Claims
- 1. A method of cementing the annular cavity between a well casing and a well borehole, from a floating vessel, wherein the casing contains a casing valve, the method comprising the steps of:
- running a drill string into the casing, said drill string including an opening positioner for opening said casing valves, an anchor means, and an isolation packer located below said opening positioner;
- engaging said opening positioner with said casing valve;
- lifting said drill string to open said casing valve;
- positioning said drill string to align said isolation packer with said casing valve, so that an upper packer assembly of said isolation packer sealingly engages the casing above said casing valve and a lower packer assembly of said isolation packer sealingly engages the casing below said casing valve;
- setting said anchor means against said casing to provide sufficient resistance between said drill string and casing to operate a motion compensator on the floating vessel; and
- pumping a cement slurry into said drill string, out a port of said isolation packer between said upper and lower packer assemblies, through the opened casing valve into the annular cavity between the casing and the well borehole.
- 2. Method of claim 1, wherein:
- said isolation packer is an extended length isolation packer having a distance between said upper and lower packer assemblies of at least fifteen feet, and said isolation packer includes a fluid bypass communicating a portion of said annular cavity between the drill string and the casing above said upper packer assembly with a portion of said annular cavity below said lower packer assembly.
- 3. The method of claim 2, further comprising the step of:
- reversing out the excess cement slurry remaining between said upper and lower packer assemblies and in the drill string, said reversing out including pumping a working fluid into the annular cavity between the drill string and the casing, through the fluid bypass into the annular area below the lower packer assembly, and up past the lower packer assembly thereby forcing the excess cement through the port in said isolation packer and up the inner bore of the drill string ahead of the working fluid.
- 4. The method of claim 3, further comprising the step of:
- releasing said anchor means, so that said drill string may be moved within said casing.
- 5. The method of claim 4, further comprising the steps of:
- engaging a closing positioner, attached to said isolation packer between said upper and lower packer assemblies, with said casing valve; and
- lowering said drill string to close said casing valve.
- 6. A method of isolation and treatment of a selected zone of an annular cavity between a well casing and a well borehole from a floating vessel, wherein the casing contains an upper and a lower borehole packer means adjacent an upper and a lower boundary of said zone, an upper casing port located below said upper borehole packer means, and a lower casing port located above said lower borehole packer means, the method comprising the steps of:
- running a drill string into the casing, said drill string including an opening positioner for opening said casing ports, an anchor means, and an isolation packer located below said opening positioner, said isolation packer including an upper packer assembly, an isolation packer port below said upper packer assembly, a closing positioner and a lower packer assembly;
- inflating said lower borehole packer means; opening said lower casing port;
- inflating said upper borehole packer means; opening said upper casing port;
- positioning said drill string to align said isolation packer with said lower casing port, so that said lower casing port is located between said upper and lower packer assemblies;
- setting said anchor means against said casing to provide sufficient resistance between said drill string and casing to operate a motion compensator on the floating vessel; and
- pumping a treatment fluid into said drill string, out said isolation packer port, through said lower casing port, and up the annular cavity between the casing and the borehole.
- 7. The method of claim 6, wherein said upper and lower borehole packer means include full opening inflatable packers with casing ports above the packers which are automatically opened upon inflation of the packers, wherein a full opening casing valve is located directly beneath said upper inflatable packer and wherein said opening positioner is a selective release opening positioner, wherein:
- said steps of inflating said lower borehole packer means and opening said lower casing port include the steps of:
- positioning the selective release opening positioner immediately below the lower full opening inflatable packer;
- activating said opening positioner;
- engaging said opening positioner with said lower full opening packer; and
- lifting said drill string to raise a sleeve in said lower packer, then inflating the packer to seal the annulus between borehole and casing and to open the casing port of said lower packer;
- said method further includes the steps of deactivating said selective release opening positioner, and lifting the drill string to position the opening positioner above the upper casing valve;
- said step of inflating said upper borehole packer means includes the steps of:
- activating said opening positioner;
- engaging said opening positioner with said upper full opening packer;
- lifting said drill string to raise a sleeve in said upper packer, then inflating the packer collar to seal the annulus between the borehole and casing and to open the casing port of said upper packer collar;
- deactivating said opening positioner;
- engaging said closing positioner with said upper full opening packer collar; and
- lowering said drill string to close said casing port of said upper packer collar; and
- said step of opening said upper casing port includes the steps of:
- activating said opening positioner;
- engaging said opening positioner with the upper full opening casing valve; and
- lifting said drill string to open said upper casing valve.
- 8. Method of claim 7, wherein:
- said isolation packer is an extended length isolation packer having a fluid bypass around the upper and lower packer assemblies.
Parent Case Info
This is a division of our co-pending application Ser. No. 958,706 filed Nov. 8, 1978.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4042014 |
Scott |
Aug 1977 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
958706 |
Nov 1978 |
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