Well logging tool for making multiple pressure tests and for bottom hole sampling

Claim 2

In a tOol for lowering into a well bore to collect samples of fluids in formations traversed by said well bore, said tool having annular sealing means and positioning means mounted thereon and means exerting pressure on an operating fluid for setting said positioning means to force said annular sealing means against the wall of said well bore, thereby sealing off an area of the wall of said well bore from fluid in said well bore, the improvement comprising port means connecting said well bore and the interior of said annular sealing means, an equalizing valve including a cylinder and a piston slidable therein, said cylinder communicating at one end with operating fluid for operating said positioning means and at the other end with said port means and fluid in said well bore, said piston, in response to a pressure of said operating fluid sufficient to set said positioning means, sliding to close off said port means and seal off the interior of said annular sealing means from said well bore fluid, and, in response to reduction in the pressure of said operating fluid sufficient to permit retraction of said positioning means, sliding to open said port means and establish communication between the interior of said annular sealing means and said well bore fluid, whereby the pressure on opposite sides of said annular sealing means is selectively made unequal to facilitate collection of said samples and then equalized to facilitate withdrawal of said annular sealing means from said well bore wall.

Claim 3

A valve according to claim 3 further comprising explosive means mounted on said tool operatively connected to said annular sealing means for perforating a low-permeability area sealed off by said annular sealing means and contact means operatively connected to said piston and mounted to cause detonation of said explosive means upon said sealing off by said piston of the interior of said annular sealing means from said well bore fluid.

Claim 4

In the combination of a fluid-sample-collecting tool, suspension means operatively connected thereto for lowering said tool into a well bore to collect samples of fluids in formations traversed by said well bore, said tool having annular sealing means and positioning means mounted thereon and means employing an operating fluid to set said positioning means to force said annular sealing means against the wall of said well bore, thereby sealing off an area of the wall of said well bore from fluid in said well bore, the improvement comprising dump chamber means in said tool operatively connected to said positioning means and valve means operatively connected to said coupling means and responsive to uncoupling thereof for dumping said operating fluid into said dump chamber means to facilitate retraction of said positioning means.

Claim 5

In a tool for lowering into a well bore traversing earth formations and having sample chamber means for collecting formation fluid samples therein, annular sealing means thereon communicating with said sample chamber means and mounted for sealing off an area of the wall of said well bore from fluid within said well bore, positioning means thereon for forcing said annular sealing means against the wall of said well bore, a source of an operating fluid under pressure, and dump chamber means therein for said operating fluid, the combination of a first valve for admitting said operating fluid under pressure to set said positioning means, thereby forcing said annular sealing means against the wall of said well bore, a second valve for connecting said sample chamber means to said dump chamber means to facilitate reduction of pressure in said sample chamber means and collection of a formation fluid sample therein, and a third valve for dumping said operating fluid into said dump chamber means, thereby facilitating retraction of said positioning means, and valve-operating means for first opening said first valve, then opening said second valve, then closing said second valve, and finally closing said first valve and opening saId third valve.

Claim 6

The combination according to claim 6 in which said valve-operating means comprises cam means mounted on a single camshaft.

Claim 7

Formation-testing apparatus adapted for obtaining a plurality of successive samples of connate fluids in earth formations traversed by a well bore and comprising: a housing adapted for suspension in a well bore; sample-receiving chamber means on said housing adapted for receiving a plurality of successive samples of connate fluids; sample-admitting means on said housing including annular sealing means adapted for sealing engagement with a well bore wall for obtaining samples of connate fluids from earth formations adjacent thereto; pressure-responsive positioning means on said housing including a wall-engaging member adapted for movement into and out of engagement with a well bore wall for selectively moving said annular sealing means into and out of sealing engagement with a well bore wall; pressure-multiplier means on said housing including piston means responsive to the hydrostatic pressure of well bore fluids operatively arranged in piston chamber means and adapted for movement therein from a first position toward a plurality of spaced positions for successively displacing a hydraulic fluid from said piston chamber means at a higher pressure than the hydrostatic pressure of well bore fluids acting on said piston means each time said piston means moves to one of said spaced positions; first means adapted for selectively extending said wall-engaging member against a well bore wall and including an inlet conduit coupling said piston chamber means and said pressure-responsive positioning means, and first valve means in said inlet conduit adapted for movement between open and closed positions for selectively admitting a hydraulic fluid from said piston chamber means to said positioning means; second means adapted for selectively discharging samples of connate fluids entering said sample-admitting means into said sample-receiving chamber means and including a sample conduit coupling said sample-admitting means and said sample-receiving chamber means, and second valve means in said sample conduit and adapted for movement between open and closed positions for selectively controlling admission of connate fluids into said sample-receiving chamber means; third means adapted for selectively retracting said wall-engaging member from a well bore wall and including an outlet conduit coupled to said pressure-responsive positioning means, and third valve means in said outlet conduit and adapted for movement between open and closed positions for selectively discharging hydraulic fluids from said positioning means; and valve-actuating means on said housing operatively engaged with said first, second and third valve means and adapted for repetitively opening and closing said valve means in a selected sequence in response to selected commands from the surface.

Claim 8

The formation-testing apparatus of claim 8 further including: pressure-measuring means on said housing in pressure communication with said sample-receiving chamber means and adapted for providing measurements representative of the fluid pressure of connate fluids admitted to said sample-receiving chamber means.

Claim 9

The formation-testing apparatus of claim 9 further including recording means operatively coupled to said pressure-measuring means and adapted for recording measurements produced by said pressure-measuring means.

Claim 10

The formation-testing apparatus of claim 10 wherein said recording means is on said housing.

Claim 11

The formation-testing apparatus of claim 8 wherein said valve-actuating means includes: motor means on said housing and adapted for movement between successive positions in response to said commands; cam means operatively engaged with said first, second and third valve means and adapted for respectively opening and closing said valve means upon movement of said cam means between first, second and third operating positions; and means operatively conNecting said motor means and said cam means and adapted for repetitively moving said cam means to each of said operating positions in sequence upon each movement of said motor means.

Claim 12

The formation-testing apparatus of claim 12 wherein said cam means includes means operatively arranged for opening only said first valve means in said first operating position of said cam means for opening said second valve means and retaining said first valve means open in said second operating position of said cam means, and for closing said first and second valve means and opening said third valve means in said third operating position of said cam means.