US3123143A

US3123143A - annis etal

Info

Publication number: US3123143A
Authority: US
Publication date: 1964-03-03
Anticipated expiration: 1981-03-03

Description

M. R- ANNIS ETAL 2 Sheets-Sheet 1 WATER PACKER FIG- 25 MUD INVENTORS. LEON H. ROBINSON, JR ROBERT H. FRIEDMAN BY MAX R. ANNIS,

S G U L P L L A B FIG. 2.

ATTORNEY.

March 3, 1964 FREEING PIPE STUCK IN A BOREHOLE Filed March 1, 1962 PERM EABLE ZONE 4 DRILL P|;PE

PA 0 KER 9 DRILL COLLARS March 3, 1964 M. R. ANNIS ETAL 3,123,143

FREEING PIPE STUCK IN A BOREHOLE Filed March 1, 1962 2 Sheets-Sheet 2 FIG- 5- INVENTORS. LEON H. ROBINSON JR., ROBERT H.FRIEDMAN,

BY MAX R. ANN|s,

wJJM/Lm ATTORNEY.

3,123,143 FREEING FEE STUCK IN A BQREHGLE Max R. Annis, Leon H. Robinson, Jr., and Robert H.

Friedman, Houston, Tex., assignors, by mesue assi ments, to Jersey Production Research Company, Tulsa,

Okla, a corporah'on of Delaware Filed Mar. 1, 1962, Ser. No. 176,591 4 Claims. (Cl. 166-187) This invention relates to appmatus for isolating a section of a borehole, and more particularly to apparatus for loosening and freeing a drill pipe stuck against a borehole wall by differential pressure between the borehole and an earth formation penetrated by the borehole.

In boreholes drilled for the punpose of recovering oil and gas from productive earth formations, it is customary to circulate a drilling fluid down a drill pipe and up the annulus thereabout for the purpose of removing earth cuttings and generally facilitating drilling operations In order to prevent blowouts, it may be necessary to make the drilling fluid quite heavy. As a result, a very large pressure difierential can exist between the interior of the borehole and the earth formations penetrated thereby. It is not uncommon for drill pipe to become stuck against the walls of a borehole as a result of this pressure differential. Oftentimes the pressure differential is so high that it is not even necessary for the drill pipe to break through the filter cake lining the walls of the borehole in order for the pipe to become stuck. Generally speaking, it is the lower part or" the drill string including the so-called drill collars that is most susceptible to differential sticking as described above. The general problem is discussed in U.S. Patent 2,865,454, Richards, and in an article at page 201 of the periodical Oil and Gas Journal, vol. 49, No. 39.

In accordance with the present invention, a fluid expansible packer is affixed to a section of a drill string, which packer is adapted to expand to the sides of an earth formation penetrated by the drill string so as to seal the space between the drill string section and the walls of the borehole. First passageway means are provided within the drill string section between the bore of the section and the interior of the packer so that the packer can be inflated by fluid from within the drill string section. A normally-closed first valve means is provided for normally closing the passageway to fluid flow therethrough until the differential pressure between the section and the borehole annulus therearound is of a first given magnitude. In parallel with the first valve means is provided a second, normally-closed valve means adapted to open when the pressure between the bore of the drill string section and the annulus around the section immediately above the packer is of a second given magnitude higher than the first given magnitude mentioned above. The second valve is adapted to remain open after release of the pressure opening it for a predetermined period of time suflicient for the packer to contract to its normal position after pressure has been released. Thus, the packer can be inflated by increasing the difierential pressure between the bore of the drill string section and the annulus to a first given magnitude, and deflated by increasing the dinerential pressure to a second given magnitude and quickly releasing the pressure. After the packer has been inflated, the hydrostatic pressure below the packer on the drill string section can be decreased to free the drill string from the walls of the borehole.

Objects and features of the invention not apparent from the above discussion will become evident upon consideration of the following detailed description taken in connection with the accompanying drawings, wherein:

FIGS. 1 and 2 are elevational views, partially in cross section, of a drill string positioned in a borehole, including BJZBJ i-B Patented Mar. 3, 1964 apparatus in accordance with the invention illustrating two operative positions of the apparatus during the course of freeing a drill string;

FIG. 3 is a cross-sectional view taken along section 33 of FIG. 1; and

FIGS. 4 and 5 are cross-sectional views of an embodiment of apparatus in accordance with the invention illustrating two operative positions of the apparatus.

With reference generally to FIGS. 1-3, there is shown a drill string 1 including drill collars 5 positioned in a borehole 2 penetrating a given earth formation 4. The borehole is filled with drilling fluid or mud 3. The drill collars 5 include a section 11 near the upper end thereof, to which fluid expansible packer 9 is afiixed. At the lower end of the drill string is a bit sub 16, to which is afiixed a drilling bit 15, here shown as a fish tail bit including at least one port or nozzle 17 for directing a jet of drilling fluid downwardly to facilitate drilling operations. The drill collars 5 are shown as being stuck against the earth formation 4. The drill string is illustrated as having been raised from the bottom of the borehole, such as is usual during a round trip for the purpose of replacing a drill bit or while adding a joint of pipe. It is during such operations that diiierential sticking often is encountered.

ln FIGS. 4 and 5 there is illustrated apparatus within drill collar section 11 for the purpose or inflation and deflating packer h by selectively increasing and decreasing the hydraulic pressure within the drill string. Packer 9 is shown as being afiixed to drill collar section ill by means of a clamping ring 23. It will be assumed that a similar clamping ring is used to aifix the lower end of the packer to the drill collar section l1. Between the interior surface of packer 9 and the bore 2 2 of the drill collar section ii there are provide two passageways for fluid. The first passageway comprises passageway section 53, chamber s3, and port 65. The second passageway comprises passageway section 25, chamber 32, and port 34. The first passageway is normally closed by a valve in chamber 63, said valve including a valve stem 61 having an extension 5'? at the lower end thereof extending into passageway section 53 for guiding and centering the valve stem. The valve stem 61 seats on the tapered surface or seat s2 at the lower end of chamber 63 for closing the passageway. A collar 6) is afiixed to valve stem 61. A helical compression spring 71 around the valve stem engages the upper end of chamber 63 and the collar 69 for urging valve stem 51 against the tapered seat 62:. The valve stem s1 extends through a wall 73 into a chamber 75. The chamber has a port 14 for providing fluid communication between chamber 75 and the exterior of the drill string above packer 9. An O-ring 74 is provided to seal around the valve stem 61 to prevent fluid communication between

chambers

63 and 75. Chamber 75 and port 14- perrnit valve stem 61 to be forced ofi of seat 52 when the pressure differential between bore 22 and the borehole around the drill collar section 11 becomes sufficiently high to overcome the force of spring 71. When valve stem 61 is forced oil of seat 62, fluid will flow through passageway section 53, chamber 63, and port 65 to inflate packer 9 as shown in FIG. 5.

For the purpose of deflating packer 9 by the simple expedient of increasing the diflerential pressure between the interior of drill collar section it and the annulus therearound and above packer 9, there is provided a second valve arrangement in the second passageway described above. Valve stem 33 has a guide extension 27 thereon including an annular sealing member 29. The valve stem seats on the tapered valve seat section 31 of chamber 32. Aflixed to the upper end of valve stem 33 and forming an integral part of the valve stem are

pistons

35 and 47 connected together by connecting rod 41 35' is adapted to reciprocate in cylindrical chamber 39, and piston is adapted to reciprocate in cylindrical chamber 45. A helical compression spring 49 in chamber engages the upper end of piston 47 to force the pistons downwardly in their chambers so that valve stem 33 will seat on valve seat 31. Within the between chambers 3? and 45 there is provided eway including a check valve 41 for permitting fluid flow from criamoer 39 to chamber 45, but preventing fluid flow therethrough from chamber 5-5 to chamber 39. Also within wall is an orifice 43 for permitting limited fluid flow in both directions between the chambers 39 and A light, clean liquid of selected viscosity fills the portion of chamber 45 below piston 4-7 and fills the portion of chamber 39 above piston 35. A port 13 permits free fluid communication between chamber 45 and exterior of the drill collar section Ill. Thus, when a given differential pressure exists between the bore of the drill collar section ill and the borehole annulus above packer 9 sufficient to overcome spring 49, valve stem 53 will pop ofl of seat 31. "l' he check valve 41 will open so that the valve stem will be forced upwardly a substantial distance when it pops off of seat 31. Check valve 41 will immediately close, and the valve stem 33 and pistons -5-7 and 35 will be forced downwardly very slowly by spring 49 because of the greatly restricted fluid flow through orifice 43. Thus, the valve stem 33 will remain off of its seat 31 for a predetermined period of time determined by the dimensions of orifice 43.

The over-all operation of the apparatus illustrated in FIGS. 1-5 is as follows. Let it be assumed that the drill string has become stuck against the wall of earth formation 4 as illustrated in FIG. 1. A quantity of a light fluid, such as water, is circulated down the well to reduce the weight of the column of fluid in the drill string until the pressure exerted by the liquid in the drill string on the borehole wall below the packer is less than the formation pressure below the packer. in the usual case it will be found that 1600 to 2000 feet of Water in the drill string bore at the top of the drill string will give satisfactory results. Nitrogen or other relatively inert gas may be used for this purpose. A number of balls 21 (see FIG. 2), which may be of rubber or a rubber-like material and of a diameter greater than the diameter of ports 17, are dropped into the drill string so as to seal the ports 17. After the balls 21 have plugged the ports 17, pressure within the bore of the drill string is increased to a first pressure whereat valve stem 61 is forced off of its seat. The fluid within drill collar section 11 will flow through passageway section 53, chamber 63, and port 65 to inflate packer 9. This condition is illustrated in FIG. 2. The pressure within the drill string may then be released to lower the pressure in the annulus below packer 9 to permit the drill collars 5 to be freed from the earth formation 3. It has been found that once the drill collars are freed they do not again tend to become stuck. The reason for this is not completely under tood, but experience has shown that it is consistently the case; see the article in the Oil and Gas Ii'ournal, supra.

The pressure in the drill string bore is again increased until valve stem 33 is forced off of seat 31. The pressure in the drill string then is quickly decreased. Valve stem 61 immediately will reseat on seat 62., but valve stem 33 will remain oil of seat 33 for a period suflicient for packer 9 to deflate. The drill string then may be retracted from the borehole or may be lowered to the bottom of the borehole so that drilling operations may be recommenced, as desired.

If it is desired to resume drilling without removing the drill string from the borehole, the pressure in the drill string bore is increased until the balls 21 extrude through ports 17. Manifestly, if it is contemplated, the balls should be formed of relatively soft rubber. Alternatively, the direction of drilling fluid circulation can be reversed so Valve piston that the balls are carried up the drill string bore to the earths surface.

It is to be noted that during normal circulation the pressure inside the drill string will be greater than the pressure in the annulus therearound because of the pressure drop across the ports in the bit. Therefore, it is manifest that the constants of

springs

49 and 71 should be chosen so that the pressures required to operate valves 26 and 54 will be greater that the maximum circulating pressure.

The invention is not to be restricted to the specific structural details or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of the invention.

We claim:

1. For use with a tubular drill string having a fluid expansible annular packer affixed to the outer surface thereof, constructed and arranged so that fluid pressure exerted on the inner surface thereof will expand thepaclter to the walls of a borehole within which the drill string is disposed, apparatus for controlling application of fluid pressure from the bore of the drill string to the inner surface of the packer, comprising:

a drill string section for supporting the packer;

first and second passageways in the drill string section between the bore of the drill string section and the inner surface of the packer supported thereby;

first, normally-closed valve means in said first passageway for controlling fluid pressure therethrough, constructed and arranged to close said fluid passageway while the pressure within the drill string section bore is greater than the pressure in the borehole annulus and while the dilferential pressure between the drill string bore pressure and the borehole annulus pressure is less than a first given differential pressure, and to open when the pressure within the drill string section bore is greater than the pressure in the borehole annulus therearound and said differential pressure between the drill string bore and the borehole annulus reaches said first given diflerential pressure;

second normally-closed valve means in said second'passageway for controlling fluid flow therethrough, constructed and arranged to close said fluid passageway while the pressure within the drill string bore is greater than the pressure in the borehole annulus and the differential pressure between the pressures in the drill string bore and the annulus around the drill string section above the packer is less than a second given differential pressure greater than said first given dilferential pressure, and to open when said differential pressure between the drill string bore pressure and the borehole annulus pressure reaches said second differential pressure; and

means connected to said second valve means for holding open said second valve means for at least apredetermined time interval after the differential pressure between the drill string section bore and the borehole annulus above the packer falls to less than said second differential pressure.

2. For use with a tubular drill string having a fluid expansible annular packer affixed to the outer surface thereof, constructed and arranged so that fluid pressure exerted on the inner surface thereof will expand the packer to the walls of a borehole within which the drill string is disposed, apparatus for controlling application of fluid pressure from the bore of the drill string to the inner surface of the packer, comprising:

a drill string section for supporting the packer; first and second fluid passageways in said drill string section connected in parallel between the bore of said drill string section and the exterior of said drill string section under the packer; a first chamber in said drill string section in fluid communication with the exterior of said drill string section and separated from said first passageway by a first wall;

a second chamber in said drill string section in fluid communication with the exterior of said drill string section and separated from said second passageway by a second wall;

a first valve seat positioned in said first passageway, and

a second valve seat positioned in said second passageway;

a first valve stem in said first passageway, extending through said first wall from said first chamber, for seating on said first valve seat to norma l close said first passageway;

a second valve stem in said second passageway, ex-

tending through said second wall from said second chamber, for seating on said second valve seat to normally close said second passageway;

first spring means engaging said first valve stem and said drill string for urging said first valve stem into seating engagement with said first valve seat;

second spring means engaging said drill string section and said second valve stem, adapted to hold said second valve stem on said second valve seat against a greater differential pressure between the bore of the drill string section and the exterior thereof than can be resisted by said first spring in holding said first valve stem on said first valve seat; and cans in said drill string section for holding said second valve stem off of said second valve seat for at least a predetermined time interval after said second valve stem has been lifted olf of said second valve seat.

3. For use with a tubular drill string having a fluid expansible annular packer afiixed to the outer surface thereof constructed and arranged so that fluid pressure exerted on the inner surface thereof will expand the packer to the walls of a borehole within which the drill string is disposed, apparatus for controlling application of fluid pressure from the bore of the drill string to the inner surface of the packer, comprising:

a drill string section for supporting the packer;

first and second fiuid passageways in said drill string section connected in parallel between the bore of said drill string section and the exterior of said drill string section under the packer;

a first chamber in said drill string section in fluid communication with the exterior of said drill string section and separated from said first passageway by a first wall;

a first valve seat positioned in said first passageway, and

a second valve seat positioned in said second passageway;

a first valve stem extending through said first wall from said first chamber for seating on said first valve seat to normally close said first passageway;

a second valve stem extending from said second wall to said second chamber for seating on said second valve seat to normally close said second passageway;

first spring means engaging said first valve stem and said drill string section for urging said first valve stem into seating engagement with said first valve seat;

second spring means engaging said drill string section and said second valve stem adapted to hold said second valve stem on said second valve seat against a greater differential pressure between the bore of the drill string section and the exterior thereof than can be resisted by said first spring in holding said first valve stem on said first valve seat;

a piston engaging the walls of said second chamber and connected to said second valve stem for reciprocating movement therewith; and

an orifice in said second wall for permitting fluid flow therethrough, and a passageway including a check valve in said second wall for permitting fluid flow through said second wall into said second chamber when said second valve stem is lifted off of said second valve seat whereby said second valve stem remains olf of said second valve seat for at least a predetermined period after said second valve stem has been lifted oif of said second valve seat.

4. For use with a tubular drill string having a fluid expansible annular packer afilxed to the outer surface thereof constructed and arranged so that fluid pressure exerted on the inner surface thereof will expand the packer to the walls of a borehole within which the drill string is disposed, apparatus for controlling application of fiuid pressure from the bore of the drill string to the inner surface of the packer, comprising:

a drill string section for supporting the packer;

first and second fluid passageways in said drill string section connected in parallel between the bore of said drill string section and the exterior of said drill string section under the packer;

first valve means positioned in said first passageway and having a portion thereof exposed to borehole pressure around said drill string section in the vicinity of said packer constructed and arranged to close said first passageway until pressure in said drill string section bore is greater by a first predetermined pressure than the borehole pressure in the vicinity of said packer;

second valve means positioned in said second passageway and having a portion thereof exposed to borehole pressure above said packer constructed and arranged to close said second passageway until pressure in said drill string section bore is greater by a second predetermined difierential pressure than the borehole pressure immediately above said packer, said second predetermined difierential pressure being greater than said first predetermined differential pressure; and

means in said drill string section for holding open said second valve means for at least a predetermined time interval.

References Cited in the file of this patent UNITED STATES PATENTS 2,497,185 Reistle Feb. 14, 1950 2,942,667 Blood et a1. June 28, 1960 2,994,378 Reistle Aug. 1, 1961

Claims

1. FOR USE WITH A TUBULAR DRILL STRING HAVING A FLUID EXPANSIBLE ANNULAR PACKER AFFIXED TO THE OUTER SURFACE THEREOF, CONSTRUCTED AND ARRANGED SO THAT FLUID PRESSURE EXERTED ON THE INNER SURFACE THEREOF WILL EXPAND THE PACKER TO THE WALLS OF A BOREHOLE WITHIN WHICH THE DRILL STRING IS DISPOSED, APPARATUS FOR CONTROLLING APPLICATION OF FLUID PRESSURE FROM THE BORE OF THE DRILL STRING TO THE INNER SURFACE OF THE PACKER, COMPRISING: A DRILL STRING SECTION FOR SUPPORTING THE PACKER; FIRST AND SECOND PASSAGEWAYS IN THE DRILL STRING SECTION BETWEEN THE BORE OF THE DRILL STRING SECTION AND THE INNER SURFACE OF THE PACKER SUPPORTED THEREBY;