124:
422:. In order to precisely place the cement slurry at a required interval on the outside of the casing, a plug is pumped with a displacement fluid behind the cement slurry column, which "bumps" in the casing shoe and prevents further flow of fluid through the shoe. This bump can be seen at surface as a pressure spike at the cement pump. To prevent the cement from flowing back into the inside of the casing, a float collar above the casing shoe acts as a
223:
140:
25:
132:
286:
of axial and hoop stresses), must be sufficient at various depths. Pipe of differing strengths often comprises a long casing string, which typically will have the greatest axial tension and perhaps highest internal burst pressure differentials in the upper parts, and the greatest collapsing loads deeper in the well from external pressure vs lowered internal pressure.
340:
The purpose of surface casing is to isolate freshwater zones so that they are not contaminated during drilling and completion. Surface casing is the most strictly regulated due to these environmental concerns, which can include regulation of casing depth and cement quality. A typical size of surface
285:
Casing design for each size of designed pipes is done by calculating the worst conditions that may be faced during drilling and over the producing life of the well. Mechanical properties such as longitudinal tensile strength, and burst and collapse resistance (calculated considering biaxial effects
277:
must be large enough to accommodate the casing to be placed inside it, allowing room for cement between the outside of that casing and the hole. Also, subsequent bits that will continue drilling obviously must pass through existing casing strings. Thus, each casing string will have a subsequently
590:
370:
In order to reduce cost, a liner may be used which extends just above the shoe (bottom) of the previous casing interval and hung off downhole rather than at the surface. It may typically be 7", although many liners match the diameter of the
366:
that can fracture shallower or deeper formations. Casing placement is selected so that the hydrostatic pressure of the drilling fluid remains at a pressure level that is between formation pore pressures and fracture pressures.
660:
158:. Similar to the bones of a spine protecting the spinal cord, casing is set inside the drilled borehole to protect and support the wellstream. The lower portion (and sometimes the entirety) is typically held in place with
262:
and others, will pick strategic depths at which the hole will need to be cased in order for drilling to reach the desired total depth. This decision is often based on subsurface data such as
333:
The conductor casing serves as a support during drilling operations, to flowback returns during drilling and cementing of the surface casing, and to prevent collapse of the loose
398:. Tubing is easier to remove for maintenance, replacement, or for various types of workover operations. It is significantly lighter than casing and does not require a
309:
Typically, a well contains multiple intervals of casing successively placed within the previous casing run. The following casing intervals are typically used in an
219:
Optimum design of the casing program decreases the well construction costs, enhances the efficiency of operations and also diminishes the environmental impacts.
278:
smaller diameter. The inside diameter of the final casing string (or penultimate one in some instances of a liner completion) must accommodate the
639:
685:
42:
608:
434:
A prolonged, recurrent axial and rotational movement within casing would cause wear to the casing interior, with the probability of
108:
301:. The lower members of the wellhead usually are installed on top of the first casing string after it has been cemented in place.
162:. Deeper strings usually are not cemented all the way to the surface, so the weight of the pipe must be partially supported by a
394:
is therefore installed inside the last casing string and the tubing annulus is usually sealed at the bottom of the tubing by a
89:
550:
46:
61:
714:
68:
35:
298:
75:
263:
435:
206:
151:
57:
655:
511:
273:
With the casing set depths determined, hole sizes and casing sizes must follow. The hole drilled for each
468:
Minimization of dogleg severity and expect real dogleg at least 1.5 times higher than the planned value.
363:
677:
123:
719:
709:
571:
566:
Fontenot, Kyle R.; Strickler, Bob; Warren, T. (2005). "Using Casing to Drill
Directional Wells".
337:
near the surface. It can normally vary from sizes such as 18 to 30 in (460 to 760 mm).
184:
Prevents unstable upper formations from caving in and sticking the drill string or forming large
682:
635:
604:
546:
395:
391:
372:
279:
255:
235:
694:
82:
596:
239:
222:
689:
282:
and associated hardware such as packers, gas lift mandrels and subsurface safety valves.
475:
267:
192:
703:
464:
The following are recommendations for preventative measures to minimize casing wear:
419:
290:
274:
243:
163:
575:
399:
387:
359:
238:, is often used without cement inside the final casing string of a well to contain
358:
Intermediate casing may be necessary on longer drilling intervals where necessary
423:
415:
178:
139:
24:
445:
383:
378:
Few wells actually produce through casing, since producing fluids can corrode
658:, "Closed-Loop Systems and Methods for Geothermal Electricity Generation"
414:
slurry through the inside of the casing and out into the annulus through the
402:
to run in and out of hole; smaller "service rigs" are used for this purpose.
270:, and is balanced against the cost objectives and desired drilling strategy.
259:
173:
Casing that is cemented in place aids the drilling process in several ways:
131:
226:
Casing arranged on a rack at a drilling rig in preparation for installation
205:
Seals off high pressure zones from the surface, minimizing potential for a
310:
294:
199:
167:
155:
484:
Select proper mud type and add lubricants to minimize wear and friction.
426:
and prevents fluid from flowing up through the shoe from the annulus.
600:
411:
185:
159:
215:
Provides a smooth internal bore for installing production equipment.
154:
that is assembled and inserted into a recently drilled section of a
438:, production loss, and other hazardous and costly complications.
379:
231:
221:
138:
130:
122:
490:
Usage of thick wall casing in the anticipated wear section area.
334:
191:
Provides a strong upper foundation to allow use of high-density
632:
Petroleum
Engineering Handbook, Volume II: Drilling Engineering
589:
Wagner, R. R.; Warling, D. J.; Halal, A. S. (January 1, 1996).
212:
Prevents fluid loss into or contamination of production zones.
18:
634:. Society of Petroleum Engineers. 2007. pp. 287–288.
202:
or fluids, in the drilled formations from one another.
441:
The following conditions contribute to casing wear:
242:and convey them to the surface from an underground
49:. Unsourced material may be challenged and removed.
198:Isolates various zones, which may have different
390:and the larger diameter can make flow unstable.
143:premium gas tight connections on a casing string
471:Usage of casing friendly tool joint materials.
8:
109:Learn how and when to remove this message
410:Cementing is performed by circulating a
503:
362:weight to prevent blowouts may cause a
683:Schlumberger Oilfield Glossary: Casing
297:, which later will be topped with the
7:
626:
624:
622:
620:
536:
534:
532:
254:In the planning stages of a well, a
47:adding citations to reliable sources
595:. Society of Petroleum Engineers.
493:Usage of software to reduce risks.
14:
289:Casing strings are supported by
23:
487:Usage of drill pipe protectors.
34:needs additional citations for
545:. springer. pp. 185–243.
323:Intermediate casing (optional)
127:Casing Diameters of a Borehole
1:
543:Oil Well Drilling Engineering
474:Minimize rotor speed and use
16:Pipe inserted into a borehole
195:to continue drilling deeper.
736:
656:US patent 2012174581A1
592:Minimum Cost Casing Design
258:, usually with input from
177:Prevents contamination of
382:or form deposits such as
266:pressures and strengths,
541:Rabia, Hussain (1986).
512:"How Does Casing Work?"
355:inches (340 mm).
227:
144:
136:
128:
58:"Casing" borehole
695:How Does Casing Work?
418:at the bottom of the
230:A slightly different
225:
142:
134:
126:
460:Well path and dogleg
364:hydrostatic pressure
293:that are set in the
150:is a large diameter
43:improve this article
715:Drilling technology
688:2012-07-16 at the
457:Tool joint coating
228:
145:
137:
129:
641:978-1-55563-114-7
451:Mud and additives
392:Production tubing
373:production tubing
326:Production casing
280:production tubing
256:drilling engineer
240:production fluids
236:production tubing
119:
118:
111:
93:
727:
665:
664:
663:
659:
652:
646:
645:
628:
615:
614:
601:10.2118/36448-MS
586:
580:
579:
563:
557:
556:
538:
527:
526:
524:
522:
508:
354:
353:
349:
346:
329:Production liner
317:Conductor casing
114:
107:
103:
100:
94:
92:
51:
27:
19:
735:
734:
730:
729:
728:
726:
725:
724:
700:
699:
690:Wayback Machine
674:
669:
668:
661:
654:
653:
649:
642:
630:
629:
618:
611:
588:
587:
583:
568:Oilfield Review
565:
564:
560:
553:
540:
539:
530:
520:
518:
516:www.rigzone.com
510:
509:
505:
500:
432:
408:
351:
347:
344:
342:
307:
252:
234:string, called
115:
104:
98:
95:
52:
50:
40:
28:
17:
12:
11:
5:
733:
731:
723:
722:
717:
712:
702:
701:
698:
697:
692:
680:
673:
672:External links
670:
667:
666:
647:
640:
616:
609:
581:
558:
551:
528:
502:
501:
499:
496:
495:
494:
491:
488:
485:
482:
479:
476:downhole motor
472:
469:
462:
461:
458:
455:
452:
449:
431:
428:
407:
404:
388:paraffin waxes
331:
330:
327:
324:
321:
320:Surface casing
318:
306:
303:
299:Christmas tree
291:casing hangers
268:well integrity
251:
248:
217:
216:
213:
210:
203:
196:
193:drilling fluid
189:
182:
135:Casing Diagram
117:
116:
31:
29:
22:
15:
13:
10:
9:
6:
4:
3:
2:
732:
721:
718:
716:
713:
711:
708:
707:
705:
696:
693:
691:
687:
684:
681:
679:
676:
675:
671:
657:
651:
648:
643:
637:
633:
627:
625:
623:
621:
617:
612:
610:9781555634230
606:
602:
598:
594:
593:
585:
582:
577:
573:
569:
562:
559:
554:
548:
544:
537:
535:
533:
529:
517:
513:
507:
504:
497:
492:
489:
486:
483:
481:Increase ROP.
480:
477:
473:
470:
467:
466:
465:
459:
456:
453:
450:
447:
444:
443:
442:
439:
437:
429:
427:
425:
421:
420:casing string
417:
413:
405:
403:
401:
397:
393:
389:
385:
381:
376:
374:
368:
365:
361:
356:
338:
336:
328:
325:
322:
319:
316:
315:
314:
313:or gas well:
312:
304:
302:
300:
296:
292:
287:
283:
281:
276:
275:casing string
271:
269:
265:
261:
257:
249:
247:
245:
241:
237:
233:
224:
220:
214:
211:
208:
204:
201:
197:
194:
190:
187:
183:
180:
176:
175:
174:
171:
169:
165:
164:casing hanger
161:
157:
153:
149:
141:
133:
125:
121:
113:
110:
102:
91:
88:
84:
81:
77:
74:
70:
67:
63:
60: –
59:
55:
54:Find sources:
48:
44:
38:
37:
32:This article
30:
26:
21:
20:
650:
631:
591:
584:
567:
561:
542:
519:. Retrieved
515:
506:
463:
440:
433:
409:
400:drilling rig
377:
369:
360:drilling mud
357:
339:
332:
308:
288:
284:
272:
253:
229:
218:
172:
147:
146:
120:
105:
99:January 2017
96:
86:
79:
72:
65:
53:
41:Please help
36:verification
33:
454:RPM and ROP
430:Casing Wear
424:check valve
416:casing shoe
384:asphaltenes
181:well zones.
179:fresh water
704:Categories
552:0860106616
498:References
446:Drill pipe
341:casing is
260:geologists
69:newspapers
720:Boreholes
710:Oil wells
406:Cementing
305:Intervals
264:formation
244:reservoir
200:pressures
686:Archived
678:Cementer
576:16241819
436:blowouts
295:wellhead
168:wellhead
156:borehole
521:July 5,
350:⁄
207:blowout
186:caverns
166:in the
83:scholar
662:
638:
607:
574:
549:
448:weight
412:cement
396:packer
250:Design
160:cement
148:Casing
85:
78:
71:
64:
56:
572:S2CID
380:steel
232:metal
90:JSTOR
76:books
636:ISBN
605:ISBN
547:ISBN
523:2018
335:soil
152:pipe
62:news
597:doi
386:or
311:oil
170:.
45:by
706::
619:^
603:.
570:.
531:^
514:.
375:.
343:13
246:.
644:.
613:.
599::
578:.
555:.
525:.
478:.
352:8
348:3
345:+
209:.
188:.
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
