealing device is a ball selected to seal against the seat.
10. The apparatus of claim 1 further comprising a packer disposed about the tubing string.
11. The apparatus of claim 10 wherein the packer is a solid body packer including multiple packing elements.
12. The apparatus of claim 11 wherein the multiple packing elements are spaced apart.