US2018283A - Method and means for well development - Google Patents

Description

R. R. SCHWEITZER ET AL 2,018,283

METHOD AND MEANS FOR WELL DEVELOPMENT Oct. 22, 1935.

3'Shets-Sheet'l Wicca Original Filed Dec. 9. 1935 Oct. 22, 1935. R. R. scHwEmR 'ET AL 2,0 8, 83

METHOD AND MEANS FOR WELL.DEVELOPMENT Original Filed Dec. 9', 1933 3 Sheets-Sheet 2 Oct. 22, 1935. R. R. SCHWEITZ ER El AL METHOD AND MEANS FOR WELL DEVELOPMENT Original Filed De 9, 1933 3 Sheets-Sheet 5 a! loc nu Patented Get. 22, 1935 PATENT OFFICE METHOD AND MEANS FOR WELL DEVELOPMENT Reuben B.- Schweitzer and Chester R. Sundquist. Norfolk, Va.; said Sundquist assignor to said Schweitzer Application December 9, 1933, Serial No. 701,712 Renewed September 11, 1935 15 Claims.

This invention is directed to a method of and apparatus for the development of wells, either of the water or oil type, wherein through the method and apparatus employed the developed well is of maximum life, with the minimum possibility of any foreign solid matter reaching the fluid being delivered.

In wells of this type, particularly water wells, the development of the well hole is by the boring process, during which, as is well known, the drilling slush or mud delivered into the bore during the boringprocess under pressure and serving primarily tofloat to the surface of the well the borings, is directly utilized to provide a mud wall to prevent a cave-in of the bore wall, particularly in the sand bearing strata thereof. As the drilling slush is delivered into the well under pressure, the mud contained in this slush will be forced under pressure against the wall of the bore and serve to hold back the sands and other like material which would otherwise tend to be delivered into the bore and prevent a proper well formation. This mud wall is a characteristic feature of all rotary process wells in strata containing sand or other like material.

It has long been recognized, and many attempts have been made as a result of this known fact, that a complete removal of this mud wall is-an essential feature of the completed well, as

otherwise the sand stratum cannot efiectively permit the passage or the fluid into the well, and furthermore the incoming fluid is more .or less contaminated by the unremoved portions of the mud wall.

In wells of this type, it has been proposed to provide a filtration area around the screen and between it and the fluid delivering strata of the well, and in order to secure the maximum flow of fluid and the proper filtration thereof to prevent 4 inflow of sand with the fluid, it is vitally necessary in a well of this type to remove not only the mud wall but the maximum possible volume of the sand and like particles in the sand strata and substitute for this removed sand area the filtration media, usually in-the form of pebbles.

Experience has proven as a result of previous efforts practically developed that ordinary washing methods will not remove the mud wall nor remove a sufiicient quantity of the sand from the fluid bearing strata to permit that quantity of filtration media as will preclude any possibility of sand particles entering the well with the fluid. The ineffectiveness of the present methods, so far as known to us, are due primarily to the inability to completely remove the mud wall from 5 the bore of the well and at the same time remove suificient of the sand and like particles from the sand strata as to provide for the maximum flow of fluid and insure the utilization of the maximum amount of filtration media. 1 Therefore, the present invention has for its primary object the method wherein the mud wall and sand strata are directly subjected to a hydraulic mining influence and action to insure complete removal of the mud wall and the fur- 15 ther removal of the maximum amount of the sand from the sandstrata, while at the same' time substituting for the material removed a properly placed amount of filtration media. The filtering media, whether delivered as one 20 grade or more than one grade of fineness, is ordinarily applied from the top of the well by merely delivering in bulk and loosely, usually in the form of pebbles or the like selected as to size, and while this means of delivery is within 25 the spirit and contemplated as a part-of the present invention, such delivery under some circumstances may constitute an interference to the otherwise free flotation of the sand washed from the interior of the well by the hydraulic system 30 forming part of this invention. The hydraulic mining system employed in the present invention operates to dislodge a considerable portion of the sand from the water-bearing strata from the well, and this sand held in suspension in the 35 muddy fluid developed in the hydraulic mining action is floated out of the well by the rising fluid. In the loose bulk delivery of the filtering media through the top of the well, which filtering media must, of course, take-the place of the washed 40 out sand volume to avoid collapse, such filtering media must pass downwardly through the rising liquid stream to reach the place of deposit, and during this passage it has been found under some circumstances that the pebbles making up the filtering media tend to carry downward a considerable portion of the sand particles which are rising through flotation in the body of water. Where this action occurs there is a tendency for these sand particles to accumulate in the inter- 0 hence there is a tendency to interfere with the flow of the water and thus unnecessarily reduce the volume of delivery. In order to insure against this possibility, the invention contemplates the delivery of the filtering media to substantially the.

point of deposit, closed against the possibility of. afiecting the sand particles moving upwardly in the body of water being discharged during hydraulic action, with a view to avoiding the carrying down of any of the sand particles by the filtering media and thus carrying out of the well all of the sand particles which may be in the flotation water.

A further object of the invention is the provision of a hydraulic element appropriately supported for delivery into and withdrawal from. the well, with one or more of the supports providing a means for delivery of water under pressure to the hydraulic element and at least one of said supports providing means for delivery of the filtration media closed against influencing the sand in the flotation water during such delivery and insuring that the delivery of. the filtration media be controlled for delivery into the well proper at exactly the desired point.

The method employed lends itself to the use of distinctive layers of filtration media entirely surrounding the well tube, with the placement of these distinctive filtration media entirely under the control of the operator.

The invention is illustrated in the accompanying drawings, wherein:-

Figure 1 is a vertical sectional view of a well showing the boring completed and the apparatus for carrying out the method in place to complete the well.

Figure 2 is a similar view, partly broken oflf, showing the lower portion of the well completed in accordance with the present method and employing the apparatus shown in Fig. 1.

Figure 3 is an enlarged section on the line 3-3 of Figure 1.

Figure 4 is a section on the line l4 of Figure Figure 5 is a view similar to Figure 1, showing a modified construction of detailed apparatus.

Figure 6 is a similar view showing a further modification.

Figure 7 is a sectional view, partly in elevation, ilustrating a modified arrangement of the hydraulic element and showing particularly a means for delivering the filtration media to avoid influencing the sand particles in the rising flotation stream, the arrangement being for use in a well employing one grade of filtration media.

Figure 8 is a broken elevation, partly in section, of. the same modification illustrating the use of the modified form in connection with a well in which filtration media of two distinct grades is employed. t

Figure 9 is an enlarged horizontal section through the modified hydraulic element, the element proper being shown in plan and partly broken out.

Figure 10 is an enlarged broken vertical section of the hydraulic element proper.

The well bore I formed by the well understood 5 rotary boring process will, when completed, have well-defined mud areas 2 overlying the sand strata 3, it being understood that the drilling slush forced into the bore during the boring process is delivered against the surface of the sand- 10 bearing strata under pressure and by action of the boring equipment for the direct purpose of holding back the sand of this strata and preventing an otherwise almost certain cave-in. Of course, this mud of the drilling slush is necessarily 5 forced to some extent into the sand and also collects more or less on the hard pan strata, indicated at l.

The fluid, for example water, is delivered into the well through the sand-bearing strata and naturally in order to obtain the maximum water flow, the mud layer 2 as well as the maximum portion of the sand strata must be removed. It is highly important that the mud wall be completely removed as otherwise it will prevent the flow of the incoming fluid to the well tube. In this type of well also, it is highly desirable that a sufiicient quantity of filtering material, such as gravel, be arranged between the sand strata and the well tube to hold back any possibility of sand entering with the water, as such would of course be fatal to the operating parts of the pump and result in a break-down and also cause final destruction of the well through collapse by caving. In most water wells, it is highly desirable to have the filtration media in two distinct layers, one a coarser media' immediately surounding the well tube, and two a finer media occupying the entire space between the coarser media and the bore of the well including, of course, the cavities ai- 40 forded by the excavation and removal of avery 'material amount of. the-sand.

The method and apparatus of the present invention contemplates the complete removal of the mud wall, the excavation and removal of a'very considerable amount of the sand; the provision of a layer of determinate thickness of relatively coarse filtration media immediately surrounding the well tube; and the application of a mass of filtration media of finer material occupying the space between the coarser media and the bore of the tube including the spaces left by the excavated sand.

In carrying out the method, a cylindrical casing, constructed of course in sections for convenience in handling, indicated at 5, is lowered into the bore of the well and to the bottom thereof. This casing has a diameter somewhat less than that of the well bore and is provided at its lower end with a hollow, circular nozzle 00 member 6 having nozzle outlets I leading therefrom and directed upwardly and outwardly or in such other directions as local conditions might dictate. The element 6, which, of course, is of ring form, may be constructed in any desired manner so long as it insures a perfect delivery of water to the nozzles 'l which are arranged in spaced relation concentrically of the casing 5 and as close together as may be necessary for the particular operation.- The external diameter or the nozzle ring 6, which is arranged exteriorly of the casing 5, is sufllciently less than the internal diameter of the bore I as to provide a space surrounding the nozzle ring to permit eflective hydraulic action of the water delivered through the nozzles 1.

Water supply pipes 8 arranged exteriorly of the casing-5 are connected to and in open communication with the nozzle ring, these pipes 8 extending to the surface of the well and being supplied in any appropriate manner, individually or collectively, with water under pressure. The well tube 9 having the screen portions [0 is then placed within the casing 5, this well tube, particularly throughout the screened portion, being of materially less diameter than that of the casing 5 and formed with the conventional pump section II. Screen portions I are ordinarily arranged in line with the sand strata 3,'and guides 12 may be employed to center the well tube .with respect to the casing 5.

As thus arranged, there is a concentric, annular area i3 between the well tube and casing 5 and an area 14 between the casing 5 and the wall of the bore I. In the initial operation, filtering media of the coarser type, as gravel I5, is delivered from the top of the well into the space l3, accumulating at the bottom of the bore surrounding the. well tube and held in a well-defined layer by the casing 5. Water under pressure is then delivered through the pipes 8 and by means of the nozzles I directed with any desired force directly against the mud wall 2 of the bore 1. Owing to this hydraulic mining action, the mud wall is completely washed away and ,floated off in suspension with the fluid rising through the well. In this hydraulic mining action, and after the mud wall has been entirely washed away from the face of the, sand-bearing strata, for example, a very considerable portion, depending on the will of the operator and the necessity of the occasion, of the sand behind the mud wall is also washed away, leaving in the sandbearing strata concentric pockets l6 of materially greater diameter than that of the normal bore of the well through the natural formation.

As the hydraulic action proceeds, the casing 5 is gradually lifted and continuous with the upward movement of the casing 5, filtering media of a finer type, as gravel ll, smaller than the gravel I5, is introduced into the space ll at the top of the well, this gravel filling out the space between the casing 5 and the bore of the well and also filling the pockets Hi. The operation is completed, the filtering media l5 being added to maintain a level sufliciently above the particular operating level of the nozzle ringas to assure the integrity of this layer ,of gravel being maintained. The level of the finer gravel is maintained at or sufficiently above the nozzle ring to insure that the hydraulic effect shall not cave down the natural formations faster than they can be replaced with the finer filtering media. levels are ascertained by feeler rods or other means.

It is desirable, in most installations, that the finer filtering media be kept somewhat above the nozzle ring, as otherwise large bodies of natural formation would cave down and if the gravel layer were below the nozzle ring, such bodies as might cave down would be below the nozzle ring and become diificult, if not impossible, to remove. With the level of the finer gravel at or somewhat above the nozzle ring, the swirling effect of the water is such as to continuously swirl the finer gravel being introduced against the natural formations being dislodged, and maintain such in constant agitation with the dislodged materials,

These the latter being replaced by the gravel and col limit of the uppermost sand strata, it being 5 understood that the usual pit It! has been placed in the bore ofthe well for a suflicient depth to .hold back surface or contaminated water, this pit casing 18 being usual in this type of well. The well is completedand the casing 5 and nozzle ring entirelyremoved, and as a result the well bore, and particularly the sand-bearing strata thereof, is entirely free or any mud wall, has been excavated to a diameter to insure a high proportionate delivery of fluid, and there is a double area of filtration media interposed between the sand-bearing strata and other portions of the well bore and the well tube.

In those types of wells where, owing to the rather extreme diameter of the bore I, the cas- 20 ing 5 would necessarily be of such diameter that its weight would be diificult to handle, such casing may be reduced in diameter except in the portion carrying the nozzle ring. For example, as shown in Figure 5, wherein the bore is indi- 25 cated at H, the sand-bearing strata at 20, a mud wall at 2|, and the well tube at 22, the casing, here indicated at 23, and corresponding to the casing 5 of the form .shown in Figure ,1, is of a diameter throughout the greater portion of its 80 length sufficiently larger than the maximum. diameter of the well tube to provide a space 24 for the introduction of the coarser filtering media. At the lower end this casing 23 is enlarged by a flaring section 25, the lower end of which carries 3 5 the ring nozzle 26, the increase of the diameter of the. portion of the casing insuring that the outer surface of the ring nozzle will be, spaced the proper distance from the wall of the bore to insure the necessary hydraulic mining action for 4Q larger diameter portion of the casing also 50 V defines the area which receives the finer gravel, for as the casing is lifted, the gravel-receiving spaces remain constant in relative proportion to that illustrated at the lower portion ofFigure 5. The operation and method employed in connec- 5 tion with the apparatus shown in Figure 5 is the same as that described in connection with Figure 1 and need not be here repeated.

It frequently happens that the well is of a type which does not require the double filtering media and under these circumstances the hydraulic mining action is, as shown in Figure 6, secured through the medium of independent nozzle members 29 secured at the lower end of water supply pipes 30 and arranged concentric with the well tubes 3! introduced into the bore. The independent nozzles 29 have upwardly directed outlets 32 and the pipes 30 carrying these nozzles are arranged in any desired number concentric with the well tube and accurately spaced from the bore of the well as to insure the efilcient hydraulic to the left in Figure 6 indicating that nozzle in rear of the well tube.

In this form, the mud wall and proper quantities of sand are washed out by the hydraulic mining action of the nozzle and the space between the well tubes 3| and the bore of the well,

including the pockets in the sand strata, and indicated at 33, are supplied with filtering media 34 of the requisite size, the delivery of the filtering media through the upper end of the bore being gradual and in accordance with the lifting of the nozzles in order to completely fill the area 33 including the sand pockets.

A well constructed as described has complete elimination of the mud wall, which is an absolute necessity in maintaining the integrity of the bore of the well during the boring process, and further a very considerable portion of the sand is washed out of the stand strata, together with the provision of an exactly defined area to receive the coarser filtering media and a further exactly defined area to receive the finer filtering media, with the certainty that these respective media will be arranged in concentric layers about the well tube to effectively restrain the admission of sand or other foreign solid matter with the water delivered to the well tube through the screen.

In Figures '1, 8, 9, and 10 is illustrated a somemedia substantially at the desired point of deposit wholly free of any influence from or influence on the rising volume of water. In the form of the invention here shown, the well bore, indicated at 35, will,incident to the well understood methods of boring, present a mud wall- 35 particularly overlying the sand strata 31 of the well as well as over the hard-pan strata 38. The hydraulic element in this form of the invention comprises a hollow cylindrical section 3901 a diameter corresponding to the conventional casing, such as shown at 5 in the form previously described, the vertical dimension of the section or shell 39 being materially less than any one section of the casing, with the upper end of such shell preferably formed or provided with' any conventional means by which it may be connected with the conventional casing and form an extension thereof under those conditions where such conventional casing is to be used as hereinafter described.

Rigidly secured to orformed integral with the exterior surface of the shell 39 is an annular enlargement in the form of a ring 40 of hollow construction to provide an annular channel 4| exteriorly of and substantially at the lower end of the shell 39. The outer wall 42 of the enlargement 40 is formed with a series of upwardly directed, relatively small outlets 43 which communicate with the channel 4| and serve, when water is delivered underpressure to the channel to provide a series of upwardly directed jets outwardly beyond the enlargement 40. It is to be understood that aside from the fact that the loosen the connection in lowering or lifting the 5 hydraulic element, and that under some circumstances it is highly desirable and important that a more rigid connection be provided at the hydraulic element. For this purpose, the hydraulic element of the modified form includes one or more pipe sections 44, which at their lower ends are welded or integrally formedwith the enlargement 4| and which extend throughout the height of the shell 39 and above the same, the pipe section or sections 44 being rigidly secured by welding or other appropriate means to the shell 39. Of course, the upper ends of the pipe sections 44 are appropriately formed to permit the removable connection therewith of additional pipe sections leading to the top of the well and 20 it is, of course, to be understood that two or any additional number of pipe sections'44 may be employed. I

' The hydraulic mining element is thus made up of a rigid member including a shell section, an 25 enlargement in which the water channel and outlets are formed, and pipe sections rising from the enlargement, with-all of the parts intimately and rigidly secured together in any appropriate ordesired manner. It is understood that at least one of the pipe sections 44 serves as a water conduit to deliver water to the channel 4|, and for this purpose a selected section 44 is of pipe-like form in open communication with the channel. At least one other such section 44 is closed against the channel 4| and may, if desired, be a solid section, indicated at 45, rigid with the enlargement and shell 39 and formed at the upper end'for the reception of additional pipe sections, exactly as is the hollow section 44.

Obviously, more than one section 44 may be employed and, if desired, more than one section 45, the essential diflerence residing in the fact that the sections 44 are employed for the delivery of water under pressure to the channel 4|, 45 while the section or sections 45' are employed to reinforce the'hydraulic mining element and as supports for pipe sections employed primarily for the delivery of filtering media at the desired point of deposit. The section or sections 44 are designed in use to receive additional pipe sections 46 leading to the top of the well through which water is delivered under pressure for the hydraulic mining action, the connection of the section 44 with the pipe sections 46 or with the adjacent pipe section 49. being threaded at 41 or through the employment of other desired type of movable connection.

' The section or sections 45 are interiorly threaded at the upper end at 45 to receive pipe sections 49 connected end to end, as the depth of the well may require, to provide a hollow pipelike conduit extending to the top of the well, which terminates or is closed at the upper end of the section or sections 45. This conduit, or more particularly the section thereof immediately connected to the sections 45, is formed with an opening or openings 50 which are of sufficient size to permit a free flow therethrough of the filtering media, indicated at 5|. The openings 59 are preferably arranged closely adjacent the upper edge of the shell 39, and while two sets of diametrically opposed openings 59 are shown,

it is understood that a single set of diametrically opposed openings may be used or more than two sets employed. The purpose is to provide an outlet for the filtering media immediately above the upper edge of the shell 39, and it is preferred that such outlet be in the form of diametrically opposed openings so that the filtering media can be directed toward the wall of the well and inwardly from said wall or in any other direction desired. The size and number of the outlets is of no particular importance in connection with the present invention so long as there is at least one outlet as closely adjacent the upper edge of the shell 39 as is mechanically possible. Therefore, in this particular it is understood that the lower end of the filtering media conduit is to be formed immediately adjacent the upper edge of the shell 39 of the hydraulic element with a filtering media outlet, and the invention contemplates the use of a single outlet directed either toward the wall of the well or inwardly therefrom, diametrically'opposed outlets opening in opposite directions or a series of such outlets.

The hydraulic mining element may, if desired, be made up in sections, as indicated in Figure 9, or may be constructed as an integral element as may be preferred, either arrangement being within the spirit and purpose of the present invention.

In the use of the modified form of the invention, the hydraulic action is identical with that described in connection with the first form. The

upwardly directed jets of water under pressurefrom the hydraulic mining element delivered through the outlets 43 wash the mud wall 36 from the bore of the well and particularly from the sand strata 38. The impinging direction of these jets upwardly tends to a scouring or washing of the mud wall from beneath and thus is to be distinguished from a hydraulic action in which the jets or streams of water are directed outwardly at substantially right angles to the mud wall, because under the latter operation the effect of the force of the water is to drive the mud of the mud wall into the sand of the sand strata and thus tend to clog or choke up the pores of the sand strata through which the water is delivered.

Therefore, one very material result of the present invention in both forms will be prevented, because it is the purpose of the present invention to clear away the mud wall overlying the sand strata particularly in order to free the surface of thegsaid strata which, when freed, tends to a collapse to some extent, which collapse of the SZLIlCP-bOdY outwardly from the normal wall of the well is materially assisted by the hydraulic mining action. Of course, it is understood that the mud wall is built up during the boring of the well to prevent at this time the collapse of the sand strata, because otherwise without the holding effect of the mud wall, the sand would tend to collapse into the well and materially impede the proper well formation, to say nothing of the difliculty and time and labor required to remove such sand. v

Therefore, it is important that the mud be removed. particularly from the face 'of the sand strata and that, incident to such removal, a not inconsiderable portion of the sand strata be removed incident to collapse and to the hydraulic mining action in order that the well within the area of the sand strata be of very materially increased diameter over the normal diameter of the bore. This removal of the mud as distinguished from forcing the mud into the sand can only be accomplished by an upwardly di rected stream or jet of water under pressure, because this action of the upwardly directed jet is to wash upwardly the mud and in effect scrape it from the sand strata and cause it to disintegrate in the volume of liquid accumulating in 5 the well and float to the surface.

The additional area or diameter of well bore at the sand strata is desirable within limits but, of course, means must be provided to prevent undue collapse of this sand strata and hence 10 it is important that the filtering media be so delivered to the well that it will take the place of the washed out or collapsed sand volume immediately such increased area is produced, that is to say, the sand washed out or collapsing in the 15 sand strata after the removal of the mud wall must be immediately replaced by the filtering media; otherwise there would be a collapse of the sand strata below the hydraulic mining element as the latter is moved upwardly of the well, and 20 the very disadvantages of the sand accumulation would be present.

Therefore, it is not only important to remove the mud wall and to enlarge the bore of the well at the sand strata, but to immediately replace this 25 withdrawn or removed sand volume by something which will prevent further collapse of this sand media. This reinforcing provision of the sand is by the filtering media, and hence the filtering media must be delivered substantially at 30 the plane of operation of the hydraulic element in order that the pebbles forming the filtration media may fall and occupy the place of the removed sand, thus not only affording 'a filtration area but preventing further collapse of the sand 35 strata. I

As previously stated, it is desirable, and in some instances vitally important, that the filtration media be delivered to the point of deposit without interfering with or passing directly through 40 the flotation medium. Of course, it is well understood in wells of this character that the sand separating from the sand strata by the hydraulic medium or by collapse remains largely, if not completely, in suspension in the flotation media 45 and is floated out the top of the well. If the filtering media is delivered in bulk through this flotation media, it will be found in some instances that the descending pebbles will force a portion of the sand held in suspension in this media 50 downwardly to accumulate among the filtration media to the detriment of the flow of the water.

To the end that the filtration media may be delivered to the point of deposit without affecting the sand particles rising in the flotation medium, the pipe section or sections 49 constitute the path of delivery of such filtration media,

' that is to say, the filtration pebbles are delivered into the pipe 49 at the upper end of the well and find their way through the opening or open- 60 ings 50 into the flotation media substantially or immediately above the line of hydraulic action of the jets from the hydraulic element. Therefore, during the entire travel of the filtration media from the top of the well to substantially 'the point of deposit, there is no contact between stood that the primary purpose of the invention is to utilize the' filtration media conduit as a part of the hydraulic element through its direct. connection therewith and thus insure the delivery of the filtration pebbles tree of influence on the sand rising in the flotation media and at the-desired point of deposit, for by connecting the filtration media. conduit with the hydraulic mining element, the outlets from such conduit are always in the same relation to the element and hence the delivery of the pebbles from the conduit always occurs at the same point of deposit relative to the cleaning influence of the jets of -water, and as this outlet is designed with a view to delivering the pebbles so as to immediately replace the sandwashed or collapsing from the sand strata under the hydraulic action or removal of the mud wall, the importance of utilizing the pebble conduit as a part or the hydra'ulic element in order to insure this delivery in exactly the same relation to the element at all times is at once apparent.

In those wells employing a single filtration media, such media is delivered through the conduit or conduits 49 and will, of course, occupy the displaced sand in the sand strata and the bore of the well between the ordinary pump casing 5| and the bore of the well. Where two distinctive layers of filtration media, as an outer fine layer and a coarse inner layer, are to be employed in the particular well, a division casing 52 made up in sections is employed, the lower end of the lower section of this casing being connected to the upper end of the shell 39 of the hydraulic element, the interior and exterior diameters of v the casing 52 corresponding to that of the shell. This arrangement is illustrated in Figure 8 or the drawings. Of course, under these-circumstances the filtration media conduits .49 are exterior of the shell 52 and are used to deliver the finer media. The coarser media is delivered in bulk between the casing 52 and the pump casing 5|, as described in connection with the form first described.

Ordinarily the hydraulic element is provided with two diametricallyopposed pipe sections, one

of which, as 44, is hollow for the delivery of water under pressure to the channel 4| and the other of which is solid or closed against the channel 4| and serves to support the pebble conduit 49. The pipe sections extending upwardly from the hydraulic medium has the water conduit 48 and .the pebbles conduit 49 aflords' means by which the hydraulic media is gradually raised in the well for progressive hydraulic action. Preferably the clamping element indicated in dotted lines at 53 in Figure 7 is clamped about the conduits 45 and 49 at the top of the well and provided with means 53 by which these pipe sections may be raised simultaneously during the raising of the hydraulic element. The elements 53 and 54 are designed to conventionally illustrate any means by which the conduits 46 or 49 or the sections of such conduits at the upper end of the well may be clamped together to insure relative rigidity and subjected to simultaneous pull in moving the hydraulic element. 01 course, the clamping element 53 cooperates with the respective sections of the conduits at the upper end of the well, it being understood that as the conduits are moved upwardly, the sections thereof are detached from time to time.

This application is a continuation in part of the application filed January 31, 1933, Serial It is, of course, to be understood that, if desired and as preferred, the filtering media introduced into the conduit 49 will be associated in such delivery with the requisite quantity of water. This water flowing through'the pebble outlets at the 5 lower end of the pebble conduit not only facilitates the delivery and placement of the pebbles,- but also augments the volume of water delivered through the jet ring and thus assists in the fio-. tation of the sand and mud to the top of the well. 10 This volume .of water introduced with the pebbles may vary from a slight trickle of water to a considerable volume of water, which may or may not be under pressure, the quantity of water required being determined to some extent by the diameter 15 of the well bore and the nature and volume of the sand and mud to be floated to the surface, as obviously the larger the well bore, the more effective the increased volume of water delivered through the pebble conduit will be in assisting in 20 flotation effect.

It is further preferred that the openings in the well tube be suflicient to admit sand particles therethrough. This will permit the conditioning pump to draw into the well tube and out the dis- 25 charge a very considerable portion of any sand particles which for one reason or another may deposit upon the filtering media during the formation of the well. 1 I

We claim:- 30

1. The herein described method of developing bored wells of the gravel envelope type, consisting in dividing the area about the well tube into distinctive gravel-receiving spaces and subjecting the wall of the outermost space to a hydraulic 35 mining action, the operative phase of which is gradually moved upwardly from the bottom of the bore, the distinctive gravel-receiving spaces being merged below and as the operative phase of the hydraulic mining action moves upwardly. 40

2. The herein described method of developing water wells of the gravel envelope type, consisting in dividing the bore of the well into distinctive gravel-receiving spaces concentric with the well tube, subjecting the outermost space to a hy- 45' draulic mining action to divest the bore of the well of the mud wall and of a material portion of the sand in the sand strata of the bore, causing the operative phase of the hydraulic mining action to move gradually upward through the top of the 50 well, filling the inner space with filtering media of one type, and filling the outer space with filtering media of another type, the application of the filtering media of both types being at all times maintained at a level substantially coincident with 55 the operative phase of the hydraulic mining action.

3. The herein described method of developing water wells of the gravel envelope type, consisting in dividing the bore of the well into distinctive 60 gravel-receiving spaces concentric with the well tube, subjecting the outermost space to a hydraulic mining action to divest the bore of the well of the mud wall and of a material portion of the sand in the sand strata of the bore, causing the 6 operative phase of the hydraulic mining action to move gradually upward toward the top of the well, filling the inner space with filtering media of one type, and filling the outer space with filtering media of another type, the filtering media of move the mud layer from the wall of the well and to increase the diameter of the well throughout the sand bearing strata, consisting in subjecting the well throughout; its length to hydraulic jet action directed upwardly and with suflicient force to dislodge material portions of the relatively soft fluid bearing strata of the well, and delivering to the well a filtering media to fill the portions of increased diameter resulting from the hydraulic action;

5. A process'for completing a bored well to remove the mud layer from the wall of the well and to increase thediameter of the well throughout the sand bearing strata, consisting in subjecting the well throughout its length to hydraulic jet action directed upwardly and with suflicient forceto dislodge material portions of the relatively soft fluid bearing strata of the well, and delivering to the well a filtering media to fill the portions of increased diameter resulting from the hydraulic action, said-filtering media being de livered to the well in quantity to maintain its upper level substantially coincident with the plane of hydraulic action whereby to prevent material dislodged by the hydraulic action falling below the plane of the hydraulic action.

6. The herein described methodof developing bored .115 of the gravel envelope type, consisting in subjecting the wall of the well bore to a hydraulic miningaction, the operative phase of which is gradually moved upwardly from the bottom of the bore, floating the materials dislodged by said hydraulic mining action to the surface of the well, and simultaneously delivering gravel into the bore of the well and substantially at the area being subjected to hydraulic mining action, the delivery of the gravel being maintained free of any influence on the materials being floated to the surface of the well.

7. The herein described method of developing bored wells of the gravel envelope type, consisting insubjecting the wall of the well bore to a hydraulic mining action, the operative phase of which is gradually moved upwardly from the bottom of the bore, and floating the materials separated from the wall of the well bore to the surface of the well and simultaneously delivering to the area of the well bore which is being subjected to hydraulic mining action a requisite quantity of gravel and water, the delivery of the stream of gravel and water being wholly free of any influence on the material being floated to the surface of the well, the volume of water so delivered being at the point of delivery released to and serving to augment the flotation movement on the materials being floated to the surface of the well.

8. The herein described method of developing bored wells of the gravel envelope type, consisting in subjecting the wall of the well bore to a hydraulic mining action, the operative phase of which is gradually moved upwardly from the bottom of the bore, the material removed in the hydraulic mining action being floated to the surface of the well and simultaneously delivering a. stream counter to the flotation stream and including gravel and water, the counter stream being segregated from the flotation stream and being'delivered into the well bore at a point approximating the area being subjected to hydraulic mining action.

9. In a well of the gravel envelope type, a nozzle ring having upwardly directed nozzles, a casing section rising from and secured to the ring, and carrier members rigid with the ring and casing section, one of said carrier members being hollow and in open communication with the ring and another of said members being hollow and closed against the ring, said latter member opening into the well bore above the ring.

10. In a well of the gravel envelope type, a nozzle ring having upwardly directed nozzles, a casing section rising from and secured to the ring, and carrier members rigid with the ring and casing section, one of said carrier members being hollow and in open communication with 10 the ring and both said sections being formed for the removable connection thereto of pipe sections leading to the top of the well, one of the pipe sections being closed against the ring and formed immediately above the casing section with an 15 opening whereby filtering mediated through said 'pipe section may be delivered into the well bore above and immediately adjacent the ring.

11. In a well of the gravel envelope type, a nozzle ring having upwardly directed nozzles, a 20 casing section rising from and secured to the ring, and carrier members rigid with the ring and casing section, one of said carrier members being hollow and in open communication with the ring and another of said members being closed against 25 the ring and open to the well bore above the casing and both said members being formed for the removable connection thereto of pipe sections leading to the top of the well, said pipe sections providing a means whereby the ring and casing 30 section may be moved upwardly for progressive upward hydraulic mining action from the jet nozzles.

12. In a well of the gravel envelope type, a nozzle ring having upwardly directed nozzles, a 35 casing section rising from and secured to the ring, and carrier members rigid with the ring and easing section, one of said carrier members being hollow and in open communication with the ring and both said sections being formed for the 40 removable connection thereto of pipe sections leading to the top of the well, that pipe section in communication with the ring providing for the delivery of water under pressure to the ring for delivery through the nozzle, the other pipe sec: Ii tion being closed against the ring and serving as a conduit for filtering media, said latter pipe section having a plurality of oppositely directed outlets above the casing section.

13. In a well of the gravel envelope type, a 60 well tube, a casing surrounding the well tube and spaced from the well tube and from the bore of the well, said casing being open at the bottom for delivery of filtering media, nozzles carried by the lower end of the casing, means for delivering 55 water under pressure to the nozzles, the. outlets of the nozzles directing jets of water toward and at an upward slant to the bore of the well, the casing being movable upwardly to compel the jets of water from the nozzles to create a hydraulic mining action on the wall of the well bore.

14. A means for developing water-gravel-pack wells including a well tube, a casing to be arranged in the well concentric with the well tube and spaced from the well tube and from the bore of the well, said casing being open at the bottom for delivery of filtering media, a nozzle ring carried by the lower end of the casing, a pipe for of water from the nozzles exert a hydraulic mining action on the surface of the bore of the well.

15. Means for subjecting the interior of a bored well to hydraulic action, including jet delivery means to be arranged in the bottom of the well, and pipelike carriers secured to said means and serving as a medium for placing and removing the said means, one of said carriers being open to the jet delivery means for serving the same with fluid under pressure, the other of said carriers being closed against the jet delivery means and open' to the interior of the well beyond said jet delivery means, whereby said latter carrier may be used for introducing any desired material into the well beyond the jet delivery means.

REUBEN R. SCHWEITZER. CHESTER R. SUNDQUIST.

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