US2404825A - Well tester - Google Patents

Description

July 30, 1946.

"A Iii-L?" IIIIII IIIIIIL 9 4a 7' 7 49 7 All. 7 awe/rm r Luff/25 BROWN 3 3 Ozuzv 7V. iVuu/ws July 30, 1946. L. E. BROWN ET AL WELL TESTER Filed Aug. 50, 1941 2 Sheets-Sheet 2 Patented July 30, 1946 WELL rns'rnn Luther E. Brown, Greggton, and Ollin W. Williams, Mount Enterprise, Tex.

Application August 30, 1941, Serial No. 408,916

Claims. (C1. 166-1) This invention relates to a well tester.

An object of the invention is to provide sample taking equipment whereby a sample of liquid or gas may be taken from the side wall of a well bore at any selected elevation and withdrawn to the ground surface for inspection without withdrawing the drill stem.

It is another object of the invention to provide equipment of the character described whereby the sample may be taken while the drill stem is filled with drilling fluid. Therefore, it is ,not necessary to lower an empty drill stem into the well and to subject the same to the risk of collapslng from the external pressure in order to make a test.

It is a further object of the invention to provide well testing equipment of the character described whereby a fluid sample may be entrapped from the side wall of the well bore at any selected elevation and maintained under pressure in the sample chamber and withdrawn to the ground surface for ascertaining the pressure thereof and for inspection.

With the above and other objects in View the invention has particular relalz'on to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein:

Figure 1 shows a fragmentary, vertical, sectional view of the drill stem showing also the packer and valve seats.

Figure 2 shows a similar view thereof showing the lower valve seated.

Figure 3 shows a cross-sectional view taken on the line 3-3 of Figure 2.

Figure 4 shows a fragmentary, vertical, sectional view of the drill stem showing the packer expanded and the upper valve assembly closed.

Figure 5 shows a similar view with the upper valve assembly in open position to admit the sample into the sample chamber.

Figure 6 shows a side view of the assembly with the lower valve closed and the upper valve in position to move downwardly onto its seat to cause expansion of the packer, and

Figure 7 shows a side elevation, partly in section, of the sample receiving chamber and the upper valve carried thereby.

Referring now more particularly to the drawings wherein like numerals of reference designate the same parts in each of the figures the numeral 1 designates a tubular drill stem as a whole. Incorporated into the drill stem there is a special coupling 2 whose lower end is reduced V a 2 in external diameter and attached to the lower end of this coupling is a drill collar 3 to which a drill 4 may be connected. This drill has the reduced channels, as 4a, through which the drill'-' ing fluid forced down through the stem is discharged. These channels 4a being reduced form a choke to reduce the velocity of the drilling fluid, for a purpose to be hereinafter stated.

Instead of the drill 4 any other type of choke may be attached to the lower end of the drill stem, if it should be desired, where drilling is not being carried on and the tool is used solely for testing. Around the'reduced lower end of the coupling there is an expansible sleeve-like packer 5 whose upper end may be secured to the coupling 2 bya surrounding collar as 6 and whose lower end may be secured in place by a surrounding collar as l. The packer when expanded will form a sealed-off area around the walls of the bore so as to seal off the drilling fluid from said area. This is clearly illustrated in Figures 4 and 5.

The lower end of the reduced portion of the coupling 2 is internally enlarged forming a downwardly facing shoulder 8 and within said lower end there is a sleeve valve 9 having the downwardly facing external shoulder In which is seated on a coil spring H which, in turn, rests on the upper end of the drill 4. The upper end coupling 2 and discharges into the packer 5 so ,that liquid forced throughthe port 13, as hereinafter explained, will expand said packer.

The upper end of the coupling 2 is enlarged internally forming an upwardly facing shoulder l5 on which a coil spring [6 is seated. There is an upper sleeve valve 11 whose upper end is enlarged forming a downwardly facing shoulder I! is limited by this stop 22 and the lower end of the valve is provided with the notches 23 for' the circulation of liquid. The upper end of the valve I1 is downwardly tapered internally forming a seat 24. Leading from this seat downwardly through the wall of the coupling 2| and through the packer are the inlet channels 25 whose lower ends are outwardly turned through the packer wall. That portionof the channel 25 leading through the flexible packer 5 is formed by a metal tube 26 which is of suflicient strength so that it will not collapse and close the channel when the packer is expanded but which is of suflicient flexibility to readily flex when the packer is expanded. The upper ends of the channels are normally closed by the seal ring 26 as shown in Figures 1, 2 and 4.

The numeral 21 designates a sample receiving chamber having a barrel 23 therein whose upper end is closed by the tubular head 29 screwed into the upper end thereof and by the cable socket 30 screwed into the upper end of said head, A cable 3| is attached to said cable socket whereby the barrel may be lowered into and removed from the drill stem. The lower end of the passageway through the drill stem is reduced in internal diameter forming a cylinder 32 and the lower end of the barrel 28 has a surrounding seal ring 33 countersunk therein which fits closely within said cylinder 32 when the barrel is lowered. Depending from the lower end of the barrel there is a tubular stem 34 whose lower end is closed and which is provided with a side port 35. Slidably mounted on this stem there is a downwardly tapering valve 36 which is shaped to fit the seat 24 when seated. The valve 36 has the upper and lower external annular seal rings 31 and'38 countersunk therein to form seals with the seat 24 when the valve 36 is seated therein. It also has the annular inside upper and lower seal rings 39 and 46 countersunk therein which form seals with the stem 34. The valve 36 also has a lateral port 4| leading out radially therethrough between said upper and lower seal rings of said valve. There is a nut 43 screwed onto the lower end of the stem which forms a stop to retain the valve Men the stem 34 and there is a strong coil spring 44 surrounding the stem 34 and interposed between the valve 36 and the lower end of the barrel 21. This spring normally holds the valve 36 in its lower position on the stem 34 with the seal ring 39 closing the port 31. A flexible tie member, such as a chain 45, has its upper end attached to the lower end of thestem 34 and its lower end is attached to the valve 46, This valve has a tapering portion 41 shaped to land on, and to close, the seat M and beneath said tapering portion is reduced to enter the sleeve valve 9 and is provided with the external seal rings 48, 49 countersunk therein to form seals withthe walls of the valve 9. The tie member 45 is of such length that the valve 46 will land on and closethe seat l4 approximately at the same time the seal ring 33 enters the upper end of the cylinder 32 and before the valve 36 lands on the seat 24.

When a sample is to be taken the drill stem may be lowered into the well-to a selected location with the packer 5 opposite the tratum to be tested. The drill stem at this time will be filled with drilling fluid. The barrel 28 may then be dropped, or lowered by the line 3|, down through the drill stem with the valve 46 attached. The tapering portion 41 of the valve 46 will land on the seat l4 and close the sleeve valve 9. .At or about the same time the seal ring 33 enters the upper end of the cylinder 32 and will be forced on downwardly by the pressure of the pump which forces the drilling fluid through the drill stem. The drilling fluid thus trapped within the cylinder 32 and within the coupling 2 beneath will be placed under pressure and the pressure exerted against the valve 46 will force the sleeve valve 9 downwardly uncovering the port l3 as shown in Figures 4 and 5 and the fluid under pressure will be forced out into, and will expand the packer 5 against the walls of the well bore thus forming a sealed-off area of the stratum to be tested. The pump pressure will continue to move the barrel 28 on downwardly until the valve 36 lands on the seat 24 as shown in Figure 4 with the ports 4| and 2| in alignment.

If the packer 5 should be located in a restricted portion of the bore, or if for any other reason, said packer cannot be expanded sufficiently to receive all of said trapped fluid the excess may escape through the channel 50 leading from within the packer on up through the coupling 2 to the outside thereof, The portion of this channel 50 through the packer 5 is formed by a metal tube 5| of suflicient strength to prevent collapsing thereof when the packer is placed under pressure when expanded. The channel 50 is controlled by an outwardly opening back pressure valve 52 which is normally held seated by a strong coil spring 53 which is of sufiicient strength to hold the valve 53 closed until the packer 5 has been fully expanded and which will open only under excessive pressure to permit the escape of the excess of the trapped fluid.

Additional pressure from the pump at the ground surface will now overcome the resistance of the spring 44 and will force theibarrel 26 on downwardly until the port 35 registers with the port 4| as shown in Figure 5. Oil, as or other fluid in the sealed-"off area of the wall formation may now flow in through the channels 25 into the tubular stem 34 and on up into the sample chamber 28 of the sample receiving barrel 28. The fluid sample will usually flow in under pressure and when the sample has entered the barrel 28 may be elevated by the cable 3|. As the barrel 26 is elevated the spring 44 will first operate to hold the valve 36 against upward movement until the port 35 has moved upwardly to closed position as shown in Figure 4 and when the nut 43 engages the lower end of the valve 36 it will also be lifted off of the seat 24 and the spring [6 will move the sleeve valve l1 upwardly to carry the port 2| out of registration with the upper ends of the channels 25 so as to close said channels. The barrel 28 may be pulled on out of thewell with the barrel.

As the barrel 28 is moved upwardly and before the valve 46 has been lifted off of its seat a partial vacuum will be created within the coupling 2 and the packer 5 will then collapse the fluid flowing back into said coupling through the port l4; but in manipulating the tool it may sometimes happen that the sample receiving chamber 21 will be suddenly elevated and the valve 46 suddenly lifted oil of its seat permitting the sleeve valve 9 to close the port l3 before the packer has had time 'to collapse. To guard against this contingency a channel 54 has been provided which leads from within the packer and discharges into the passageway through the coupling 2 and is controlled by a back pressure valve 55 which is normally held closed by the spring 56, Should the port I3 be prematurely closed, therefore, th fluid within the packer 5 and between it and the reduced end of the coupling may escape through the channel 54. If desired, more than one of these channels 54 may be provided.

A choke of some kind at the lower end of the drill stem is necessary as otherwise the velocity of the fluid through the drill stem might move the valve 9 downwardly and open the port 13 and permit premature expansion of the packer before the sample receiving chamber 21 and valve 46 are dropped into place.

The head 29 of the sample receiving chamber 21 is provided with a valve assembly 51 screwed through the wall thereof and having a tapped hole 58 into which a gauge may be screwed for testing the pressure of the sample in the barrel 28 or into which a tubular nipple may be screwed for permitting the discharge of said sample. This valve assembly 51 contains an inwardly opening valve 59 which is normally held closed by said pressure but which will automatically open when the gauge or discharge nipple is screwed into the tapped hole 58 so as to permit the escape, thereby, of the entrapped sample. While going into the well and while making the test the tapped hole 58 is closed by a plug screwed therein to prevent drilling fluid from entering the sample chamber. When the tester is withdrawn the plug may be removed for allowing the withdrawal of the sample.

With the use of the present invention drilling of the well bore may progress in the usual manner and as drilling progresses a test of the formation may be mad at any time desired; also as many tests of the formation as desired may be made without withdrawing the drill stem.

The drawings and description are illustrative merely while it is to be understood that mechanical changes may be made without departing from the principle of the invention as defined by the appended claims.

What we claim is:

1. A well tester comprising a tubularstring of pipe adapted to be lowered into a well and having separate openings through the wall thereof, sleeve valves normally closing said openings, an expansible packer around the string enclosing one of said openings and having an inflow channel extending through the wall of the packer and opening outwardly of the packer at one end thereof and which continues on to and communicates fluid sample through said channel and means for communicating said channel with the chamber to allow the entrance of the sample into the chamber.

2. A well tester comprising a tubular string of pipe adapted to be lowered into a well and having an upper and a lower opening through the thereon to land on the lower and upper valves in succession to entrap liquid between said valves and move said valves to open position to permit the liquid entrapped between the upper and lower means to pass into the packer to expand the same against the walls of the well to form a sealed off area of the wall stratum and to permit the inflow of a fluid sample from said stratum through said channel and means for communicating said channel with the chamber to allow the entrance of the sample into the chamber.

3. A well tester having means for connecting the same to a tubular string of pipewhereby the tester may be lowered into a well said tester including a tubular member having an upper and a lower opening through the wall thereof, sleeve valves normally closing said openings and movable to open positions, an expansible packer enclosing the lower opening and having an inflow channel leading inwardly therethrough and which continues on to the upper opening, a sample receiving chamber adapted to be lowered into the well and having lower and upper means thereon to land on the lower and upper sleeve valves in succession to close the passageways through said valves to entrap liquid in the tubular :nem ber between said valves and to move said valves to open position to open said upper and lower openings and to thereby permit the liquid entrapped between the upper and lower means to pass into the packer toexpand the same against the walls of the well to form a sealed ofi area of the wall stratum and to permit the inflow of fluid from said stratum through said channel and means for communicating said channel with the chamber to allow the entrance of the fluid into the chamber. 1

4. Apparatus for obtaining samples of the fluid content of earth formations traversed by a bore hole, comprising a support adapted to be lowered into a bore hole, an enclosure of flexible material on the support, means for inflating and expanding said enclosure to pack oif the bore hole, test fluid inlet means in the wall of said enclosure, means for containing the sample obtained, and means providing communication between said inlet means and sample containing means.

5. Apparatus for obtaining samples of the fluid content of earth formations traversed by a bore hole, comprising a casing adapted to be lowered into a bore hole, a sleeve of flexible material on the casing and secured thereto at the ends thereof, means for introducing fluid under pressure into said sleeve to expand it into packing position in the bore hole, fluid inlet means in said sleeve and intermediate the ends thereof, sample containing means in the casing, a conduit communicating with said fluid inlet means and sample containing means, and valve means in the casing for controlling communication between said fluid inlet means and sample containing means.

LUTHER E. BROWN. OLLIN W. WIILIAMB.

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