Method and apparatus for a monodiameter wellbore, monodiameter casing and monobore

• US 20040149431A1
• Filed: 11/13/2002
• Published: 08/05/2004
• Est. Priority Date: 11/14/2001
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Hardin, John, Wilson, John, Brothers, Lance, Zamora, Frank, Gleitman, Dan, Terry, James, Walker, Colin, Wylie, Glenda, Boulton, Roger, Palmer, Anthony, Culotta, Anne, Weaver, Jimmie, Rao, M., Gaynor, Thomas, Murali, Beegamudre, Eoff, Larry, Reddy, Baireddy, Chen, Chen-Kang, Whitfill, Donald, Fitsgerald, Russell
• Granted Patent: US 7,066,284 B2
• Time in Patent Office: Days
• US Class Current: 166/242.1
• CPC Class Codes: C09K 8/12 containing synthetic organic macromolecular compounds or their precursors
• CPC Class Codes: C09K 8/34 Organic liquids
• CPC Class Codes: C09K 8/512 containing cross-linking agents
• CPC Class Codes: E21B 33/138 Plastering the borehole wall; Injecting into the formation
• CPC Class Codes: E21B 43/103 of expandable casings, screens, liners, or the like

Abstract

An assembly and methods are disclosed for constructing a Monowell having a monodiameter casing disposed in a monodiameter wellbore having diametric efficiency with a monobore production delivery system disposed within the monodiameter casing. An assembly for constructing a monodiameter wellbore includes a bottomhole assembly having a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool; a work string attached to the bottomhole assembly and extending to the surface; drilling fluids flowing through the work string and bottomhole assembly; chemical casing casing the borehole; expandable casing disposed in the wellbore; and a sealing composition disposed between the expandable casing and the wellbore. A method for drilling a monodiameter borehole includes drilling an initial portion of the borehole with a drilling assembly having a bit, downhole motor and reamer; applying a catalyst base material to the borehole wall during drilling; back reaming the borehole as the drilling assembly is raised through the initial borehole portion; applying a set up material to the borehole wall as the borehole is back reamed; forming a chemical casing by reacting the set up material with the catalyst material; repeating the above steps by drilling additional borehole portions until the borehole is drilled; and installing a string of casing in the borehole.

Claims

1. A monodiameter well extending from the surface through the reservoir barrier and reservoir and including a casing having an outer casing diameter, comprising:

a wellbore extending from the surface to at least the reservoir barrier;

said wellbore having a consistent nominal diameter from the surface to at least the reservoir barrier; and

said consistent nominal diameter being only large enough to allow the installation of the casing.

2. The monodiameter well of claim 1 wherein said consistent nominal diameter varies no more than three inches larger than the outer casing diameter.

3. The monodiameter well of claim 1 wherein said consistent nominal diameter is substantially one inch larger than the outer casing diameter.

4. The monodiameter well of claim 1 wherein said wellbore has a tortuosity index below 1.10.

5. The monodiameter well of claim 1 wherein the casing is a monodiameter casing.

6. The monodiameter well of claim 5 wherein said monodiameter casing is expandable casing.

7. The monodiameter well of claim 5 further including a monobore production conduit installed within said monodiameter casing.

8. The monodiameter well of claim 1 further including a material disposed on a wall of the wellbore filling any wash outs in the wellbore wall to achieve a consistent nominal diameter.

9. The monodiameter well of claim 1 further including a chemical casing installed in the wellbore.

10. A method for achieving a monodiameter wellbore extending through various formations, the method comprising:

extending a work string into the wellbore, the work string having a bottomhole assembly;

flowing drilling fluids through the work string and bottomhole assembly;

drilling the wellbore using an extended gauge drilling member to minimize spiraling of the wellbore;

sending to the surface real-time downhole information from a measurement while drilling tool, a logging while drilling tool, and one or more sensors in the extended gauge drilling member tool; and

altering the direction of drilling based on the real-time downhole information using a directional steering assembly.

11. The method of claim 10 wherein extended gauge drilling member includes an energy balanced bit.

12. The method of claim 10 wherein the directional steering assembly includes a rotary steerable assembly associated with the extended gauge drilling member.

13. The method of claim 10 further including a downhole motor matched to the extended gauge drilling member.

14. The method of claim 10 further including circulating drilling fluids which are matched to the formations.

15. The method of claim 14 wherein the drilling fluids use a membrane efficient mud system which allows the drilling of a consistent tight wellbore.

16. The method of claim 15 wherein the membrane efficient mud system is a water or synthetic based system.

17. The method of claim 16 wherein the drilling fluids produce a mud cake that effectively controls hydraulic pressure, chemical differences, and electrical differences in the formation.

18. The method of claim 10 further including flowing a spottable material through the wellbore.

19. The method of claim 10 further including chemically casing the borehole.

20. The method of claim 10 further including installing expandable casing in the wellbore.

21. The method of claim 10 further including flowing a sealing composition between the expandable casing and a wall of the wellbore.

22. A monowell comprising:

a monodiameter casing; and

a monobore production delivery system within said monodiameter casing.

23. The monowell of claim 22 further including a monodiameter wellbore in which is disposed said monodiameter casing.

24. The monowell of claim 23 wherein said wellbore has diametric efficiency.

25. An assembly for drilling a diametrically efficient borehole through a formation from the surface for installing expandable casing, the assembly comprising:

a bottomhole assembly including a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool;

a work string attached to said bottomhole assembly and extending to the surface; and

drilling fluids flowing through the work string and bottomhole assembly.

26. The assembly of claim 25 wherein said overgauge drilling member is an extended gauge bit.

27. The assembly of claim 26 wherein the bottomhole assembly further includes:

a rotary shaft having a lower central axis offset at a selected bend angle from an upper central axis by a bend;

a housing having a substantially uniform diameter housing outer surface, the housing containing at least a portion of the upper axis of the rotary shaft;

the bit powered by the rotating shaft, the bit having a bit face defining a bit diameter;

a gauge section having a substantially uniform diameter cylindrical surface spaced above the bit face; and

the bit and gauge section together having a total gauge length of at least 75% of the bit diameter and a portion of the total gauge length which is substantially gauge is at least 50% of the total gauge length.

28. The assembly of claim 27 wherein an axial spacing between the bend and the bit face is less than twelve times the bit diameter.

29. The assembly of claim 27 wherein the bit is a long gauge bit supporting the gauge section.

30. The assembly of claim 27 wherein the housing comprises a rotary steerable housing.

31. The assembly of claim 27 further including one or more sensors positioned substantially along the gauge section of the bit for sensing one or more desired borehole parameters.

32. The assembly of claim 27 wherein the bottomhole assembly further includes a telemetry system for communicating data from one or more sensors to the surface in real time.

33. The assembly of claim 25 further including one or more sensors contained within the bottom hole assembly for sensing one or more desired borehole parameters.

34. The assembly of claim 25 wherein said bottomhole assembly further includes a rotary steerable assembly.

35. The assembly of claim 34 wherein said overgauge drilling member is a rotary steerable extended gauge bit.

36. The assembly of claim 34 wherein said rotary steerable is a point the bit rotary steerable.

37. The assembly of claim 25 wherein said bottomhole assembly further includes a downhole motor.

38. The assembly of claim 37 wherein said overgauge hole drilling member is a bit and said bit is matched with said downhole motor.

39. The assembly of claim 25 wherein said overgauge drilling member includes a bit and a near bit reamer.

40. The assembly of claim 25 wherein said bottomhole assembly further includes a downhole motor.

41. The assembly of claim 25 wherein said bottomhole assembly further includes a slickbore drilling assembly.

42. The assembly of claim 41 wherein said slickbore drilling assembly includes a rotary steerable, a matched mud motor and bit, and a combined near bit reamer.

43. The assembly of claim 25 wherein said directional steering assembly is a geo-pilot directional tool.

44. The assembly of claim 25 wherein said overgauge drilling member is a bi-center bit.

45. The assembly of claim 25 wherein said bottomhole assembly includes a pressure while drilling tool.

46. The assembly of claim 25 wherein said bottomhole assembly includes a member for real time measurements ahead of the bit.

47. The assembly of claim 46 wherein said member includes a bi-modal acoustic tool.

48. The assembly of claim 25 further including in-line turbulators in the work string for removing cuttings.

49. The assembly of claim 25 wherein drilling fluids are a membrane efficient water base fluids system.

50. The assembly of claim 49 wherein said membrane efficient water base fluids system is BarOmega.

51. The assembly of claim 25 wherein said drilling fluids include a mud efficient mud system.

52. The assembly of claim 51 wherein said mud efficient mud system includes a water-base mud system.

53. The assembly of claim 52 wherein said water based mud system includes a lubricant additive.

54. The assembly of claim 51 wherein said mud efficient mud system includes a vegetable ester and internal olefin based synthetic mud system.

55. The assembly of claim 54 wherein said vegetable ester and internal olefin based synthetic mud system is Accolade.

56. The assembly of claim 25 wherein drilling fluids are an ester based drilling fluid.

57. The assembly of claim 56 wherein said ester based drilling fluid is Petrofree LV.

58. The assembly of claim 25 wherein drilling fluids are a calcium chloride base drilling fluid.

59. The assembly of claim 58 wherein said calcium chloride base drilling fluid is N-Flow.

60. The assembly of claim 25 wherein said drilling fluids are aldehyde based drilling fluids.

61. The assembly of claim 25 wherein said drilling fluids contain calcium chloride or potassium chloride.

62. The assembly of claim 25 wherein said drilling fluids are formate mud systems.

63. The assembly of claim 25 further including Sweep-Wate to sweep the borehole.

64. The assembly of claim 25 wherein said drilling fluids are matched to the formation being drilled.

65. The assembly of claim 25 further including chemically casing the borehole.

66. The assembly of claim 65 wherein said chemical casing includes a set up material and a catalyst.

67. The assembly of claim 25 further including a spot up system

68. The assembly of claim 67 wherein said spot up system includes Channel Seal.

69. The assembly of claim 65 wherein said spot up system includes chemical casing.

70. The assembly of claim 25 further including a drill ahead system.

71. The assembly of claim 25 further including a sealing composition disposed between the borehole and the expandable casing.

72. The assembly of claim 71 wherein said sealing composition includes a latex, dithio carbamate, zinc oxide, and sulfur.

73. The assembly of claim 71 wherein said sealing composition is a compressible foamed sealant composition comprising:

a hydraulic cement;

a rubber latex;

a rubber latex stabilizer;

a gas; and

a mixing of foaming and foam stabilizing surfactants.

74. The assembly of claim 71 further including a chemical spacer passed through the borehole ahead of said sealing composition.

75. The assembly of claim 71 further including a spacer between the drilling fluids and the sealing composition.

76. The assembly of claim 25 further including a buoyancy system disposed on the casing.

77. The assembly of claim 71 wherein said sealing composition includes a mixture of latex, dithio carbamate, zinc oxide, and sulfur.

78. The assembly of claim 77 wherein said sealing composition further includes a foaming agent.

79. The assembly of claim 77 wherein said sealing composition further includes a weighting agent.

80. The assembly of claim 71 wherein said sealing composition is a compressible foamed sealant composition including a hydraulic cement, a rubber latex, a rubber latex stabilizer, a gas and a mixture of foaming and foam stabilizing surfactants.

81. An assembly for drilling a diametrically efficient borehole for expandable casing, the assembly comprising:

a bottomhole assembly including an extended gauge bit with sensors, a point the bit rotary steerable assembly, a combo tool, a rock mechanics compression and slow shear sonic tool, a magnetic resonance imaging tool, a near bit reamer, and a cutting removal device.

82. The assembly of claim 81 wherein said combo tool may be a triple combo tool or a quadruple combo tool.

83. The assembly of claim 81 wherein said bottomhole assembly is connected to the end of a work string extending to a second or third generation drilling vessel.

84. An assembly for constructing a monodiameter wellbore, the assembly comprising:

a bottomhole assembly including a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool;

a work string attached to said bottomhole assembly and extending to the surface;

drilling fluids flowing through the work string and bottomhole assembly;

chemical casing casing the borehole;

expandable casing disposed in the wellbore; and

a sealing composition disposed between said expandable casing and the wellbore.

85. The assembly of claim 84 further including a spottable material filling wash outs in the borehole.

86. The assembly of claim 84 further including a fullbore delivery system disposed within said expandable casing.

87. The assembly of claim 86 wherein said fullbore delivery system includes production tubing.

88. A method for drilling a monodiameter borehole, the method comprising:

drilling an initial portion of the borehole with a drilling assembly having a bit, downhole motor and reamer;

applying a catalyst base material to the borehole wall during drilling;

back reaming the borehole as the drilling assembly is raised through the initial borehole portion;

applying a set up material to the borehole wall as the borehole is back reamed;

forming a chemical casing by reacting the set up material with the catalyst material;

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a string of casing in the borehole.

89. The method of claim 88 wherein a string of casing is installed in the initial borehole portion and a string of expandable casing is installed in each of the additional borehole portions.

90. The method of claim 89 wherein a particular borehole portion may be selectively chemically cased or cased with expandable casing.

91. The method of claim 88 wherein the set up material is only applied to selected borehole portions.

92. The method of claim 88 wherein the set up material is varied in accordance with the geology of the formation around the borehole portion.

93. The method of claim 89 wherein chemical casing is no longer used after reaching a predetermined temperature in the borehole.

94. The method of claim 88 wherein a liner is set in the casing and extends through a target formation.

95. A method for drilling a monodiameter borehole, the method comprising:

mixing a chemical casing with drilling fluid for drilling the borehole;

drilling an initial portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a string of casing in the borehole.

96. The method of claim 95 wherein a string of casing is installed in the initial borehole portion and a string of expandable casing is installed in each of the additional borehole portions.

97. The method of claim 95 wherein only selected additional borehole portions are chemically cased.

98. The method of claim 95 wherein the formulation of the chemical casing is varied with the geology around the borehole portions.

99. A method for drilling a monodiameter borehole, the method comprising:

utilizing chemical casing as drilling fluid for drilling the borehole;

drilling an initial portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a string of casing in the borehole.

100. The method of claim 99 wherein a string of casing is installed in the initial borehole portion and a string of expandable casing is installed in each of the additional borehole portions.

101. A method for drilling a monodiameter borehole, the method comprising:

utilizing chemical casing as drilling fluid for drilling the borehole;

drilling an initial portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a string of casing in the borehole.

102. The method of claim 101 wherein a string of casing is installed in the initial borehole portion and a string of expandable casing is installed in each of the additional borehole portions.

103. A method for drilling a monodiameter borehole, the method comprising:

drilling an initial portion of the borehole with a drilling assembly having a bit and downhole motor;

raising the drilling assembly in the initial borehole portion;

introducing chemical casing into the initial borehole;

allowing the chemical casing to set up and form a chemical casing on the borehole wall;

drilling through the chemical casing in the initial borehole; and

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a string of casing in the borehole.

104. The method of claim 103 wherein a string of casing is installed in the initial borehole portion and a string of expandable casing is installed in each of the additional borehole portions.

105. A method for drilling a monodiameter borehole, the method comprising:

(a) drilling an initial portion of the borehole with a drilling assembly having a bit and downhole motor;

(b) installing a string of casing in the initial borehole portion;

(c) drilling an additional portion of the borehole with the drilling assembly;

(d) installing a string of expandable casing in the additional borehole portion; and

repeating steps (c) and (d) by drilling further borehole portions until the borehole is drilled.

106. The method of claim 105 wherein the expandable casing is installed by lowering a non-expanded string of casing into the borehole portion with the upper end overlapping the previously installed casing string and then expanding the non-expanded string of casing to have an inner diameter substantially the same as that of the previously installed casing string.

107. The method of claim 105 further including cladding the overlapped ends of adjacent casing strings.

108. The method of claim 105 wherein the expandable casing string is cemented within the borehole portion using cement having a sealant.

109. A method for drilling a monodiameter borehole, the method comprising:

drilling the borehole with a drilling assembly having a bit and downhole motor;

installing a string of casing in an initial borehole portion; and

installing successive strings of expandable casing in additional borehole portions until the borehole is fully cased.

110. A method for drilling a monodiameter borehole, the method comprising:

drilling a first portion of the borehole with a drilling assembly having a bit, downhole motor and reamer;

applying a catalyst base material to the borehole wall during the drilling of the first borehole portion;

back reaming the borehole as the drilling assembly is raised through the first borehole portion;

applying a set up material to the borehole wall as the borehole is back reamed;

forming a chemical casing by reacting the set up material with the catalyst material;

installing a string of casing in the first borehole portion;

drilling a second portion of the borehole with a drilling assembly having a bit, downhole motor and reamer;

applying a catalyst base material to the borehole wall during the drilling of the second borehole;

back reaming the borehole as the drilling assembly is raised through the second borehole portion;

applying a set up material to the borehole wall as the borehole is back reamed;

forming a chemical casing by reacting the set up material with the catalyst material;

installing a string of expandable casing in the second borehole portion; and

repeating the above steps using expandable casing by drilling any further borehole portions until the borehole is drilled.

111. A method for drilling a monodiameter borehole, the method comprising:

mixing chemical casing with drilling fluid for drilling the borehole;

drilling a first portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

installing a casing string in the first borehole portion;

drilling a second borehole portion using the drilling fluid;

forming a chemical casing on the borehole wall;

installing an expandable casing string in the second borehole portion; and

repeating the above steps by drilling additional borehole portions and installing expandable casing until the borehole is drilled.

112. A method for drilling a monodiameter borehole, the method comprising:

utilizing chemical casing as drilling fluid for drilling the borehole;

drilling a first portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

installing a casing string in the first borehole;

drilling a second portion of the borehole using the drilling fluid;

forming a chemical casing on the borehole wall;

installing an expandable casing string in the second borehole;

repeating the above steps by drilling additional borehole portions and installing expandable casing until the borehole is drilled.

120. The method of claim 112 wherein the first borehole portion is a non-producing borehole and the second borehole portion is a producing borehole.

113. A method for drilling a monodiameter borehole, the method comprising:

utilizing chemical casing as drilling fluid for drilling the borehole;

drilling a first portion of the borehole using the drilling fluid with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the borehole wall;

repeating the above steps by drilling additional borehole portions until the borehole is drilled; and

installing a plurality of strings of expandable casing in the borehole.

114. A method for drilling a monodiameter borehole, the method comprising:

drilling a first portion of the borehole with a drilling assembly having a bit and downhole motor;

raising the drilling assembly in the first borehole portion;

introducing chemical casing into the initial borehole;

allowing the chemical casing to set up and form a chemical casing on the borehole wall;

drilling through the chemical casing in the initial borehole;

installing a casing string in the first borehole;

drilling a second portion of the borehole with a drilling assembly;

raising the drilling assembly in the second borehole portion;

introducing chemical casing into the second borehole;

allowing the chemical casing to set up and form a chemical casing on the borehole wall;

drilling through the chemical casing in the second borehole;

installing an expandable casing string in the second borehole; and

repeating the above steps by drilling additional borehole portions and installing expandable casing until the borehole is drilled.

115. A method for drilling a monodiameter borehole, the method comprising:

drilling one or more portions of a non-producing borehole with a drilling assembly having a bit and downhole motor;

forming a chemical casing on the wall of the non-producing borehole wall;

installing one or more strings of expandable casing in the non-producing borehole;

drilling a producing borehole with a drilling assembly; and

installing production tubing in the producing borehole.

116. The methods of claim 115 wherein the borehole portions are drilled using a drilling assembly disposed on the end of a coiled tubing string.

117. The method of claim 116 wherein the coiled tubing string is made of non-metal.

118. The method of claim 116 wherein the borehole portions are cased while drilling.

119. The method of claim 116 wherein a structural casing string may be installed in one borehole portion to form a second barrier.

121. A method for drilling a monodiameter well bore, the method comprising:

drilling an initial portion of the well bore with a drilling assembly having a bit, downhole motor and reamer;

back reaming the well bore as the drilling assembly is raised through the initial well bore portion;

placing expandable pipe in said well bore portion;

placing a sealant composition in said bore portion wherein said sealant composition remains competent when compressed in the annulus between said well bore and said expandable pipe;

allowing said sealant composition to harden;

expanding said expandable pipe whereby said hardened sealant composition is compressed; and

repeating the above steps by drilling additional well bore portions until the well bore is drilled and cased.

122. The method of claim 121 wherein said sealant composition is foamed with a gas.

123. The method of claim 122 wherein the volume of gas is sufficient to accommodate the volume decrease in an annulus between the walls of the well bore and said expandable pipe or pipe string when said pipe or pipe string is expanded.

124. The method of claim 123 wherein said gas is present in said foamed sealant composition in an amount in the range of from about 5% to about 35% by volume of the non-foamed sealant composition.

125. The method of claim 121 wherein said sealant composition is compressed in an amount that is substantially equal to the volume reduction of the annular space from said expandable pipe or pipe string being expanded.

126. The method of claim 121 wherein said sealant composition comprises a rubber latex.

127. The method of claim 121 wherein said sealant composition is comprised of a hydraulic cement, a rubber latex, a rubber latex stabilizer, a gas and a mixture of foaming and foam stabilizing surfactants.

128. The method of claim 127 wherein said hydraulic cement is selected from the group consisting of calcium aluminate cement, Portland cement and Portland blast furnace cement.

129. The method of claim 127 wherein said rubber latex is selected from the group consisting of a styrene/butadiene copolymer latex emulsion, polychloroprene emulsion, polyisoprene emulsion and acrylonitrilibutadiene emulsion.

130. The method of claim 127 wherein said rubber latex is a styrene/butadiene copolymer latex emulsion containing water in an amount in the range of from about 40% to about 70% by weight of said latex.

131. A method for drilling a monodiameter well bore through an unconsolidated formation, the method comprising:

drilling an initial portion of the well bore with a drilling assembly having a bit, downhole motor and reamer;

drilling said well bore with a drilling fluid having a pH in the range of from about 6 to about 10 and comprised of water, a polymeric cationic catalyst capable of accepting and donating protons which is adsorbed on said unconsolidated formation, a water soluble or dispersible polymer which is capable of being cross-linked by a thermoset resin and causing said resin to be hard and tough when cured and a water soluble or dispersible thermoset resin which cross-links said polymer, is catalyzed and cured by said catalyst and consolidates said unconsolidated formation;

repeating the above steps by drilling additional well bore portions until the wellbore is drilled; and

installing a string of casing in the borehole.

132. The method of claim 131 wherein said polymeric cationic catalyst is selected from the group consisting of polyethyleneimine, poly(dimethylaminoethylmethacrylate) and poly(dimethylaminopropylmethacrylate).

133. The method of claim 131 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polymers containing one or more of hydroxyl, amide, carboxyl and epoxy functional groups.

134. The method of claim 131 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polyvinylalcohol, polyvinylbutyral, polyesters, polyalkylacrylic acids, polyurethanes, acrylamide polymers, proteins, polyols and polysaccharides such as chitosan, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, water soluble starches, guar gum, xanthan gum, welan gum, carragenan gum and arabic gum.

135. The method of claim 131 wherein said water soluble or dispersible thermoset resin is selected from the group consisting of melamine-formaldehyde type resins, urea-formaldehyde type resins and phenol-formaldehyde type resins.

136. The method of claim 131 wherein said water soluble or dispersible thermoset resin is selected from the group consisting of an alkyl ether of a melamine-formaldehyde resin and an alkyl ether of a urea-formaldehyde resin.

137. The method of claim 131 wherein said polymeric cationic catalyst is present in said drilling fluid in an amount in the range of from about 1% to about 15% by weight of water in said drilling fluid.

138. The method of claim 131 wherein said polymer which is cross-linked by said thermoset resin is present in said drilling fluid in an amount in the range of from about 0.5% to about 20% by weight of water in said drilling fluid.

139. The method of claim 131 wherein said thermoset resin is present in said drilling fluid in an amount in the range of from about 5% to about 80% by weight of water in said drilling fluid.

140. The method of claim 131 wherein the pH of said drilling fluid is about 8.

141. A method for drilling a monodiameter well bore through an unconsolidated formation, the method comprising:

drilling an initial portion of the well bore with a drilling assembly having a bit, downhole motor and reamer;

drilling said well bore with a drilling fluid having a pH in the range of from about 6 to about 10 and comprised of water and a polymeric cationic catalyst capable of accepting and donating protons which is adsorbed on said unconsolidated formation;

contacting said well bore with a treating fluid having a pH in the range of from about 6 to about 10 and, comprised of water, a water soluble or dispersible polymer which is capable of being cross-linked by a thermoset resin and causing said resin to be hard and tough when cured and a water soluble or dispersible thermoset resin which cross-links said polymer, is catalyzed and cured by said catalyst and consolidates said unconsolidated formation.

repeating the above steps by drilling additional well bore portions until the wellbore is drilled; and

installing a string of casing in the borehole.

142. The method of claim 141 wherein said polymeric cationic catalyst is selected from the group consisting of polyethyleneimine, poly(dimethylaminoethylmethacrylate) and poly(dimethylaminopropylmethacrylate).

143. The method of claim 141 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polymers containing one or more of hydroxyl, amide, carboxyl and epoxy functional groups.

144. The method of claim 141 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polyvinylalcohol, polyvinylbutyral, polyesters, polyalkylacrylic acids, polyurethanes, acrylamide polymers, proteins, polyols and polysaccharides such as chitosan, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, water soluble starches, guar gum, xanthan gum, welan gum, carragenan gum and arabic gum.

145. The method of claim 141 wherein said water soluble or dispersible thermoset resin is selected from the group consisting of melamine-formaldehyde type resins, urea-formaldehyde type resins and phenol-formaldehyde type resins.

146. The method of claim 141 wherein said water soluble or dispersible thermoset resin is selected from the group consisting of an alkyl ether of a melamine-formaldehyde resin and an alkyl ether of a urea-formaldehyde resin.

147. The method of claim 141 wherein said polymeric cationic catalyst is present in said drilling fluid in an amount in the range of from about 1% to about 15% by weight of water in said drilling fluid.

148. The method of claim 141 wherein said polymer which is cross-linked by said thermoset resin is present in said treating fluid in an amount in the range of from about 0.5% to about 20% by weight of water in said treating fluid.

149. The method of claim 141 wherein said thermoset resin is present in said treating fluid in an amount in the range of from about 5% to about 80% by weight of water in said treating fluid.

150. The method of claim 141 wherein said drilling fluid and treating fluid both have a pH of about 8.

151. A method for drilling a monodiameter well bore, the method comprising:

drilling an initial portion of the wellbore with a drilling assembly having a bit, downhole motor and reamer;

drilling the wellbore portion with drilling fluid having a pH in the range of from about 6 to about 10 and comprised of water, a water soluble or water dispersible polymer which is capable of being cross-linked by a thermoset resin and causing said resin to be hard and tough when cured, a particulate curable solid thermoset resin, a water soluble or dispersible thermoset resin, and a delayed dispersible acid-catalyst for curing said solid thermoset resin and said water soluble thermoset resin, said drilling fluid forming a filter cake on the walls of said well bore that cures into a hard and tough cross-linked chemical casing thereon;

forming a chemical casing on the wellbore portion;

repeating the above steps by drilling additional wellbore portions until the wellbore is drilled; and

installing a string of casing in the wellbore.

152. The method of claim 151 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polymers containing one or more of hydroxyl, amide, carboxyl and epoxy functional groups.

153. The method of claim 151 wherein said water soluble or dispersible polymer which is cross-linked by said thermoset resin is selected from the group consisting of polyvinylalcohol, polyvinylbutyral, polyesters, polyalkylacrylic acids, polyurethanes, acrylamide polymers, proteins, polyols and polysaccharides such as chitosan, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, water soluble starches, guar gum, xanthan gum, welan gum, carragenan gum and arabic gum.

154. The method of claim 151 wherein said particulate curable solid thermoset resin is selected from the group consisting of particulate solid melamine-formaldehyde type resins, particulate solid urea-formaldehyde type resins and particulate solid phenol-formaldehyde type resins.

155. The method of claim 151 wherein said particulate curable solid thermoset resin is selected from the group consisting of an alkyl ether of a melamine-formaldehyde resin and an alkyl ether of a urea-formaldehyde resin.

156. The method of claim 151 wherein said water soluble thermoset resin is selected from the group consisting of water soluble melamine-formaldehyde type resins, water soluble urea-formaldehyde type resins and water soluble phenol-formaldehyde type resins.

157. The method of claim 151 wherein said water soluble or dispersible thermoset resin is selected from the group consisting of an alkyl ether of a melamine-formaldehyde resin and an alkyl ether of a urea-formaldehyde resin.

158. The method of claim 151 wherein the acid in said delayed dispersible acid catalyst is an organic or inorganic acid selected from the group consisting of p-toluene sulfonic acid, dinonylnaphthalene sulfonic acid, dodecyl benzene sulfonic acid, oxalic acid, maleic acid, hexamic acid, a copolymer of phthalic and acrylic acid, trifluoromethane sulfonic acid, phosphonic acid, sulfuric acid, hydrochloric acid, sulfamic acid and ammonium salts that produce acids when dissolved in water.

159. The method of claim 151 wherein said drilling fluid further comprises one or more insoluble chemical casing reinforcing materials selected from the group consisting of carbon fibers, glass fibers, mineral fibers, cellulose fibers, silica, zeolite, alumina, calcium sulfate hemihydrate, acrylic latexes, polyol-polyesters and polyvinyl butyral.

160. The method of claim 151 wherein said water soluble or water dispersible polymer which is cross-linked by said thermoset resin is present in said drilling fluid in an amount in the range of from about 0.5% to about 20% by weight of water in said drilling fluid.

161. The method of claim 151 wherein said particulate curable solid thermoset resin is present in said drilling fluid in an amount in the range of from about 5% to about 50% by weight of water in said drilling fluid.

162. The method of claim 151 wherein said water soluble thermoset resin is present in said drilling fluid in an amount in the range of from about 5% to about 80% by weight of water in said drilling fluid.

163. The method of claim 151 wherein said acid in said delayed dispersible acid catalyst is present in said drilling fluid in an amount in the range of from about 0.5% to about 8% by weight of thermoset resin in said drilling fluid.

164. The method of claim 163 wherein said one or more insoluble chemical casing reinforcing materials are present in said drilling fluid in an amount in the range of from about 2% to about 25% by weight of water in said drilling fluid.

165. The method of claim 151 wherein the pH of said drilling fluid is about 8.

166. A method of consolidating unconsolidated formations and forming a chemical casing in a well bore penetrating the formations to improve the mechanical strength thereof while drilling the well bore comprising drilling said well bore with a drilling fluid having a pH in the range of from about 6 to about 10 and comprised of water, a polymeric cationic catalyst capable of accepting and donating protons which is adsorbed on said unconsolidated clays, shale, sand stone and the like, a water soluble or dispersible polymer which is capable of being cross-linked by a thermoset resin and causes said resin to be hard and tough when cured, a particulate curable solid thermoset resin, a water soluble thermoset resin and a dispersible delayed acid catalyst for curing said thermoset resins, said drilling fluid forming a filter cake on the walls of said well bore that cures and consolidates said unconsolidated formations penetrated by said well bore and forms a hard and tough cross-linked chemical casing on the walls of said well bore.

167. A method of consolidating unconsolidated formations and forming a chemical casing in a well bore penetrating the formation to improve the mechanical strength of the well bore while drilling the well bore comprising:

drilling said well bore with a drilling fluid having a pH in the range of from about 6 to about 10 and comprised of water, a polymeric cationic catalyst capable of accepting and donating protons which is adsorbed on said unconsolidated formations, a particulate curable solid thermoset resin and a delayed acid catalyst for curing said solid resin, said drilling fluid forming a filter cake on the walls of said well bore that cures and consolidates said unconsolidated formations penetrated by said well bore; and

contacting said well bore with a treating fluid comprised of water, a water soluble or dispersible polymer which is capable of being cross-linked by a thermoset resin and causing said resin to be hard and tough when cured and a water soluble or dispersible thermoset resin, said treating fluid components depositing on said filter cake formed in the previous step and said thermoset resin curing into a hard and tough cross-linked chemical casing on the walls of said well bore.