Claims
- 1. In a well testing apparatus to be used in conjunction with a testing tool string having open interior means including flow passage means operable to communicate will well formation fluid under the control of valve means for opening and closing said flow passage means in response to changes in pressure of fluid in a well annulus surrounding said apparatus, the improvement comprising:
- normally closed, well annulus pressure change responsive, circulating valve means adapted to communicate a portion of said open interior means of said string with said well annulus; and
- opening means responsive to at least a predetermined minimum number of said pressure changes for opening said circulating valve means to enable fluid to be removed from said open interior means of said testing tool string by circulation of fluid between said well annulus and said open interior;
- said opening means being operable to prevent said opening of said circulating valve means until after said predetermined minimum number of said pressure changes has occurred; and
- said circulating valve means, prior to said opening thereof, being operable to prevent fluid communication between fluid in said well annulus and fluid in said open interior means of said tool string, through said opening means.
- 2. The improvement in the well testing apparatus of claim 1 wherein
- said open interior means has a normally closed port in communication therewith, and
- said circulating valve means includes a slidable sleeve arranged to span said port in one position and is movable to another position to open said port.
- 3. The improvement in the well testing apparatus of claim 2 wherein said opening means includes piston means within said apparatus having
- a transverse surface area subject to the pressure of fluid in the well annulus surrounding said apparatus so that fluid pressure can act to shift said piston means in one longitudinal direction, and
- means for urging said piston means in the other longitudinal direction.
- 4. In a method of well testing to be used in conjunction with a testing tool string having open interior means including flow passage means operable to communicate with well formation fluid under the control of valve means for opening and closing said flow passage means in response to changes in the pressure of fluid in a well annulus surrounding said apparatus, the improvement comprising:
- providing in said testing tool string normally closed, well annulus pressure change responsive circulating valve means adapted to communicate a portion of said open interior means of said tool string with said well annulus;
- responsive to at least a predetermined minimum number of said pressure changes for opening said circulating valve means, opening said circulating valve means to enable fluid to be removed from said open interior means of said testing tool string by circulation of fluid between said well annulus and said open interior;
- preventing said opening of said circulating valve means until after said predetermined minimum number of said pressure changes has occurred; and
- prior to said opening of said circulating valve means, maintaining said circulating valve means closed to prevent fluid communication between fluid in said well annulus and fluid in said open interior means of said tool string, through said opening means.
Parent Case Info
This is a division of application Ser. No. 288,287, filed Sept. 11, 1972, now U.S. Pat. No. 3,850,250, issued Nov. 26, 1974.
US Referenced Citations (13)
Divisions (1)
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Number |
Date |
Country |
Parent |
288187 |
Sep 1972 |
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