US2122697A - Instrument carrier - Google Patents

Description

July 5, 1938. I

C. M. POTTER INSTRUMENT CARRIER Filed Oct. 1, 1935 Fig. 5

JILVQI 'LZOJ CHARLES M. POTTER Fig.1

' Patented July 5,1938

UNITED STATES PATENT OFFICE Standard Oil Company, San Francisco, Calif.,

a corporation of Delaware I gApplication October 1, 1935, Serial No. 43,078

' 6 Claims. '(01. sa-zos) This invention relates to a carrier for instruments of the type that are sent to the bottom of deep wells for the purpose of determining the pressure, temperature, inclination, and the like, and more particularly relates to a free carrier that is impelled to the bottom of the well under the action of a fluid pumped downwardly through a pipe, and thereafter returns by its own buoyancy, as distinguished from one which is lowered at the end of a wire or cable and is subsequently raised thereby.

In the drilling of deep wells it is the practice to use a hollow stem'or drill pipe to support and turn the drill bit. Fluid such as water, or mud to the surface. Instruments for determining inclination. of the drill hole, for example, are usu-" ally sent down the bore-of the drill pipe at the end of a wire or cable and, after a suitable time, withdrawn to the surface and observed. Under certain circumstances, theintroduction of such wires or cables is hazardous and objectionable. An alternative that is sometimes followed is to securethe instrument in a section of the drill pipe, immediately above the bit, which requires removal of the entire string of pipe before the instrument can be taken out and read.

It is an object of this invention to provide a free carrier for an instrument which is to be sent down a well, which is adapted to be positively carried down by the circulating fluid in the drill pipe, and which will be equally positively returned to the surface by virtue of its construction and inherent buoyancy in the fluid.

Another object is to provide a carrier that will automatically be actuated when it arrives at the bottom of the drill pipe, so that it will be in condition to return to the surface.

Another object is to provide a buoyant carrier with means for initially overcoming its buoyancy so that it may be sent down a drill pipe with the circulating fluid, and thereafter be-actuated to cause it to return to the surface of its own accord.

Another object is to provide an improved means for positioning and selectively actuating a collapsible packer on a device of this nature.

' These and other objects and advantages will be more fully apparent fromthe following description and from the accompanying drawingr which forms a part of this specification and illustrates a preferred embodiment of this invention.

In the drawing:

the drill pipe.

Figure 2 is a horizontal sectional view on the line IIlI of Figure 1, and illustrates the arrangement of the packer skirt and expander therefor.

Figure 3 is a vertical sectional view of a porthe packer in its closed or collapsed position.

Referring to the drawing and particularly to Figure 1, the reference number III represents the body of the carrier threaded at II onto the mandrel I2 which carries the packer I3. Packer I3 is preferably of a molded flexible material such as vulcanized rubber andvis clamped between the lower end of mandrel I2 and base I4 as by the threaded connection I5. Base I4 may tion of the carrier shown in Figure l, but with terminate at its lower end in a spring or other shock absorbing device to prevent too great shock to the instrument under conditions to be described below.

as by the hinged'brackets 2|.

Springs I9 are biased to collapse the packer I3 to the closed position shown in Figure 3, and in order to do so must first rotate latch ring I! in a clockwise direction relative to packer I3, from the position shown in Figure 2. Conversely, if latch ring I! is rotated counterclockwise with respect to packer I3, the. skirt of packer I3-will be expanded outwardly to the open position shown in Figure 1.

In order to secure latch ring Ilin the open position of Figure 1, mandrel I2 is provided with a slot 22 in which is pivoted apawl 23, theouter notch 24 in ring I'l.

held in the upper position shown as-by spring II.

-end of which is adapted to be received in aA cover plate 25 may be secured over slot 22 andpawl 23 as by ascrew 26. Theinner end ofpawl 23 extends into abore 21 in mandrel I2, 111 which bore thestem 28 of aninertia member 29 is adapted to move. The main body ofinertia member 29 is received in abore 30 in the carrier body III and is normally in Figure An instrument carrying section .32 is secured to the top of body was by the threadedconnection 33, and is provided with achamber 34 into which any suitable surveying instrument may placed. A short threadedstub 35 is pref= erably provided. on top ofsection 32 so that a fishing tool may be used to recover the carrier should it become stuck in theedrill pipe.

The body l0, mandrel I 2, base I and instrument section .32 are preferably made of a very light metal alloy such as an aluminum or a magnesium alloy, in order that the whole assembly will beibuoyant in the mud or circulating fluid To this end, the base l4 may be hollow for a ortion of its length.

In operation, the skirt of packer I2; is pulled outwardly until latch ring I! is turned counterclockwise to the position shown in Figure 1,

whereupon the outer end ofpawl 23 will engage notch 24 in ring I! and hold it in that position, with the packer l3 expanded. The carrier, with the instrument in place inchamber 34, is then placed in the drill pipe 36in the usual manner and pumped down with the circulating fluid, the expanded packer serving to assist in the operation by sealing the space between thedrill pipe 36 and the carrier body.

As soon as the carrier strikes the bottom of the drill pipe, which is ciosed by the drill bit, except for one or two small fluidpassages, theinertia member 29 will move downwardly relative to the carrier body so thatstem 28 will strike the inner end ofpawl 23. This will release ring I! so that springs l9 will collapse the packer l3 to the position shown in Figure 3. Continued pumping of circulationfiuid will assist the rim-of the packer l3 to fold downwardly, as shown, and will also serve to hold the carrier at the bottom of the drill pipe until the normal operating or recording period of the instrument has elapsed. As .soon as the pumping is stopped, the carrier, by virtue of its positive buoyancy, will rise to the surface and can then be removed from the drill pipe in thenormal manner.

Although a specific construction embodying this invention has been described and illustrated, it

/ is to be understood that the invention is not limited to that specific device, and all such'modifications and changes as come within the scope of the appended claims are embraced thereby.

I claim:

An instrument carrier adapted to be pumped down a drill pipe with a circulatingfluid, comprising a buoyant body, a flexible packer secured to said body,'a rotatable ring on said body, spring means connecting said packer withsaid ring, a latch for said ring to hold said packer in expanded position and means associated with said body and adapted to release said latching means to retract said packer when said body reaches the bottom of said pipe. 1

2. An instrument :carrier according to claim 1 in which said last named means comprises an inertia member carried by said body and movable with respect thereto, and said latching means comprises a pawl adapted to be contacted bysaid member when said body reaches the bottom of said pipe. i V Y 3. An instrument carrier adapted to be pumped down a drill pipe with a circulating fluid, comprising a buoyant body, a flexible packer secured to. .said body, a rotatable ring on said body, spring means connecting said packer with said ring and adapted to urge said packer to a collapsed position, an inertia member slidably mounted in said body, and a pawl for holding said ring in position to expand said packer, said member being normally restrained from contacting said pawl but adapted to release it when said body strikes the 1 bottom of said pipe.

4. An instrumentcarrier adapted to be pumped down a drill pipe with a circulating fluid, comprising a buoyant body, a flexible extensible packer carried by and surrounding said body, a movable ring on said body, means connecting said:

packer with said ring, and releasable latching means in said body for holding said ring in a position to maintain said packer in its extended position, said latching means comprising an inertia member carried by said body and movable with respect thereto, said inertia member so constructed and arranged as to actuate said latching means when said body reaches the bottom of said pipe.

5 An instrument carrier according to claim 4 in which said movable ring is rotatable to expand said packer and to contract the same.

6. An instrument carrier adapted to be pumped down a drill pipe with a circulating fluid, comprising a. buoyant body, a flexible extensible

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