CA2069179A1 - Tieback adapter for a subsea well - Google Patents

Abstract

ABSTRACT
An improved tieback system for a subsea well and an improved tieback adapter (20) for a tieback casing string connecting from a platform to a subsea well. The tieback adapter connects to the hanger (22) and to the top end of the inner tieback casing string (18) and includes adjustable means (30) for connecting between the hanger and the inner tieback casing string. A tool (84) for moving said hanger relative to a head (14) on the upper end of the outer tieback casing string (12) and relative to the inner tieback casing string (18) and for tensioning the inner tieback casing string is provided. The adjustable connecting means has a ratcheting latch means (40,64,66) allowing such relative movement between the two tubular mandrels of the adapter and means (40,70) for preventing movement of the inner tieback casing string relative to said banger against upward loads.

Description

2 ~

~IEBACX ~E~ FOR A
SUBSEA ~EL'I~

r~c~nt ~nv~ntion relata~ to ~ tle~ac~c ~d~pt-r natal 8~al to be u~2d ~lth ~ sub6ea v~ll to co~plete ~h~ conn~ct'~on ~rom t~e ~ w-ll to th- pl~tfon~l and pro~rlde a paclng ou'c or ad~u~t~ng to ~ ~or~ect l~ngth o~
~be tleback c~ng tr~n~ ~o that lt ~ay b~ u~ ly l~nded in a ~h-~t hea~. Prlcr to ~ ~resent lnvent1on ~t hae ~een tl~- practlc- to ~aJc~ ~uch len~ ~d~u~ ent ln tbe a~k cz~ g At t;ta~l platfos~ ~y ~~æ~oning t:h~
~trln~ and t~en supposting ~t ~ llp~ ln lt~ extende~
poe~ltlon. 1~ lt 1~ too lon~ ~t ~ay t~n bQ cut to the d~ss~rcd l~ng~h.
tent No. 4,1572,708 ~icclo-~s ~ subs~ t~Qback connector .rhle~ u~e~ to seat ~ e ~ub6e~ Ye~lh~ad ~nd to rec-lv~ equQnt? y run cond~lctor ~t~ c ~hlc~ ~r~
l~tc2 ~l ~nto ~ lt~on l~y ~ ~pl~t latc~ing rlng.

The present invention provides an imprc~ved tieback ~y6~e~ ~or a ~lub-~a v ll in~ludlng ~n l~pro~-d tl-~ack adapt~r rOr a tl-:ba~lc cag!Ln~J ~tr~ 4nn~ing fro~ a plat~or~ t~ a ~U~8~ v~ll. Th~ tl~back ad~pt connects to th- ~ang-~ ~n~ to th~ ~o~ ~n~ o~ th- ln~r t$eb~k c~ng ~trlng an~ lnclude~ two tele~coping tubular ~andr~l~
~n~ an ad~u~t~ble ~ans ~or ~onn~ct$ng ~4t~n th~ ~andr~l~
to provide an adjustment of the length of the inner tieback ca~ing ~t~ng hn~ to d lov lan~ng of ~h~ han~-r. ~ tool 1~ us~d ~or ~o~ng ~ld hangar ~lativa to ~ h~ad ~nd ~al~ $nn-r ti-ba~ ca~ln~ ~trlng an~ rO~ tan~or.~ng the ~ner t~-b~c~ caslng ~trlng. ~h~ conn~ctin~ ~e~n~ ~a~ a ra~chQting latG~ ~e~ns allovlng ~cb r~lat~ o~a~ent ~n~

-2- 2~9~.7~

~ean~ ~or pr~v~nt~ uvement o~ t~e lnn~r tlebac~ 6~ng ~trir~ r-l~t~vs to ald hAnger aga~n~t upvard lo~d~.
Addltlonally the l~prov~d t~ebacJc ~Idapter lnolud~ ean~
for pro~ldl~g a ~OEtal-to-met~l ~eal to en~ at U~8 ~ressurQ ~ro~ ntorior o~ lnn~ t~ac~ 6~ng ~trlnq do~s rlot reach t~ annulus ~urround~ uoh ~t~ng and wit~ln th~ out~r t~ebaclc ca~in~ ~trlng.
An ob~-ct of t~la pre~ent inv~ntlon ~- to p~ov~dQ an apparatu~ ~o~ ~pacing out a tieb~:)t c~ng 6trlnq ~ the u~ ~at a ~ang-r.
l~nDt)~sr ob~ect ~ to pro~d~ ro~d t~ e~ac~c adapt~r orl~ allow~ the preci~4 load ~or prQ-~snsionlng tl~back strl~g.
A fu~er ob~ect ~e; to provld~ proYed t~ e~ac~c ~dapt~r wlttl ~etal-to-~tal 6eal~ ~or ~s~ol~t~ng tbo lnt-rnal ~md ex~erJ~al pres3ur~- ~lth re~p~ct to ~ r ti~bsck ¢~ing l~tr~nq .
8tlll anotbar ob~ect 1~ ~o provld~ ~n ~rov~d tl~ack ~d~ptsr wh$c~ allow~ G r~ s~ng o~ ~ha ti-back ca~lng et~ tenslon prlor to unlatc~ling tho ~ wellhead or mudlln~ ~uspen~ion tieback eool.
A ~t~ urth~r ob~ect 1- to pro~lde ~ 'cle~aclc adapter wt~lctl c~n ~ securQ~ ~galnst upward tt~

T~es~ ct2~Qr ob~ct~ and ad~antage~ o~ t~e pre~ont lmr~n~lon ar~ ~-r~lna~t-r ~et ~ort~ an~ xpla~n~l v~h rQ~pect te~ wing~ ~-roln~
n~ lA, lE~ and lC ar ~c~ partl~l long~tud~nal ~ectlon~ eY~ 0~ th- l~prov~d apparatu~ pos~oned ~lt.h~n tho plat~o~ hea~. FIC~ lu~tr~t4~ tho top portlon o~ apj~asatu-. FI~UR~ lEI lllu~trat~ ntral p~rlon o~ tho apparatu~ ~nd PIG~ IC lll?~Etrat - ~Q low-lr portlon o~ apparatu~ 3- glgur~ o r tbo adap~or ot th~ ~r-~-nt lm~ntion dur~n~ t~ o~ oi~
string.

-3- 2~9~7~

FIGIJR~S 2a, 2~ ~nd 2C nr~ eac~ l lDngltudlr~l ~ect~onal Vi~ o~ mproved apparetu~ r tJl~ ~dapter h~ be~n actuat~d to land ~Q hanger onto th~ nsa~ 6eat.
~6URE 2A ~llu5~rat~ toE~ portlon of tll~ ap~aratu8, PI~ 2~ illustrate~ portlon of t)~ ~p~aratu~
~md r~GU~ 2S~ u6t~lt~A t~e lower ~o~tlon o~ tl~e ~pp~ratu~.
F~ 3 ~- ~ part~l tran6YQr~e ~a~t~on~l ~r$~w to ~llu~trat~ tlon o~ tt~e ~and poælt1one/i in ~h- spac~
ot tt~- ratch~tlng ~pl~t rlng.
F$6U~ ~, 18 el deta~lQ~ 9~ctional ~rle~ tO ~lluctrat~
~e po~ltlon o~ such band.
FICURE 5 11~ an ~nterna~L Y~-~ o~ hown $n ~I~ lC.
YIGU~ 6 1~ a longitudin~l ~ectional ~i-w o~ a tD~l for rel-a~ng t~e ten6~0n lc~d on tl-~ lnner l~ack ca~ng ~tr~rg pr~or to reD~ov~ng t~e hanger an~!l t1e~clc ~aptQr.
~ICUR~ 7A, 7~ an~l!l 7C ~r~ ~art~al longitudinal ~;ectional vlev~ of A ~odl~1-d ~ona o~ ~ pr~ t ~n~ent~on ~nd lllUstrat~ tool us-~ ~or runn~ng and ~ett~ng t~e ad~ust4~1a connectlon of ilDproY-d ti~ac~ pt~r.
FlGUR~ 7A lllu~trate~ ~- upp~r porelon of such ~on~ o~
in~,rent1On, F~ 7b lllu~t~at~ dle po~tion o~ ~u~
for~ o~ the lmr~n~lon land rIG~ 7C ~l~;trat~Y t~e low~
portlon o~ BUI~h ~OrJQ 0~ nv~ntlon.
~IG~US 8A, 8B ~Ind ~C ~re ~artlal ~-ctlon~ll Yl~w~ o~
or~ c~f t~- ~pre~ent 6h~ n FIGl~S 7A, 7~ ~ 7C w~th t~e tool w~ ro~de~ ;ettlng to~ or t~ ~et~
to-metal 6~al ~n~ al-o t~sts ~uch se~l to ~nsuro t~at th~re lt~ no com~unicatlon b~tw~ prQ~u~ oun~llng th-~nnor tl~ac~ ing strln51 ~na tha pr~s~ur~ 1n ~uc~
~tr~n~.

!rbO ~p~e~ tilE~bAC~C ~yBt~ 10 0~ t~10 pr~s~nt lnY~ntlon is 1~1ust~ated i~ drawlng~ u~ ~ FIÇUR~ 1, ~y~t~a 10 lncludc~ outer tl~l~a¢lc c~;lng 6t~ng 13 W}~ ia 2~ 79 connected at ~tfi lower and o~ aa well (not ahown) and at .itR upp~r end to he~a~t 14 which ha- ~nt~ upwa~dly fa~ing landing 6~at 16 tbere1n, 1nn~r t~c~ r~Jlg 18 wh$c~ also conneot~ ~t lt~ lower n~ to ~- sul~s~a well, ~pro~e~ t~Qbaok adap~r 20 conneoted to t~- upp~r nd o2`
~nner t~ebaclc ~n~ 6trlnç~ 18 ~nd ~ al-o c:onnected ~o th~
lc~wer er~d of has~g~r 2a at t~ upper ~n~ o~ dapt~r 20.
r~g~ 22 lnclud~ externsl land~n~ ~oulder 2~ hic~ i~
adapted to ~nga~e landinçl eeAt 1~ ln ~ea~ en properly l~d~d.
T~e2~c~c aaa~t~r 2~ lnclu~e~ upp~r tu~ul~r ~an~lrQl 26 and low~r tu~ular ~andr~l 28, ~e~n~ 30 for r~leasal~ly latcb~ng ~h- tubular ~andr-l~ 26 and ~8 togeth~r to allo~lr lnw~rd te~e~c~plnq Dl~ e~ent bet~Q~ two tubular sl~andr-l~ and ~D~ant~ 32 ~or providin51 A D~etal-to-~etal sea3, ~twQen ~aid t~ul~r ~andrel~ 26 and 28. Vpper t~ular ~an~ l Z 6 ~nclud~- sklrt 3~. 61~CUr-~ to ~k~ low~ ~nd 2~
by t~road~ng. ~nd rlng 36 1~ ~ecured to t~ lo~r~r ~nd o~
fiXi~C 3~ h~s an inner dla~QtQr wh~ lldc3 o~r~r t~-20 ex'cerlor o~ ~nner t~ c~ lng ~tr~q a~ shown. ~Qupp~r portion of ~nd rin~ 36 proYide~ upward~y Saeing 6t~0ulder 38 ~hicl~ ~upports low~r tu~ular ~andrel as dur~ng ~n~tlal runnlng ~nd dur~nq ~-tr1e~va~. ~na ln~r~e~t-lon o~ 8Xlrt 3~ i'B p~rlded Yit~ t~ 40 vbls~ aveup~er Slat ~url'ac-- ~2 An~ r ta~r~l ~ ac~- 4J. .
~ppos tub~lar wadr~l 26 ~r~clud~ r l~ealin~ ~urfac~ 46 ~nd ~nclud~ low~r d~pena~ng ~-al rlQI 48 whld~ apt~d to ~e~l agninot oxt~rlc~r ~ urfac- S0 on th~ rlo~
oS ~nn-r tubu~r ~e~bRr 2B. Upp~r ~nd o~ lower tubul~
30 ~D~nd~e~l 28 lnclud~-l u~wa~y extsnd~ng ~-al~ng r~a S2 whlc~
~ ~da~t~d to ~al ~galn~t ~ se~ aoo 4S on upper tubular ~r-l 26. Cxt-~r~or ~ $nq ~ a¢~ 50 on lo~rer tubular ~em~er 28 ba~ nn out~r d~ t~r a~
rnal pro~ct$on 54 ~ lid-~ VlthiA loe~er upp~
tubular ~andrel ~6 as ~hown. 6-al~ng rl~ 52 1~ b~ac~d r~d~-lly outlfa~ to ~n~ure it~ aeal~ng ~aga~t vlt~
~o~llng ~ur~ac 4~ and ~ ri3~ 48 1~ b~s~!l radial~y 2 ~ 7 9 inward t~ en6ur- lt~ ~ea~ cng~ge~De~t Yl'ch a~2~nS~
surfac- S0. Below pro~ect~on 54 t~ ~xterlor o~ lo~-r tubul~r mandrol 28 lncludes re~e~s 5~ lncluua3 ~ap~r~a l~nd- 5~ and 60 w)~ch ba~r~ tap~r~ l~e~ ~n~ low~r ~quar- ~ ~ d~d l~n~ 62 . Split ~in~a 64 ~r~ 66 ~ bia~d ou~ardly nn~ ar- po61~$one~1 in reCQ~ 56 u~t~ a ~ac~
thQrebetWeQ5~ to ~cco~odat~ ~pllt th~ust ~lng 6~ wh~
bi~Ged inwsr~ly- ~ingB 64 ~nd 66 ~ncl~ad~ t~read~ 70 on thel~ exterio~ surfac~ to ~at~ ~iith and coact ~ U~re~d~
~.0 on thQ ~Jlt~rior o~ s)c~rt 34 ~hen ~andrels 26 ~nd 28 h~ve been tele~coped ~nwardly to pre~r~nt an outYar~ t~l~sc~p~ng retur~ open end~ o~ pllt r~q~ 64, as ~n ~n PSG~ 3, are ~a~t~ne~ $r~ lr ~slrs~ annul~r po~ltion by ~and 72 whlc)l 16 ~ocure~ on t~o irltio~ o~ ~clrt 3~ ~n~
eYtetl~ the les~ of tbread~ ~0. The lcsv-r ~nt-rlor o~
lower tu3wlar ~andr-l 23 1~ t~readed c~nto t~- uppsr ~nd or ~nner t~l~clc c~lng strlng 18 and lnclnde~ ~eca-se~ 7~ a ~ort ~i~tanc~ ~bo~ upper nnd o~ ~u~ cor~¢tion.
Dur$ng th- runnlng and certain operatio~ ~rot-otlon 20 ~le~ve 76 $- s~etain-d ln po~lt$on prot~ctlng ~eallng surfacQ ~6 ~rom ~agQd. Sle~ 76 i~ ~pllt ~ b~l~
~n plnce by upper ring 78 and lower r~ ~0 ~lch ~rQ
pinn~ to ~ 76 to hol~ it in it~ ~ositlon prot~ctlng seal~ng ~ur~ee ~,6 and w)a~n t~e t~le~co~ng ~o~re~Qnt b~gin-, tl~ holdlng rl~g~ 78 a~ 0 to ~ 7~ Dr-s~Qar~, to ~low all thze- co~onent~ to ~o~e rad~ally ~nwar~ lntc~ ¢e~ 82 in tool 8~ a~ h4s~ a~t~lr ~cplaln~. ~ ~innlng o~ ring~ 7~ and 80 ~n ~o ~pac~
~n spllt ~ r- ~6 so t~at ~hen rel4a~Qd all tb~e~ ~rh~h 3~ arc ~la6~d ln~ ~ll n~ve to ~uc2~ lnw~r~ po~it~on.
n ~ PIGUR~S lA, lB and lC, ~dapt-r ~0 ha- ~en connect~d to tl~ upper end ot lnnar ti~ac~c caslng ~trlng 18 ~nd to ~nger 2~ and t~B ~ ly ~- Y~u~n hQ~
outer tl-baak ca-lng ~tr~ng 12. In t~ ltlon tool ~
ten~lon1n5~ hJUI to~ting tool ha~ n lowQrQd lnto t~ tlon ~ tr~ Rl~CQ~ or x~on~on o~ ~Ictu~or 86 ~ga-nst t~e upp~r ~ Or ~nger -6~ 9~79 22. Actua~o~ ~6 ~ncl~dee upp~r tu~>ular houslng 88 alnd outer ~l~e~r4 90 w~t)~ anr~ul~r cha~b~r 92 de~isted between hou3ing as ~nd 61e~v- 90 in -dh~c~ anntll~r ~l~ton 9~ 1 po~tio~ea. 8ultabl~ comwn~catlon, ~uc~ ~- pa~a~ 96, i~
prov~d-d to conduct flula un~r pr~ into c~-r 92 ton 94. Tu~ul~r 2~ou~inS~ 8~ YtQn~ to ~ rQl ~elow ~ce~sQ~ 74 and carrie- engaglng lug~ 97 ln radial open~ng~ 98. 8Ore lO0 e~ctend~ throug~ upper nou~ng g8 and lower tubular hou6~ng 102 Q~ tool 84 an~l co~munic2~t~ tb bor- 104 ln th~ low~r portlon c~ lower tu~ular hou~ g 102.
Bor~ lO~. ba~ a ~aller dlameter than ~or~ lO0 an~ xte~d~
fron a ~ho~ di6tarlce above openlng~ 9~ to t~- lo~ n~ o~
lo~Qr tubular ~ r ~02. Camm~ng ~luq 106 ha- its 1~g~d head 108 s~al-d within bo~ 100 ~n~ include~ reduc-d ~ection b~lo~ head 108 f itting wi1~1n low~r bcsra lO.~ and extQnd~ng to t~par~d Qct~on llO ~rhic~ 1B u~ta~1~ wh~n plug ~06 i- Jnaved to ~ ition ~o~n 1~ FICUR~ 18 to nçJ~g~ ard t~- ~nner ~n~ of lu~ 97 an~ to~oa tS~e~ ou~ward ~n~o ~nqaçlQIt%nt w~thln ~-c~ 74. ~to~ .12 16 6ecur~ to t~- lowQr end o~ cam~ing plug lO~ ~nd eng~g-~
~ lo~r ~r~d of lowQr tu~ulAr hou~nç~ 102 ~hexl c~ming pluq 106 1s ln lts upper pos~tion. Tool 84 ~o lnclud~6 tQ~t; pl~9~g~ vh~ch com~u~icat~ u~ port ~,16 to t~
lnt~r~oF ot lowe~ tu~ular m~ndrQl 28 ~o~ r~ nt c~al~
llB c~rrled on t~Q ~xt~-rior o~ tool 84 ~nd b~ pp~r 120 carr~-~ by r~ng 122 ~urroundlnSI tb.~ r~or o~
t~o upp~ low~r tubular mandr~, 2~ B pr~scur~
wlll b- ap~ d d~r~c'cly to t~t th~ metal-to~ se~1 b-tw~n s~ ng rlm 52 on low~r tubular ~ndr~l 28 and lnne~ ~allng ~urrac~ 46 on upp r tubular ~an~l 26 ~t-r tl~¢~ ~d~pt-~ h~e bs-n ~d to lt~ ~Q~ t~on ~ o~n ~n Y~GURES 2A, a~ and 2C. 'rool a~ o ~n~ludlas pa~6ag-113 vhlab co~unlc~t~s t~rou~h ~ 5 lnto bo~- 100 ~lov he~ 108. l~s pa~sago u~n bo U5-~ 'CO c:onduct pre~ r~
flu~d~ 2~lo~ hQ~ 108 to caus~ ~lu5~ 106 to 3110V~ up~rdly lug- 97 to r~er~ct ~ro~ th~r ~ngAg~nt withln roc~6s~ 74.

~7~ 20~17~

~ o plac~! t~a i~roved tiebaoX 6y~te~ ln operatlon, tho follow~ procod~ ~6 ~ct:o~pl~sh~d:
., ~lce up tl~bhck t~l (eithYr ~u~lliD~ or w~llhead) to 10 -3/4 ~ in~ .
2 . Run 1~ ~ol~ with r~qulr-~ num~ o~ 15-3~4 "
oasing ~oln~ to achl~ J- 5~ Rtae~c-u;~.
3. Ma1C~ UP 10-3/4" Ca~ng b~J~g~ coa~ QtQ ~it~
tiebac)c mandr-l and ~unnl~g tool to 10~3/~, c2s~ng st~ng.
~. Lan~ su~ea t~obac~c tool on cub~ lo-3/~l~ han~r an~l ~e~ of~ ~e~u~r-d v~ig~t to engago.
r hol~ wSth ar~ll pip~ ~n~l torgu-~te~t too~.
Tor~ up ~ s~a tiebacX tool to ~anq~
6. ~Sake up 6ur~ac~ tQBt h-ad to 'cop t~ 10-3/~"
running st~insl ~nd prQ-eure t~-t ~ ~egu~re~.
7, ~-~r~evo ~ur~ac- t~t h~a~ rill pi~ and tor~u~/te~t tool.
8 . R~tr~ve 10-3~4~ ng ~ toolO
~ . ~un in 21ol- ~ith ~ydraul ~ ~: tS~aalc DlanBrel ~tting too~. Land on top o~ 10-3~a hanger.
10. PrQ~sur~ down drlll pl~- to lock ~Qtt~ng tool to lo~r al~vR of ti~ac)c 3an~rel.
11. Apply ~r~ur- down drlll plpe to ~ ln~
ar on tt~-~ GO~pllO~ a l~ c>ul~r.
~ncr~ ro~ to obt~ln r~quirod t-n6~0n ln 10-3/4~ t~ck ~trlng.
Not~ 10, 000 PS~ on ~ool 1~ e~ lent to S~O,OOO lb~ Or t~n-~on ln 10~3~a ca~ng etr~
o~ tt~ng pres~lr~ on too~
13. Pres-ura down 1/~ xtQrn~ n (~o~t 1) ~o te~t lnt~ l h~gh ~ro~ur~ ~10, 000 Ps~ ~x. ) o~t~l J~al ~n ti~a~ r~l.
14 . Bl-Q~ o2~ t~t pr~s~ure.
15. PrQs~ o~ cos~ 1/4" ~YtQ~~
to r~ca~ ¢ett~ tool. R~trl~ t~sol ~rough ~taclc.
16. ~nst~ B 10-3~ co~Qp~ bly.

-8~ 9 ~ hQ opar~tlon o~ tool 8~ once ~1: 16 ~n pos$tion, proceRda w~th plug 106 bo~ ng ~o~red downwar~ly w~t~ln bore 100 and 104 re~pon~ Q to prel66UrO l;uppl$Q~ ~hroush ~orc 100, and ~ u~e~ lug- ~7 to ~ rorc~d lnto rec8~e~ 7~.
po~ition o~ tho co;~ponsntl~ a~ter complotlon o~ t)~
o~rnt~on o~ tool 84 er~ ohown ~n yIauREs ZA~ 28 and 2C.
qq~er~fter, pr~aur~ ppl~-14 to 3~assag~ 96 c~u~
r~lat~e ~o~ ent of pi~ton 94 downw~r~ly and low~r tu~ulax 28 ~ndrel upwar~. ~h~ ~ova~ hanger 22 onto land~ng 8~al 16 in head 14 and thereaft~r create~ ~n upward fo:rc~ on innor t$eb~X c~ ng st~lng IB . Th~ ~el~tl~ ~ove~en'c ~etwecn u~p-~ ~nd low-r tu~ul~r 211an~1r-13 26 and 2S ~
rQlatively ~r-~ but t~s engag~nt of ~plit r$ng~ 6~ ~nd 66 wl~h t~- thr~a~s 40 on t.h- int~r~or Or s1clrt 3~ pr~nt~
the outw~r~ t~lescoping ~ovem~nt o~ th- twc~ ~andrel~ w ~umption or any load~ l~y 6pl~t rlng~ 64 ~nd 66 ~u~o~
to ~ov- upwardly over lan~l- 58, 60 ~nd 62 ~I rlng 64 ~bovo l~nd ~2 ~nd into ~ng~e7~nt ~t~ thc sguar upper s~dQ o~ l~nd 62 as shown ln FIaUR~ 2B. Upon co~pl~tion o~
2~ tl~l~ s~ttlng, ~rle-æure i~ ~uppli~d t~rough pa5sag~ 124 to ~ lowcr ~nd o~ ~or- ~00 to cause c~ls~g ~lug 106 to ~o~r-upwAr~ and thu- remov- lts 8uppo~t; for 1~.2g~ 97. ~ plug ~06 re~ov~ th- ;pr~ng- blasing l~g~ 97 ~n~ard~y wlll ~o~e the~ ~acX to ~cheir ~ ltlon out of engagement wlt~ r~ ;
7~ n tool 8~1 ~8 re~
In th~ vent ttlat it 1- dQ~ir~d to re~o~rs h~sl~r 22 and tl~b~cX a~apt-x 20 ~ro~ upp~r ond o~ r ti~back ca~inq ~trln~ erl tool ~26 ~hown ln ~ 8 l~e~.
Tool ~26 ha~ ~ub6tantially tbQ ~ lower tubu~ar ~ou61ng 128 ~ houu~ln~ 102 but include~ a 6ilDpl~ tubular ~andr~l 130 tt~are~or. No ~ctu~tor 12~ pro~lcle~ th tool 12~. Sn F~CU~ 6, pa~t~ are tb~ ~a~ a- pr~rlou~ly d~-crl~ed h~ o been s~lve~ th- ~o nw:~r- ~nd c~ng~ part~ ~r~
~scrl~d an~ g~en n~ numb~r~ r~t~lo~ al l~
nc¢om~ h~ ~y landin~ tool 126 ~Irithln hang~r ~2 ~nd ~d~pt~r 20, ottln~ lug- 97, ~ rting ~ lon on ~crlng 18 to r~llov~ load on t~l- ra~ch-tlng l~t~b DQan!- end " _9_ 2~g~ 79 t~ero~ter ro~a~on o~ h~ger 22 w111 c~u~ d~ng of ~e connectlon ~etween upper ~nd lower t~ula~ hous~n~
88 and 102.
In th~ $ed ~or~ o~ tl~e pre~ent ~nyQr~tlon 8hown ~n ~IGU~ES 'tA, 7B ~d 7C, tleba~:k ~y~t~ 150 1~
sub~tantially tll- 6ama a~ cy6t~ 10 pre~louBly de~cr~bed an~ tbQ ~i~ilar parts ~Ir- ~v~n t~ ~a~Q numer~cal de6~gnat~ ons a~ ~o~e usQd vlth re~pect to ~yfito~ 10.
Metal-to-~netal ~eal~ng ~ean~ 152 between Upp~ ~nd lower tu2~u~ar ~andrele 26 and 28 includ~ w~dgo ~haF~d ring 15~
wh~ch ~ po~lti~nQd betv~ taper~d ~ur~c~ 156 on th-~xterior o~ lo~r tubular ~andr~l 2B and cy~indr$~1 ~urfac~ 158 Yhid~ i- on tb- lnterior ot th~ lower end Or UppQr tubul~r ~andrel 26. Sett~ng sl~v- 160 i8 po~i~lonod on t~ lnt~r~or o~ upp~r tubular ~andrel 26 and i- tbr-n~Qd lnto thre~d~d ~x~c~ 162 on the xt~r~or o th~ lo~ r tubul~r m~narel 2B. Sotting ~le~e 160 ln~ud-~ lover rl~
~ hi~ engage- w-d~ 6e~ ring ~S4 an~ ~h~n prop~rly rotat-d w~l Porcs rin~ 154 downward ~n th- narro~ing ~paGQ
betwe~n ~urSaca- 156 ~n~ 15~ to orcg lt into tig~t ~e~l$ng engage3e~t thereb~twQen. T~ls provides an ~roved ~tal-to-metsl se~l to Rn~urs t~at th-r~ i- no co~unlc~tion between th- ~nnulus b~tweQn outer tiebac~ casln~ ~rlnq and ~nner ~lebask ~ g ~tslnQ an~ the lntsr~or oS ~fln~r t~Qbac~c c slr,g Istr~g. ~ 18 vell ~ t th~ pre65Ur-~h~d 1B ~110Wed to be ~rte~ upon outQr tl-bac~ ca6ing ~tr~ng ~ ~uch l~wer than th- pres~ur~ whlch i9 ~llow~ to b- eY~rte~ wlt~in lnne~ t~bac~ c~ing ~tring.
As 8hoYn ~n FICURES 3A, 8B ~n~ 8C, too~ 170 ~ us~
~or thi~ rotat~on an~ lncludco annular actuato~ 172 Yhi lnclud~ pln- 174 pro~otlng ~nw~r~ ~n tbo low ~o~tlon Or pls~on 176 lnto 910t- 177 ln u~r tubula~ ~ou-~ng 17~ of tool 170. Thi~ caufies ~ rel~tlv~ rotation bqtYe~n torqu-drlvo 180 ~ich 1~ ~ounted on ~le~- Yh~ch l~ h~ld by ~y and ~lot ~tructur~- to ~ovo v~th pi~ton 176 ~h~ch rot~t~d by th n~ag~nt o~ p~n~ 1~4 ln ~loC~ 177.

Claims (8)

1. A tieback system (10) between a subsea well and a surface platform, comprising an outer tieback casing string (12) connected to the subsea well, an inner tieback casing string (18) connected to the subsea well, a head (14) at the upper end of the outer casing string having an internal landing seat (16), a hanger (22), a tieback adapter (20) having an upper tubular mandrel (26) connecting to the hanger at the upper end of said upper mandrel and a lower tubular mandrel (28) connecting to the inner tieback casing string at the lower end of said lower mandrel, means (30) slidably connecting the upper tubular mandrel to the lower tubular mandrel for inward and outward telescoping movement thereof, a tool for providing relative movement between said upper and lower mandrels, a ratcheting latch having a thread (40) on one of said mandrels and movable ratcheting latch means (64,66) on the other mandrel, said movable latch means being cammed out of engagement by the inward telescoping movement of said mandrels and locking against outward telescoping movement of said mandrels, and a tool (84) for engaging said hanger and said lower mandrel to cause inward telescoping movement of said mandrels, to seat said hanger on said landing seat and to apply tension to said inner tieback casing string.

2. A tieback adapter for connecting between a hanger (22) and an inner tieback casing string (18), comprising an upper tubular mandrel (26) connecting to the hanger at the upper end of said upper mandrel, a lower tubular mandrel (28) connecting to the inner tieback casing string at the lower end of said lower mandrel, means (30) slidably connecting the upper tubular mandrel to the lower tubular mandrel for inward and outward telescoping movement thereof, and a ratcheting latch having a thread (40) on one of said mandrels and movable ratcheting latch means (64,66) on the other mandrel, said movable latch means being cammed out of engagement by the inward telescoping movement of said mandrels and locking against outward telescoping movement of said mandrels.

3. A tieback adapter according to claim 2, including an annular metal-to-metal seal (46-52) between said tubular members to prevent leakage of pressure fluids therebetween.

4. A tieback adapter according to claim 2 or claim 3, including a tool (84) for providing relative movement between said upper and lower mandrels.

5. A tieback adapter according to claim 4, wherein said tool also includes means (114,116) for testing the sealing of said annular metal-to-metal seal.

6. A tieback adapter according to claim 5, wherein said tool includes a hydraulic actuator (86) to provide said relative movement.

7. A tieback adapter according to any of claims 4 to 6, wherein said tool also includes means providing relative rotation between said tubular mandrels to wedge said seal into sealing engagement between said mandrels.

8. A tieback adapter according to claim 2, wherein one of said tubular mandrels includes an internal sealing surface (46), the other of said tubular mandrels includes a seal (52) engaging said sealing surface, and a protection sleeve (76) positioned within said internal sealing surface in protecting relationship thereto and having means for collapsing said sleeve away from said internal sealing surface responsive to the inward telescoping movement of said inner and outer tubular mandrels.