International Journal of Advancements in Research & Technology, Volume 2, Issue 12, December ISSN

Transcription

1 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 48 ISSN A SIME ANAYIA MODE FOR ESIMAING OOM HOE RESSURE IN GAS ONDENSAE WES Omhimia hales Uliukhif, M.Sc and Aydele hales O., M.En Depatment f etleum Enineein, Univesity f Ibadan, Nieia. Depatment f Mineal Resuces Enineein, Fedeal lytechnic, Ad-Ekiti, Nieia. chales_4eal@yah.cm, chales..aydele@mail.cm Abstact he pessue paamete is a vey imptant fluid ppety in esevi enineein cmputatins. he success f pessue tansient analysis hweve, en depends n the accuate measuement estimatin f the bttm hle pessue. Knwlede f hw as cndensate and mixtue flw simultaneusly in vetical pipe is necessay. A simple mathematical mdel was used t stimulate multiphase system flw fm sinle phase flw and the cespndin mixin ule t the fluid flw patten f as cndensate was develped that incpates the effects f slippae at the as-liquid inteface. his methd was bette f estimatin the bttm hle pessue f as cndensate wells than the Sukka and nell in tems f deviatin Keywds: ttm hle pessue, as cndensate, pessue tansient, deviatin, multiphase flw Intductin he success f pessue tansient analysis en depends n the accuate measuement estimatin f the bttm hle pessue. Measuement can be accmplished by a descendin pbe. he ability t analytically pedict the pessue at any pint in a flw stin is essential in deteminin ptimum pductin, stin dimensin and in the desin f as li installatins. he pblem f accuate estimatin pessue dps in flwin as li wells have iven ise t many specialized slutins f limited cnditins; the easn bein that the tw phase flw is cmplex and difficult t analyze even f the limited cnditin studied (,,,4) Unde sme cnditins, as mves at a much hihe velcity than the liquid. At the time f discvey as cndensate ae en fund cntainin sinle phase as vapu. As esevis ae bein pduced, the pessue deceases fm the esevi t the wells and t the suface installatins, the dwn hle flwin density f the as liquid mixtue is eate than the cespndin density cected f dwn hle tempeatue and pessue that wuld be calculated fm the pduced as liquid ati. A numbe f methds ae available f accuate estimatin f bttm hle pessue in il well. hese ae based n multiphase mixtue behaved like a hmeneus sinle phase. Hweve, the pyiht 0 SciResub.

2 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 49 ISSN multiphase fluids behaved as hmeneus mixtues; the as and liquid phases wee assumed t tavel at the same velcity, this assumptin is knwn as the n slip cnditin (,6). his methd develped a simple analytical mdel f estimatin bttm hle pessue in as cndensate well. heetical Famewk A simple analytical mdel is develped by adaptin basic Eney Equatin. he basic assumptins wee:. Steady state flw f fluids was cnsideed thuhut the pcess. hane in kinetic eney is small and can be nelected. empeatue f the system is assumed cnstant at sme aveae value 4. Fictin is assumed cnstant ve the lenth f the cnduit Fllwin the basic eney equatin (,) 44Vdp Udu dz α fu d W D s c c c = 0 Assumin n mechanical wk is dne n the fluid by the fluid and chane in kinetic eney is neliible/ Nelectin kinetic eney and sha wk Equatin can be educed t: dz fu 44Vdp d = 0 D c c he appaent density f a multiphase mixtue is defined bsevin mixin ule () tp ( H ) = H he classic appach t the shut-in bttm pessue calculatin iinates fm the pessue adient in a as clumn d dh = 44 4 Density f as ( ) at a pint in a vetical pipe at pessue and tempeatue (5,7,8) he pessue in a vetical pipe at tempeatue with as density ( ) ZR = γ pyiht 0 SciResub.

3 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 50 ISSN he density f the liquid (cndensate and wate) is defined as (6) 6.4γ 0.06γ R 6.4γ h s w w = h 6 w w Mass f well fluid (as and liquid) is defined as () Mass f the fluid = Mass f the as Mass f the liquid M R R ( γ ) 50γ = O in avity as: γ R Rγ 4584γ = 8 R,800γ / MW he mlecula weiht f the k tank il is iven by the fllwin celatin: MW = 960. AI. 894 ( ) 0.06γ Rs h 6.4γ h 8.97 H Substitutin equatin (5) and (6) int t btain tw-phase density/cmbinin equatins (5), (6) and () f tw-phase density ( 6.4γ ) γ ( ) w w tp = H 0 w w ZR he velcity f fluid flw at a css sectin in a vetical pipe (6) U m q q = A ( 5.65) 6 0 q b Z w = q / sec A b ( 5.65) Z 0 qw = q D Π /sec U 0.45q Z wq = 4 D D m pyiht 0 SciResub.

4 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 5 ISSN pyiht 0 SciResub. Replacin equatins (0) and (4) and manipulated int the fllwin fm: = γ w s H Z R Z Z d Z 5 A plt f the as deviatin fact as a functin f pessue and tempeatue, f the dmain f inteest Z m = 6 he equatin (6) can be cmbined with equatin (5) t yield: = γ w s H m R m m d m 7 Result and discussin Equatin (7) is a simple analytical mdel f estimatin bttm hle pessue in as cndensate wells. he esults f bttm hle pessue usin equatin (7) as cmpae with Sukka and nell ae pesented in Fiues and. Equatin (7) mdels accuately bttm hle pessue in as cndensate wells. Fi : f ue Dy Gas and ndensate Fi : Gas nly Fi : ndensate nly

5 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 5 ISSN nclusin Impved analytical mdel f estimatin bttm hle pessue in as cndensate wells has been develped. he mdel has a deviatin f five (5%) pecent as cmpae t existin Sukka and nel that has a deviatin f twenty (0%) pecent. If n liquid is pduced, the mdel falls back f the estimatin f bttm hle pessue in dy as wells. A css sectinal aea f pipe, AI AI avity, deee bbl fmatin vlume fact, stb NOMENAURE D inside diamete f the pipe, f = mdy fictin fact, dimensinless m acceleatin due t avity, sec lbm c cnvesin fact,.7 lbfs γ - specific avity, dimensinless h vlume factin in the liquid H liquid hld up distance aln tubin, (f a vetical flw stin, = Z) M mlecula weiht f ai, pessue, psia lb dp pessue diffeential, R pseud educed pessue q vlumetic flw ate, sec 8.97γ pyiht 0 SciResub.

6 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 5 ISSN R as cnstant 0.7 psia lb mle R tempeatue, R p _ pseud educed tempeatue pc _ citical tempeatue p _ pseud educed pessue pc _ citical pessue U aveae velcity f the fluid, sec V specific vlume f fluid, lbm W s mechanical wk dne n by the as (W s = 0) Z as cmpessibility fact, dimensinless dz incemental depth udu α c - pessue dp due t kinetic eney fu dl - pessue dp due t fictin effects D c lbm - density, α - cectin fact t cmpensate f the vaiatin f velcity ve the tube css sectin. Subscipts b = base = as = liquid pyiht 0 SciResub.

7 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 54 ISSN s = slid = k tank cndensate w = wate REFERENES. Adekmya Olufemi edictin f flwin bttm hle pessue f wells fm the well head, M.Sc thesis, Dept. f etleum Enineein, Univesity f Ibadan, Nieia (007).. axendell,.., he alculatin f essue Gadients in Hih-Rate Flwin Wells. ansactin AIME (96) Vl. ; 0.. aufet A. and Ahmed Rasl and Mhammed, edictin f ttm hle Flwin essue in Multiphase Systems Usin hem-dynamic Equatin f State s 9479 esented at the 95 SE ductin Opeatin held in Oklahma, Apil -4, haath Ra iled ubin Hydaulics Mdelin (May 0 999), p ullende M.H and R.V. Smith actical Slutin f Gas- Flw Equatin f Wells and ipelines with lae empeatue Gadients. ans. AIME 07 pp8-87, Eatn.A. and Knwles.R., he edictin f Flw attens, iquid Hld up and essue sses Occuin Duin ntinuus w-hase Flw in Hizntal ipeline, J (967), Fauk ivan, Includin Nn-Equilibium Effects in Mdel f Rapid Multiphase Flw in wells. ape SE Annual echnical nfeence and Exhibitin held in Hustn, USA, 6-9 Septembe, Fwle F. alculatin f ttm Hle essues, etl En, 9 N., (947) 9. Gee H. Fanche, Jn and wn K.E., edictin f essue Gadients f Multiphase Flw in ubin, ansactin AIME (96) Vl. 8, Gu yun, An Analytical Mdel f Gas-Wate-al paticle Flw in cal bed-methane ductin well, ape SE 769, esented, at the SE Easten Reinal Meetin held in antn, Ohi, 7-9 Octbe, 00.. Haedn A.R. and wn K.E. Expeimental Study f essue Gadients Occuin Duin ntinuus w-hase Flw in Small Diamete Vetical cnduit. J (Apil 965), Ikku Natual Gas Enineein Handbk pyiht 0 SciResub.

8 Intenatinal Junal f Advancements in Reseach & echnly, Vlume, Issue, Decembe-0 55 ISSN Isehunwa O.S. and Falade G.K. Impved haacteizatin f Heptanes lus Factins f iht udes. ape SE, esented at the st Annual SE Intenatinal echnical nfeence and Exhibitin in Abuja, Nieia, Auust 6-8, Michael J. Ecnmides, Shut In and Flwin ttm Hle essue alculatin F Gethemal Stem Wells. Shell Oil mpany Hustn exas, USA. 5. Okiszewski, J edictin w-phase pessue Dp in Vetical ipe. J (June, 967) Osman E.A., Ayub, M.A., and Au, M.A. Atificial Neual Netwk Mdel f edictin ttm Hle essue in Vetical Multiphase Flw, ape SE 96, esented at the 4 th SE middle East Oil and Gas shw and nfeence held in ahain Intenatinal Exhibitin cente, ahain, -5 Mach, ettmann, F.H., and apente..g. Multiphase Flw f Gas, Oil and Wate huh Vetical Stins with Applicatin t the Desin f Gas i Installatin, Dillin and ductin actice 8. Rs N..J. Simultaneus Flw f Gas and iquid as Encunteed in Well ubin. ansactin AIME (96) Vl. ; Sukka Y.K. and nell D. Diect alculatin f ttm Hle essues in Natual Gas Wells. ans. AIME 04 pp 4-48, ek M.R., Multiphase Flw f Wate, Oil and Natual as huh Vetical Stins. ansactin AIME (96) Vl., 09, 05. pyiht 0 SciResub.