US 4,113,012 AGranted

Reclosable circulation valve for use in oil well testing

AssigneeHalliburton Company

InventorsRobert T. Evans, David L. Farley

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Abstract

Disclosed is a circulation valve for use in the testing of an oil well wherein the circulation valve may be reclosed by application of well annulus pressure to allow a subsequent treating or testing program. A spring means is subjected to well annulus pressure on two ends of a volume of fluid. The volume of fluid is divided by a dividing means which includes pressure relief means such that fluid on one side of the dividing means is either higher or lower than the well annulus pressure. This different pressure is applied to one set of a piston means, and the other side of the piston means is subject to well annulus pressure such that movement of the piston means may be controlled by changing the well annulus pressure. An indexing means is additionally disclosed which controls opening of the circulation valve after a selected number of piston means movements, and which closes the circulation valve upon a selected movement of said piston means when the circulation valve is in the open condition.

Claims7

Dependent claims

A circulation valve apparatus for use in a test string having a flow channel therethrough and extending within a well bore from the surface to a formation to be tested comprising:

a tubular housing having an axial bore therethrough and arranged for incorporation into said test string with said axial bore communicating with said test string flow channel, said tubular housing having a circulation port providing fluid communication between the well bore exterior of said housing and said axial bore;
circulation valve means slidably located in said axial bore and movable between a first position preventing fluid communication through said circulation port into said axial bore, and a second position opening said circulation port and allowing fluid communication through said circulation port into said axial bore;
power mandrel means slidably located in said axial bore;
piston means on said power mandrel means responsive to pressure changes in said well bore for moving said power mandrel means;
operating means between said power mandrel means and said tubular housing for imparting a bias to said piston means for holding said power mandrel means in the last position to which said power mandrel means moved responsive to said well bore pressure changes;
and
indexing means operatively connecting said power mandrel means to said circulation valve means for moving said circulation valve means from its first position to its second position responsive to a predetermined movement of a plurality of movements by said power mandrel means, and for subsequently moving said circulation valve means from its second position to its first position responsive to a later predetermined movement of said power mandrel means.

4 more elements

A method of testing a formation using a testing string within an oil well bore extending from the surface to the formation to be tested, said testing string including a tester valve for opening and closing a flow channel through said testing string responsive to pressure changes in the well bore exterior of the testing string, said method comprising:

lowering said testing string into said well bore;
setting a packer mechanism at the end of said testing string for isolating said formation from the annulus of the oil well between the walls of the well bore and the testing string;
increasing the pressure in the well annulus;
responsive to said pressure increase, opening the tester valve in the testing string flow channel allowing fluid communication from the formation, through the testing string flow channel to the surface;
releasing the pressure increase in the well annulus;
responsive to said pressure release, closing said tester valve for closing-in said formation;
stepping an indexing means in a circulation valve in said testing string above said tester valve, which indexing means maintains said circulation valve in the closed condition until after a predetermined number of steps;
repeating the increasing and releasing pressure steps a predetermined number of times to conduct a formation testing program;
responsive to a predetermined pressure release, opening said circulation valve;
circulating fluid through the well annulus, the open circulation valve and the flow passage in the testing string for displacing fluid in the testing string flow channel to the surface;
increasing the pressure in the testing string flow channel and the well annulus;
responsive to said pressure increase, closing said circulation valve;
and
repeating the increasing and releasing pressure steps a predetermined number of times to conduct a subsequent formation testing program.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/846,232Filed 27 Oct 1977
Granted: 12 Sep 1978
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

E21B 49/0813
With down-hole means for trapping a fluid sample: sampling valve actuated by annulus pressure changes
E21B 23/006
Indexing systems for guiding relative movement between telescoping parts of downhole tools: "J-slot" systems, i.e. lug and slot indexing mechanisms
E21B 34/108
Operated by control fluid supplied from outside the borehole: with time delay systems, e.g. hydraulic impedance mechanisms
E21B 49/001
Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to…:…