US2747405A - Sub-surface bore hole gages - Google Patents

Description

May 29, 1956 G. B. THOMAS ET AL 2,747,405

SUB-SURFACE BORE HOLE GAGES Filed 001;..10, 1951 5 Sheets-Sheet 2 GERALD B. YZ S A? James Moo/v INVENTORS.

HTTORNEY.

y 1956 G. B. THOMAS ET AL 2,7414% SUB-SURFACE BORE HOLE GAGES Filed Oct. 10, 1951 5 Sheets-Sheet 4 33 %fi-- T M Pres s sureE-PSfiflNVENTORQ flv-Toran/Ey,

2,747,405 SUB-SURFACE sans iron: GAGES GeraldlL Tlgomas, Los Angeles and James Moon, Corona dcl Mar, Califg, assignors to Signal Oil and Gas Company, Los Angeles, Calif., a corporation of Delaware Application October-10, 1951, semi No. 250,714 4 Claims. (Cl. is-345 Thisinvention relates to a subsurface device for performing surveys in bore holes drilled into the earth and more particularly in bore holes for the production of petroleum or gas from below the surface of the earth.

In all such prior art procedures, it is necessary to determine the depth at which the temperature of pressure recordis made. It has been the practice to employ a clock in the instrument and to make the temperature or pressure rccorda function of time by means of some sort of mechanical connection between the clock and the recording means. A trace is thus obtained which is a function of both tiine and temperature on the one hand or time and pressure on the other hand. The instrument is lowered into the bore hole and a record is kept at the surface of the relationship of time to the amount of time passed in lowering the instrument, so that time and depth are thus correlated.

In this procedure there is always an interval of time between the starting of the clock and the start of the lowering process. This is occasioned by the fact that the instrument must be in partly disassembled condition when the clock is started, Then the instrument is assembled and introduced into the well, adjustments made, and the lowering started. Time is kept at the surface of the duration of this procedure and a correction must be made by measuring back on the record the recorded time, and, by interpolation on the record, determining the value of the recorded characteristics at the corrected time corresponding to the depth recorded at the surface for such time.

Additionally, temperature in bore holes increases with depth, and the driving mechanism connecting the clock and recording mechanism is aifected by such temperature and introduces an important error in the recordation of the time function in the instrument. 7 In other words, the clock record in the instrument is out ofstep with the clock record at the surface so that it cannot be said with certainty that the interval of time recorded by the clock in the instrument is the same as that recorded by the clock at the surface.

In order to avoid such uncertainties, it is often the practice to stop the descent of the instrument for a recorded period of time at successive depths the value of which is known from surface measurements. Where the characteristics recorded change progressively with depth, the stopping of the instrument at a known depth for a short time will produce a plateau in which such characteristics do not change with time. This will permit of a check on the depth measurement and or; correlation and correction of clock timing with depth. Thisprocedure has tlie disadvantage that it introduces an undesirable delay in the traverse.

In another method the instrument is lowered to a series of depths, measured by recording the amount of lowered line, and allowed to come to rest at each depth so that equilibrium is established. No effort is made to take the measurements between such depths. In other words,- the clock merely acts to cause an advance of the chart that a trace can be made. The chart between the stopping United States Patent r 2,747,405 Patented May 29, 1956 2 point is ignored and since the number of stops made and the corresponding depth at each succeeding stop is known, the actual depth at each plateau is known and the magnitude of the recorded characteristic at each plateau may be measured from the chart.

It will be recognized that in order to make a deterrriiiiable plateau, at si nificant time interval must be al-' lowed ateach stop. This makes it impracticable, espec'ially in deep bores, to make the interval between stops small so that frequently significant variations of the characteristics between stops are missed.

The correlation inetho'd has the difliculty arising from the indeterminacy of the effect of temperature on the clock mechanism or, in the case of pressure measurement, on the pressure 'rec'or'dation, and in the case of the step method the value of the characteristics between the stops is not obtained.

The pressure gages of the prior art are affected by temperature so that it is necessary to calibrate the pressure gage for temperature variations. Thus pressures as measured by sub-surface gages are not accurately determined unless they are corrected for sub-surface temperature at the point of measurement. Such temperature depends not only on the geothermal gradient, but also upon such accidental factors as entry of fluid into the bore hole, the velocity and quantity of fluid, nature of fluid, and the mechanical condition of the bore hole at the point of measurement. it is thus always necessary to estimate the temperature at the point of measurement. The usual procedure is to determine this from the known regional geothermal gradient. This, while more satisfactory in the case of a shut-in well, where thermal equilibrium is established, may, in a flowing well, give largely erroneous results. It is thus necessary to make a separate thermometric survey to obtain accurate temperatures at the same depths as that at which the pressure is to be determined. This introduces another time-consuming operation.

One of us has devised an instrument which does not have these disadvantages. The said instrument is described and claimed inapplication Serial No. 127,181, new U. S. Patent 2,690,674.

we have devised a mechanism which obviates these difficulties and permits a recordation of a mark which is correlatable with depth, temperature, and pressure without any substantial interruption of the progress of the traverse. We have devised an instrument for measuring pressure and temperature simultaneously which avoids the above difiiculties. V I

Instead of employing the clock mechanism, weemploy in the invention of this application a temperature responsive device and a pressure responsive device which are mounted in such manner that a simultaneous record of temperature, pressure, and depth is made. The instrumerit may be lowered or raised in the bore hole at the desired rate to obtain a continuous record under equilibrium conditions so that the trace of the recorded characteristies is a true record thereof throughout the traverse of the instrument. We superimpos'e on such record a mark which is correlatable with temperature, pressure, and depth, and does not require any recordation of the time interval involved. I u I I r In the preferred embodiment of our invention we nt'roduce a motor means attests from the surface in the preferred form of an inertially operated device which actuate's a recording mechanism. In our preferred embodiment, we employ a resiliently suspended mass, which may be the instrument or a portion thereof or a separately sus ended mass. By suddenly stopping, accelerating or decelerating the descent of the instrument, the variation in acceleration actuates the inertial device so as to make a mark. Since we may so stop, accelerate, or decelerate the device as frequently as we wish and since the interval of descent during such stoppage, acceleration or deceleration may be made as short as desired or even reduced to zero, i. e., by stopping the instrument, we may make as many such marks as we wish and thus obtain an accurate record of the variations of the characteristics with depth and, of course, record the depth, i. e., length of passedout line at each point of such acceleration or deceleration.

in order to obtain these advantages we mount a thermomctric device in the instrument to actuate a record making device so that the record making device is actuated in proportion to the ambient temperature in the bore hole at the place of measurement, and we also mount a pressure responsive element in the bore hole and connect the same to actuate a record making device in proportion to the pressure in the bore hole at the location at which the measurement is to be made. Means are provided in the instrument to be actuated from the surface so that a mark is made on the record which is correlatablc with depth. The result of the functioning of the thermometric pressure and inertial device is that we may at any desired location in the bore hole produce a record which is correlatable simultaneously with the pressure, temperature, and at the location and correlatable with the depth at said location.

in a preferred embodiment we mount a chart holder which is actuated by a thermometric motor and connect a marking system to a pressure bomb. The relationship of parts is such that at any location of the instrument the relationship of the stylus, employed to mark the chart, to the chart is determined both by the temperature and by the pressure. It will be observed that when such an instrument is lowered into the bore hole in which both temperature and/or pressure exist, the stylus will make a line trace the co-ordinates of which are pressure and temperature. in a preferred embodiment we mount the chart holder so that it is resiliently suspended and may be inertially actuated by an alteration of the acceleration or" the instrument via the lowering line, so that when so actuated the chart holder bounces to cause the stylus to form a discernible mark on the chart which is thus correlated with depth as well as the temperature and pressure at the depth recorded.

The instrument is so constructed that it is possible, while lowering it in the bore hole, to maintain the instrument in equilibrium with its environment so that the record will be a true measure of the magnitude of gradient of pressure and of temperature throughout the bore hole.

Because, as is well known to those skilled in the art, the temperature may not be a continuous function of de th, due to local variations in thermal gradient, it is particularly desirable to have a continuous trace of the actual variation of temperature. Our device permits of such contimtous trace of the temperature and the other recorded variable (e. g. pressure) function and the recording of the depth mark at close intervals of the depth measurements.

This in ention is an improvement upon the construction of the device and will also have the advantages inherent in the. device of said application.

in our device the stylus is subjected to a compound motion over the chart. One element of the compound motion of the stylus is under the influence of the pressure responsive device and another of the elements of said motion is under the influence of the temperature responsive device. The stylus is in marking relation to the chart in such manner that the trace of the stylus on the will be in a line, one coordinate of which will be pressure and the other coordinate will be temperature.

This is accomplished by employing pressure and temperature resonsive devices and a marking means, and suitable connections between the marking means and the temperature and pressure resonsive means of such character that the direction of motion of the marking means over the chart isperpendicular to the direction of motion of the stylus responsive to pressure variations.

In order to introduce a third variable, i. e., the depth 2; at which any pressure and temperature are measured, we employ the expedient of the inertially actuated marking device invented by one of us and for which applications have been filed, Serial No. 72,450, January 24, 1949, now U. S. Patent 2,690,673, and the above-mentioned Serial No. 127,181, filed November 14, 1949.

In the specific embodiment illustrated here, we suspend the chart holder on the inertial device in such manner that any sudden acceleration, upward or downward, will cause the chart to reciprocate vertically under the stylus, thus mar 'ng a recognizable mark which will be correlatable with depth.

Since the driving of the stylus introduces but a light load and since the stylus mechanism has a low inertia, the forces necessary to mark the chart are low. Thus it will take av much smaller force to drive the stylus than will be necessary to drive the chart mechanism in the prior art clock actuated devices. The error introduced by the oi the inertia of the stylus is thus insignificant and an accurate response of the stylus to temperature and pressure is obtainable.

In the specific device, the stylus is moved over a relatively stationary cylindrical chart-holding member; the stylus is moved circumferentially over the chart under the influence of one of the variables and is moved axially of the chart, i. e., parallel to the axis of the cylinder, over the chart under the influence of the other of the variables. The stylus is mounted on a vertically reciprocable stylus rod which is reciprocated by means of a bellows the extension of which is under the influence of one of the variables. The stylus rod is also so mounted that it can rotate in any position of its vertical reciprocation, and the angular rotation is under the influence of a Bourdon tube so that the degree of rotation of the rod is a function of the other of said variables.

Thus, for example, in the specific device illustrated, the Bourdon tube is connected to a thermometric bulb and in the form of a thermometric motor, i. e., a thermal responsive device for moving the stylus, and the bellows is connected to a flexible bulb the compression of which is obtained by the pressure of fluids in the bore hole and is thus in the form of a barometric motor, i. e., pressure responsive device for moving the stylus. In this manner the longitudinal component (parallel to the axis of the chart holder and chart) measures pressure, and the horizontal component (along the circumference of the chart holder and the chart) measures temperature. The reciprocation of the chart holder by actuation of the inertial marking device will cause an interruption of the line formed by the tomperature-pressure trace which will be a recognizable record of depth.

Whereas in the prior description we have described our specific form of the combined pressure and temperature gage in which the pressure responsive element causes an elevation of the stylus parallel to the axis of the chart holder and the temperature responsive element causes a proportional rotation of the stylus about the axis, the motion may be reversed and the pressure responsive element causes a rotation of the stylus arm and stylus and the temperature responsive element a movement of the stylus parallel to the axis of the chart. This may be accomplished by interchanging the barometric motor and the thermal motor connections so that the Bourdon tube is connected to the barometric motor and the bellows to the thermal motor.

To obtain these results in the instrument of the preferred embodiment of our invention, we have devised and have assembled various elements into a unitary wellcontained instrument, of which the following is a detailed description. In the drawings,

Figs. la, lb, and 1c are longitudinal views of section of the mechanism employed and the manner in which they are assembled;

Fig. 2 is a section taken on the line 2-2 of Fig. la;

Fig. 3 is a partial vertical section taken on the line 3-3 of Fig. 2;

Fig. 4 is a section taken on the line 4-4 of Fig. Fig. 5 is a view partly in section illustrating the manner in which the inertial device is assembled with the inner sleeve plug;

Fig. 6 is a vertical view in section taken on the line 6-6 of Fig. 1a; p Fig. 7 is a horizontal section taken on the line 7-7 of Fig. lb; V

Fig. 8 is a vertical section taken on the line 88 of Fig. 7;

Fig. 9 is a section taken on the line 9--9 of Fig. 10 and also Fig. lb; I I I Fig. 10 is a vertical section taken on the line 10-10 Fig. ll is a section taken on the line 11--11 Fig. 10; Fig. 12 is a hypothetical trace chart showing the markings produced by the stylus on the chart sheet; I

Fig. 13 is a vertical section taken on the line 13-13 of Figs. 14 and 15; and also Fig. 1b; I I

Fig. 14 is a section taken on the line 14-14 of Fig. lb, alsoonFig. 13; I II I Fig. 15 is a section taken on the line 15-15 of Fig. 1b, also Fig. 13. I p

In the drawings (see Figs la to 1c) the end piece 1 is provided with the lowering cable 1' and the screw-eye 2" is connected to the housing cap 2 by means of the threaded connection 2'. The lower end of the housing cap 2 is threaded and this threaded end is screwed into the upper end of the outer housing tube 3 which is closed at the lower end by being screwed onto the housing cap 2.

Within the housing tube 3 is nested varioiis units coinprising the instrument in the following progressioni adjacent the housing cap 2 is located the inner housing cap from which is suspended the inner housing tubular shell which is centered in housing cap 2 by the teat 4 which enters the bore 3 in the lower end of the housing cap 2. Connected to the inner housing cap 4 by means of the rods 5, made fast in the inner housing plug 4, is the assembled inertial device 6. The inertial device is composed of a disk 5a, slotted at 55 to permitthe entry of the guide bar 7 mounted on the tubular wall 7'. The disk 5a is also provided with a slot 5c to permit the entry ofthe head 5d positioned at the top of the rod se. The cylinder 6d is slidablyinourited on the rod 5a.. The top of 6a is also slotted at 65 to permit the entry of the bar 7. Between the slotted portion 611 and the nut 5 screwedon the end of the rod 5c, is positiened a spring 5g. The bottom of the cylinder 6a is closed by a plug 9 formed with a T- slot 9.1 into which the T-head 8a, mounted at the top of the plug 8, passes. I I

The upper end of the plug 8 is attached to the tiibular, open-end hollow sleeve 10 which acts as the chart carrier. The sleeve 10 is suspended below the inertial device 6 by means of the T-shaped top extension of the plug 8. I To the inner circumferential face of the sleeve ll) isattached the chart clamp 11 for receiving the chart on the inner face of the chart holder. The chart ends are slipped underneath the clamp 11 to hold the chart in position on the inner-surface 13 of the chart holder 10. I I

The lower face of the plug 8 is boreda't the center to receive the rod 15 to which it ,is secured and this red acts as the stylus centering means and telescopes inside the hollow tube 19. The stylus 14.is attached to the upper end of the stylus spring arm 16. The spring arrn 16 is made fast at its lower end to the stylus lift arm collar 17 mounted on the tu be 19. The centering spring 18 mounted on collar 17 eiitends upwardly to assist in centering the collar 17. I I I I The lift arm collar 17 is made fast at the upperend of the stylus actuating tube 19. The inner plug 20 is fast in the lower end of 19. This plug rests upon and is centered on a washer-shaped spring 21 which is located between the base of the tubular stylus arm guide 22 and the stylus arm support 23. This arm suppert is made fast to the stylus actuating shaft 24 by co I set screw 23'. This shaft 24 passes thrcugh an anti-friction bear- 6 ing 25 located in the top of the housing coupling 3. The housing coupling is bored to permit the passage of this rod tsee Figs. la and 6) j v The lower endof the housing coupling is threaded into a lower tubular outer housing 26. In this housing is located a Bourdon pressure coiled tube 27 wound in spring-like fashion and this Bourdon tube is attached at its upper end to the collar 28 fixed on rod 24. The lower end of the Bourdon tube is attached to the enlarged end 29 of the spring housing 31 (see Fig. 13). The stylus actuating shaft 24 is slidably mounted in upper collar 28 and continues downward through the center of the Bour-don tube coil. It is provided with a half-round groove 29a (see Fig. 8). A ball 29' located in the collar 28 projects into the groove 29a and acts as a key in the shaft 24. The collar 28 is maintained against vertical displacement by the ring 28' fast to the tube 2 6. This limits the motion of the Bourdon tube coil and the collar 28 ton rotary motion, thus maintaining a fixedrotative relationship between the shaft 24 and the collar 28. The groove 29a (see Figs. 1b and 8) extends from above the top collar 28 of the Bourdon tube, downward to a point adjacent the base of the Bourdon tube.

Referring to Figs. 1a, 10 and 13, it will be seen that the adjacent double-walled, annular Sylphon bellows 33 surrounds the rod 24 which is concentrically mounted inside the hollow core of the bellows. The guide tube 24 is mounted in the enlarged collar 29. The base of the bellows 33 is connected to the enlarged end 29 of the spring housing 31. Thus each of the lower ends of walls 33a and 33b may be brazed or soldered to the enlarged end 29.

At the top of the guide tube 24' is mounted the antifriction bearing 24a in which the rod 24 rotates. The tops of walls 33a and 33b of the Sylphon bellows are clinched in the collar 36 to make a fluid-tight sealat the top of the annulus between the walls 33a and 33b, I A collar 30a is pinned to the shaft 24 and is spaced from the collar 30b also pinned tothe shaft 24. A plurality of circumferentially spaced jewel pins 30 are clamped in the collar 30 by means of the nut 33' against a suitably provided shoulder in the interior surfac e of 30. The collars 30a and 30b will slide over the pins 30 when the collars are rotated by the shaft 24, but the collars and the shaft are held against vertical displacement by the pins 30''.

I The shaft 24 eiitends downwardly through the guide tube 24 into the enlarged spring chamber 32 formed in the extension 38d of the outer housing coupler 38 seerigs. la and 13). The lower end of the rod 24 is formed with a spring retaining shoulder 24a. The spring 32 is positioned around the rod 24 and between the spring retaining shoulder 24a and the end of the spring chamber 32. A tube 36 passes through and is secured to the upper enlarged end 29 and terminates in the annular space between the bellows walls 33a and 33b. Thistube' 36 is part of the channel for the passage of the fluid for transmitting pressure from the fluid filled flexible pressure bulb 41. I

A The housing coupling 38 is formed with a counterbore 44 at the top into' which the tube 36 is secured by a fliiidtight joint and also with atapped counterbore 43 at the bottom and is provided with a channel 38' connecting the two counterbore's. The coupling is screwed into the tube 415 into which also is received the connector 39. I The .counterhore 43 at thebottom is threaded to receive the threaded piece 45 of the flexible pressure bulb 41 by afluid-tight connection. The bulb 41 is mounted in the chamber 41a which communicates with the space outside the tubular wall 41b of the chamber by means of port 41'. I

I A tube 46 (see Figs. 1c, 1b and. 13) is connected to the bottom of the Bourdon tube 27 into which it opens and to which it is secured by a fiuid tight joint. .The tube 46 extends down through the packing gland 49" the coupling 49 and then passes downward to enter the coupling 49. The tube 46 is provided with the filling port 50 which, after the desired filling has been accomplished, is then closed in any suitable manner, such as with a plug 54) as shown or in any other suitable manner.

The tube 46 is soldered or secured in any appropriate manner in the bottom of the tube coupling. It then continues downward through a vertical bore 47 in the coupling 33 and thence through the bore 47 in the cap 39. The lower end of the bore 4'7 is provided with packing retained in place by a packing gland 52. Below and contacting the packing gland 52 is a packing washer 53 of insulating material through which the temperature vapor tube 46 passes. The outside diameter of the washer 53 is such that it contacts the inside wall of the depending tubular bulb sleeve 54 which is screwed onto the lower end of the cap 39.

A spacer sleeve 5'5 located inside the tubular bulb sleeve abuts at its upper end the washer 53 and at its lower end contacts a screen 56 in the form of a dish; a short spacer 57 at its upper end abuts the screen 56 and at its lower edge this spacer abuts the top edge of a closed-end tubular temperature bulb 58 screwed into the bulb sleeve 54.

The upper end of too temperature bulb 5? is screwed into the bulb sleeve 54 until it presses all of the spacers and the interposed screen and the top packing Washer 53 into their proper assembled leak-proof formation.

The temperature tube 46", after passing through the packing gland, and the washer 53 containues downward through the center of the screen 56 until the open bottom end of the tube 46 reaches a point adjacent the closed end 59 of the temperature bulb 58.

it will thus be observed that the stylus arm is mounted coaxially with the chart holder and is slidably responsive to pressure along the axisof the chart holder under influence of expansion or contraction of the bellows 33 without any possibility of rotative movement when so moved, and that the expansion or contraction of the Bourdon tube induces a rotary motion without introducing any axial movement, and that the inertial motor will move the chart in relation to the stylus without influencing the absolute position of the stylus with respect to the rest of the system.

In operating the device, the instrument assembled as above is lowered on the cable 1'. As it is lowered into the bore hole it enters progressively zones of higher pressure. This pressure is exerted through the ports ill into the chamber 41a. The compression of the bulb 4i exerts fluid pressure which is communicated via tube 38, 33 (Fig. l3) to the space between the walls 33a and 33b (Figs. 1 and 13). This causes the sylphon bellows 33 to becomc extended. The collar 30 is thus lifted and this lift raises the pins 3-9 vertically lifting the rod 24. In doing so the rod slides through the collar 23, the groove 29 passing over the ball 29' and the rod through the bear ing (Fig. 6). This lift compresses the spring 32 (Fig.

13). it also lifts the stylus actuating tube 19 via the spring washer 21 and this causes the stylus to travel over the chart mounted on the chart holder in a direction parallel to the axis of the rod, chart holder and instrument. The rod is prevented from rotating by reason of the groove 2% and ball 2," which permits axial, but not rotary, motion of the rod. Thus the rod and stylus move over the chart in a direction parallel to the axis of the chart holder and in an amount proportionate to the pres sure exerted in the chamber 41a.

The instrument also introduces a rotary motion of the stylus arm proportionate to temperature. Thus the pressure of the fluid in the bulb 58 is proportional to temperature and thus pressure is communicated through the tube 4 47 (Fig. lc) 46 (Figs. 16 and 3) to the Bourdon tube 2'7 The Bourdon tube 27 is connected to the collar 28 (Fig. .8). The collar is prevented from movement axially of the rod 24 on the Bourdon tube 27 by reason of the ring 28' which is welded to the casing 26. Thus when the pressure in the Bourdon tube changes due to temperature changes at the bulb 53, the Bourdon tube cannot expand longitudinally and can only change its dimensions radially by winding into a tighter or looser spiral. This causes the collar to rotate on its bearing. The ball 29 in the groove 29 moves with the collar 23 introducing a rotary motion to the rod 24.

This rotation because of the groove and ball combination may occur at any permissible vertical position of the rod 24 as it moves under the influence of the pressure exerted in the bulb 41. The rotation of the rod 24 in its bearing 25 (see Fig. 6) causes the rotation of the stylus tube 19 via the spring washer combination 21.

A rotation of the stylus arm is thus introduced circumferentially of the chart holder which is proportional to the temperature of the bulb 58. The stylus is thus moved over the chart mounted on the inner wall of the chart holder and a line is traced one coordinate of which is pressure and the other of which is temperature.

in order to introduce the depth variable in the chart the instrument is jarred. This may be accomplished by checking the ascent or descent of the instrument on its line or jiggling the line.

An accelerating or decelerating force is thus introduced into the instrument, due to the inertia of the chart holder in which is suspended on the spring 5g. This causes the cylinder 6 and the plug 3 and the chart holder to oscillate vertically. It is to be observed that the chart holder will not rotate due to the bar 7 b in the slots 5b.

This will introduce a jiggle in the chart which will be in the form of a track or break parallel to the chart holder axis. Such a chart is illustrated in Fig. 12.

Fig. 12 gives the trace of an illustrative case of tem perature and pressure measured in the annulus outside the fluid-flow tube in an oil well to illustrate the advantages of of the record made in the instrument of our invention. The jiggles a to i, inclusive, for case I, are the markings caused by the initial marking device on the depths indicated for the depths shown for such marking in Fig. 12. These depths are recorded at the surface from the length of line 1 measured when the respective marks were made.

While we have described a particular embodiment of our invention for the purpose of illustration, it should be understood that various modifications and adaptations thereof may be made within the spirit of the invention as set forth in the appended claims.

We claim:

1. A sub-surface temperature, pressure gage comprising a tubular housing, a cylindrical chart holder mounted coaxially in the upper part of said tubular housing, a stylus in marking relation to said chart holder, a stylus supporting rod mounted axially of said tubular housing, an annular bellows mounted in said tubular housing, a collar, a mechanical connection between said bellows and said collar for movement of said collar with said bellows axially of said chart holder, said stylus support rod being rotatably mounted in said collar, a mechanical connec tion between said collar and said stylus support rod for movement of said stylus support rod with said collar axially of said chart holder 21 barometric fluid motor mounted in said tubular housing, an operative fluid connection between said barometric motor and the annulus of said annular bellows, a thermal fluid motor, said thermal fluid motor comprising a Bourdon tube, a second collar, a mechanical connection between said second collar and the end of said Bourdon tube, means for rotatably mounting said second collar in said tubular housing, said rod being slidably received in said second collar, means for restricting said second collar against longitudinal movement axially of said rod, said rod having a keyway axially thereof, a key in said second collar, said keyway being adapted to travel along said key.

2. A sub-surface temperature, pressure gage comprising a tubular housing, a cylindrical chart holder, a resilient suspension for said chart holder, a support in said chart holder, a support in said tubular housing for said resilient suspension, a stylus in marking relation to said chart holder, a stylus supporting rod mounted axially of said tubular housing, an annular bellows mounted in said subular housing, a collar, a mechanical connection between said bellows and said collar for movement of said collar with said bellows axially of said chart holder, said stylus support rod being rotatably mounted in said collar, a mechanical connection between said collar and said stylus support rod for movement of said stylus support rod with said collar axially of said chart holder, a barometric fluid motor mounted in said tubular housing, an operative fluid connection between said barometric motor and the annulus of said annular bellows, a thermal fluid motor, said thermal fluid motor comprising a Bourdon tube, a second collar, a mechanical connection between said second collar and the end of said Bourdon tube, means for rotatably mounting said second collar in said tubular housing, said rod being slidably received in said second collar, means for restricting said second collar against longitudinal movement axially of said rod, said rod having a keyway axially thereof, a key in said second collar, said keyway being adapted to travel along said key.

3. A sub-surface temperature and pressure gage comprising a tubular housing, a cylindrical chart holder mounted in the upper part of and coaxial with said tubular housing, a stylus in marking relation to said chart holder, a stylus support mounted in said tubular housing, an annular bellows mounted in said tubular housing, a mechanical collar connected to said annular bellows, a mechanical connection between said collar and said stylus support, said stylus support being rotatably mounted in said collar and fixed with respect to said collar against axial movement therethrough, a barometric fluid motor mounted in said tubular housing, an operative fluid connection between said barometric fluid motor and the annulus of said annular bellows, a thermal fluid motor positioned in said tubular housing, said thermal motor comprising a Bourdon tube, a second collar, a rotary motion transmitting connection between said second collar, and said stylus support, a mechanical motion transmitting connection between said second collar and the end of said Bourdon tube, said support being fixed with respect to said second collar against rotary movement in said second collar, said support being slidably received Within said second collar for axial movement therein means for rotatably mounting said second collar in said tubular housing, and means for restraining said second collar against longitudinal movement in said housing.

4. A sub-surface temperature and pressure gage comprising a tubular housing, a cylindrical chart holder, a resilient suspension for said chart holder, a support in said tubular housing for said resilient suspension, a stylus in marking relation to said chart holder, an elongated stylus support mounted in said tubular housing, a barometric fluid motor in said housing, said motor including an annular bellows in said housing, a collar, a mechanical motion transmitting connection between said collar and the top of said bellows, a mechanical connection between said collar and said stylus support for motion of said stylus suport and said collar along the axis of said support, said support being rotatably mounted in said collar, a thermal fluid motor positioned in said tubular housing, said thermal motor comprising a Bourdon tube, a second collar mounted on said stylus support, a mechanical connection between said second collar and the end of said Bourdon tube, said support being fixed with respect to said second collar against rotary movement in said second collar, said support being slidably received Within said second collar for axial movement therein means for rotatably mounting said second collar in said housing, and means for holding said second collar against longitudinal movement in said housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,297,725 Spilhaus Oct 6, 1942 2,593,285 Fay et a1 Apr. 15, 1952 2,690,673 Thomas Oct. 5, 1954 2,690,674 Thomas Oct, 5, 1954

Claims (1)

1. SUB-SURFACE TEMPERATURE, PRESSURE GAGE COMPRISING A TUBLUAR HOUSING, A CYLINDRICAL CHART HOLDER MOUNTED COAXIALLY IN THE UPPER PART OF SAID TUBULAR HOUSING, A STYLUS IN MARKING RELATION TO SAID CHART HOLDER, A STYLUS SUPPORTING ROD MOUNTED AXIALLY OF SAID TUBULAR HOUSING, A AN ANNULAR BELLOWS MOUNTED IN SAID TUBULAR HOUSING, A COLLAR, A MECHANICAL CONNECTION BETWEEN SAID BELLOWS AND SAID COLLAR FOR MOVEMENT OF SAID COLLAR WITH SAID BELLOWS AXIALLY OF SAID CHART HOLDER, SAID STYLUS SUPPORT ROD BEING ROTATABLY MOUNTED IN SAID COLLAR, A MECHANICOL CONNECTION BETWEEN SAID COLLAR AND SAID STYLUS SUPPORT ROD FOR MOVEMENT OF SAID STYLUS SUPPORT ROD WITH SAID COLLAR AXIALLY OF SAID CHART HOLDER A BAROMETRIC FLUID MOTOR MOUNTED IN SAID, TUBULAR HOUSING, AN OPERATIVE FLUID CONNECTION BETWEEN SAID BAROMETRIC MOTOR AND THE ANNULUS OF SAID ANNULAR BELLOWS, A THERMAL FLUID MOTOR, SAID THERMAL FLUID MOTOR COMPRISING A BOURDON TUBE, A SECOND COLLAR, A MECHANICAL CONNECTION BETWEEN SAID SECOND COLLAR AND END OF SAID BOURDON TUBE, MEANS FOR ROTATABLY MOUNTING SAID SECOND COLLAR IN SAID TUBULAR HOUSING, SAID ROD BEING SLIDABLY RECEIVED IN SAID SECOND COLLAR, MEANS FOR RESTRICTING SAID SECOND COLLAR AGAINST LOGITUDINAL MOVEMENT AXIALLY OF ROD, SAID ROD HAVING A KEYWAY AXIALLY THEREOF, A KEY IN SAID SECOND COLLAR, SAID KEYWAY BEING ADAPTED TO TRAVEL ALONG SAID KEY.

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