Plug of extended reach

Abstract

A settable down hole tool is of increased drillability and/or of increased expansibility. The improvement in drillability can be caused by fracturing cast iron slips into a large number of small pieces that can be circulated out of a well without further reduction in size. The improvement in expansibility can be partially caused by providing an expander cone of increased hardness thereby allowing an increased angle on the expander cone and slips. The improvement in expansibility can be partially caused by increasing the thickness of the slips.

I claim: 
     
       1. A settable isolation tool sized and configured to be capable of being used in fracing past at least one casing patch within 4½ inch outer diameter (O.D.) casing in a horizontal leg of a hydrocarbon well, the tool comprising:
 a mandrel with a longitudinal axis; 
 first and second expanders around the mandrel, each expander having a frustoconical section; 
 first and second slips around the mandrel, the first expander and the first slip being a first expander/slip pair and the second expander and second slip being a second expander/slip pair, each slip having an inner surface complementary to its paired expander's frustoconical section and an outer surface having outer teeth or inclusions for being set into the casing; 
 each slip being in a retracted slip position and sized and configured to be capable of being moved radially outward by axial movement of over its paired expander to an expanded slip position for being set into the casing; 
 the mandrel, expanders and slips are configured, sized and comprised so the retracted slips' O.D. is small enough so the tool is capable of being run through and past a 0.125 inch thick casing patch within a 3.92 to 4.09 inch inner diameter (I.D.) casing in the horizontal leg; and so the first and second expander/slip pairs are large enough to be located about the mandrel and large enough so axial movement of the expanders will expand the slips to an expanded slip configuration within the range of a radial inner limit of an at least 20% expansion of the plug's O.D. and a radial outer limit of the inner diameter of the casing, and the slips capable of setting into the casing and holding the tool to the casing during fracing to isolate an upper zone in the horizontal leg above the tool from a lower zone in the horizontal leg below the tool; 
 each slip has zones of weakness comprising at least four predetermined zones of weakness parallel to the longitudinal axis of the mandrel and each slip is configured so expanding the slip to set the slip against the casing will cause the slip to fracture along at least some of the zones of weakness into slip pieces; 
 each slip is configured, sized and comprised so after being fractured along at least some of the zones of weakness by the setting, the fractured slip is capable of being more easily drilled with a coiled tubing bit in the horizontal leg than a similar slip without zones of weakness; 
 the tool is configured, sized and comprised so the retracted tool is capable of being run past the casing patch in the horizontal leg, and then capable of being expanded to set into the casing, and used in isolating and fracing in the horizontal leg, and the post-set tool with the more easily drillable fractured slips is then capable of being drilled out of the horizontal leg by a single coiled tubing bit run; and 
 the tool is configured, sized and comprised so five such tools are capable of being run past the casing patch in the horizontal leg within the casing, set within the casing, and used in isolating and fracing zones in the horizontal leg past the casing patch; the first tool being run in set and used in isolating and fracking, then the second tool being run in, set and used in isolating and fracking above the first tool, then the third tool being run in, set and used in isolating and fracking above the second tool, then the fourth tool being run in, set and used in isolating and fracking above the third tool, then the fifth tool being run in, set and used in isolating and fracking above the fourth tool, and then all of the five such tools drilled out by a single coiled tubing bit run. 
 
     
     
       2. The tool of  claim 1  wherein each slip is configured, sized and comprised so the setting fracturing along at least some zones of weakness, the drilling fracturing along at least some of the zones of weakness, and the drilling of the fractured slip with the single coiled tubing bit will produce slip pieces which have an average weight of less than one ounce and the slip pieces from the five tools are capable of being circulated out of the horizontal leg by a completion fluid having an upward velocity of 300 feet/minute, the fluid being 2% by weight KCl in water and having a density of 9#/gallon. 
     
     
       3. The tool of  claim 1  wherein the retracted slip O.D. is 3 inches, the retracted tool O.D. is 3.25 inches and the tool is capable of reaching an expanded tool O.D. of 4.1 inches. 
     
     
       4. The tool of  claim 1 , wherein the tool is capable of reaching an expanded tool O.D. 25% greater than the retracted tool's O.D. 
     
     
       5. The tool of  claim 1  further comprising,
 the zones of weakness are comprised of grooves or separations transverse to the axis of the mandrel, and the expanders and the slips are sized and configured so the expanders are capable of fracturing the slips along at least some of the transverse grooves or further separating the slips along at least some of the transverse slip separations during setting as the expanders expand the slips into gripping engagement with the casing; 
 the zones of weakness are comprised of grooves or separations parallel to the axis of the mandrel, and the expanders and the slips are sized and configured so the expanders are capable of fracturing the slips along at least some of the parallel grooves or further separating the slips along at least some of the parallel slip separations during setting as the expanders expand the slips into gripping engagement with the casing; 
 the exterior side of the expanders is hard enough, namely, having a Rockwell B hardness of at least 70, so the expanders will not extrude through the fractured grooves or slip separations during the setting to prevent the slips from expanding from the retracted slips' small O.D. to the expanded slips' large O.D., setting the slips into the casing and holding the tool to the casing during fracing, and the expanders are drillable enough so the five tools are capable of being the drilled out of the horizontal leg with a single coiled tubing bit run; and 
 the tool is configured, sized and comprised so the five such tools are capable of being drilled out with a single coiled tubing bit run, producing tool pieces from the five tools which have an average weight of less than one ounce and are small enough to be capable of being circulated out of the horizontal leg and the well without further reduction in size by a completion fluid in the casing having an upward velocity of 300 feet/minute, the fluid being 2% by weight KCl in water and having a density of 9 #/gallon. 
 
     
     
       6. The tool of  claim 1  wherein the expanders, the slips and coiled tubing bit are sized so the bit can pass through the expanded slip pieces set against the casing and drill on the upper expander, the slip pieces created by the setting fracturing of the slips having an average weight of less than three quarters of an ounce and the drilled slip pieces from the five tools are capable of being circulated out of the horizontal leg and the well by completion fluid in the casing having an upward velocity of 100 feet/minute, the fluid being 2% by weight KCl in water and having a density of 9#/gallon. 
     
     
       7. The tool of  claim 1  wherein each slip has zones of weakness comprised of grooves transverse to the axis of the mandrel, and the expanders and the slips are sized and configured so the expanders are capable of fracturing the slips along at least some of the transverse grooves or further separating the slips along at least some of the transverse slip separations during setting as the expanders expand the slips into gripping engagement with the casing. 
     
     
       8. A settable isolation tool sized and configured to be capable of being used in fracing past at least one casing patch within 5 inch outer diameter (O.D.) casing in a horizontal leg of a hydrocarbon well, the tool comprising:
 a mandrel with a longitudinal axis; 
 first and second expanders around the mandrel, each expander having a frustoconical section; 
 first and second slips around the mandrel, the first expander and the first slip being a first expander/slip pair and the second expander and second slip being a second expander/slip pair, each slip having an inner surface complementary to its paired expander's frustoconical section and an outer surface having outer teeth or inclusions for being set into the casing; 
 each slip being in a retracted position and sized and configured to be capable of being moved radially outward by axial movement over-its paired expander to an expanded slip position for being set into the casing; 
 the mandrel, expanders and slips are configured, sized and comprised so the retracted slips' O.D. is small enough so the tool is capable of being run through and past a 0.125 inch thick casing patch within a 4.044 inch inner diameter (I.D.) casing in the horizontal leg; and so the first and second expander/slip pairs are large enough to be located about the mandrel and large enough so axial movement of the expanders will expand the slips to an expanded slip configuration within the range of a radial inner limit of an at least 15% expansion of the plug's O.D. and a radial outer limit of the inner diameter of the casing, the slips are capable of setting into the casing and holding the tool to the casing during fracing to isolate an upper zone in the horizontal leg above the tool from a lower zone in the horizontal leg below the tool; 
 each slip has zones of weakness comprising at least four predetermined zones of weakness parallel to the longitudinal axis of the mandrel and each slip is configured so expanding the slip to set the slip against the casing will cause the slip to fracture along at least some of the zones of weakness into slip pieces; 
 each slip is configured, sized and comprised so after being fractured along at least some of the zones of weakness by the setting, the fractured slip is capable of being more easily drilled with a coiled tubing bit in the horizontal leg than a similar slip without zones of weakness; 
 the tool is configured, sized and comprised so the retracted tool is capable of being run past at least one casing patch in the horizontal leg, set with the casing, and used in isolating and fracing in the horizontal leg, and then the post-set tool is capable of being drilled out by a single coiled tubing bit run; 
 the tool is configured, sized and comprised so the retracted tool is capable of being run past the casing patch in the horizontal leg, and then capable of being expanded to set into the casing, and used in isolating and fracing in the horizontal leg, and the post-set tool with the more easily drillable fractured slips is then capable of being drilled out of the horizontal leg by a single coiled tubing bit run; and 
 the tool is configured, sized and comprised so five such tools are capable of being run past the casing patch in the horizontal leg within the casing, set within the casing, and used in isolating and fracing zones in the horizontal leg past the casing patch; the first tool being run in, set and used in isolating and fracking, then the second tool being run in, set and used in isolating and fracking above the first tool, then the third tool being run in, set and used in isolating and fracking above the second tool, then the fourth tool being run in, set and used in isolating and fracking above the third tool, then the fifth tool being run in, set and used in isolating and fracking above the fourth tool, and then the five such tools drilled out by a single coiled tubing bit run. 
 
     
     
       9. The tool of  claim 8  wherein the tool is configured, sized and comprised so the drilling out of the five tools by the single coiled tubing bit run produces tool pieces which have an average weight of less than 1 ounce. 
     
     
       10. The tool of  claim 8  wherein the retracted slip O.D. is 3.6 inches, the retracted tool O.D. is 3.75 inches and the tool is capable of reaching an expanded tool O.D. of 4.6 inches. 
     
     
       11. The tool of  claim 8 , wherein the tool is capable of reaching an expanded tool O.D. 25% greater than the retracted tool's O.D. 
     
     
       12. A settable isolation tool sized and configured to be capable of being used in fracing past at least one casing patch within 4½ inch to 5½ inch outer diameter (O.D.) casing in a horizontal leg of a hydrocarbon well, the tool comprising:
 a mandrel with a longitudinal axis; 
 first and second expanders around the mandrel, each expander having a frustoconical section; 
 first and second slips around the mandrel, the first expander and the first slip being a first expander/slip pair and the second expander and second slip being a second expander/slip pair, each slip having an inner surface complementary to its paired expander's frustoconical section and an outer surface having outer teeth or inclusions for being set into the casing; 
 each slip being in a retracted slip position and sized and configured to be capable of being moved radially outward by axial movement over its paired expander to an expanded slip position for being set into the casing; 
 the mandrel, expanders and slips are configured, sized and comprised so the retracted slips' O.D. is small enough so the tool is capable of being run through and past a 0.125 inch thick casing patch with a 4 inch to 4.892 inch inner diameter (I.D.) casing in the horizontal leg; 
 and so the first and second expander/slip pairs are large enough to be located about the mandrel and large enough so axial movement of the expanders will expand the slips to an expanded slip configuration within the range of a radial inner limit of an at least 20% expansion of the plug's O.D. and a radial outer limit of the inner diameter of the casing, and the slips are capable of setting into the casing and holding the tool to the casing during fracing to isolate an upper zone in the horizontal leg above the tool from a lower zone in the horizontal leg below the tool; 
 each slip has zones of weakness comprised of grooves or separations parallel to the axis of the mandrel, and the expanders and the slips are sized and configured so the expanders are capable of fracturing the slips along at least some of the parallel grooves or further separating the slips along at least some of the parallel slip separations during setting as the expanders expand the slips into gripping engagement with the casing; 
 each slip is configured, sized and comprised so the setting fracturing or separating along at least some of the zones of weakness, and the drilling of the fractured slip with a coiled tubing bit will fracture and drill the slip into slip pieces which have an average weight of less than one ounce; 
 each slip is configured, sized and comprised so after being fractured or further separated along at least some of the zones of weakness by the setting, the fractured slip is capable of being more easily drilled with a coiled tubing bit in the horizontal leg than a similar slip without zones of weakness; 
 the tool is configured, sized and comprised so the retracted tool is capable of being run past the casing patch in the horizontal leg, and then capable of being expanded to set into the casing, and used in isolating and fracing in the horizontal leg, and the post-set tool with the more easily drillable fractured slips is then capable of being drilled out of the horizontal leg by a single coiled tubing bit run; and 
 the tool is configured, sized and comprised so five such tools are capable of being run past the casing patch in the horizontal leg within the casing, set within the casing, and used in isolating and fracing zones in the horizontal leg past the casing patch; the first tool being run in, set and used in isolating and fracking, then the second tool being run in, set and used in isolating and fracking above the first tool, then the third tool being run in, set and used in isolating and fracking above the second tool, then the fourth tool being run in, set and used in isolating and fracking above the third tool, then the fifth tool being run in set and used in isolating and fracking above the fourth tool, and then the five such tools drilled out by a single coiled tubing bit run. 
 
     
     
       13. The tool of  claim 12  wherein the retracted slip O.D. is 3 to 3.88 inches, the retracted tool O.D. is 3.25 to 4.18 inches and the tool is capable of reaching an expanded tool O.D. of 4.1 to 5.05 inches. 
     
     
       14. The tool of  claim 12  wherein the tool is capable of reaching an expanded tool O.D. 25% greater than the retracted tool's O.D. 
     
     
       15. A settable isolation tool sized and configured to be capable of being used in fracing past at least one casing patch within 4½ inch to 5½ inch outer diameter (O.D.) casing in a horizontal leg of a hydrocarbon well, the tool comprising:
 a mandrel with a longitudinal axis; 
 first and second expanders around the mandrel, each expander comprising a frustoconical section having a first end with a first outer diameter and a second end having a second outer diameter, the first outer diameter being larger than the second outer diameter; 
 first and second annular slips around the mandrel, the first expander and the first slip being a first expander/slip pair and the second expander and the second slip being a second expander/slip pair, each slip having a inner surface complementary to its paired expander's frustoconical section and an outer surface having outer teeth or inclusions for setting into the casing, 
 each slip comprising a series of individual slip segments which extend about the periphery of the mandrel, each slip segment being separate and independent of each of the other slip segments ad the slip segments being restrained about the mandrel by fragile wire; 
 the slips and expanders are sized and configured so each slip, in a retracted slip position, has a slip outer diameter of 3 inches to 3.8 inches, and the slip's outer diameter is smaller than the first outer diameter of the slip's associated expander and small enough so the slip may be moved past the casing patch in the horizontal leg while being inserted into the well; 
 the retracted tool has an outer diameter of 3.25 inches to 4.18 inches, and the retracted tool's outer diameter is small enough so the retracted tool may be moved past the casing patch in the horizontal leg while being inserted into the well; 
 each slip is movable radially outward by axial movement of relative to its paired expander to a expanded slip position; the slips and expanders each being large enough to be located about the mandrel ad large enough so axial movement of each slip over its paired will expand each slip to an expanded slip configuration where the slip has an outer diameter of 4.1 inches to 5.05 inches and is 20% wider than the slip's outer diameter in the retracted slip position; 
 each expanded slip is capable of gripping the inner diameter of the casing and setting the outer teeth or inclusions into the casing during setting of the tool to the casing; 
 each slip is configured, sized and comprised so after setting separates the slip into slip segments, drilling the post-set slip pieces in the horizontal leg with a coiled tubing bit will reduce the slip segments into slip pieces; 
 the tool is configured, sized and comprised so the retracted tool is capable of being run past the casing patch in the horizontal leg, and then expanded to set into the casing, and then used in isolating and fracing in the horizontal leg, and the post-met tool with the more easily drillable fractured slips is then capable of being drilled out of the horizontal lea by a single coiled tubing bit run; and 
 the tool is configured, sized and comprised so five such tools are capable of being run past the casing patch in the horizontal leg within the casing, set within the casing, and used in isolating and fracing ones in the horizontal leg past the casing patch; the first tool being run in set and used in isolating and fracking, then the second tool being run in, set and used in isolating and fracking above the first tool, then the third tool being run in, set and used in isolating and fracking above the second tool, then the fourth tool being run in, set and used in isolating and fracing, above the third tool, then the fifth tool being in, set and used in isolating and fracking above the fourth tool, and then the five such tools drilled out by a single coiled tubing bit run. 
 
     
     
       16. The tool of  claim 15  wherein the retracted slip O.D. is between 3 to 3.8 inches, the retracted tool O.D. is between 3.25 to 4.18 inches and the tool is capable of reaching an expanded tool O.D. of between 4.1 to 5.05 inches. 
     
     
       17. The tool of  claim 15  wherein the tool is capable of reaching an expanded tool O.D. 25% greater than the retracted tool's O.D. 
     
     
       18. The tool of  claim 15  wherein the five such tools' slips are configured, sized and comprised so drilling out the five tools with the single coiled tubing bit run will produce slip pieces which have an average weight of less than one ounce and the slip pieces from the five tools are capable of being circulated out of the horizontal leg's 4.0 inch I.D. casing by a completion fluid having an upward velocity of 300 feet/minute, the fluid being 2% by weight KCl in water and having a density of 9 #/gallon. 
     
     
       19. The tool of  claim 15  wherein the slip segments are restrained about the mandrel and expanders by frangible wire. 
     
     
       20. The tool of  claim 15  wherein the tool is capable of reaching an expanded tool O.D. 25% greater than the retracted tool's O.D.