Drillable bridge plug

A method and apparatus for use in a subterranean well is described. The apparatus typically includes a subterranean plug including a mandrel having an outer surface and a non-circular cross-section and a packing element arranged about the mandrel, the packing element having a non-circular inner surface matching the mandrel outer surface such that concentric rotation between the mandrel and the packing element is precluded. The apparatus may include slips having cavities to facilitate quick drill-out of the plug. The apparatus may include a valve for controlling fluid flow through a hollow mandrel. The apparatus may include a composite mandrel having radial vents that establish fluid communication from within to without the mandrel. Also, the apparatus may include a wire line adapter kit for running the apparatus in a well bore.

 

What is claimed is:

1. A subterranean apparatus comprising:

a mandrel having an outer surface and a non-circular cross-section;

an anchoring assembly arranged about the mandrel, the anchoring assembly having a non-circular inner surface such that rotation between the mandrel and the anchoring assembly is precluded; and

a packing element arranged about die mandrel, the packing element having a non-circular inner surface such that rotation between the mandrel and the packing element is precluded.

2. The apparatus of claim 1 wherein the outer surface of the mandrel and the inner surface of the packing element exhibit matching shapes.

3. The apparatus of claim 1 wherein the mandrel comprises non-metallic materials.

4. The apparatus of claim 1 wherein the mandrel comprises metallic materials.

5. The apparatus of claim 4 wherein the mandrel comprises brass.

6. The apparatus of claim 4 wherein the mandrel is circumscribed with thermoplastic tape.

7. The apparatus of claim 6 wherein the thermoplastic tape is reinforced with carbon fiber.

8. The apparatus of claim 3 wherein the non-metallic materials comprise reinforced plastics.

9. The apparatus of claim 1 wherein the non-circular cross-section is a hexagon.

10. The apparatus of claim 1 wherein the non-circular inner surface of the packing element matches the mandrel outer surface.

11. The apparatus of claim 1 wherein the non-circular inner surface of the anchoring assembly matches the mandrel outer surface.

12. The apparatus of claim 1 wherein the anchoring assembly further comprises a first plurality of slips arranged about the non-circular mandrel outer surface, the slips being configured in a non-circular loop such that rotation between the mandrel and the first plurality of slips is precluded by interference between the loop and the mandrel outer surface shape.

13. The apparatus of claim 12 wherein the anchoring assembly further comprises a slip ring surrounding the first plurality of slips to detachably hold the first plurality of slips about the mandrel.

14. The apparatus of claim 13 wherein the slips are ranged in a shape matching the outer surface of the mandrel.

15. The apparatus of claim 12 further comprising a metallic insert integrally formed into or mechanically attached to each of the first plurality of slips wherein the metallic insert is engagable with a wellbore wall.

16. The apparatus of claim 12 wherein the first plurality of slips comprise cast iron.

17. The apparatus of claim 12 wherein each the first plurality of slips each contain a cavity.

18. The apparatus of claim 12 further comprising a wickered edge integrally formed into each of the first plurality of slips wherein the wickered edge is engagable with a wellbore wall.

19. The apparatus of claim 12 wherein the first plurality of slips abuts a first cone, the first cone facilitating radial outward movement of the slips into engagement with a wellbore wall upon traversal of the plurality of slips along the first cone.

20. The apparatus of claim 19 wherein the first cone is ranged about the mandrel, the first cone comprising a non-circular inner surface such that rotation between the mandrel and the first cone is precluded by interference between the first cone inner surface shape and the mandrel outer surface shape.

21. The apparatus of claim 20 wherein the non-circular inner surface of the first cone matches the outer non-circular surface of the mandrel.

22. The apparatus of claim 19 wherein the first cone further comprises a plurality of channels, each of the plurality of channels being receptive of at least one of the plurality of slips, the channels being arranged such that rotation between the first cone and the slips is precluded.

23. The apparatus of claim 19 wherein the first cone comprises non-metallic materials.

24. The apparatus of claim 19 further comprising at least one shearing device disposed between the first cane and the mandrel, the at least one shearing device adapted to shear upon the application of a predetermined force.

25. The apparatus of claim 24 wherein the shearing device is a pin.

26. The apparatus of claim 12 further comprising a second plurality of slips arranged about the non-circular mandrel outer surface, the slips being configured in a non-circular loop such that concentric rotation between the mandrel and the second plurality of slips is precluded by interference between the loop and the mandrel outer surface shape.

27. The apparatus of claim 26 wherein the anchoring assembly further comprises a second slip ring surrounding the second plurality of slips to detachably hold the second plurality of slips about the mandrel.

28. The apparatus of claim 26 wherein the second plurality of slips is arranged in a shape matching the outer surface of the mandrel.

29. The apparatus of claim 26 wherein the second plurality of slips comprise cast iron materials.

30. The apparatus of claim 26 wherein each the second plurality of slips each contain a cavity.

31. The apparatus of claim 26 further comprising a wickered edge integrally formed into each of the second plurality of slips wherein the wickered edge is engagable with a wellbore wall.

32. The apparatus of claim 26 further comprising a metallic insert integrally formed into or mechanically attached to each of the second plurality of slips, wherein the metallic insert is engagable with a wellbore wall.

33. The apparatus of claim 26 further comprising a second collapsible cone arranged about the non-circular outer surface of the mandrel, the second collapsible cone comprising a non-circular inner surface such that rotation between the mandrel and second collapsable cone is precluded, wherein a second plurality of slips abuts the second collapsable cone, facilitating radial outward movement of the slips into engagement with the wellbore wall upon traversal of the second plurality of slips along the second collapsable cone.

34. The apparatus of claim 33 wherein the non-circular inner surface of the second collapsable cone matches the outer non-circular surface of the mandrel.

35. The apparatus of claim 33 wherein the second collapsable cone comprises non-metallic materials.

36. The apparatus of claim 33 wherein the second collapsable cone is adapted to collapse upon the application of a predetermined force.

37. The apparatus of claim 33 wherein the second collapsable cone further comprises at least one metallic insert attached thereto, the at least one metallic insert facilitating a locking engagement between the cone and the mandrel.

38. The apparatus of claim 37 wherein the locking engagement precludes rotation and translation between die anchoring assembly and the mandrel.

39. The apparatus of claim 33 further comprising at least one shearing device disposed between the second collapsable cone and the mandrel, the at least one shearing device being adapted to shear upon the application of a predetermined force.

40. The apparatus of claim 33 wherein the packing element is disposed between the first cone and the second collapsable cone.

41. The apparatus of claim 12 further comprising a that cap attached to a first end of the mandrel.

42. The apparatus of claim 41 wherein the first cap comprises non-metallic materials.

43. The apparatus of claim 41 wherein the first cap is attached to the mandrel by a plurality of pins.

44. The apparatus of claim 41 further comprising a push ring disposed between the first cap and the first plurality of slips.

45. The apparatus of claim 41 wherein the first cap is adapted to rotationally lock with a top surface of the mandrel of a second identical plug.

46. The apparatus of claim 41 wherein the first cap and die top surface of the mandrel are each tapered to facilitate the rotational lock therebetween.

47. The apparatus of claim 41 further comprising a second cap attached to a second end of the mandrel.

48. The apparatus of claim 47 wherein the second cap comprises non-metallic materials.

49. The apparatus of claim 48 wherein the second cap is attached to the mandrel by a plurality of non-metallic pins and exhibits a non-circular inner surface such that rotation between the mandrel and the second cap is precluded as the outer surface of the mandrel and inner surface of the second cap interfere with one another in rotation.

50. The apparatus of claim 49 wherein the inner surface of the second cap matches the non-circular outer surface of the mandrel.

51. The apparatus of claim 50 wherein a second push ring is disposed between the second cap and a second plurality of slips.

52. The apparatus of claim 1 wherein the packing element further comprises a first end element, a second end element, and an elastomer disposed therebetween.

53. The apparatus of claim 52 wherein the packing element further comprises a booster ring disposed between the elastomer and the second element.

54. The apparatus of claim 53 wherein the packing element further comprises a lip to which the booster ring abuts in operation.

55. The apparatus of claim 54 wherein an O-ring surrounds mandrel to seal the elastomer on the mandrel.

56. The apparatus of claim 55 wherein the elastomer is adapted to form a seal about the non-circular outer surface of the mandrel upon application of compressive force by a first and a second end element.

57. A method of isolating a portion of a well comprising the steps of:

running a plug into a well, the plug comprising a mandrel with a non-cylindrical outer surface, an anchoring assembly, and a packing element ranged about the mandrel;

setting the packing element by the application of force; and

locking the anchoring assembly to the mandrel to lock the plug in place within the well.

58. The method of claim 57 wherein the anchoring assembly further comprises

a first cone arranged about the outer surface of the mandrel;

a first plurality of slips arranged about the first cone;

a second cone spaced from the first cone and arranged about the outer diameter of the mandrel;

and a second plurality of slips arranged about the second cone.

59. The method of claim 57 wherein the first and second pluralities of slips are engagable with the wall of a wellbore and the first and second cones are engagable with the mandrel.

60. The method of claim 57 wherein the first and second cones each include a plurality of channels receptive of the first and second pluralities of slips.

61. The method of claim 59 wherein the first and second slips are cast iron.

62. The method of claim 60 wherein the step of locking the plug within the well further comprises the first and second pluralities of slips traversing the first and second cones and engaging with a wall of the well.

63. The method of claim 61 wherein the step of locking the anchoring assembly to the mandrel further comprises collapsing the second cone and engaging the second cone with the mandrel.

64. A subterranean apparatus comprising:

a mandrel having an outer surface and a non-circular cross-section;

an anchoring means arranged about the mandrel such that rotation between the mandrel and the anchoring assembly is precluded; and

a packing means arranged about the mandrel such that rotation between the mandrel and the packing element is precluded.

65. The subterranean apparatus of claim 64 in which the mandrel further comprises a means for controlling flow of fluids therethrough.

66. A subterranean apparatus comprising:

a hollow mandrel having a non-circular cross-section; and

a packing element arranged about the mandrel, the packing element having a non-circular inner surface such that rotation between the mandrel and the packing element is precluded, the mandrel having a valve for controlling flow of fluids therethrough.

67. The apparatus of claim 66 wherein the hollow mandrel further comprises:

a first internal diameter;

a second internal diameter being smaller than the first internal diameter; and

a connecting section connecting the first internal diameter and the second internal diameter.

68. The apparatus of claim 67 further comprising a ball, die connecting section defining a ball seat, the ball adapted to rest in the ball seat thus defining a bail valve to allow fluids to flow in only one direction through the mandrel, the ball valve preventing fluids from flowing in an opposite direction.

69. The apparatus of claim 68 in which the mandrel is comprised of a metallic core wound with carbon fiber tape.

70. The apparatus of claim 68 in which the mandrel has grooves on an end to facilitate the running of the apparatus.

71. The apparatus of claim 66 wherein an outer surface of the mandrel and the inner surface of die packing element exhibit matching shapes to precluded rotation between the mandrel and the packing element as the outer surface of the mandrel and the inner surface of the packing element interfere with one another in rotation.

72. The apparatus of claim 66 wherein the mandrel comprises non-metallic materials.

73. The apparatus of claim 72 wherein the non-metallic materials comprise reinforced plastics.

74. The apparatus of claim 66 wherein the non-circular cross-section is a hexagon.

75. The apparatus of claim 66 further comprising an anchoring assembly arranged about the mandrel, the anchoring assembly having a non-circular inner surface such that rotation between the mandrel and the anchoring assembly is precluded.

76. The apparatus of claim 75 wherein the non-circular inner surface matches the mandrel outer surface.

77. The apparatus of claim 75 wherein the anchoring assembly further comprises a first plurality of slips arranged about the non-circular mandrel outer surface, the slips being detachably securable about the non-circular outer surface of the mandrel by a slip ring such that rotation between the mandrel and the first plurality of slips is precluded by interference between the slips and the outer surface of the mandrel.

78. The apparatus of claim 77 wherein the slips are arranged to match the outer surface of the mandrel.

79. The apparatus of claim 77 wherein the first plurality of slips comprise non-metallic materials.

80. The apparatus of claim 77 further comprising at least one metallic insert integrally formed into or mechanically attached to each of the plurality of slips wherein the metallic insert is engagable with a wellbore wall.

81. The apparatus of claim 77 wherein the first plurality of slips abuts a first cone, the first cone facilitating radial outward movement of the slips into engagement with a wellbore wall upon traversal of the plurality of slips along the first cone.

82. The apparatus of claim 78 wherein the first cone is arranged about the mandrel, the first cone comprising a non-circular inner surface such that rotation between the mandrel and the first cone is precluded by interference between the first cone inner surface shape and the mandrel outer surface shape.

83. The apparatus of claim 82 wherein the non-circular inner surface of the first cone matches the outer non-circular surface of the mandrel.

84. The apparatus of claim 82 wherein the first cone further comprises a plurality of channels, each of the plurality of channels being receptive of at least one of the plurality of slips, the channels being arranged such that rotation between the first cone and the slips is precluded.

85. The apparatus of claim 82 wherein the first cone comprises non-metallic materials.

86. The apparatus of claim 82 further comprising at least one shearing device disposed between the first cone and the mandrel, the at least one shearing device adapted to shear upon the application of a predetermined force.

87. The apparatus of claim 77 further comprising a second plurality of slips arranged about the non-circular mandrel outer surface, the slips being detachably securable about the non-circular outer surface of the mandrel by a second slip ring such that rotation between the mandrel and the second plurality of slips is precluded by interference between the slips and the outer surface of the mandrel.

88. The apparatus of claim 87 wherein the slips are arranged to match the outer surface of the mandrel.

89. The apparatus of claim 87 wherein the second plurality of slips comprise non-metallic materials.

90. The apparatus of claim 87 further comprising at least one metallic insert integrally formed into or mechanically attached to each of the second plurality of slips, wherein the metallic insert is engagable with a wellbore wall.

91. The apparatus of claim 87 wherein each first and second pluralities of slips further comprise slips having at least one cavity.

92. The apparatus of claim 87 further comprising a second collapsible cone arranged about the non-circular outer surface of the mandrel, the second collapsible cone comprising a non-circular inner surface such that rotation between the mandrel and second collapsible cone is precluded, wherein a second plurality of slips abuts the second collapsible cone, facilitating radial outward movement of the slips into engagement with the wellbore wall upon traversal of the second plurality of slips along the second collapsible cone.

93. The apparatus of claim 92 wherein the non-circular inner surface of the second collapsible cone matches the outer non-circular surface of the mandrel.

94. The apparatus of claim 92 wherein the second collapsible cone comprises nonmetallic materials.

95. The apparatus of claim 94 wherein the second collapsible cone is adapted to collapse upon the application of a predetermined force.

96. The apparatus of claim 92 wherein the second collapsible cone further comprises at least one metallic insert attached thereto, the at least one metallic insert facilitating a locking engagement between the cone and the mandrel.

97. The apparatus of claim 92 wherein the locking engagement precludes rotation and translation between the anchoring assembly and the mandrel.

98. The apparatus of claim 92 further comprising at least one shearing device disposed between the second collapsible cone and the mandrel, the at least one shearing device being adapted to shear upon the application of a predetermined force.

99. The apparatus of claim 95 further comprising a second cap attached to a second end of the mandrel.

100. The apparatus of claim 99 wherein the second cap comprises non-metallic materials.

101. The apparatus of claim 99 wherein the second cap is attached to the mandrel by a plurality of non-metallic pins and exhibits a non-circular inner surface such that rotation between the mandrel and the second cap is precluded as the outer surface of the mandrel and inner surface of the second cap interfere with one another in rotation.

102. The apparatus of claim 101 wherein the inner surface of the second cap matches the non-circular outer surface of the mandrel.

103. The apparatus of claim 102 wherein the second cap abuts a second plurality of slips.

104. The apparatus of claim 103 having a first cap adapted to rotationally lock with atop surface of the mandrel of a second identical plug.

105. The apparatus of claim 104 wherein the first cap and the top surface of the mandrel are each tapered to facilitate the rotational lock therebetween.

106. The apparatus of claim 87 wherein the packing element is disposed between the first cone and the second collapsible cone.

107. The apparatus of claim 66 further comprising a first cap attached to a first end of the mandrel.

108. The apparatus of claim 107 wherein the first cap comprises non-metallic materials.

109. The apparatus of claim 107 wherein the first cap is attached to the mandrel by a plurality of nonmetallic pins.

110. The apparatus of claim 107 wherein the fast cap abuts a first plurality of slips.

111. The apparatus of claim 66 wherein the packing element further comprises a first end element, a second end element, and an elastomer disposed therebetween.

112. The apparatus of claim 111 wherein the elastomer is adapted to form a seal about the non-circular outer surface of the mandrel upon compressive force applied by the first and second end elements.

113. The apparatus of claim 68 in which the ball valve is adapted to prevent flow of fluids from a reservoir to a surface of the earth.

114. A subterranean device comprising:

a hollow mandrel having a non-circular cross-section;

a first cone arranged about an outer diameter of the mandrel;

a first plurality of slips arranged about first cone;

a second cone spaced from the first cone and arranged about an outer diameter of the mandrel;

a second plurality of slips arranged about the second cone;

a packing element disposed between the first and second cones, the packing element arranged about the mandrel, the packing element having a non-circular inner surface such that rotation between the mandrel and the packing element is precluded as the outer surface of the mandrel and the inner surface of the packing element interfere with one another in rotation; and

a valve arranged within an inner diameter of the mandrel for controlling flow of fluids therethrough.

115. The device of claim 114 in which the first and second pluralities of slips are adapted to traverse the first and second cones to engage with a wall of the well.

116. The device of claim 114 in which the mandrel is comprised of a metallic core wound with carbon fiber tape.

117. The device of claim 114 in which the mandrel has grooves on an end to facilitate the running of the apparatus.

118. The device of claim 114 wherein the first and second pluralities of slips are rotationally locked within channels formed in the first and second cones.

119. The device of claim 114 wherein the second cone is collapsible onto the mandrel upon the application of a predetermined force.

120. The device of claim 114 wherein the mandrel, cones, and slips comprise non-metallic materials.

121. The device of claim 114 wherein the non-metallic materials are reinforced plastics.

122. The device of claim 114 wherein each of first and second cones comprise non-circular inner surfaces such that rotation between the mandrel and the cones is precluded.

123. The device of claim 114 wherein each first and second pluralities of slips further comprise slips having at least one cavity.

124. A method of controlling flow of fluids in a portion of a well comprising the steps of:

running a frac plug into a well, the frac plug comprising a hollow mandrel with a non-circular outer surface and a ball valve, an anchoring assembly, and a packing element arranged about the mandrel;

setting the packing element by application of force; and

locking the anchoring assembly to the mandrel to lock the frac plug in place within the well.

125. The method of claim 124 wherein the anchoring assembly further comprises a first cone arranged about the outer surface of the mandrel;

a first plurality of slips arranged about the first cone;

a second cone spaced from the first cone and arranged about the outer diameter of the mandrel;

a second plurality of slips arranged about the second cone; and

a metallic insert disposed in an inner surface of the second cone and adjacent to the mandrel.

126. The method of claim 125 further comprising:

engaging the wall with the first and second pluralities of slips.

127. The method of claim 126 further comprising:

engaging the mandrel with the metallic insert.

128. The method of claim 125 wherein the first and second cones each include a plurality of channels receptive of the first and second pluralities of slips.

129. The method of claim 125 wherein the step of locking the plug within the well further comprises the first and second pluralities of slips traversing the first and second cones and engaging with a wall of the well.

130. The method of claim 125 wherein the step of locking the anchoring assembly to the mandrel further comprises collapsing the second cone and engaging the second cone metallic insert with the mandrel.

131. The method of claim 125 wherein the step of running the frac plug into the well comprises running the plug on a wireline.

132. The method of claim 125 wherein the step of running the plug into the well comprises running the plug on a mechanical or hydraulic setting tool.

133. The method of claim 125 wherein the first and second pluralities of slips each include at least one cavity.

134. A method of drilling our a subterranean apparatus comprising:

running the apparatus into a wellbore, the apparatus being substantially non-metallic and comprising

a hollow mandrel having a non-circular outer surface and a ball valve, and

a packing element arranged about the mandrel, the packing element having a non-circular inner surface precluding rotation between the packing element and the mandrel;

running a drill into the wellbore; and

drilling the apparatus.

135. The method of claim 134 wherein the non-circular inner surface of the packing element matches the mandrel outer surface.

136. The method of claim 134 wherein the step of running the drill into the wellbore is accomplished by using a coiled tubing.

137. The method of claim 136 wherein the step of drilling is accomplished by a coiled tubing motor and bit.

138. A method of milling out a subterranean apparatus comprising:

running the apparatus into the wellbore, the apparatus being substantially non-metallic and comprising a hollow mandrel having a non-circular outer surface and a ball valve, and a packing element ranged about the mandrel, the packing element having a non-circular inner surface precluding rotation between the packing element and the mandrel;

running a mill into the wellbore; and

milling the apparatus.

139. The method of claim 138 wherein the non-circular inner surface of the packing element matches the mandrel outer surface.

140. The method of claim 139 wherein the step of drilling is accomplished by a coiled tubing motor.

141. The method of claim 138 wherein the step of running the mill into the wellbore is accomplished by using a coiled tubing.

142. A subterranean apparatus comprising:

a hollow mandrel having a non-circular cross-section, the mandrel having radial vents for allowing fluid communication from an inner surface of the mandrel to an outer surface of the apparatus;

a packing element arranged about the mandrel, the packing element having a non-circular inner surface such that rotation between the mandrel and the packing element is precluded;

a plug having a concentric seal attached to an end of the mandrel to prevent fluid flow therethrough; and a collet moveably attached to the inner surface of the mandrel, the collet having a first position preventing fluid communication through the ports, the collet being moveable to a second position that provides fluid communication through the vents.

143. The apparatus of claim 142 in which the concentric seal further comprises an O-ring.

144. The apparatus of claim 142 wherein an outer surface of the mandrel and the inner surface of the packing element exhibit matching shape, the outer surface of the mandrel and inner surface of the packing element interfering with one another in rotation.

145. The apparatus of claim 142 wherein the mandrel comprises non-metallic materials.

146. The apparatus of claim 145 wherein the non-metallic materials comprise reinforced plastics.

147. The apparatus of claim 146 wherein the non-metallic material comprise thermoset plastics.

148. The apparatus of claim 142 wherein the non-circular cross-section is a hexagon.

149. The apparatus of claim 142 further comprising an anchoring assembly arranged about the mandrel, the anchoring assembly having a non-circular inner surface such that concentric rotation between the mandrel and the anchoring assembly is precluded.

150. The apparatus of claim 149 wherein the non-circular inner surface matches the mandrel outer surface.

151. The apparatus of claim 149 wherein the anchoring assembly further comprises a first plurality of slips arranged about the non-circular mandrel outer surface, the slips being configured in a non-circular loop such that rotation between the mandrel and the first plurality of slips is precluded by interference between the loop and the mandrel outer surface shape.

152. The apparatus of claim 151 wherein the slips are arranged in a shape matching the outer surface of the mandrel.

153. The apparatus of claim 151 wherein the first plurality of slips comprise cast iron.

154. The apparatus of claim 151 further comprising a metallic insert integrally formed into or mechanically attached to each of the plurality of slips wherein the metallic insert is engagable with a wellbore wall.

155. The apparatus of claim 151 wherein the first plurality of slips abuts a first cone, the first cone facilitating radial outward movement of the slips into engagement with a wellbore wall upon traversal of the plurality of slips along the first cone.

156. The apparatus of claim 151 wherein the first cone is arranged about the mandrel, the first cone comprising a non-circular inner surface such that rotation between the mandrel and the first cone is precluded by interference between the first cone inner surface shape and the mandrel outer surface shape.

157. The apparatus of claim 156 wherein the non-circular inner surface of the first cone matches the outer non-circular surface of the mandrel.

158. The apparatus of claim 155 wherein the first cone further comprises a plurality of channels, each of the plurality of channels being receptive of at least one of the plurality of slips, the channels being arranged such that rotation between the first cone and the slips is precluded.

159. The apparatus of claim 155 wherein the first cone comprises non-metallic materials.

160. The apparatus of claim 155 further comprising at least one shearing device disposed between the first cone and the mandrel, the at least one shearing device adapted to shear upon the application of a predetermined force.

161. The apparatus of claim 151 further comprising a second plurality of slips arranged about the non-circular mandrel outer surface, the slips being configured in a non-circular circular loop such that concentric rotation between the mandrel and the first plurality of slips is precluded by interference between the loop and the mandrel outer surface shape.

162. The apparatus of claim 161 wherein the slips are ranged in a shape matching the outer surface of the mandrel.

163. The apparatus of claim 161 wherein the second plurality of slips comprise cast iron materials.

164. The apparatus of claim 161 further comprising a metallic insert integrally formed into or mechanically attached to each of the second plurality of slips, wherein the metallic insert is engagable with a wellbore wall.

165. The apparatus of claim 161 wherein each first and second pluralities of slips further comprise slips having at least one cavity.

166. The apparatus of claim 161 further comprising a second collapsible cone arranged about the non-circular outer surface of the mandrel, the second collapsible cone comprising a non-circular inner surface such that rotation between the mandrel and second collapsible cone is precluded, wherein a second plurality of slips abuts the second collapsible cone, facilitating radial outward movement of the slips into engagement with the wellbore wall upon traversal of the second plurality of slips along the second collapsible cone.

167. The apparatus of claim 166 wherein the non-circular inner surface of the second collapsible cone matches the outer non-circular surface of the mandrel.

168. The apparatus of claim 166 wherein the second collapsible cone comprises nonmetallic materials.

169. The apparatus of claim 168 wherein the second collapsible cone is adapted to collapse upon the application of a predetermined force.

170. The apparatus of claim 166 wherein the second collapsible cone further comprises at least one metallic insert attached thereto, the at least one metallic insert facilitating a locking engagement between the cone and the mandrel.

171. The apparatus of claim 166 wherein the locking engagement precludes rotation and translation between the anchoring assembly and the mandrel.

172. The apparatus of claim 166 further comprising at least one shearing device disposed between the second collapsible cone and the mandrel, the at least one shearing device being adapted to shear upon the application of a predetermined force.

173. The apparatus of claim 172 wherein the packing element is disposed between the first cone and the second collapsible cone.

174. The apparatus of claim 142 further comprising a first cap attached to a first end of the mandrel.

175. The apparatus of claim 174 wherein the first cap comprises non-metallic materials.

176. The apparatus of claim 174 wherein the first cap is attached to the mandrel by a plurality of pins.

177. The apparatus of claim 174 wherein the first cap abuts a first plurality of slips.

178. The apparatus of claim 142 wherein the packing element further comprises a first end element, a second end element and an elastomer disposed therebetween.

179. The apparatus of claim 178 wherein the elastomer is adapted to form a seal about the non-circular outer surface of the mandrel upon compressive force applied by the first and second end elements.

180. The apparatus of claim 179 further comprising a second cap attached to a second end of the mandrel.

181. The apparatus of claim 180 wherein the second cap comprises non-metallic materials.

182. The apparatus of claim 180 wherein the second cap is attached to the mandrel by a plurality of non-metallic pins and exhibits a non-circular inner surface such that rotation between the mandrel and the second cap is precluded as the outer surface of the mandrel and inner surface of the second cap interfere with one another in rotation.

183. The apparatus of claim 182 wherein the inner surface of the second cap matches the non-circular outer surface of the mandrel.

184. The apparatus of claim 182 wherein the second cap abuts a second plurality of slips.

185. The apparatus of claim 182 wherein the first cap is adapted to rotationally lock with a top surface of the mandrel of a second identical plug.

186. The apparatus of claim 185 wherein the first cap and the top surface of the mandrel are each tapered to facilitate the rotational lock therebetween.

187. A subterranean apparatus comprising:

a mandrel having first and second ends;

a packing element;

an anchoring assembly;

a first end cap attached to the first end of the mandrel;

a second end cap attached to the second end of the mandrel;

wherein the first end cap is adapted to rotationally lock with a top end of another mandrel.

188. The apparatus of claim 187 wherein the first end cap and the mandrel each comprise engagable tapered surfaces to facilitate the rotational lock between the first end cap and the top end of another mandrel.

189. The apparatus of claim 188 wherein each of the mandrel, packing element, anchoring assembly, and end caps is constructed of substantially non-metallic materials.

BACKGROUND OF THE INVENTION

2. Field of the Invention

This invention relates generally to methods and apparatus for drilling and completing subterranean wells and, more particularly, to methods and apparatus for a drillable bridge plug, frac plug, cement retainer, and other related downhole apparatus, including apparatus for running these downhole apparatus.

3. Description of Related Art

There are many applications in well drilling, servicing, and completion in which it becomes necessary to isolate particular zones within the well. In some applications, such as cased-hole situations, conventional bridge plugs such as the Baker Hughes model T, N1, NC1, P1, or S wireline-set bridge plugs are inserted into the well to isolate zones. The bridge plugs may be temporary or permanent; the purpose of the plugs is simply to isolate some portion of the well from another portion of the well. In some instances perforations in the well in one portion need to be isolated from perforations in another portion of the well. In other situations there may be a need to use a bridge plug to isolate the bottom of the well from the wellhead. There are also situations where these plugs are not used necessarily for isolation but instead are used to create a cement plug in the wellbore which may be used for permanent abandonment. In other applications a bridge plug with cement on top of it may be used as a kickoff plug for side-tracking the well.

Bridge plugs may be drillable or retrievable. Drillable bridge plugs are typically constructed of a brittle metal such as cast iron that can be drilled out. One typical problem with conventional drillable bridge plugs is that without some sort of locking mechanism, the bridge plug components tend to rotate with the drill bit, which may result in extremely long drill-out times, excessive casing wear, or both. Long drill-out times are highly undesirable as rig time is typically charged for by the hour.

Another typical problem with conventional drillable plugs is that the conventional metallic construction materials, even though brittle, are not easy to drill through. The plugs are generally required to be quite robust to achieve an isolating seal, but the materials of construction may then be difficult to drill out in a reasonable time. These typical metallic plugs thus require that significant weight be applied to the drill-bit in order to drill the plug out. It would be desirable to create a plug that did not require significant forces to be applied to the drill-bit such that the drilling operation could be accomplished with a coiled tubing motor and bit; however, conventional metallic plugs do not enable this.

In addition, when several plugs are used in succession to isolate a plurality of zones within the wellbore, there may be significant pressures on the plug from either side. It would be desirable to design an easily drilled bridge plug that is capable of holding high differential pressures on both sides of the plug. Also, with the potential for use of multiple plugs in the same wellbore, it would be desirable to create a rotational lock between plugs. A rotational lock between plugs would facilitate less time-consuming drill outs.

Additionally, it would be desirable to design an easily drillable frac plug that has a valve to allow fluid communication through the mandrel. It would be desirable for the valve to allow fluid to flow in one direction (e.g. out of the reservoir) while preventing fluid from flowing in the other direction (into the reservoir). It is also desired to design an easily drillable cement retainer that includes a mandrel with vents for circulating cement slurry through the tool.

Finally, it is desired to provide a wire line adapter kit that will facilitate the running of the drillable downhole tool, but still be releasable from the tool. Once released, the wire line adapter kit should be retrievable thus allowing the downhole tool to be drilled. Preferably, the wire line adapter kit should leave little, if any, metal components downhole, thus reducing time milling and/or drilling time to remove plugs.

The present invention is directed to overcoming, or at least reducing the effects of, one or more of the issues set forth above.

SUMMARY OF THE INVENTION

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