US2824612A

US2824612A - Means for isolating, treating, and testing a section of well formation

Info

Publication number: US2824612A
Application number: US418352A
Authority: US
Inventors: Lynes John
Original assignee: Lynes Inc
Current assignee: Lynes Inc
Priority date: 1954-03-24
Filing date: 1954-03-24
Publication date: 1958-02-25
Anticipated expiration: 1975-02-25

Description

Feb. 25, 1958 .,J. LYNEs 2,824,612

MEANS FOR ISOLATING, TREATING AND TESTING A SECTION 0F WELL FORMATION Orlglnal Flled Aug. 23, 1951 3 Sheets-Sheet 1 Nr R 2 NW w u M J Feb. 25, 1958 J. LYNEs MEANS FOR ISOLTING, TREATING AND TESTING A SECTION OF WELL FORMATION Original Filed Aug. 23, 1951 3 Sheets-'Sheet 2 IN V EN TOR.

.0 rra/ava' y J. L MEANS Foa IsoLATING,

YNl-:s 2,824,612 TREATING AND TESTING A WELL FORMATION Y Feb. z5, 1958 SEUTION OF Original Filed Aug. 23, 1951 I Il www JOHN os/5.

- INVENTQR.

OQQ 000 VUnited States Patent MEANS FOR ISOLATING, TREATING, AND TEST- ING A SECTION OF WELL FORMATION John Lyues, Albuquerque, N. Mex., assignor to Lynes, Inc., Houston, Tex., a corporation of Texas Continuation of application Serial No. 243,307, August 23,8195521. This application March 24, 1954, Serial No. 41 ,3

12 Claims. (Cl. 166-187) The invention relates to a hydraulically inflatable packer assembly for isolating a section of a formation in a well bore whereby the introduction of a treating fluid into the isolated section may be accomplished or the liquid content of the isolated section may be retrieved to the surface for inspection, or where such operations may be accomplished in sequence.

This application is a continuation of my prior copending application, Serial Number 243,307, for an invention in Means for isolating, Treating and Testing a Section of Well Formati-on, tiled August 23, 1951, now abandoned, which is in turn a continuation of my prior application, Serial No. 676,926 for an invention in Means for Isolating, Treating and Testing a Section of Well Formation, filed June 15, 1946, now abandoned. This application is entitled to the benefit of the filing date of June 15, 1946.

The invention relates generally to the type of tool disclosed in my prior Patents 2,227,729, 2,227,730 and 2,227,731 issued January 7, 1941.

lt is one of the objects of the invention to provide a simple and economical assembly which may be manipulated in a well bore to isolate a section of a formation by hydraulically inflatable packers spaced to seal olf the desired portion of the formation in order to apply treating fluid thereto or to obtain an accurate sample of the liquid content thereof. t

Another object of the invention is to provide a well tool wherein the packer assembly may be suspended on an operating or supporting pipe and lowered into position in the well bore and thereafter the packers inflated and the assembly opened to the isolated section of the formation by manipulation of the supporting pipe to receive or discharge uid content.

Another object of the invention is t-o provide a well tool wherein a packer assembly is lowered into the well bore and circulation through the assembly accomplished in yorder to wash the well or condition the circulation liquid and where the packer assembly is thereafter expanded to seal and isolate the desired section of the formation to be treated or tested.

Another object of the invention is to provide a well tool having a pair of spaced hydraulically inflatable packers wherein circulation may be had through the supporting pipe and tool to wash the well and condition the circulation liquid, the packers thereafter inflated and by manipulation of the operating pipe the inflation pressure locked within the packers so as to maintain packers in inated condition while treating and testing operations are being conducted.

Still another object of the invention is to provide a well tool having inilatable spaced packers thereon where the packer assembly is freely floating upon the operating or supporting pipe.

It is also an object of the invention to provide a well It is also an object of the invention to provide atool 2,824,612 Patented Feb. 25, 1958 ICC having a pair of hydraulically inflatable packers thereon which can be expanded to isolate a section of the wall of the well and to also equalize the pressure inthe well above and below the packers so as to protect `the packers against excessive pressures.

Still another object of the invention is to provide a Well tool having spaced hydraulically inflatable packers thereon to isolate a section of a formation in the well bore, to open the tool, by manipulation of the supporting pipe, for access to the isolated section so as to apply a treating fluid such as acid to the isolated section in order to disintegrate an oil bearing formation and increase the production and wherein While the packers continue'to maintain a seal with the well wall the operation may be reversed and the fluid content of the isolated section retrieved to the surface through the supporting pipe for inspection either by natural flow, pumping, bailing, swabbing or otherwise.

Still another object of the invention is to provide a tool with spaced hydraulically inflatable packers adaptable for creating a seal in a well bore of irregular contour.

Still another object of the invention is to provide a tool with inflatable packers that may be readily inliated or deated to permit subsequent removal from the well bore.

Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawings, wherein:`

Fig. 1 is a vertical sectional view illustrating the well tool and the packer assembly with the parts in the position they will occupy as the tool is lowered into the well;

Fig. 2 is a vertical sectional view with the packers inflated prior to locking the inating liquid therein and just prior to opening the tool to the isolated section of the formation.

Fig. 3 is a vertical sectional view with the parts in the position they will occupy when the tool is open to the isolated .section of the formation after the packers are inflated and the intlating liquid locked therein.

Fig. 4 is a side elevation of the tool isolating a section of a formation and showing the arrangement of the packers.

Fig. 5 is a section taken on the line 5 5 of Fig. 3.

Fig. 6 shows a modified arrangement of the tool where a by-pass connection is arranged to equalize the pressure above and below the inflated packers in the well.

Fig. 7 is a section taken on the line 7 7 of Fig. 6.

Fig. 8 is an enlarged sectional view of the bottom section of the packer assembly.`

In Fig. 1 a well b-ore is illustrated at 2 as having been drilled through a formation 3 which formation it is desired to treat with a suitable material or investigate. It is well understood of course that a well bore of this sort which has been drilled by rotary methods is filled with drilling mud or uid which has been increased in specific gravity soas to maintain a predominant pressure against the wall of the well. In many instances such pressure causes the blocking oi of a porous formation, such as the formation 3, and it is desirable to remove the pressure of the column of drilling mud from such formation in order to test it for desirable uid while in other instances it is desirable to apply an excessive pressure to such isolated formation in order to cause acids or other' materials to permeate the formation either for the purpose of dissolving some of the materials therein in order to produce a desirable fluid such as oil or gas or in some instances to block olf such formations by the application of a hardenable material. l

In any event, whether the operation be for the purpose of testing or treating the formation, the present tool has been devised with a view of isolating a section of a formation in order to accomplish the testing or treating thereof.

The tool in assembled position is shown in Figyl as being lowered into the well bore by means of the oper- 3 ating pipe 5 which has an enlargement or collar 6 thereon which provides a shoulder. The lower section of the mandrel or pipe 5 may be of any desired length but is preferably slightly in excess of the length of the packer assembly which is shown as being suspended upon the collar 6 by means of the head 11 which is reduced in diameter to fit closely about the periphery 12 of the operating pipe 5.

With the parts in the position shown in Fig. 1 the operating pipe will be lowered into the well bore until the center portion 14 of the packer assembly 10 is opposite the formation 3. The upper packer 17 and the lower packer 18 will thus be above and below such formation 3 and capable of being inflated to form a seal with the wall 19 of the well bore.

The packers are made up of a resilient sealing member 21 which may be made up in any desired form but it is preferably that disclosed and claimed in my prior co-pending application, Serial Number 473,928 led January 29, 1943, for High Pressure Hydraulic Inflatable Packer and Assembly for Testing and Treating Form-ations, reiiled as Serial Number 65,843 on December 17, 1948, and now issued as Patent No. 2,611,437 on September 23, 1952. This resilient member 21 is anchored to a coupling 22 threaded at 23 in the head 11 and in a similar manner is connected to the central portion 14 of the packer assembly, The lower packer 1S is similarly formed. Thus the central portion 14 connects or joins adjacent packed ends to unite the packer assembly 10 so that it is freely iioating on the operating or supporting pipe 5.

A collar 25 on the operating pipe 5 within the packer 17 serves as a stop to limit the downward movement of the pipe relative to the packer assembly in the course of operation of the tool as seen in Fig. 3 and as will be later described.

In order to inflate the interior area 26 of the upper packer 17 a plurality of openings 27 are arranged in the operating pipe 5 at such an elevation with respect to the collar 6 that such openings will be inside of the packer when the assembly is suspended upon the collar 6.

A somewhat similar opening or outlet 28 is arranged inside of the lower packer 18 as best seen in Fig. l. This opening serves to partially inflate and drain packer A conduit 29 through the central portion 14 of the packer assembly serves as aninterconnection between the two packers so that the pressure will be equalized in the two packers. This opening also serves to drain the interior of the upper packer into the lower packer when the packers are being deflated.

With the parts in the position shown in Fig. 1 liquid will be pumped downwardly through the pipe 5 and will discharge from the pipe through the openings 30 below the lower head 31 of the packer assembly. A housing 32 connected to such lower head forms a chamber 33 into which the liquid will discharge. Addition-al openings 34 in the operating pipe 5 spaced below the openings 30 serve as an outlet for the liquid from the chamber 33 so that it may discharge through the ports 35 in the foot piece 36. The liquid is caused to flow out of the pipe 5 and into the chamber 33 by virtue of the foot valve 37 which is mounted for sliding movement in the lower end of the operating pipe 5, which valve is supported by means of a spring 38. The slots 39 in the foot valve screen the liquid entering the tool and permit the flow of liquid therethrough.

The valve 37 is reduced in size to permit a flow of llquid thereby andthe nipple 42 and lock nut 43 permit adJustment so as to provide the desired compression in the spring 38 so that the valve can be adjusted to open at a desired pressure.

The shoulder 41 in the operating pipe serves as an upper limit for the head of the valve 37.

It seems obvious that when the rate of circulation through the pipe 5 is increased, that a pressure will build up within the pipe due to the size of the

openings

30 and 34 which form a choke structure. This increase in pressure thus caused will exert a downward pressure upon the head of the foot valve 37 and cause it to move downwardly to the position shown in Fig. 2 whereby it blocks off the openings 34 and closes the operating pipe.

In actual operation the rate of circulation will be such that the valve 37 will not close until the well has been Vsufficiently washed and reconditioned to remove any excessive materials to equalize the column of drilling mud or to replace the drilling mud with any other suitable material desired in the operations. When the well has been properly conditioned, it is only necessary to increase the rate of circulation to cause the valve 37 to move to closed position so that there can be no further discharge of liquid from the operating pipe.

The closing of the lower end of the operating pipe thus causes the flow to be directed into the

openings

27 and 28 in the upper and lower packers respectively and through the conduit 29, thus inating the packers simultaneously. During the inflation of the packers, the packers contract axially so that the lower portion of the assembly will creep upward on operating pipe 5 as best indicated in Fig. 2 until the periphery of the packers bear against the well bore 19 of the well above and below the increment of formation at 3, thus forming a seal with the wall of the well bore. The upward movement of the packer assembly on the operating pipe 5 causes housing 32 to move over the

openings

28 and 30 so that they are confined in the chamber 33. This leaves only the opening 27 within the upper packer 17 in com munication with the inside of the packers. Any further increase in pressure applied to the packers is now equalized between the two packers due to the conduit 29 and when the desired pressure has been applied to firmly set the packers against the wall of the well, the operating pipe can be lowered to the position shown in Fig. 3. It will be noted here that the opening 27 is now within the confines of the central portion 14 of the packer assembly and is positioned in the recessed area 45 which is `an annular space around the inside of the portion 14 so as to insure a connection through the passage 46 with the perforated openings 47 opening into the isolated section 48 in the well bore between the upper and lower packers. The movement of the openings 27 into the central portion 14 and out of the upper packer 17 serves to lock the liquid within the two `packers so las to insure their remaining in inated position and thus maintaining a seal with the wall of the well bore during testing and treating operations.

A plurality of packing or sealing means 60 are provided in the assembly as illustrated in the drawings whereby the

packers

17 and 18 and intermediate portion 14 is ysealed about the pipe 5. l

The positioning of the passage 27 in communication with the perforated openings 47 serves to open the tool to the formation 3. If a treating operation is to be performed, the treating liquid will have been pumped downwardly through the operating pipe 5 to such an extent that the entire assembly both within and without is completely submerged in the treating liquid. After it has been calculated that the treating liquid has moved out through the bottom of the tool and upward in the well bore suici'e'nt distance to submerge the assembly within the treating uid, the packers are then inflated and the tool opened to the isolated section of the formation so ,as to permit the treating agent to permeate the isolated section of the formation. In cases where the supporting pipe is filled with liquid such as drilling mud, it is necessary to displace such liquid with the treating element. rThis isaccomplishedby pumping the treating liquid downward on top of the liquid present in the supporting pipe until calculations indicate that the supporting pipe is free of liquid other than the treating agent and that sufficient treating liquid has passed out ofthe bottom of the tool and upward in the well bore suicient distance to submerge the assembly in the treating agent. The assembly is submerged in the treating liquid to avoid pumping the drilling mud or other' liquid that might be present in the well bore into the isolated section of the formation to be treated.

If the volume of treating liquid is less than the volume of operating pipe to the surface, the treating liquid of course will be followed by any other suitable liquid such as water, oil or drilling mud. In any event, the desired amount of treating liquid will be pumped through the tool into the formation. The tool can be closed to prevent any back flow or if pressure is to be maintained upon the treating material in the formation for any substantial period of time, this can be accomplished by closing the valve on the supporting pipe 5 at the surface. It is desirable to follow the treating liquid with a liquid of less speciic gravity than that in the well bore so that the static pressure in the supporting pipe S would be less than that within the isolated section.

If the action of the treating material on the isolated. formation fails to develop suiicient pressure to force the liquid to the surface through the supporting pipe 5, a swab is used to relieve the static pressure in the supporting pipe against the isolated section of the formation.

If it is now desired to move the tool to a new location, the operating pipe will be lraised so as to move the openings 27 into the upper packer which allows the liquid which has been trapped in the packers tot'move back into the operating pipe in order to equalize the pressure. The packers being of resilient material will assume their normal position as shown in Fig. 1. The setting and resetting of the tool may be continued as many times as desired without removing the assembly from the well bore.

In Vsome instances, particularly where the treating material is a type which solidies, then the tool may not be submerged in the treating liquid, but the well will be washed out, the packers set, and then the treating liquid discharged.

It will be borne in mind that during this entire time, there has been an excessive pressure upon the head of the foot valve 37 which will have maintained it in closed position. When the pressure is released, the foot valve will raise up to its uppermost position `as seen in Fig. 3, but circulation cannot be initiated due to such movement because `of the fact that the openings 34 are spaced below the lower portion of the housing 32 which excludes liquid from entering or being discharged from the supporting pipe and assembly.

When the packers are to be deflated, the operating pipe will be raised to the position of Fig. 2 and then finally to the position of Fig. l so that the inherent resiliency of the packers will cause them to Vdeflate and ofcourse any predominant pressure in the well bore over that occurring in the packer will also tend to squeeze out any liquid remaining in the packers.

The foot valve 37 will of course resume its position ask seen inrFig. l and the well may now be washed or circulation resumed to remove any treating material remaining in the operating pipe or to equalize the liquid lin the well bore.

This circulation operation may be accomplished by pumping the liquid downward through the well bore on the outside of the supporting pipe entering the assembly through the opening 34 upward through the supporting pipe to the surface which would vretrieve to the surfacer any liquid that may have entered the supporting pipe from the isolated section as a result of the treating operations. If the specific gravity of the liquid in the supporting pipe is less than the specific gravity of the uid of the well bore, the uid in the supporting pipe .would be forced upward by the column of uid .in the l 6 well bore without the necessity of such circulation lor pumping until the two pressures were equalize'd.

It is to be understood that by treating material, any chemical composition or other liquid including such materials as cement or other substances used in blocking off porous formations may be used.

The tool is capable of use as a testing tool to test the nature of the contents of the formation 3. To use the tool as a testing device, it will be manipulated as previously described in washing the well and inflating and locking the packers. When the tool assumes the position of Fig. 3, however, it will be desirable to have a reduced pressure inside ofthe operating pipe as regards the pressure in the formation 3 so as to enlarge a flow of formation fluids into the operating pipe. This can be accomplished in several ways such as by swabbing'or emptying the operating pipe or by utilizing in the operating pipe a liquid having a low specific gravity. When a sample has been received in the operating pipe, the tool can be closed and the sample then swabbed out of the hole or the tool may be opened and circulation reversed and pumped downwardly through the well bore and upwardly through the operating pipe to retrieve the sample. If desired, of course the entire tool can be removed and the sample recovered as the operating pipe approaches the surface.

Figs. 6, 7 and 8 show the same construction as previously described except the operating pipe has been modied somewhat to provide a by-pass pipe 50 which has its upper end arranged in a tubing 51 connected to the ports 52 so as to open the pipe 50 to the area within the well bore above the upper packer 17. This by-pass pipe 50 is also seen in the lower portion of Fig. 6 as projecting through a central opening 53 in foot valve 37 so as to communicate with the lower end 54 of the foot piece and the area below the lower packer 18.

The passage 55 is shown in Fig. 7 as extending through the tubing 51 to permit the flow of liquid into the packer assembly. V

Fig. 7 shows a section of the inlet ports 52 through the coupling 51 and Fig. 8 shows an enlarged view of the foot valve and by-pass pipe.

This by-pass pipe is desirable in many instances in a well bore because when the operating pipe moves downwardly through the packer assembly, if the assembly has been set, the valve of the operating pipe moving into the closed area below the sealed packers in the well bore would tend to build up a tremendous pressure and if the entire lower end of the well bore below the lower packer 18 happened to be impervious formation, it would be impossible to move the operating pipe downwardly because a hydraulic` lock would have been formed.

The by-pass 50 tends to equalize the pressure above and below the packer assembly and permits easy and ready manipulation of the parts.

When desired the tool may be used for the combination of treating and then testing the formation. To accomplish this, the tool is operated to force a treating material into the isolated 'formation and then holding such treating material into position for a desired period of time and then operating the tool as a testing tool to recover the treating material as well as any other fluid which can be extracted from the earth formation due to the action which has occurred by virtue of the treating material. In other words, as an illustration, suppose an acid is used to dissolve certain material in the formation so as to open up the pores thereof and permit an inow of fluid or liquid resident in the formation when the treating material is extracted by a testing operation, the resident fluid or liquid can then follow the treating material into the tool so that a result of the treating is thus obtained.

Broadly the invention contemplates the process of testing and treating well formations wherein there is a single operating member for effecting all of the functionsrnecessary to carry outsuch testing and treating of an isolated section of a formation.

What is claimed is:

l. A well tool comprising, a packer assembly, said assembly 4including a pair of inflatable `packers and an intermediate portion connecting said packers together, there being an opening in said portion communicating with the exterior thereof, an operating mandrel movable through said assembly, there being port means in said mandrel for directing fluid into said packers, said packer assembly movable axially relative to said mandrel as said packers inflate, means sealing said packer assembly about -said mandrel whereby fluid may be retained in said packers, and cooperable means on said mandrel and said assembly for positioning said mandrel to first direct fluid to inflate said packers, and to thereafter position and align at least part of said mandrel port means and portion opening upon movement of said mandrel relaitve to said inflated packers.

2. A well tool including a pipe, a packer assembly movably mounted on and sealed about said pipe, said assembly including spaced upper and lower inflatable packers having an intermediate portion connecting the adjacent ends of said packers, cooperable means on said assembly and pipe positioning said assembly relative to said pipe, there being port means in said pipe to discharge inflating fluid to said packers, and there being port means in said intermediate portion opening to the exterior thereof between said packers with which the port means in said pipe are alignable upon movement of said pipe relative to said packer assembly.

3. A testing and treating tool for wells comprising an operating pipe, a packer assembly, means supporting said assembly on said pipe, said assembly including a pair of spaced inflatable packers and an intermediate portion for connecting the adjacent ends of said packers, means to seal said packer assembly about said pipe, and there being port means in said pipe for discharging fluid from said pipe to said packers to inate said packers.

4. A well tool comprising, a packer assembly, said assembly including a plurality of inflatable packers and an intermediate portion connecting the adjacent ends of said packers together, there being an opening in said assembly communicating with the exterior thereof, an operating mandrel movable longitudinally through said assembly, means sealing said assembly about said mandrel, cooperable means on said assembly and operating mandrel supporting said assembly on said mandrel, there being port means in said mandrel for directing fluid to inflate said packers, said mandrel thereafter movable longitudinally of said assembly whereby some of said mandrel port means are alignable with said assembly opening.

5. In a well tool, spaced inflatable packers, an intermediate portion connecting the adjacent ends of said packers together, and an operating mandrel extending through and supporting said packers and intermediate portion, and means sealing said packer assembly about said mandrel whereby inflating fluid may be retained in said packers.

6. In a well tool, a pair of inflatable sealing elements for isolating a section in a well, an intermediate section connecting the adjacent ends of said elements together, an operating mandrel movable through said elements and intermediate section, means sealing between said elcments and said mandrel, means supporting said elements on said mandrel, there being port means in said mandrel for directing inflating fluid to said elements, whereby said elements may be expanded to bear `against the wall of the well to isolate a section thereof, and therebeing an opening in said intermediate section communieating with the exterior thereof and with which at least one of said mandrel port means is alignable for communication between said mandrel and the isolated section of the well upon longitudinal movement of said mandrel relative to said elements.

7. A Well tool including an operating pipe, a packer assembly slidable on said pipe, said assembly including spaced inflatable packers and an intermediate portion connecting adjacent ends of said packers together, there beingport means in said pipe for directing fluid to inflate said packers, means sealing said packer assembly about said pipe whereby fluid may be retained in said packers, and cooperable means on said assembly and pipe positioning them together.

8. A well tool including an operating pipe, a packer assembly, cooperable means on said assembly and pipe suspending said assembly on said pipe, said assembly including spaced packers and an intermediate portion connecting the adjacent ends of said packers together, there being port means in said pipe to direct fluid into said packers, and means sealing said packer assembly about said pipe whereby inflating fluid may be retained in said packers.

9. A well tool including a pipe, a packer assembly sealed about and slidable on said pipe, said assembly including spaced inflatable packers and an intermediate portion connecting said packers together, there being an opening in said intermediate portion communicating with the exterior thereof, there being port means in said pipe for directing inflating liquid from said pipe to said packers, said packer assembly movable axially relative to said pipe as said packers inflate, and cooperable means on said pipe and assembly for positioning said pipe to direct liquid so as to inflate said packers and to thereafter position and align at least some of said pipe port means and intermediate portion opening to communicate said pipe with the exterior of said intermediate portion.

10. A well tool comprising a packer assembly, said assembly including spaced inflatable packers and an intermediate housing connecting said packers together, an 0perating mandrel movable through said assembly, means supporting said assembly on said mandrel, there being port means in said mandrel for directing inflating fluid to said packers from the mandrel, said assembly movable axially relative to said mandrel as said packers inflate, means sealing said packers about said mandrel whereby inflating fluid may be retained in said packers, there being port means in said intermediate housing communicating with the exterior of said housing and with which at least some of said mandrel port means is alignable upon movement of said mandrel relative to said inflated packers for communication between said mandrel and the exterior of said tool between said packers, and a by-pass means in said packer assembly for equalizing the pressure above and below said assembly, said means including a pipe extending through said mandrel and assembly and open at one end to the exterior of said mandrel above said assembly and open at its other end to the exterior of said mandrel below said assembly.

11. ln a well tool a packer assembly, said assembly including inflatable packers and an intermediate portion connecting the adjacent ends of said packers together, there being opening means in said assembly communicating with the exterior of said tool, an operating mandrel movable relative to said assembly, there being port means in said mandrel whereby fluid may be directed to inflate said packers, means sealing said assembly relative t0 said mandrel, and cooperable means on said assembly and mandrel to position said mandrel whereby at least-a part of said mandrel port means may be communicated with the exterior of said tool through said opening means in said assembly.

12. A Well tool comprising, an operating mandrel, a packer assembly slidable on said mandrel and including, upper and lower inflatable packers having upper and lower heads and an intermediate portion connecting the adjacent ends of said packers together, there being opening means in said assembly for communication ywith the exteriorof said tool, therebeing port means in said mandrel for discharging fluid from said mandrel to inflate said packers, said assembly movable axially relative to said mandrel as said packers inflate, means in said heads sealing said packers about said mandrel whereby inflating uid may be retained in said packers, and cooperabie means on said mandrel and assembly to position said mandrel longitudinally relative to said assembly so as to inflate said packers, whereupon said mandrel is movable to then communicate at least some of said mandrel port means with the exterior of said tool through said opening means in said assembly.

UNITED STATES PATENTS Boynton Mar. 27, 1928 Stamps Ian. 16, 1940 Lynes Ian. 7, 1941 Halliburton Mar. 18, 1941 Lynes July 25, 1950 Lynes et al. July 25, 1950