US1565574A - Well-cleaning process - Google Patents

Description

C. LARSEN WELL cpaANlNG PROCESS Dec. 15, 1,925"

Filed June 27, 1924 marie; L a

attoz wmj Parenteel Dec.' 15, 1925.

CHARLES LARSEN, OF DENVER, COLORADO.

WELL-CLEANING PROCESS.

Application led June 27,

To all whom, itv may concern:

Be. it known that I, CHARLES LARSEN, a citizen of the UnitedStates. residing at Denver. the city and county of Denver and State of Colorado. have invented certain new and useful Improvements in Tell-Cleaning Processes; and I do declare the following to bc a -ency to` gum up and choke, thereby greatly decreasing the amount of their production. This is one of the most serious problems confronting the producing end ofthe industry and many experiments have been made for the purpose of producingv some satisfactory method of cleaning the well and of restoring yit to production. It is not alone paraiiine that causes the sealing or choking of the 'well, but salt also adds to the'ditliculty.

In the past deparailining has been attempted in many different ways, some of which have been partially successful, but none of which have been generally adopted.

In a process of this type it is necessary to dissolve the saltas well as to melt the paraifine and to remove the salt and paraiine while they are in a fluid state, and this can only be accomplished when the pump line and pumping apparatus is in place. I have found that if superheated steam at a pressure of substantially one thousand pounds is con- D ducted to the bottom of the well and there liberated, the heat transferred and liberated will soon raise the temperature of the walls ofthe well to such an extent that the parafline will-me1t'andflow out into the sump where it is removed by 'the pump. The water which is formed from the condensed steam is a goodsolvent of salt 'and will cause the latter to go into solution, whereby it, as well as the paralhne, will be removed by the pump. Actual experiments have shown that wells which have been treated for jless thantwenty-'four hours, have had their production increased approximately eighty-live per cent.

The steam is introduced into the well and 19,24. serial No. 722,s1s.

,conducted to the bottom by means of a small pipe located within a larger pipe, from the walls of which it is spaced so as to be entirely surrounded by an air space that'serves as a heat insulator. A special litting is provided at the lower end of the larger pipe, which forms a seal between it and the smaller pipe, whereby liquid Vis prevented from entering the air space between the pipes. v

In order to carry out my process successfully, I employ an apparatus which I will now describe in detail, reference for this purpose being had to the accompanying drawsoy ing in which the apparatus .is shown in a general way, and in which:

Fig. 1 is a vertical section through a well and shows the location of the pump line, the steam line and the boiler; andy Fig. 2 is a section through the lower end of the steam line and shows the special fitting.

Numeral'l represents an oil well whose bottom has been enlarged by shoot-ing into a chamber 2, which varies in size, but which is usually about twenty feet in diameter. After a well has been in operation for some time, the parafline will gum or clog the pores in the sand, producing astratum 3 which is practically impervious and whichtherefore prevents oil from the surrounding sand to flow into the well. vThis fsealing action is further aggravated b the presence of salt, which precipitates an forms a crust onthe inner surface. The ultimate result of this sealing action is to render the well entirely nonproductive.

The pump line 4, with its working barrel 5 and pumping jack 6 is of ordinary construction, and is not interfered with or al-` tered in the least. For the purpose of generating the steam I have provided a boiler 7 which, together with the remaining parts of the apparatus, -is'specially built of bronze and Monel steel so as'to enable it to Withstand the terrific heat landl yressure. The heat is derived from an oil last which is produced by means of well known apparatus. The' steam is conducted by means of a three-quarter inch, gt/f) pipe 8 (from the boiler), which exten s downwardly within the two inch (2) pipe 9. The lower end of pipe 9 is provided 'with an ordinary hydraulic coupling 10, to which isl threadedly connected a special fitting 11. This fitting has an axial opening 12 approximaly Aone and one-half inches (1l/2)in diameter, extending substantially one-halt1 fthe' length thereof, Another opening 13 co-axial with opening 12, but of a smaller diameter (about one inch) extends the remainder of the le ngth,of the tting. The shoulder 14, which joins the inner surfaces of the two openings, is inclined at degrees and forms vents water or other liquid from cntering the space between the pipes and at the same time permits the withdrawal of pipe 8. Secured to the part 16 is a nozzle 17 which is provided with vperforations 18.

The lower'end ofthe fitting 11 is threaded,

as indicated by numeral 19,'for connection of an anchor in case thisv should be necessary., l f When the partsare in place in the manner shown and described, steam is vgenerated in the boiler 7 and raised to a pressure of about 1000 pounds per square inch and superhveatedto eleven hundred de ees Fahrenheit. This intensely hot, hig pressure .steam is permitted to flow through-pipe 8 land enters the well through the openings 18 in the nozzle 17. The pump is kept in constant'operation while the process is carried out and serves to remove the molten paraiine from the walls.

b By means of theprocess outlihed above, it

will become possible to restore to production a4 large percentage of the many thousand wells that have become partially or entirely choked bv paraiiine or salt and thereby make available a large amount of oil that at present is unattainable.

This application is a continuation in part of my (zo-pending application, Serial No. 664,130', filed September 21, 1923.

Having now described my invention, what I claim as new is:

l. A method of cleaning oil wells, which consists in generating steamat a pressure of substantially one thousand pounds per square inch and conducting' the same to the bottom of a Well where it is permitted to expand and liberate its heat whereby the Walls of the well become heated sufficiently to Vmelt any solidified paraifine, and whereby the water of condensation will cause solublefmatter to enter ntosolution, a-nd simultaneously removing the liquids from the well.

2.'A method of cleaning oil wells, which consists in generating steam at a pressure of substantially one thousand pounds per square inch and superhated to eleven hundred degrees Fahrenheit and conducting the same to the bottom of aJ well where itis permitted to expandand liberate its heat whereby the walls of the well become heated suiciently to vmeltA any solidified paraliine,

Iand whereby the water `of condensationwill cause soluble nfatter to enter into Solution,

and simultaneously removing the liquids from 'the well. p

In testimony whereof I affix my signature.`

CHARLES LARSEN.

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