OTTM thread coupling connections for casing pipes

 

Application

Coupling connection for casing pipes with a thread of trapezoidal profile is intended for construction and operation of vertical wells in oil, gas, and gas-condensate fields.

 

Design description

The peculiar design feature of casing pipes with OTTM thread connection is high resistance of the threaded connection to tensile loads. The OTTM thread profile has a shape of non-isosceles trapezoid with the pitch of 5.08 mm and taper of 1:16. The stab side receiving the load during stabbing and working in compression is at an angle of 10°, which ensures easy stabbing and reduces thread seizure. The load side of the profile receiving the tensile load has the angle of 3°, which reduces the risk of pipe thread coming out of contact with the coupling thread under significant tension and bending.

 

The tightness is ensured by thread-sealing lubricant pressure in design clearances of the connection thread profile. Upon consumer’s request, it is possible to manufacture the threaded connection with a fluoroplastic O-ring in the coupling, which ensures the additional seal.

Geometry of coupling

It is possible to manufacture couplings of two types: standard and special coupling with reduced outer diameter and increased external bevel. The design of the special coupling with reduced outer diameter improves passage of the casing string in points of high well deviation.

Make-up control

The make-up quality is controlled by the position of coupling face relative to pipe thread run-out end. The correctly assembled connection implies that the coupling face is aligned with the thread run-out end or is at a distance of no more than 5 mm from it.

Main features of OTM connection

Pipe Coupling
Pipe nominal diameter, mm Outer diameter D, mm Wall thickness S, mm Inner diameter d, mm Weight* of 1 m pipe, kg Outer diameter DC, mm Coupling length L, mm Weight*, kg
114 114,3 6,4 101,5 16,9 127,0
123,8**
170 4,0
7,4 99,5 19,4
8,6 97,1 22,3
10,2 93,9 26,7
127 127,0 6,4 114,2 19,1 141,3
136,5**
174 4,8
7,5 112,0 22,1
9,2 108,6 26,7
10,7 105,6 30,7
140 139,7 6,2 127,3 20,4 153,7
149,2**
182 5,3
7,0 125,7 22,9
7,7 124,3 25,1
9,2 121,3 29,5
10,5 118,7 33,6
146 146,1 6,5 133,1 22,3 166,0
156,0**
182 7,9
7,0 132,1 24,0
7,7 130,7 26,2
8,5 129,1 28,8
9,5 127,1 32,0
10,7 124,7 35,7
168 168,3 7,3 153,7 29,0 187,7
177,8**
190 9,5
8,0 152,3 31,6
8,9 150,5 35,1
10,6 147,1 41,2
12,1 144,1 46,5
178 177,8 6,9 164,0 29,1 194,5
187,3**
198 8,6
8,1 161,6 33,7
9,2 159,4 38,2
10,4 157,0 42,8
11,5 154,8 47,2
12,7 152,4 51,5
194 193,7 7,6 178,5 35,0 215,9
206,4**
206 13,4
8,3 177,1 38,1
9,5 174,7 43,3
10,9 171,9 49,2
12,7 168,3 56,7
15,1 163,5 66,5
219 219,1 7,7 203,7 40,2 244,5
231,8**
218 18,0
8,9 201,3 46,3
10,2 198,7 52,3
11,4 196,3 58,5
12,7 193,7 64,6
245 244,5 7,9 228,7 46,2 269,9
257,2**
218 9,9
8,9 226,7 51,9
10,0 224,5 58,0
11,1 222,3 63,6
12,0 220,5 68,7
13,8 216,9 78,7
15,9 212,7 89,5
273 273,1 8,9 255,3 57,9 298,5
285,8**
218 22,2
10,2 252,7 65,9
11,4 250,3 73,7
12,6 247,9 80,8
13,8 245,5 88,5
15,1 242,9 96,1
299 298,5 8,5 281,5 60,5 323,9 218 24,1
9,5 279,5 67,9
11,1 276,3 78,3
12,4 273,7 87,6
324 323,9 9,5 304,9 73,6 351,0 218 25,1
11,0 301,9 84,8
12,4 299,1 95,2
340 339,7 9,7 320,3 78,6 365,1 218 27,3
10,9 317,9 88,6
12,2 312,3 98,5
13,1 313,5 105,2
* — estimated value
** — diameters of special couplings