US2439542A - Water detector for oil wells - Google Patents

Description

R.'S. HUNT WATER DETECTOR- FOR OIL WELLS April 13, 1948;'

lFiled April 4, 1945 w1 mf v w 5 e. n nu 2M W U 0 v1| 1mm m JM if.

Patented Apr. 13, 1948 UNITED STATES PATENT OFFICE WATER DETECTOR FOR OIL WELLS Raymond S. Hunt, Mount Pleasant, Mich.

Application April 4, 1945, Serial No. 586,511

4 Claims. (Cl. 166-1) This invention relates to a water detector forv oil wells.V

In drilling wells for oil, the hole drilled downward through the earth frequently goes through a .water bearing stratum whereupon the hole or passage is filled with water. Upon this occurring and after a solid rock stratum has been reached, it is customary to drive a casing .down and attempt to provide a seal between the casing and the solid seat against which it engages, thereafter continuing drilling with a smaller diameter hole or passage. In such drilling beyond the casing and seal, frequently more water appears and previously there has been no way of knowing whether such additional water came from a new water bearing stratum which had been opened or whether the seal has been broken permitting inflow of water from the iirst source.

It is a primary object and purpose of the present invention to provide a novel detector means, which is a carrier or container for dye, for coloring water from the first source of water which has been passed through, andwhich will give, to any Water coming from the first water bearing stratum, a distinctive color whereby upon further drilling beyond the lower endof the casing and its seal water thereafter encountered, if it is colorless, will be known to have come from a new water bearing stratum below the casing. On the contrary if the water is colored, it is then known that it is water from the first water bearing stratum which was drilled through, and which has escaped from the drilled hole or passage and thence into the casing because of leakage due to ineiectiveness or rupture for any reason of the seal described.

A further object of the invention is to provide such container r carrier for the dye and safeguard it so that the mixture of dye with water from the first water bearing stratum in the -drilled passage or hole will not occur until after the casing has been introduced and has been moved downwardly the full length of the drilled passage and seated and sealed at its lower end, whereby the distinctive color given to the water will not manifest itself and show up too early and, therefore, defeat the purpose for which it is to be used.

The invention for the attainment of the objects stated, and for others which will be hereafter enumerated, may be understood from the following description taken in connection with the accompanying drawing, in which,

Fig. 1 is a section and elevation illustrative of strata passed through in drilling an oil well and 2 with the well cased and my invention utilized in connection therewith.

Fig. 2 is a horizontal section, enlarged substantially on the plane of line 2-2 of Fig. 1, looking in a downward direction.

Fig. 3 is a transverse section substantially on the plane of line 3-3 of Fig. 2, and

Fig. 4 is a section similar to Fig. 3, fragmentary only, at one side of the dye carrying member.

Like reference characters refer to like parts in the different figures of the drawing.

Illustrative of a series of strata which may be drilled through in the production of an oil well, in Fig. 1 the upper stratum I may be of very considerable thickness and start at the surface of the earth. Below it there may be a water bearing stratum 2 of sand or other porous material, below it a stratum of shale 3 which rests upon limestone stratum 4 and below it the oil bearing stratum 5 may be located. It is of course to be understood that the strata encountered in drilling oil wells are of many and varied characters and what is shown is merely for illustrative purposes.

In the drilling of the well, a downward passage or hole 6 is made through all of the upper strata until the solid rock stratum 4 is reached. In such drilling `the water bearing sands at 2 will be passed through and the hole filled with water. When a solid rock foundation is reached as at 4, the drill is pulled and the Well cased. In such operation the successive casing sections 'l of pipe are introduced into the well, new sections being successively connected at their lower ends to the upper ends of the sections last'introduced, using coupling collars 8 interiorly threaded. The first casing section 'l which is introduced into the well at its entrance or lower end has a sealing sleeve or collar 9 threaded thereon and in usual practice a ring I0 is placed around the lowermost section 1, which for example may be made of a rubber composition and is of an elastic nature, the hope being that it will prevent passage of water below it, but no certainty of such prevention of water passage can be had. The lower end of the sealing collar 9 rests upon the bottom of the drilled hole 6, and because of the weight of the casing, which may be hundreds of feet in length, will tend to snugly engage the surface and seal off water passage. But such sealing off against water passage cannot be insured and frequently water does pass between the lower end of the seal 9 and the seat against which it is engaged.

. thereof.

`. are drilled downwardly into the walls of the sleeve but terminate before reaching; the l0wer.-..end Said holes are partially Avfilled with a `crystallin water soluble dye which prefer'ablyis mixed with some water eervescent-substance which reacts when mixed together in the presence of water with high effervescence. Abovezfsuch mixture of dye and water effervescent substance aeseal lfwhich 'isalso watersoluble. b ut-` slowly so as to take a considerab'letimeris:.placed. .For .examplepal hard-candy. mightafbe-fused, introduced 1 -iiquid form,'-.'and..e:llowed's to `harden.

Such dye carrier sleeve-oncollar-:willflhavethe seals' at i i? exposed-.to `the-actionfo 'wateigfwlrich in general is saltfwfatergrand.such-fwateresoluble .eealf-i @will slowly'rdissolve so that: eventuaily'the .mixture pf crystallin'dye and waterfeie'rvescent substance is reached. This provides the timeelelmept'inecessaryor casingathe fwellrand getting the sealing collars-@tto its-lowermost,position and fseated againstfethekbottom-of the driiledr'hole 6. Suclr time lag :is: essential asrl'otvlierwiseuthe: Water i weuld becomecolcredsandlthere: would 4loecolored avaterwithin `the casingfasrweltas outside. Aiter ftheiwell haswbeen cased, :drillingis then'continu'ed inv-a :hciewor'passage i 'ixsor smaller-:diameter than the-r drilled liolesor, passage. 6 .until either thexoil bearing stratum his:y reached or `waters is again encountered.

if water; appears fwit'hin .theicasin'ggupon' a lcontinuationof drilling: the passage-:l "li'andithewater isrco-lored, litnis .thenwknownfthat iitfis not from a fresh or new source of supply but fromtthesame uwater #bearingl stratum ":r'st nencountered. fAlso fifgras occurs lat times;ithe-'oilfibearingf-stratumzis reached :and mixed fwith'f thewoil` `vwater: iap'pears, and smcl'iv wateniscolored', itfis thereuponsknown Vthat there lisclealsageat: the'lower endiof the fse'al Iisandthaithezwater does notcomefrom theoil 'bearingristratum i .inv4 addition? to' the: oiliobtained.

*.But: clear vfwater. 'coming iin ...therisuccee'ding c illing of the: smaller f passage li 'his l`rnecessarily indicative oft the factfthat` #ane ad ditionak source f 'atei1 supply has `loeeir reached.

It isrnotifimportant-at what position,- .between `theflowerniost'collar:Brandthefrubber .packerf'ring al il; that fthesdyecarrying member IZmay be positioned. 'In'lanyfcase upon the'water1 solubleseal- `ing.' material 1* at" lI 6 being dissolved',= there 'ris-an "and type of dye'carrying :sleeve provided. Man

eervescence of the water effervescent material i5 with a consequent throwing out of the dye to the water within the hole 6 around the casing and it is dissolved in said water.

It is of course to be understood that there are other ways of insuring the necessary time lag before the dye is reached by the water and to give ample time for completing the casing of the well, many hours at times being required. Nor is the i invention restricted to 'the particular fori Variations in detail of structure may be resorte to for supplying the dye to color the water an for locatingV and retaining it below the lowermost connecting collar in the casing and for delaying -tliessolution ofthe dye in the water until the well has .been cased. The invention is to be considered comprehensive of all forms of structure coming-:within the scope of the appended claims which denne the invention.

' Although this-invention has been; described as applied to oil wells it is anticipated thatvzlitzfm'ay .also Vbe used` inotherxwells suchtas gas fwells.

I claim:

L1A structure as describedcomp1fising;.a,.-sleeve ..open-. at both Vends i-throughP-whicha.: iowermost section of .-a casing of Van roilwell isadapted toz be passed, said fsleeve,havingf-awcavity formed :be-

` tween the inner f 'andA outer-:sides '-of the sleeve,

ile of this patent:

'Water'soluble' dye vpartially. iilling said `cavity,rand

a lseal of material which dissolves s-lewlyzin vvi/falter closing-said cavityiadjacent itslupper; end.

2. yA@construction.-as' dened in' claim.1,'-, said sleeve-:around it# being-'- provided lwith a plurality of said cavities spaced from eachfotheryeach'open at its upper-end, filled-with water solubleV dye qan'd sealed adjacent itsuupperendwitha waterzsoluble seal of vslowly dissolving material.

v35A construction as'ldeiinedrin-:claim 1-,5 and a plurality of spaced 'apart .projections'f extending upwardly from the. Vupper- -endof?V the sleeve.

fl.der-construction AAas defined "inf claiml; andY watereervescent' material mixedwith i the'water `sol-ubledye.

1 RAYMOND" S. tHUNT.

-REFERENCES l CITED `"The' following /referencesare of 'record'inthe UNITED .STATES. PATENTS TNumber' V)Name ffDate 133,218 Beecher Mar'.23,=` 1915 2 ;007,465 vBurrl` July'9y1935 2,173,034 Armentrout etal. Sept. l2i,1939 2,280,785 Boynton AprL28, i942 VFor-trims :PATENTS Number .Country f Date 201,888 -Germany .M1908

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