| 主权项 |
1. A downhole comprising:
a tubular body having an axial bore, wherein the axial bore of the tubular body houses first and second inner sleeves, and the axial bore of the tubular body is configured to accommodate independent axial movement of the first and second sleeves within the axial bore to provide multiple fluid flowpath configurations through the tool; said fluid flowpath configurations being selectively established by use of circulation fluid pressure and a first circulation valve in the first inner sleeve and a second circulation valve in the second inner sleeve, each valve comprising a valve seat and an obturator to be introduced in the circulation fluid when a fluid flowpath configuration change is required, wherein the tubular body has deployable anchor means recessed within a surface of the tubular body, said anchor members being deployable by effecting a fluid flowpath configuration change and thereby effecting a circulation fluid pressure change within the tool to cause the anchor means to deploy, wherein the first inner sleeve comprises a valve seat at a leading end of the sleeve, which seat is formed by a tapered reduction in diameter of the sleeve bore, and fluid by-pass channels are provided in the inner sleeve upstream and downstream of the valve seat. |
