US 2007465 A
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c. BURTY- V `July 9; T1935.-
METHOD AND MEANS FOR `INDICATING THE POSITION oF AV DRILLING` BIT 1N A 'WELL cAsING Filed Sept. 12, '1934 "INI/ENTOR. v @f/wm BY" ATTORNE.
t Patented Julya 193e tirarsi) STA-'r Eis PATENT OFI-ICEl 2,007,465 e t METHOD AND MEANSFOR INDICATING THE POSITION OF A nmLLrNG Brr 1N A WELL I Clarence E. Burt, Los Angeles, Calif., assignor to A Baker Oil'l'ooyls,` Inc., Huntington Park, Calif., I
` a' corporation of California 1 Amiiicatnmseptember 12, 19341,` serial No. 743,644 sclaims. (c1. 25e- 1) This invention relates to the art of drilling deep oil wells and particularly pertains to a method and means for indicating to the driller at the surface thefdepth ofthe bit in the tbore.
" 5 `In practicallyall oilelds it is common practice to discontinue drilling just before entering the oil sands and to set a string ofcasing. This casing `is 'cemented into placel-and acts 'to prevent the walls from caving and to exclude waters and gases from intermediate strata vfrom migrating along the casing. After this casing is set and cemented in,` drilling is` usually proceeded with vinto lower strata or into the oil producing sands.
For various reasons it is desirable that the driller be able to determine whenn the drilling bit is passing through the lower endofthis'casing;` and therefore it isthe principalv objectof the pres-- lentinvention to provide a method andgmeans form s indicating tothe .driller that the' drill isgorjhas penetrated through the ylower Jendof thel casing.
To practice my invention, I iit the lower end of the casing with a member formed of drillable material and which willrbe eng'aged by thedrill when I it is' desired to` proceedwiththe drilling through the casing. This member is so constructed that a visible indication willbe given to thedriller by the circulating `uid when the drill commences pulverizing thesame.
One form which the invention may assume' is exempliiied in the followin`g^descriptionand vil-v lustratedby way of examplein the accompanying` drawing, inwhich: Fig.` 1 is a view in central vertical section through an oil well bore showing the water string of casing set therein andthe drilling aboutxto be e proceeded with, the lcasing beingttedfwith a device for practicing my invention.
Fig. 2 is an enlarged `central vertical section through a device for practicing 4my invention.
`In .practically all instances the water string of casing. III for an oil well bore is fitted at itsv lower end with what is knownas a casing shoe I I which in turn is usuallyfltted` with a'guide plug or a' guide float plug I2. The function and operation of these devices is well known and understood and in prior practice these plugs have been construct-l ed out of such materials as concrete and cast iron in order that they can be drilled out.
My present invention contemplates so constructing such a plug that when it `is drilled up,'a
Vvisible indication will be givenftat the mouth ofthe well indicating to the driller that the drill is t passing through the lower end of the water string of casing, To accomplish lthis I prefertto `construct the plug out of a granular or lapideous ma-t terlal such as a-concrete mixture so that when it is pulverized by the drill, the granularV particles thereof will be carried to the surface by the circulating fluid.v I intend that the drilling of this plug furnish a visible indication in the drilling fluid that the drill is-penetrating through the lowerend of the water string. For this purpose. during the constructionof the plug, aV quantity ofcoloring agent is added to the cement mixture so that the `material when drilled up will be of a color clearly distinguishable from the drilling mud or fluid. In actual practical have found that iron or. ferric oxide FeaOs is a very suitable agent for this purpose and I prefer to use this agent in When such `a mixture is used,the`material of the plug assumesv avery vivid redcolorclearly distinguishable from the drilling mud,` and when the drillpulverizles the plug and these cuttings are ,carried to rthe surface by the drilling mud'.
Etheycan be readilyV detected, thereby indicating tothe driller that the drill is penetrating` through the lower end of the water string of casing. y
the present instance, I have` also shown a second medium for indicating that the drill is penetrating through the lower end of the' casing.
This second medium is a coloring agent which is ahi'ghly concentrated water "soluble red dye in dry powder form. The dye which I have used in practice is what is` known as Safranine dye.
-This'dye iscontainedjin dry form in chambers I4 formed within the plug so' that when the drill pulverizes the plus, this dyewill be released into the mud or circulating fluid, khighly coloring the `same so that when this uid reaches the surface,
a clear visible indication will be given to the driler that the drill is penetrating through the shoe of the water string. e l
In the present instance, I have enclosed the drypowder dye in two glass vials which are embedded withinvthe plug during the formation thereof; 'Theamount of dye which I have used is `approximately one-half ounce, which I have .found will' giveV a very definite distinguishing color (red), to approximately one barrel of cir--l culating fluid.
I havefound that the plug is satisfactory withthatthe dye can be'used alone without coloring the'material of the plug, but, however, I prefer J to use both. V
t Inthe present instance, I have disclosed -nrv invention'as'being practiced by means of the l x l plug forming the guide or oat shoe but it is obvious, v'of course, that this is not essential as it may be practiced in various other ways.
In practicing the invention, the plug is constructed as previously described and the water string of casing is set in place and cemented in. This cementing process usually leaves from twenty to forty feet of cement tailings in the lower end of the well casing which must be drilled up. After the casing has been cemented in, the drill is run downwardly through the casing to drill up the cement tailings remaining inthe casing and to proceed through the casing into lower strata. During drilling, of course, mud fluid is circulated downwardly through the drill pipe, returning up the casing to the surface.
When the drill commences penetrating the plug at the lower end of the casing, the returns will show the cuttings of the plug due to their being of a color clearly distinguishable from the mud. Likewise, when the drill pulverizes the plug releasing the Safranine dye, this dye will immediately color the mud fluid so that the returns at the mouth will clearly indicate to the Ydriller that the drill is penetrating kthrough the lower end of the casing. This gives the driller an accurate check on the depth and also has a number of other advantages. e
While Il have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art withoutjdeparting from the spirit of the invention as deiined in the appended claims.
Having thus described my in\ ention, what I claim and desire to secure by Letters Patent is:
1. A method of determining when the drilling bit passes a certain point in a well casing ina deep oil well which includes the step of positioning a drilling iluid coloring agent in the well casing at said certain point where it will be released into the drilling iiuid.V by the drilling bit when the latter passes that point. f
2. A method of indicating that the drilling bit passing through a well casing in `a deep oil well has passed a certain point in the well casing which includes the step of positioning a circulating fluid coloring agent consisting of a highly concentrated dry dye within the casing at said point in amanner whereby it will be released into the drilling fluid when the drilling bit passes said point.
a. A method of indicating that the arming bit Vhas penetrated through the lower end of a string of well casing in a well bore which includes the step of positioning a drilling fluid coloring agent in an obstructing position within the `lower end of Asaid casing in a manner whereby it will be released into the drilling iiuid to color the same 'when the drilling bit passes through the lower end of the casing.
4. A method of indicating that the drilling bit has passed through the lower end of a. string of well casing in a Well bore which comprises securing a drillable container in the lower end of the well casing and containing a highly concentrated circulating uid coloring agent, said container being positioned to be drilled up by the drilling bit as it passes through the lower -end of the well casing to release said coloring well casing, container means mounted interiorly of said tubular member and adapted to obstruct the passage ofa drill through said tubular member, said container means being capable of being drilled up by a drilling bit, and a highly concentrated coloring agent contained within the container means whereby it will be released into the drilling mud when the drilling bit penetrates said container means. l
7. As an article of manufacture, a casing shoe adapted to be secured to the lower end of va well casing, a plug secured within said casing shoe .and of a material capable of being drilled up,
said plugcontaining a highly concentrated circulating iluid coloring agent which will be re' leased into the circulating uid while a drilling bit is drilling'up" said plug.
8. As an article ofmanufacture, a casing shoe to be fitted to'the lower end of a string of well casing, a cementitious plug secured in said casing shoe, the cementitious material of which said plug is formed being highly colored in contrast with the drilling fluid, said plug having a chamber formed therein, and a highly concentrated dye in said chamber releasable into the circulating fluid when the plug is drilled up by a drilling bit.
CLARENCE E. BURT.