US2681795A

US2681795A - Sampling sub with removable cutting collector

Info

Publication number: US2681795A
Application number: US179340A
Authority: US
Inventors: James N Gregory
Original assignee: Shell Development Co
Current assignee: Shell Development Co
Priority date: 1950-08-14
Filing date: 1950-08-14
Publication date: 1954-06-22
Anticipated expiration: 1971-06-22

Description

June22,1954 J. N. efizc zdm ,681,795- SAMPLING 'sma WITH REMOVABLE CUTTING COLLECTOR med Aug. 14, 1950 2 Sheets-Sheet 1 lnven-Por: James N. Gn-eqorg En; I 1-115 A'Hbrneq June 22, 1954 J. N. GREGORY SAMPLING SUB WITH REMOVABLE CU'iTING COLLECTOR Filed Aug. 14, 1950 lnyenl'or Jame; N .Gre B Patented June 22 1 954 SAMPLING SUB WITH REMOVABLE CUTTING COLLECTOR James N. Gregory, Fullerton, Calif assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware Application August 124, 1950; Serial No. 179,340

9 Claims.

The present invention relates to apparatus for drilling and logging wells-and pertainsmore particularly to apparatus for collecting samples of formation cuttings from a stream of drilling fluid at a point near a drill bit during rotary drilling.

During well drilling operations, a'well may be logged bystudyingthe earthcuttings as they return. tov the top of the well inthe circulating stream of drilling fluid. The. fluid is either run through a screen upon which the cuttings are collected, ora sample of fluid is periodically taken from the drilling fluid stream, ditch or pit, and

the cuttings contained'therein' are later separated. from the fluid inla laboratory. The main disadvantages of collecting samples of bit' outtimes at the top of the well is that the cuttings are generally small in size and have been contaminated by being carried in the stream of drilling ,fluidfor as long, as an hour or more. It is furthermore difficult to correlate the cuttings with the particular depths to which they belong.

Thus, in orderto obtain relatively large; uncontaminated samples of the formation being traversedbya borehole, it"is generally necessary to resort to bottom-hole or side-wall coringi These methods of coring, while normally adequate, result in' considerable lost operating time in" that drillingoperationst must be stopped'while acore is taken. Additionally, side-wall samples obtained by'conventional apparatus are often inadequate for microfaunal determination because microfauna specimens occur in streaks which'are' often missed lay-taking spot core samples.

Sampling devices for obtaining bit cuttings from the bottom of aboreholehave the common Another object of this invention is to provide a removable sampling device for continuously receivingbiticuttings inone portion of the device while permitting the flow of drilling fluid through another portion thereof;

These and other obiectsor this invention will;

be understoodfrom the: following description of the invention: as shown in the accompanying drawing, wherein:

Figures. 1 and 6 are views, partly in cross section, of two embodiments of the'present apparatus, comprising a sampling device positioned in aspecialsub or sectionlof a drillstring.

Figure 2 is a cross-sectional view taken along the line 2--2 of Figure: 1.

Figure 3 is an elevation view of another embodiment of the present sampling device.

Figure 4 is a view in the longitudinal or verticalcrosssection of the deviceofFigur-e 3.

Figureb is a view, taken" in crosssectionillus trating the present sampling device and its as sociated sub positioned .in a drill string at the bottom of a well borehole:

Figure 7 is a View in crosssection of a sleeve adapted torbe lowered into the special sub in place ofasampling device.

Figure 8 is a top view of the sleeve illustrated ment of a removable liner adapted to fit within the chamber of a samplingdevice.

Referring to Figure l of the drawing, the present sampling apparatus comprises an elongated tubular member ID adapted to receive and anchor in its bore II a sampling device or cutting collector Ill. The tubular member l8, otherwise known as a subor short section'of drill pipe or drill collar, is threaded at its upper and lower ends 13 and [4, respectively, whereby the upper end l3 may be connected to a section of drill string or a drill collar l5, as shown in Figure 5, andthe lower end I 4-may be connected to another section of the drill string or toa bit H6. The special sub I0 is preferably connected into the drill string 15- directly above a wall scraper or drill bit it, as'shown, but it is to be understood that the present sub may be connected between any two sectionsof the drill string.

The tubular member I0 is provided with one or more slots or ports ll and l'la through the Wall [3 thereof. to permit earth cuttings to enter thebore l l. Preferably, theaxis of the slot ll slants However, the slot-opening should have an area:

of several times the size-of the cuttings which-it is-desircd to" collect,

However, the

The axial bore II may be of substantially the same diameter as the bore of the drill string I and has a constriction I9 which forms annular shoulder 2 I, beveled downwardly, whose function will be described hereinafter. Obviously, the shoulder 2|, or an equivalent shoulder 44, may be located either above or below the slot I! as shown in Figures 1 and 6, respectively.

The sampling device or cutting collector I2 comprises a cylindrical member containing a chamber 22 in which earth cuttings may be collected. The cross-sectional area of the chamber 22 generally constitutes a major portion of the cross-sectional area of the entire collector I2, as shown in Figure 2. Extending axially through the collector body I2 is a channel or by-pass conduit 23 through which a drilling fluid, passing downwardly through the drill string I5 (Fig. 5), may be delivered to the cutting tool I6 during drilling operations. The conduit 23 may be arranged n any desired manner within the collector body I2, either eccentrically as shown in Figures 1 and 2, or concentrically as shown in Figure 6. Also, if desired, the upstream end of the conduit 23 may have more than one inlet port, as shown at 2A and 25 in Figure l.

The upper end of the collector body I2 is provided with an upwardly-extending fishing neck 26 which projects into the bore 27 of the drill string 55. The fishing neck 21 may be secured to the collector body I2 by a plurality of spaced lugs 28 as shown in Figure 8.

The outside wall of the collector body I2 is decreased in diameter along a portion thereof to form an annular shoulder 29 which engages and is supported by the shoulder 2| on the inner wall of the sub iii, thereby supporting the collector body I2 within the tubular member IQ. The collector body i2 is also provided with one or more windows 38, 3| and 32 which are of such dimensions and are so disposed in the wall of the collector body I2 that at least one of them is always in register with at least one of the slots I1 and Na in the sub It (Figures 1 and 2), whereby earth cuttings may pass through said slots and windows into chamber 22.

In another embodiment of the present invention (Figures 3 and 4) the sub II] and the cutting collector I2 may be provided with a single slot I1 and a single window 33, respectively. When a cutting collector I2 is provided with a single window 33, it is necessary to provide suitable orienting means for aligning the collector I2 within the sub Ill so that the windows of each are in register. Hence, the body of the cutting collector I2 may be provided with a longitudinal slot or keyway 34 from which diverging shoulders 35 and 3E slant downwardly and meet at a point 31. An alignment pin or key 38 is fixedly mounted in the sub body It so that it projects horizontally a short distance into the bore I I thereof. As the collector I2 is lowered into the sub body I0, the projecting pin 38 will engage a point on either

shoulder

35 or 36. Thereupon, the pin 38 will ride up the

shoulder

35 or 36 and cause the collector I2 to rotate in the bore of the sub i ll until the pin 38 and slot 34 are in vertical alignment. In this position the windows I? and 33 in the sub I0 and collector I2, respectively, are in register.

In order to secure a more fluid tight seal between the cutting collector I2 and the inner wall of the sub Ill, one or more annular grooves 39 (Fig. 1) may be cut or formed in the outer surface or the collector I2 to accommodate rings 49 of any suitable packing material. Generally, however,

an adequate seal is provided at the point where the two shoulders 2| and 29 are in contact.

During drilling operations when no sampling of cuttings is desired, the cutting collector I2 may be removed and replaced with a suitable plug or closure means for closing the slots I? and Ila in the sub, whereby a drilling fluid being circulated down the drill string it will not by-pass the bit and fiow out the slots ii and Ila. As shown in Figures 7 and 8, one embodiment of a slot closure means may comprise a tubular member or closure sleeve which is decreased in diameter near the lower end thereof to form an annular shoulder 42 which is adapted to engage the shoulder 2! on the inner wall of the sub it (Fig. i). The length of the tubular member ll is such that the top of said member extends above the slots I? and Ila, efiectively closing them. The upper end of the closure sleeve li is provided with a fishing neck 43 secured thereto by a plurality of spaced lugs 28.

It is realized that various changes and modifications may be made in the elements described herein without departing from the principles of ing 38, shown in Figure l.

The cutting collector 48 is provided with an axial fluid by-pass 59 having two inlet ports 50 and iii. Thus, an annular collecting chamber 53 is formed within said collector 48. Cuttings enter the chamber 53 through a window 52 in the wall of the collector 48. The bottom of the chamber 53 is closed by a removable plate 54 which is secured in any suitable manner, as in screwthreaded engagement, to the bottom of the collector 48. By removing the plate 5 the collected cuttings may be readily removed from the chamber 53. If desired, the collector may be equipped with a removable liner 55 (Fig. 9), having an open top and a closed lower end. The liner is formed of a thin material shaped to fit within the annular chamber 53. While a thin metallic liner 55 may be used, it is preferably made of a transparent plastic material whereby the diiferent-layers of cuttings, collected from the various strata traversed by the drill bit, may be visually inspected before removing them from the liner. The layers of cuttings in the liner 55 will be arranged in the inverse order in which the strata are penetrated.

For closing the slot at in the sub 35 when the cutting collector 48 is removed therefrom, the sub is provided with a slidable sleeve 53 mounted above a compression spring 5? in the bore of said sub it. The spring 57 is limited in its downward movement by a holding ring 58 which is fixedly secured, as by welding, to the inner wall of the sub 45. As the cutting collector (i3 is lowered into the sub it, the weight of the collector 48 forces the sleeve 56 downwardly to compress the spring as illustrated in Figure .6. Upon removal of the collector 48, the spring 5? forces the sleeve upwardly until it is positioned opposite the slot d6, effectively closing it.

At any time during drilling operations, when a drill string I5 (Fig. 5) is made up, the special ages-1,795

sub |;:'may be connected into the spring, preferably directly above the bit It; When 110- bit cuttings'arebeing collected; theslot 33 may be closed bythe sleeve 4| (Fig; 7 which may be droppedor lowered down the drill string l5 and into the sub; H1. Before taking samples of the cuttings, a suitable fishing device 59 (Fig. 5) is-lowered on a cable 60 into contact with the fishing head43 (Fig. 7) The fishing device 59- latches ontothe head 43 and the sleeve M is; withdrawnfrom the well on the end of the cable.

The cutting collector I2 is then lowered by cable-or dropped through the drill string i5" and into position in the sub It, asshown in- Figure 5. Ira cable 69 is employed to lower the collector l2; the cable is withdrawn to thesurface before drilling operations are resumed. Drilling fluid being circulated down the drill string [5 passes through the'fluid by-pass 23 in the collector l2, through the bit I6", and up the annular passage- Way 61 between the drill-string l5 and the wall of" the borehole.

The present, cutting collector l2 operates on the principle that the velocity'of the circulating fluid. rising in the annular-passageway BI is reducedwhen the fluid passes the slots 33 andwindows H in the sub I (l-and collector l2, respectively. The resulting decrease in the circulating; fluid velocity together, with the turbulence created by the slots reduces the. carrying power of the circulating fluid. The earth cuttings, especiallythe larger and more desirable ones, are thrown outofthe mud' stream.- and into the chamber-22 of the collector I2; The collected cuttings may be raised'to the surface of the well along with the collector l2; by a fishing tool 59 at the end of a cable 6D, ina manner similarto that described above for removing a sleeve 4|.

I, claim as my invention:

1 Apparatus for collecting earth cuttings frommudfiush circulating in a borehole, comprising in, combination a. tubular. member adapted to be connected into a drill string, radial port means in. the walls of said tubular member opening from the Qutside to the bore therethrough, an elonated cylindrical container. snugly fitting slidably within said bore, means within said bore for anchoring said container within said bore, a first axiallyeelongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either sideof said container, a second axially-elongated chamber in saidcontainer closed atits lower end and to the space within said drill string, and radial, window means opening to saidsecond chamber through the walls of said container near the upper end thereof, said window means being adaptedto register with the port means of said tubular member when said container is anchored within said tubular member and being of a size to permit earth cuttings to enter said container and settle .to' the closed. lower end thereof.

2;..Apparatus for collecting earth cuttingsfrom mudflush circulating, in a borehole, comprising in combination a tubular memberadaptedto be connected into. a drill string, radial port means inthe walls of said tubular member opening from the outside to the bore therethrough, an elongated cylindrical container snugly fitting slidably within said bore, means formed on the inner wall of said bore and the outer wall of said container for anchoring said container within said bore. a first axially-elongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either side of saidcontainer, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, removable plate means forming the lower closure of said chamber, and radial windows opening to saidsecond chamber through the walls of said container near the upper end thereof, said windows being adapted to register with the ports of said tubular member when said container is anchored within said tubular'member-and being of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof.

3. Apparatus for collecting earth cuttings from mudfiush circulating in a borehole, comprising in combination a tubular member adapted to be connected into a drill string, radial port means in the Walls of said tubular member openingfrom the outside to the bore therethrough, an elongated cylindrical container snugly fitting slidably within said bore, means formed on the inner wall of said bore and the outer wall of said container for anchoring said container within said bore, a first axially-elongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either side of said container, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, radial windows opening to said second chamber through the walls of. said container near the upper end thereof, said windows being adapted to register with the ports of said tubular member when said container is anchored within said tubular member and being of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof, and

removable liner means carried within the lower end of said container means below the windows thereof.

4. Apparatus for collecting earth cuttings from mudflush circulating in a borehole, comprising in combination a tubular member adapted to be connected into a drill string, substantially radial port means inthe walls of said tubular member opening from the outside to the bore therethrough, an elongated cylindrical container snugly fitting slidably within said bore, means formed on the inner wall of said bore and the outerwall of said container for supporting said container within said bore, a first axially-elongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either side of said container, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, radial windows opening to said second chamber through the walls of said container near the upper end thereof, said radio windows being of a size to permit earth cuttings to enter said container settle to the closed lower end thereof, and registering first and second guide means, said first means being carried by said cylindrical container and said second means being carried by the tubular member, whereby the engagement of said first and second guide means upon the sliding of said container within the bore of said tubular member moves said container to a position wherein the windows thereof register with the ports of said tubular member.

5. Apparatus for collecting earth cuttings from mudflush circulating in a borehole, comprising in combination a tubular member adapted to be connected into a drill string, substantially radial port means in the walls of said tubular member opening from the outside to the bore therethrough, an elongated cylindrical container snugly fitting slidably within said bore, first shoulder means formed on the inner wall of said bore, second shoulder means formed on the outer wall of said container, said first and second shoulder means contacting each other for supporting said container within said bore, a first axiallyelongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either side of said container, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, radial windows opening to said second chamber through the walls of said container near the upper end thereof, said radio windows being of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof, and registering pin and guide means, one of said means carried by the tubular member and the other by the container means, whereby the engagement of said guide means with said pin means upon the entry of said container into the bore of said tubular member causes said container to rotate until the windows thereof are in register with the ports in said tubular member.

6. Apparatus for collecting earth cuttings from circulating drilling fluid in a well borehole during drilling operations, said apparatus comprising, in combination, a tubular sub adapted to be connected into a drill string, said sub having port means through the wall thereof, a projecting shoulder arranged on the inner Wall of said sub, container means insertable into said bore of said tubular sub to engage the projecting shoulder thereof and withdrawable upwardly therefrom, said container means forming an elongated chamber closed at the upper and lower ends, open window means through the wall of said member near the upper end thereof, said window means being at least partially in register with said port means of said sub and being of a size to permit earth cuttings to enter said container means and settle to the closed lower end thereof, and conduit means extending through said chamber opening to the spaces above and below the ends thereof.

7. The combination of a tubular sub, having port means through the wall thereof and internally projecting shoulder means, with a sample collecting device adapted to be dropped into the bore of said sub and seat on said projecting shoulder, said device comprising a closed elongated cylindrical container having radial window means near the upper end thereof in register with said port means in said sub, said window means being of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof, and fluid conduit means in communication with the bore of said sub above and below container extending through said container.

8. Apparatus for collecting earthcuttings from mudfiush circulating in a borehole, said apparatus comprising, in combination with a tubular member adapted to be connected into a drill string and having radial port means in the walls thereof opening from the outside to the bore of said tubular member, an elongated cylindrical container snugly fitting slidably within said bore, means formed on the inner wall of said bore and the outer wall of said container for supporting said container within said bore, a first axiallyelongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to either side of said container, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, and radial window means opening to said second chamber through the walls of said container near the upper end thereof, said window means being adapted to register with the port means of said tubular member when said container is anchored within said tubular member andbeing of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof, and tubular sleeve means fitting slidably within the bore of said tubular member to close the radial port means thereof when said container is withdrawn therefrom, said cylindrical container and tubular sleeve being alternatively insertable into the core of said tubular member.

9. Apparatus for collecting earth cuttings from mudfiush circulating in a borehole, comprising in combination a tubular member adapted to be connected into a drill string, radial port means in the walls of said tubular member opening from the outside to the bore therethrough, tubular sleeve means slidably mounted in the bore of said tubular member, spring means supported within the bore of said tubular member for normally urging said sleeve means to a position closing said radial port means, an elongated cylindrical container fitting slidably within said bore, said container being adapted to depress said tubular sleeve means and open said port means, means formed on the inner wall of said bore and the outer wall of said container for supporting said container within said bore, a first axially-elongated chamber in said container, said chamber opening at both axial ends thereof to the space within the drill string to eitherv side of said container, a second axially-elongated chamber in said container closed at its lower end and to the space within said drill string, and radial window means opening to said second chamber through the walls of saiol container near the upper end thereof, said window means being adapted to register with the port means of said tubular member when said container is anchored within said tubular member and being of a size to permit earth cuttings to enter said container and settle to the closed lower end thereof.

References Cited in the file of this patent Weiler Mar. 6,1951.