Method And Apparatus For An Equalizing Valve

Abstract

An apparatus for a surface controlled subsurface safety valve including a rotatable ball closure member for controlling flow of fluid through the valve and a by-pass flow means for equalizing fluid pressure about the closed ball when desired. The by-pass flow means is operable either by opening the flow means while blocking opening rotation of the ball or automatically when rotating the ball open to enable flow through the valve. A method of operating the equalizing valve is also disclosed.

Parent Case Text

This is a continuation of application Ser. No. 214,685, filed Jan. 3, 1972, now abandoned.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to the field of a valve and more particularly to a subsurface safety valve having a rotatable ball closure means and a flow by-pass means for equalizing fluid pressure urging on the ball.

Prior art production tubing retrievable valves have sought, until now unsuccessfully, to provide a long and reliable operating life for a safety valve to shut in a well at a subsurface location. The cost in time and in lost production from the well along with the expense incurred in pulling the tubing to replace defective valves have been prime factors in limiting widespread use and acceptance of these valves. More importantly, the failure of a faulty safety valve to operate could result in a catastrophic well blow-out with all of the attendant hazards to life and property therefrom as well as in environment damage from the escaping hydrocarbons and other well fluids.

Having sealing surfaces shielded from the well flow, a low inherent flow resistance and numerous other desirable characteristics have made rotatable ball valves a preferred type of valve for subsurface well service. One drawback in using rotatable ball valves has been that when the ball was rotated to the open position while holding a large pressure differential thereacross, the ball and valve sealing surfaces were frequently scored, galled or otherwise damaged which would thereafter enable leakage through the valve. The initial high velocity flow, as the ball was rotated open, cut, eroded or otherwise damaged the valve sealing surfaces which would also enable leakage through the valve. Prior attempts to incorporate a flow by-pass to equalize the fluid pressure about the ball prior to rotating open the ball such as disclosed in my co-pending United States Patent Application, Ser. No. 72,034, now abandoned, utilized the same operating means to effect operation of the ball and the flow by-pass. With such arrangement, an operator at the well head was unable to ascertain that pressure equalization across the ball was effected by the by-pass valve or by the potentially damaging partial rotation of the ball.

SUMMARY OF THE INVENTION

A method of operating and apparatus for a surface controlled subsurface safety valve including a flow housing having a bore therethrough and a rotatable ball type bore closure member movably disposed in the bore to control flow of fluid therethrough. The valve also includes a by-pass flow means for equalizing the fluid pressure about the ball that is operable either independently when desired of the ball operation or automatically when rotating open the ball. The method includes the steps of blocking movement of the ball while flowing fluid about the ball to equalize the fluid pressure and thereafter releasing and rotating the ball to the open position for enabling flow through the valve.

An object of the present invention is to provide a new and improved apparatus for an equalizing valve.

Another object of the present invention is to provide a new and improved method for operating an equalizing valve.

A further object of the present invention is to provide a new and improved apparatus for an equalizing valve having independent modes of operation for effecting pressure equalization and for operating the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are side views, partially in section, illustrating the equalizing valve of the present invention with the ball rotated closed;

FIGS. 2A and 2B are views, similar to FIGS. 1A and 1B, respectively, illustrating the equalizing valve of the present invention enabling pressure equalization about the closed ball while blocking movement of the ball; and

FIGS. 3A and 3B are views, similar to FIGS. 1A and 1B respectively, illustrating the equalizing valve of the present invention, with the ball rotated to the open position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The equalizing valve of the present invention, generally designated V, is illustrated in the Figs. with the upper portion thereof illustrated in the A reference figure and the lower portion thereof in the B reference figure. The equalizing valve V includes a flow control housing or assembly F and a movable bore closure means C operably connected therewith for controlling flow of fluid through the valve V. The flow control housing F further includes means for moving the bore closure means C to and from open and closed positions for controlling the flow of fluid through the valve V and a means for equalizing the fluid pressure urging on the bore closure means C before moving the bore closure means C to enable flow of fluid through the valve V.

The flow control housing F includes a tubular member 10 which extends downwardly from an upper annular shoulder 10a (FIG. 1A) to a lower annular shoulder 10b (FIG. 2B) and which has a longitudinally extending bore 11 formed therethrough. The tubular member 10 mounts suitable fastening means for securing the tubular member 10 with a well conduit or production tubing T above and below the valve V such as an upper threaded box connection 12, adjacent the shoulder 10a, and a threaded lower pin connection 13, adjacent to the shoulder 10b. The threaded connections 12 and 13 enable connection of the tubular member 10 in the production tubing T at any desired subsurface location in a well to form a portion of the production tubing T with the bore 11 of the tubular member 10 communicating with a bore X of the production tubing T above and below the tubular member 10 to enable flow of fluid through the bore X of the production tubing T to flow through the bore 11 of the tubular member 10 in producing or flowing hydrocarbons and the like from the well.

Preferably, both for simplicity and ease of assembly, the tubular member 10 includes an upper sleeve member 10c, an intermediate sleeve member 10d and a lower sleeve member 10e which are secured together by suitable fastening means to provide the single tubular member 10 unit. The intermediate sleeve 10d is fastened to the upper sleeve 10c and the lower sleeve 10e by threaded engagement at 10f and 10g respectively, and is secured thereto against inadvertent disengagement by suitable anti-rotation members (not illustrated). The sleeve 10d and the sleeve 10e mount O-rings 14 and 15 thereon, respectively, adjacent the threads 10f and 10g to block leakage of fluid along the engaged threads 10f and 10g about the sleeve 10d.

The bore closure means C includes a ball member 20 having a flow port or opening 20a formed therethrough and which is movably disposed in the bore 11 of the tubular member 10 between an open position (FIG. 3B) for enabling flow of fluid through the bore 11 of the tubular member 10 and a closed position (FIG. 1B) blocking flow of fluid through the bore 11 of the tubular member 10. The flow control housing F includes a pivot means P and an operator assembly S for co-acting together to effect movement of the ball 20 to and from the open and closed positions.

The pivot means P includes a pivot sleeve 30 positioned in the bore 11 of the tubular member 10 and secured thereto concentrically adjacent the lower portion of the ball 20. The ball 20 includes a spherical outer sealing surface 20b with two separate portions of the ball 20 removed to form a pair of parallel flat surfaces 20c with each of the circular flat surfaces 20c having an elongated, radially extending recess 20d formed therein for receiving an eccentrically positioned inwardly extending pin 30a secured with the sleeve 30 for operably connecting the ball 20 with the tubular member 10. Movement of the center of the ball 20 relative to the eccentric pins 30a will rotate the ball 20 to the closed position when the center of the ball 20 is above the pivot pins 30a (FIG. 1B) and to the open position when the center of the ball 20 is below the pivot pins 30a (FIG. 3B). One skilled in the art may vary this arrangement to close the ball 20 in the lower position and to rotate the ball 20 open in the upper position.

Reference is made to my co-pending U.S. Pat. application Ser. No. 72,034, entitled "PRESSURE OPERATED SAFETY VALVE WITH LOCK MEANS," filed Sept. 14, 1970, for a more detailed disclosure of the rotational operation of the ball 20.

The sleeve 30 may be secured to the tubular member 10 by any suitable fastening means, such as the lug receiving slot system illustrated. The intermediate sleeve 10d of the tubular member 10 includes a plurality of inwardly projecting lugs 10h with each lug 10h having a flat downwardly facing locking shoulder 10i formed thereon for engaging the pivot sleeve 30. The sleeve 30 includes an annular recess 30b formed in the outer surface 30c thereof having a flat upwardly facing annular shoulder surface 30d thereof for engaging the locking surface 10i of the lugs 10h to block upward movement of the sleeve 30 relative to the tubular member 10. The outer surface 30c of the sleeve 30 has a plurality of longitudinally extending recesses 30e formed therein for enabling the movement of the sleeve 30 relative to the lugs 10h to enable the locking shoulders 10i and 30d to be brought into engagement by relative rotation of the sleeve 30 and the tubular member 10 when the annular recess 30 b is aligned with the lugs 10h. The locking shoulders 10i and 30d are maintained in engagement by a spacer sleeve 31, positioned below the sleeve 30 and engaging a lower annular shoulder 30f thereof and an upwardly facing annular shoulder 10j of the sleeve 10e to block downward movement of the sleeve 30 relative to the tubular member 10.

The operator assembly S includes a sleeve or wash pipe 40 movably disposed in the bore 11 below the ball 20 and in engagement therewith and a spring or urging means 41 for effecting longitudinal operating movement of the ball 20. The wash pipe 40 includes an upper constant diameter outer surface 40a adjacent an inner diameter surface 30g of the sleeve 30 and a lower constant diameter surface 40b adjacent a bore 11 defining surface 10k of the sleeve 10e concentrically positioning the wash pipe 40 in the bore 11 for guiding longitudinal movement of the wash pipe 40 in the bore 11 between an upper position (FIG. 1B) and a lower position (FIG. 3B). The wash pipe 40 further includes a constant diameter inner surface 40c defining a longitudinal bore 40d extending through the wash pipe 40 communicating with the bore 11 for enabling flow of fluid through the equalizing valve V and an upwardly facing arcuate annular shoulder 40e in engagement with the spherical surface 20b of the ball 20. The wash pipe 40 includes an annular collar 40f formed thereon above the guide surface 40b having a downwardly facing annular shoulder 40g formed thereon engaging the spring 41 concentrically positioned between the tubular member 10 and the wash pipe 40 above the upwardly facing shoulder 10j to provide an upwardly urging to the washpipe 40 to move the wash pipe 40 and the ball 20 to the upper position for rotating the ball 20 closed.

As illustrated in FIG. 1B, the operator assembly S further includes an upper or first operating sleeve 50 and a second or lower operating sleeve 60 both of which are located in the bore 11 above the ball 20. The lower operating sleeve 60 extends downwardly from an upwardly facing annular shoulder 60a to a downwardly facing annular shoulder 60b adjacent the ball 20. The sleeve 60 includes a constant diameter outer surface 60c in engagement with an inwardly projecting annular collar 10m of the tubular member for concentrically positioning the sleeve 60 in the bore 11 and for guiding longitudinal movement of the lower sleeve 60 between an upper position (FIG. 1B) and a lower position (FIG. 3B). The sleeve 60 includes an inner surface 60d having an inwardly projecting valve seat ring mounting annular collar 60e formed thereon adjacent the ball 20 and an annular recess 60f formed therein adjacent the annular shoulder 60a. The collar 60e provides a downwardly facing annular shoulder surface 60g for mounting a seat ring 61 with the sleeve 60 to effect an annular seal between the spherical surface 20b of the ball 20 and a downwardly facing sealing surface 61a of the seal ring 61. The seal so effected blocks upward flow of fluid through the bore 11 between the ball 20 and the seat ring 61. The seat ring 61 mounts an O-ring 62 thereon for effecting a seal with the sleeve 60 to block leakage of fluid therebetween.

The upper operating sleeve 50 extends upwardly from a lower annular shoulder 50a, adjacent the sleeve 60 (FIG. 1B), to an upper annular shoulder 50b and includes a constant diameter inner surface 50c defining a bore 50d aligned longitudinally with and communicating with a bore 60h formed by the surface 60c of the sleeve 60 to enable flow of fluid through the bore 11 above the ball 20. The sleeve 50 is also longitudinally moveable between an upper position (FIGS. 1A and 1B) and a lower position (FIGS. 3A and 3B).

The operating sleeves 50 and 60 are operably connected to enable limited longitudinal relative compound movement therebetween by a pair of spaced annular collars 50e and 50f (FIG. 1B) formed on the outer surface 50g of the sleeve 50 for receiving therebetween a portion of a pin member 63, secured to the sleeve 60 by suitable fastening means such as threaded engagement at 63a. The pin 63 is in engagement with the collar 50f when the sleeves 50 and 60 are in the relative extended positions (FIG. 1B) and which move toward the annular collar 50e when the sleeve 50 telescopes into the bore 60h of the sleeve 60. In the fully compressed or engaged positions (FIG. 3B) the annular collar 50e is brought into engagement with the upwardly facing shoulder 60a of the sleeve 60 to block further telescoping movement of the sleeve 50 into the bore 60h of the sleeve 60.

As illustrated in FIG. 1A, the operator assembly S includes an urging means or spring 51 for urging movement of the sleeve 50 to the upper position which is concentrically mounted about the exterior surface 50g of the sleeve 50 between a collar 50i formed thereon to provide a downwardly facing annular shoulder 50j and an upwardly facing annular shoulder 10n of the tubular member 10.

The operator assembly S further includes a first or operating piston ring member 52 and an equalizing flow or bypass operating piston ring 53 which are concentrically mounted about the sleeve 50 and movable relative thereto which are located above the collar 50i. The rings 52 and 53 are movable relative to both the tubular member 10 and the slide 50 in response to fluid pressure urgings thereon to effect operation of the equalizing valve V. The collar 50i also forms an upwardly facing annular shoulder 50k which engages a downwardly facing annular shoulder 52a of the piston ring member 52 which is blocked from longitudinal upward movement by partial engagement of an upwardly facing annular shoulder 52b with the downwardly facing annular shoulder 10p of the tubular member 10 to provide an upward movement limit stop for the sleeve 50. The ring 53 is blocked from upward movement when an upwardly facing annular shoulder 53a partially engages the downwardly facing annular shoulder 10q of the tubular member 10. The second piston ring 53 includes a downwardly facing annular shoulder 53b partially engaging a detent 54 secured in an annular recess 50m formed in the outer surface 50g of the sleeve 50 to block downward movement of the piston ring 53 relative to the sleeve 50. The operating piston ring 52 includes a pair of O-rings 52c and 52d for slidably sealing with the sleeve 50 and the tubular member 10 to block leakage of fluid between the piston ring 52 and the sleeve 50 and the tubular member 10, respectively. The ring 53 is slidably sealed to the sleeve 50 and the tubular member 10 by O-rings 53c and 53d, respectively, to block leakage of fluid about the piston 53. The operator assembly S further includes a pair of O-rings 16 and 17 for slidably sealing between the tubular member 10 and the sleeve 50 above the piston ring 53 and below the spring 51, respectively.

By sealing against leakage of fluid in this manner, the operator assembly S thus includes three annular expansible chambers for providing pressure urging on the piston rings 52 and 53 to effect valve operating movement of the piston rings 52 and 53. The fluid seals effected by the O-rings 52c and 52d, 14 and 17, define an annular expansible chamber 71 formed between the sleeve 50 and the tubular member 10 below the piston ring 52 for enabling fluid pressure in the chamber 71 to urge on the pressure responsive annular shoulder 52a for urging upward movement of the piston ring 52. The fluid seals effected by the O-rings 52 c, 52d, 53c and 53d define an annular expansible chamber 72 formed between the sleeve 50 and the tubular member 10 between the piston rings 52 and 53. Fluid pressure in the chamber 72 will urge on the upwardly facing annular shoulder 52b of the piston ring 52 for urging the piston ring 52 to move downwardly and also urges on the downwardly facing annular shoulder 53b of the piston ring 53 for urging the piston ring 53 to move upwardly. The seals effected by the O-rings 53c, 53d and 16 form a third annular expansible chamber 73 between the sleeve 50 and the tubular member 10 which is located above the piston ring 53. Fluid pressure in the expansible chamber 73 urges on the upwardly facing shoulder surface 53a of the piston ring 53 for urging the piston 53 to move downwardly in response to the fluid pressure urging thereon.

The operator assembly S provides a means for controlling the fluid pressure communicated into the expansible chambers 71, 72 and 73 to effect desired operation of the equalizing valve V, including a pair of control fluid conduits 81 and 82 formed in the tubular member 10 and a pair of tubings 91 and 92 communicating with a fluid pressure means, such as a pump and the like (not illustrated) at the surface. Tubings 91 and 92 independently communicate fluid pressure from the surface to the subsurface location of the equalizing valve V, for controlling the operation thereof as is well known in the art.

The tubing 91 communicates with the expansible chambers 71 and 73 through the flow channel 81, which is preferably formed in the tubular member 10 to communicate the controlled fluid pressure introduced into the tubing 91 at the surface directly into both chambers 71 and 73. The flow channel 81 extends downwardly from the threaded engagement 91a of the tubing 91 with tubular member 10 to a location adjacent the spring 51 and includes an enlarged portion 81a adjacent the threaded portion 91a of the conduit 91 for enabling communication therebetween and a pair of horizontally disposed ports 81b and 81c for communicating the flow channel 81 with the expansible chamber 73 above the piston ring 53 and the expansible chamber 71 below the piston ring 52 respectively. Thus, fluid pressure communicated through the conduit 91 will urge on the annular surface 53a to move the piston ring 53 downwardly and will urge on the annular surface 52a for moving the piston ring 52 upwardly.

As illustrated in FIG. 1A, the flow channel 82 extends downwardly from an enlarged area 82a communicating with the conduit 92 adjacent the threaded engagement 92a of the conduit 92 with the tubular member 10 to a horizontally disposed flow port 82b for communicating the control fluid pressure in the conduit 92 into the expansible chamber 72. The control fluid pressure introduced into the conduit 92 and the expansible chamber 72 urges on the shoulder 53b for imparting movement to the piston 53 and also urges on the shoulder 52b for moving the piston ring 52 downwardly. By controlling the pressure differential across the piston rings 52 and 53, the operation of the equalizing valve is also controlled.

With the control fluid pressure in the conduit 92 and the expansible chamber 72 greater than the fluid pressure in the conduit 91 and the expansible chambers 71 and 73, a pressure differential urging across the piston ring 52 is established for moving the piston ring 52 downwardly. The downward movement of the piston ring 52 by engagement of the surface 52a with the collar 50i will also overcome the spring 51 and move the sleeve 50 downwardly in response to the fluid pressure in the expansible chamber 72. The piston ring 53 will move upwardly in response to the pressure differential also established thereacross until it engages the shoulder 10g.

When the control fluid pressure in the conduit 91 communicated into the expansible chamber 71 is greater than the pressure in the chamber 72, the pressure differential will urge upwardly on the shoulder 52a of the O-ring 52 to maintain the ring 52 in engagement with the shoulder 10p of the tubular member 10. This same greater control fluid pressure is communicated into the expansible chamber 73 to urge on the shoulder 53a of the piston ring 53 for moving the piston ring 53 downwardly which by engagement with detent 54 will move the sleeve 50 downwardly until the lower shoulder 53b of the piston ring 53 engages the upper shoulder 52b of the piston 52. The piston ring 52 includes a greater radial thickness than the piston ring 53 for providing a greater effective surface area upon which the fluid pressure communicated through the conduit 91 may urge on. Thus, the piston ring 53 will move downwardly into engagement with the piston ring 52 where it will be blocked from further downward movement by the same greater fluid pressure. Therefore, the fluid pressure in the conduit 91 will effect downward movement of the sleeve 50 to an intermediate position while insuring that the sleeve 50 may not move below this intermediate position.

As illustrated in FIG. 1A, the sleeve 50 includes an upwardly facing tapered annular shoulder 50n formed on the collar 50e and mounting an O-ring 55 in recess thereon for effecting a fluid seal with a tapered downwardly facing annular sealing shoulder 10r of the tubular member 10 when the sleeve 50 is in the upper position. The sleeve 50 includes a flow equalization means or by-pass ports 50q formed through the sleeve 50 immediately above the annular shoulder 50n. Downward movement of the sleeve 50 to either the lower or intermediate position will space the O-ring 55 from the surface 10r to eliminate the seal therebetween and enable flow of fluid through the ports 50q.

In the use and operation of the present invention, the equalizing valve V is connected in the desired location in a production tubing using the box and pin threaded connections 12 and 13, respectively, as is well known in the art, for enabling the equalizing valve V to form a portion of the production tubing T. The control fluid pressure tubings 91 and 92 are connected and the equalizing valve V is lowered into the well with the production tubing T. When the equalizing valve V is at the desired subsurface location, the production tubing T is suitably supported and the well is enabled to produce through the bore X of the production tubing T.

When it is desired to produce hydrocarbons and other fluids from the well, the control fluid pressure in the conduit 91 is increased while venting the fluid in the conduit 92 to establish pressure differentials across the piston rings 52 and 53. The pressure in the expansible chamber 73 urges the piston ring 53 to move downwardly from the upper position (FIG. 1A) into engagement with the piston ring 52 (FIG. 2A) where it is blocked from further downward movement by the same fluid pressure communicated into the expansible chamber 71 urging upwardly on the piston ring 52. The limited downward movement of the piston ring 53 moves the sleeve 50 by engagement with detent 54, to the intermediate position (FIGS. 2A and 2B) which spaces the O-ring 55 from the surface 10r. This movement thus enables fluid flow through the plurality of by-pass ports 50q about the ball 20 to equalize the pressure differential across the ball 20 while insuring that the ball 20 is blocked from rotating open. The leakage of fluid about the wash pipe 40 between the ball 20 and the tubular member 10 is sufficient to communicate the well pressure below the closed ball 20 to the area between the sleeve 60 and the tubular member 10 where it will flow through the ports 50q into the bore 11 above the ball 20. When the operator observes that the well shut in pressure has been achieved at the surface, the control fluid pressure in the conduit 91 is reduced and the sleeve 50 will be moved back to the upper position by the urging of spring 51.

With the sleeve 50 back in the upper position fluid pressure in the conduit 92 is increased, while venting the conduit 91 for introducing fluid pressure into the expansible chamber 72 to establish pressure differentials across the piston ring 53 and the piston ring 52. The pressure differential across the piston ring 53 will maintain the piston ring 53 in engagement with shoulder 10q of the tubular member 10. The pressure differential across the piston ring 52 will overcome the upwardly urging of the spring 51 to move the sleeve 50 downwardly in a telscoping relation with the sleeve 60. Initially, the O-ring 55 is spaced from the wall 10r of the tubular member 10 to automatically equalize the fluid pressure in the bore 11 above and below the ball 20 through the ports 50q when rotating the ball 20 open. Continued downward movement of the sleeve 50 brings a downwardly facing annular shoulder 50r of the collar 50e into engagement with the shoulder 60a of the sleeve 60 while overcoming the upwardly urging of the spring 65 for moving the sleeves 50 and 60 to the lower position as a unit. Subsequent downward movement overcomes the urging of the spring 41 for moving the wash pipe 40 and the ball 20 longitudinally downward along with the sleeves 50 and 60 for effecting opening rotation of the ball 20. In addition to reducing wear and possible damage to the spherical surface 20b of the ball and the seating surface 61a of the seat ring 61 during rotation of the ball, the by-pass port 50q also enables the ball 20 to move downwardly with a smaller urging pressure in the expansible chamber 72 by reducing the effect of the well pressure resisting movement of the ball 20.

When it is desirable to rotate the ball 20 closed to block the flow of well fluids through the bore X of the production tubing T, the pressure in the conduit 92 is vented or otherwise reduced for enabling the urging of the strongest spring 41 to urge the engaged ball 20 upwardly for rotating the ball 20 closed.

When the ball 20 is rotated closed, the annular seals effected between the ball 20 and the seat ring 61 and by the O-rings 55 and 64, block upwardly flow of fluid through the bore 11 of the tubular member 10. It will also be appreciated that by sealing the sleeve 60 with the O-ring 64 in the position illustrated, the pressure differential urging on the sleeve 60 to move the sleeve 60 upwardly will be quite small and the urging of the weakest spring 65 will be more than sufficient to maintain the sealing surface 61a of the seat ring 61 in engagement with the ball 20.

Whenever there is a substantial pressure differential across the ball 20, the pressure should be equalized thereacross by injecting or introducing control fluid pressure into the conduit 91 for equalizing the fluid pressure urging on the ball 20 prior to introducing control fluid pressure through the conduit 92 for rotating the ball 20 open to enable the well to produce.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims

What is claimed is:

1. A subsurface safety valve adapted for mounting with a well conduit for controlling flow of fluid through the well conduit at a subsurface location in the well including:

a. a flow housing having a bore therethrough communicating with a flow passage of the well conduit above and below the safety valve;

b. bore closure means mounted with said flow housing for movement to and from an open position for enabling flow of fluid through the flow passage and a closed position for blocking flow of fluid through the flow passage of the well conduit;

c. means with said flow housing for effecting operating movement of said bore closure means to and from the open and closed positions, said means for effecting movement moving said bore closure means to the open position in response to a first control signal communicated from the surface through a first control means;

d. fluid pressure equalizing means for enabling desired fluid communication about said bore closure means when said bore closure means is in the closed position to substantially balance the urging of the fluid pressure on said bore closure means; and

e. means for operating said fluid pressure equalizing means to equalize the fluid pressure about said bore closure means in response to a second control signal communicated to said flow housing from the surface through a second control means independent of the well conduit and said first control means wherein fluid pressure urging on said bore closure means may be equalized.

2. The structure as set forth in claim 1, wherein:

said means for effecting movement of said bore closure means operates said fluid pressure equalizing means to balance the urging of the fluid pressure on said bore closure means prior to commencing to move said bore closure means to the open position wherein the fluid pressure urging is automatically offset prior to opening movement of said bore closure means.

3. The structure as set forth in claim 1, wherein:

said bore closure means includes a ball member rotatable to and from the open and closed positions and having a flow port formed therethrough for enabling fluid communication through said flow port when said ball is in the open position and with said flow port moving to a position for enabling said ball member to block flow of fluid when said ball is rotated to the closed position wherein said ball member rotates to control the flow of fluid.

4. The structure as set forth in claim 3 wherein said means for effecting movement of said bore closure means includes:

a. pivot means for rotating said ball to and from the open and closed positions; and

b. an operator assembly movably disposed in said bore of said flow housing for co-acting with said pivot means to effect rotation of said ball when said operator moves a predetermined distance wherein the safety valve is operated.

5. The structure as set forth in claim 4, wherein:

said fluid pressure equalizing means is mounted with said operator assembly to enable the desired fluid communication about said ball member when said operator moves less than the predetermined distance to effect opening rotation of said ball wherein the fluid pressure is offset before said ball rotates open to enable flow.

6. A subsurface safety valve adapted for connection in a well conduit to form a portion thereof;

a. a flow housing having a bore therethrough communicating with a flow passage of the well conduit above and below the safety valve;

b. a ball-type bore closure means mounted in said bore of said flow housing which is movable to and from an open position enabling flow of fluid through said bore and to and from a closed position blocking flow of fluid through said bore;

c. means with said flow housing for effecting operating movement of said bore closure means to and from the open and closed positions;

d. fluid pressure equalizing means for enabling desired fluid communication about said bore closure means when said bore closure means is in the closed position to substantially balance the urging of the fluid pressure on said bore closure means;

e. means for operating said fluid pressure equalizing means while blocking operating movement of said bore closure means from the closed position;

f. pivot means for rotating said ball to and from the open and closed position; and

g. an operator assembly movably disposed in said bore of said flow housing for co-acting with said pivot means to effect rotation of said ball when said operator moves a predetermined distance,

h. said operator assembly and said flow housing forming an expansible by-pass operating chamber therebetween, with said operator assembly having a pressure responsive surface thereon in communication with said by-pass operating chamber for urging movement of said operator assembly a sufficient distance to operate said fluid pressure equalizing means to enable desired fluid communication about said ball while blocking movement of the operator assembly to the predetermined distance to effect operation of said ball in response to the urging of the fluid pressure in said by-pass operating chamber wherein the pressure urging on the ball is offset.

7. The structure as set forth in claim 6 wherein:

said operator assembly and said flow housing forming a second expansible ball operating chamber therebetween, said operator assembly having a second pressure responsive surface thereon communicating with said second chamber for urging movement of said operator assembly to operate said fluid pressure equalizing means to enable the desired fluid communication about the said ball before rotating open said ball in response to the urging of the fluid pressure in said second chamber wherein the pressure urging on said ball is offset prior to rotating open said ball.

8. The structure as set forth in claim 7, including:

a. by-pass control means for controlling the fluid pressure in said by-pass operating chamber urging on said operator assembly; and

b. ball operating control means for controlling the fluid pressure in said second chamber urging on said operator assembly wherein the movement of said operator mechanism is controlled.

9. The structure as set forth in claim 7, including:

a. said operator assembly having a first member operably connected to a second member for enabling limited relative movement therebetween with said first member mounting said first and said second pressure responsive surfaces and said second member operably engaging said ball; and

b. said fluid pressure equalizing means mounted with said first member for enabling the desired fluid communication prior to said first member effecting movement of said second member to rotate open said ball wherein the fluid pressure urging on said ball is offset.

10. A safety valve adapted to be mounted with a well conduit for controlling flow of well fluids through the well conduit at a subsurface location in a well, including:

a flow housing having a bore therethrough communicating with a flow passage of the well conduit above and below the safety valve;

bore closure means mounted with said flow housing for movement to and from an open position for enabling flow of well fluids through the flow passage of the well conduit and a closed position for blocking flow of well fluids through the well conduit;

first expansible chamber means for effecting operating movement of said bore closure means to the open position in response to a first control fluid pressure communicated into said first expansible chamber;

fluid pressure equalizing means for enabling desired well fluid communication about said bore closure means when said bore closure means is in the closed position to substantially balance the urging of well fluid pressure on said bore closure means; and

second expansible chamber means for operating said fluid pressure equalizing means to substantially balance the urging of well fluid pressure on said bore closure means in response to a second control fluid pressure communicated into said second expansible chamber wherein well fluid pressure urging on said bore closure means may be equalized.

11. The structure as set forth in claim 10, wherein:

said bore closure means including a member rotating to and from the open and closed position.

12. The structure as set forth in claim 11, wherein:

said rotating member moving downwardly in said bore when rotating to the open position.

13. The structure as set forth in claim 10, including:

first control fluid conduit means for communicating the first control fluid pressure into said first expansible chamber from the surface; and

second control fluid conduit means for communicating the second control fluid pressure into said second expensible chamber from the surface wherein the safety valve is controlled from the surface.