US3066735A

US3066735A - Hydraulic jetting tool

Info

Publication number: US3066735A
Application number: US31596A
Authority: US
Inventors: Warren M Zingg
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1960-05-25
Filing date: 1960-05-25
Publication date: 1962-12-04
Anticipated expiration: 1979-12-04

Description

Dec. 4, 1962 w. M. zmscs HYDRAULIC JETTING TOOL Filed May 25, 1960 fivvlflillrhom a/ 9 1 8 5 5 M5@ 2 6 O 2 4 4 6 8 76 a 5 66 49 4 28 6 1 6 42 0 7 502 Z 5 Z 1& 65 M6 2% 5 is 2 f H 1 fi Muv/ i 5 n/AL I 4 6 f g K J 5 2% M 5 INVENTOR. Warren M. Z myg 2AM). A

HGENT United States Patent Qfifice dfifififl d Patented Dec. 4, was

jerk

Chemical Company, Midland, Mich, a corporation of Delaware Filed May 25, 195i der. No. 31,596 9 Claims. (Cl. 16655) The invention relates to hydraulic jetting and particularly to down hole hydraulic jetting in earth wells.

It has been known to perforate casing, cut into the earth formation adjacent to bore holes and clean formatrons by means of hydraulic jets employing water, oil and abrasive slurries. One of the problems encountered in such operations is the rapid Wearing of the jetting orifice through which the fluid is pumped. When the individual jetting orifices become worn to such a degree that an imperfect jet is formed, the cutting or cleaning efliciency of the stream passing through the orifice rapidly decreases and in many cases soon becomes impractical for continued usage in a well treatment. Previously it has been necessary to withdraw the jetting tool, usually attached at the lower end of a string of tubing, from the well bore and replace worn jet orifices with new ones. Such procedure is expensive both from a treating time standpoint and because of the fact that the well must be disturbed each time the tubing is withdrawn.

Accordingly, a principal object of this invention is to prolI/ide an improved jetting tool for use in treating earth we s.

Another object of this invention is to provide an improved jetting tool in which the jetting can be switched selectively to different jetting orifices without drawing the tool from the bore hole.

A further object of this invention is to provide an improved, simple, economical to use jetting tool.

In accordance with this invention, there is provided a jetting tool comprising a hollow cylindrical body having a plurality of jet orifices disposed in substantially planar arrays which are perpendicular to the longitudinal axis of the tool. In a two array type of tool sleeve or slide cylinder means having a seat for a ball valve at its upper end is telescoped into the tool body above the lowest array of jet orifices and held in place by a shear pin which extends inwardly from the wall of the tool. When the exposed orifices become worn, a ball is pumped down the tubing to which the tool is attached, the ball seating in the aforementioned seat. Pressure is applied to break the shear pin and force the sleeve downwardly to block the flow of fluid to the previously exposed orifices and to expose an array of orifices which had previously been covered by the sleeve. Arrangements of more than one set of sleeves disposed along the tool body are provided if more than two arrays of jet orifices are included in the tool.

The above and related objects and advantages of this invention will best be understood when the following detailed description is read in connection with the accompanying drawing, in which:

FIG. 1 is a side elevational view, partly broken away and in section, of a jetting tool made in accordance with this invention;

PEG. 2 is a sectional view taken along the line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a fragmentray view of the tool shown in FIG. 1 showing the lower jets covered by the internal sleeve;

FIG. 5 is an enlarged side elevational view, in section, of an individual jet insert of the type used in the 1 in REG. 1, and

FIG. 6 is a sectional view taken along line 6-6 of FIG. 5.

Referring to FIG. 1, there is shown a jetting tool, indicated generaly by the numeral 10, comprising a hollow tubular upper body section 12, a hollow tubular middle body section 14, and a hollow tubular lower section 16, the upper and middle sections each having a threaded female connector 13, 20 respectively at their upper ends and a threaded

male connector

22, 24 at their lower ends. The upper end or" the lower section has a threaded male connector 26 by means of which it is connected through a coupling 28 to the male lower end connector of the middle section. The lower end 30 of the lower section in has a bore 32 extending therethrough and a valve seat 34 at the upper end of the bore.

Referring to FIGS. 2, 3 and 4, as well as to FIG. 1, there is disposed within the upper body section 12 and middle body section 14 a slide cylinder 3-6 or 38 respectively. Each of the slide cylinders has an outer diameter small enough to slidably fit within the cylindrical

inner wall

37, 39 respectively of its body section and contains a pair of grooves near its upper end and a pair of grooves (4d) near its lower end which each contain an O ring seal 42.

The

upper end

44, 46 respectively of each of the

slide cylinders

36, 38 has a

valve seat

48, 50 respectively therein which is adapted to seat a ball valve (ball 51 is shown seated in FIG. 4). The throat of the seat 48 and inner wall diameter in the upper cylinder 36 is larger than the throat diameter of the seat 50 in slide cylinder 38. Correspondingly, the throat diameter of the seat 5t and the bore below it is larger than the throat of the valve seat 34 in the lower body section 16.

The middle body section 14 has an upper array of jetting apertures 52 and a lower array of jetting apertures 54 disposed along its length. Each aperture of each array lies in substantially the same plane which is generally perpendicular to the longitudinal axis of the section. A jetting orifice element 58, shown in detail in FIGS. 5 and 6, which presents a curved surface to the interior of the section, is secured within each aperture. Each jetting orifice element 58 is made of an abrasion resistant substance such as tungsten carbide or boron carbide, for example. Each orifice, while presenting a curved surface to the interior of the body section, has a blunt, sharply cornered outer end 56.

The arrays of apertures are spaced apart along the body section 14 a distance such that when the slide cylinder 33 is held in place (by shear pin 60) with the array of apertures 52 disposed between the pairs of 0 rings 42, the array of apertures 54 is below the cylinder 38. Similarly, therefore, when the slide cylinder 38 is in its lower position as shown in FIG. 4, the array of apertures 52 are exposed to the interior of the body section and the array 54 is disposed between the pairs of 0 rings 42. The limit of downward movement of the cylinder 38 is controlled by the inwardly extending seat 56 near the lower end of the body section 14, although other position limit ing means, such as a bolt extending inwardly through the body wall, may be used, for example.

The upper body section 12 has a single array of jetting apertures 52'; which, like the previously mentioned arrays, lie substantially in a plane which is generally perpendicular to the longitudinal axis of the body section. The apertures 53 are disposed along the body section in such a position that they lie between the 0 ring pairs 42 of the slide cylinder 36 when it is held in place by its shear pin 62 which extends into the cylinder from the wall of the body section. The body section 12 is long enough, however, to permit the jetting apertures 58 to be entirely exposed to the open interior of the section and not covered by the cylinder 36 when the cylinder is at its lower position (not shown) abutting against the inwardly extending surface 63 near the lower end of the body section 12.

he outer surface of each of the body sections 12., 14 adjacent to the jetting apertures comprises a

sleeve

64a, 64b of specially hard abrasion resistant composition such as tungsten carbide, for example. The sleeves 64 are necessary in order to prevent excessive wear on the body of the tool because of jetted fluid or slurry which is refiected back onto the tool from the surface being treated.

In operation the tool it is lowered into the well at the lower end of a string of tubing 65 (for example). When the tool 1;; is in position adjacent to the formation or part of the casing to be acted upon by the jets, clear (usually) fluid is pumped down the tubing, through the tool and out through the aperture 32 in the lower end of the lower body section so. This pumping of fluid tends to drive loose scale or other particulated material large enough to plug the jet orifices through the tool 10 before actual jetting is begun.

When it is considered that the scale has been removed, a bail 66 which is small enough to pass through the tool and seat against the seat 34 is dropped into the fluid being pumped down the tubing and slowly pumped down the tubing until it is seated and cuts off the fiow of fluid through the tool except through the jetting array 54 of apertures in the middle body section 14. Slow pumping of fluid as the ball seats is desired in order to prevent possible rupturing of the tubing due to water hammer effects when the ball seats.

The abrasive is then added to the fluid (in the event it had not already been done) and the abrasive containing fluid or slurry is pumped down the tubing and out through the orifices of the array 54 mentioned above. While the array may contain various numbers of orifices (3, 4, or 6, for example), the orifices are preferably symmetrically disposed around the body section i4 is a manner to balance the forces of reaction when fluid or slurry is jetting through the orifices 58.

When a substantial pressure drop at the surface pump (at constant pumping rate) or a substantial increase in pumping rate (at constant pressure) is noted, this indicates that the orifices have become enlarged (often egg shaped) and are no longer working efficiently. To change from using the array 54 to the array 52, a ball or plug 51 which is small enough to pass through the upper body section 12 but large enough to be retained on the seat 56 of the slide cylinder 33 is inserted in the fluid stream while fluid is pumped at a slow rate in order to prevent undue physical shock along the tubing.

When the ball 51 seats, the pumping pressure is in creased to cause the breaking of the shear pin 655, permitting the fluid pressure to drive the cylinder 33 down wardly to the limit of its movement, covering the array 54 and uncovering the upper array 52 of orifices in the middle body section 14. With the ball 51 seated and the rings providing seals to prevent fluid passage between the cylinder 38 and the inner wall 39 of the section, fluid or slurry is then pumped through the array 52 to continue the treating of the casing or earth formation. It is assumed that the tubing is displaced downwardly a distance equal to the spacing between the previous and presently operating arrays of orifices. In addition, the tubing may be rotated to the extent necessary to achieve 360 (or other amounts) of cutting action around the well casing or well bore wall.

When it becomes apparent, as discussed before, that the orifices of the array 52 are becoming excessively enlarged, a ball 68 of such diameter that it will pass into the upper body section 12 but be retained on the valve seat 43 of the cylinder 36 is passed down the tubing (with the fluid being pumped at a slow rate), the ball valve seated, and the slide cylinder 36 forced downwardly after pressure is increased to break its retaining shear pin es. With the slide cylinder in its lower position, the orifices of the array 57 are exposed to fiuid flow through the tool and the treatment continued through the array of orifices 57.

It is recognized that jetting tools having more or less than three arrays of orifices may .be made. However, the tool described herein shows that additional body sections (it is easier to machine separate body sections but this is not essential to the invention) maybe added providing the throat diameters of the valve seats and the inner diameter of the slide cylinders are enlarged in the slide cylinders which are disposed in the tool successively nearor to the tubing attachment end of the tool.

With respect to the types of abrasive which may be .used with the tool 1-5), it has been found that sand over the range of mesh size from 10 to has been found to be satisfactory. Sand of 20-40 mesh size (as measured on a standard sieve) is most commonly used. It has been found that jet orifices last longer when round sand grains are used in the slurry.

Carrying fluids such as water, oil and acids (commonly hydrochloric) have all been used, both thickened and unthickened. With regard to concentration of sand in the fluid, 1.0 to 1.5 pounds per gallon is an optimum range. letting is also done using fluid without abrasives being added. Acid jetting into limestone is an example of such use of this invention. The use of excessive amounts of sand is believed to erode the jets out of pro- ;portion in comparison to the amount of cutting accomplished. Successful treatments, however, have been performed using about 0.25 to 2.5 pounds of abrasive material e.g. sand per gallon.

A differential pressure across the jets of about 2500 psi. appears to be optimum. In some tests pressure as high as 3,000 psi. have been used and show that proportionately more rapid cutting of dense formations can be accomplished at this higher pressure. Further tests show that little is to be gained by increasing the pressure above 3 ,000 p.s.-i. 'While several jet orifices may be used in any of the anrays, the number of orifices is limited, in the final analysis, by the pumping capacity available to achieve the desirable pressure differential across the jet orifices in order that they may work effectively.

As an example of how the tool It} may be used to perforate casing, a test 'was run in a section of 5 /2. inch L55 casing cemented between a 12 inch limestone block and a 12 inch sandstone block. The jetting fluid was water carrying one pound of 40-60 mesh sand per gallon. Pumping pressure was 2500 psi. through two W inch jetting nozzles. The casing was penetrated in only 23 seconds. In 7 minutes and 58 seconds the cement and the 12 inch sandstone block were penetrated and the limestone block was penetrated to a depth of 9 /2 inches in the same length of time.

While, as mentioned previously, tools having more than three arrays of jet orifices may be used, the treating life of three arrays is long enough to permit most wells to be treated without serious loss of jetting efiiciency.

It should also be noted that the lower body section 16 is not essential to the basic operation of the invention, but is very desirable, from a practical standpoint, to assure that jet orifices will not become clogged during a treatment.

The invention thus provides a simple, easy to assemble tool which is positive acting and can be used for rather long treating times without pulling the casing string and replacing individual jet orifices.

What is claimed is:

l. A hydraulic jetting tool comprising an elongated hollow tubular body section having coupling means at its upper and lower ends an outer surface and having a uniform minimum inner cross-sectional configuration extending a substantial distance intermediate its ends, said body section having at least an upper and a lower spaced apart array of jetting apertures disposed intermediate of its ends, the jetting apertures of each of said arrays lying substantially perpendicular with respect to the longitudinal axis of said body section, an elongated tubular slide cylinder having an upper and lower end said slide cylinder being disposed within said body section and ha ing an outer configuration which fits closely and slidably within said uniform inner configuration of the body section, said cylinder being shorter than the spacing between said arrays, said cylinder having a valve seat across its open inner diameter, releasable retaining means responsive to a predetermined pressure exerted upon it for temporarily holding said cylinder adjacent to said upper array of jetting apertures, and movement limiting means for holding said cylinder opposite said lower array of jetting apertures when said pressure retaining means is inactivated on application of said predetermined pressure.

2. A hydraulic jetting tool in accordance with claim 1, wherein said slide cylinder has a pair of O ring seals adjacent to each end, said seals circumscribing said cylinder.

3. A hydraulic jetting tool in accordance with claim 1, wherein said body section is provided with valve closure means at its lower end.

4. A hydraulic jetting tool in accordance with claim 1, wherein said jetting apertures of each array are dispersed symmetrically around said body section.

5. A hydraulic jetting tool in accordance with claim 1, wherein said valve seat in said cylinder is near its upper end and is shaped to receive a ball valve.

6. A hydraulic jetting tool in accordance with claim 1, wherein a lower end section having a ball valve closure seat therein is coupled to the lower end of said body section.

7. A hydraulic jetting tool in accordance with claim 1, wherein more than two arrays of apertures are disposed along said body section and there are one less of said slide cylinders disposed in said body section tian there are arrays of apertures, said slide cylinders each having a longitudinal bore, the longitudinal bore of each slide cylinder being larger in diameter than the diameter of the longitudinal bore of the slide cylinder next nearest to the lower end of the body section, and releasable retaining means for individually holdin said cylinders in position whereby all the arrays of jetting apertures above the array closest to the lower end of the body section are covered until said retaining means are released.

8. A hydraulic jetting tool in accordance with claim 1, wherein said body section is composed of at least two tubular elements joined in end to end relationship.

9. A hydraulic jetting tool in accordance with claim 1, wherein said jetting apertures extend through said body section in the part thereof which has a uniform minimum inner cross-sectional configuration.

References Cited in the tile of this patent UNITED STATES PATENTS 2,260,487 Scott Oct. 28, 1941 2,562,458 Hartsell July 31, 1951 2,633,916 Baker et al. Apr. 7, 1953 2,740,612 Phipps Apr. 3, 1956 2,777,455 Daudelin Jan. 15, 1957