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BI GING CNG NGH KHAI THC DU KH

HON THIN GING KHAI THC

Ging vin : Email Tel : :

PGS.TS. L Phc Ho [email protected] 84-8-8654086

NI DUNG+ Phn loi + Cc phng php hon thin + Tnh ton thit k + Dung dch hon thin ging + Bn m va + Gi dng sn phm

Cng ngh khai thc du kh

159

PGS. TS. L Phc Ho

PHN LOI+ Theo s tng khai thc: n tng, a tng + Theo s cn khai thc: Cn n, cn i, cn ba + Theo b mt phn cch gia y ging v tng sn phm: . Hon thin ging thn trn . Hon thin ging vi ng lc v chn si . Hon thin ging vi ng chng, trm xi mng v bn m va + Theo phng php khai thc: . T phun . Cc phng php c hc: - Gaslift - Bm ly tm in chm - Bm cn ht - Bm pittng thu lcCng ngh khai thc du kh 160 PGS. TS. L Phc Ho

H S HON THIN GING - tnh ton tn tht p sut gy ra bi cng tc hon thin ging, h s hon thin c b sung ging vo phng trnh dng vo:Vertical or Inclined Tubing Flowing Wellhead Pressure Horizontal Flowline Gas Sales Separator Stock Tank

PR Pwf = A.q0 + B.q02 PR2 Pwf2 = A.qsc + B.qsc2

Intake

Flow Through Porus Media P, K, IPR

Cng ngh khai thc du kh

161

PGS. TS. L Phc Ho

H S HON THIN GING

q0 =

0 . 00708 k 0 .h ( p r p wf )

0 . B 0 [ln( 0 . 472 re / rw ) + S '

qsc =

703.10 k g .h( p r p

6

2

2

wf

)

g .Z .T [ln(0.472re / rw ) + S '

A : h s chy tng B : h s chy ri

Cng ngh khai thc du kh

162

PGS. TS. L Phc Ho

H S HON THIN GING A = AR + AP + AG B = BR + BP + BG AR, BR: cc thnh phn chy tng v ri trong va AP, BP: cc thnh phn chy tng v ri trong l bn AG, BG : cc thnh phn chy tng v ri trong ln si

Cng ngh khai thc du kh

163

PGS. TS. L Phc Ho

HON THIN GING THN TRN - ng chng t trn nc ca tng sn phm, thnh h khng trm xi mng v khng bn m va - Thch hp vi tng sn phm c chiu dy ln, cu to bi loi cng, vng chc khng b sp l - Cc u nhc im (tham kho C s khoan & khai thc du kh)Cng ngh khai thc du kh 164 PGS. TS. L Phc Ho

H THNG IM NT3 P 3-1 = P wh - P sep ) 1

Node 1 3 6 8

Location Separator Wellhead Pwf Pr

P 6-3 = (P wf - P wh )

P 8-6 = (P r - P wf ) 6 8

Cng ngh khai thc du kh

165

PGS. TS. L Phc Ho

H S HON THIN GING nh hng ca qu trnh hon thin ging n c tnh dng chy l lm thay i h s thm ca va do b nhim bn hoc c kch thch

141.2 0 .B0 0.472re [ln + Sd i vi du: AR = k 0 R .h rwi vi kh: AR =

141.2 g .Z .T k gR .h166

0.472re [ln + Sd rwPGS. TS. L Phc Ho

Cng ngh khai thc du kh

H S HON THIN GINGSd = (kR/kd -1)ln(rd/rw) koR: thm khng i ca va i vi du kgR: thm khng i ca va i vi kh Sd: h s skin do thay i thm xung quanh ging kR: thm ca va kD: thm ca vng nhim bn rw: bn knh ging rd: bn knh vng b nhim bn

Cng ngh khai thc du kh

167

PGS. TS. L Phc Ho

H S HON THIN GING Ta tnh BR t cc phng trnh sau: i vi du: BR= i vi kh: BR=2 . 3 10 14

R . B 02 . 12 2

0

h 2 .r w

3.161 10

R . g .Z .T10

h .rwH s vn tc

2.33 10 R = 1, 2 kR168

Cng ngh khai thc du kh

PGS. TS. L Phc Ho

HON THIN BNG NG CHNG LNG, C L V LN SI - Trong va trm tch, xi mng gn kt gia cc ht yu dn nn ct s theo dng sn phm vo ging -S dng ng chng lng c c l i din vi tng sn phm - Vnh xuyn gia thn ging v ng lng c ln y ct th hn ct va - Hu ht cc ging c ln si c thm cao do tnh khng gn kt t nhin ca si ln - Si ln lm gim tn tht p sut do vng nn p gy ra xung quanh l lc - Sau mt thi gian khai thc, tn tht p sut ca dng chy dc theo nhng l lc b lp y ct s tng ng kCng ngh khai thc du kh 169 PGS. TS. L Phc Ho

H THNG IM NT3 2 1A

4

1 1B

Node 1 2 3 4 5 6 7 8 1A 1B

Location Separator Surface Choke Wellhead Safety Valve Restriction Pwf Pwfs Pr Gas Sales Stock Tank

Remarks Functional Functional Functional

5

6

7

8

Cng ngh khai thc du kh

170

PGS. TS. L Phc Ho

H S HON THIN GING- i vi du: AG= BG=

282.4 0 .B0 .L kG .N .rP2 9.21014GB20.0L4 N2.rP

2844 Z . G . L - i vi kh: AG= k G . N .r P2N: tng s l bn kG: thm ca si ln L: chiu di knh dn ca l bnCng ngh khai thc du kh

BG=

1.263 10 11 G g .Z .T .L N 2 .rP4 1.47 107 G = 0 k G., 55171 PGS. TS. L Phc Ho

H S HON THIN GING Chiu di knh dn bng hiu gia bn knh ging khoan v bn knh ngoi ca ng lc (hay bn knh ging khoan tr bn knh trong ca ng chng). phn tch cng tc hon thin ging bng ng lc c ln si, cn tch hai thnh phn tn tht p sut trong va v tn tht dc theo lp si ln: PR Pwf = PR- Pwfs + (Pwfs- Pwf)Cng ngh khai thc du kh 172 PGS. TS. L Phc Ho

H S HON THIN GING Phng trnh biu din hai loi tn tht p sut ny c dng: i vi du: PR- Pwfs = AR.q0 + GR.q02 Pwfs- Pwf = AG.q0 + BG.q02 i vi kh: PR2- Pwfs2 = AR.qsc + BR.qsc2 Pwfs2- Pwf2 = AG.qsc + BG.qsc2

Cng ngh khai thc du kh

173

PGS. TS. L Phc Ho

HON THIN GING BNG NG CHNG, TRM XI MNG V BN M VA- Chiu di ng chng khai thc c t sut thnh h v xi mng phi c lp y khong khng vnh xuyn gia ng chng v thnh ging khoan - Cho php chn la tng cn bn m va - Dng cho ging su, thnh h yu v km bn vng - Vn quan trng nht l xc nh hiu sut bn m va. Hiu qu ca cng tc hon thin ph thuc vo: s lng l bn, kch thc v chiu su l bn , kiu l bn, gc pha - S nn p ca thnh h xung quanh l bn sau khi bn va c th lm gim ng k hiu qu hon thin ging - Cn xc nh chnh xc khong bn m va, trnh cc vng c thnh h qu yu hoc khng c sn phm, trnh dng cht lu khng mong mun chy vo

Cng ngh khai thc du kh

174

PGS. TS. L Phc Ho

H S HON THIN GINGHiu qu ca cng tc hon thin ging ph thuc vo c va v l bn PR- Pwf = (AR + AP) + (BR + BP)q02 PR2 Pwf2 = (AR + AP)qsc + (BR + BP)qsc2 Thnh phn chy tng trong l bn bao gm nh hng ca mt v kiu l bn, nh hng ca s nn cht xung quanh l bn. Nhng nh hng ny c tnh n trong cc phng trnh:Cng ngh khai thc du kh 175 PGS. TS. L Phc Ho

H THNG IM NTPwh P8 P6 P5 PsepSeparator Stock Tank Gas Sales

P DSV P4 P USV P7

P DR P3 P UR

P1 = (Pr - Pwfs) P2 = (Pwfs - Pwf) P3 = (P UR - P DR ) P4 = (P USV - P DSV ) P5 = (Pwh - P DSC ) P6 = (P DSC - Psep) P7 = (Pwf - Pwh) P8 = (Pwh - Psep)

= Loss in Porus Medium = Loss across Completion = Loss across Restriction = Loss across Safety Valve = Loss across Surface Choke = Loss in Flowline = Total Loss in Tubing = Total Loss in Flowline

Pwf P2

Pwfs P1

Pr

Cng ngh khai thc du kh

176

PGS. TS. L Phc Ho

H S HON THIN GINGi vi du: AP =

i vi kh: AP =

141 2 0 .B 0 ( S P + S dp ) k 0 R .h 141 2 g .Z .T ( S P + S dp ) k gR .h h h 1 ln h r P w kR k v 0 .5

Khi bit thm dc: SP =

h: chiu di tng cng ca va, ft

2

hp: chiu di khang bn m va, ft kR thm ca va theo phng ngang, md K: thm dc, mdCng ngh khai thc du kh 177 PGS. TS. L Phc Ho

DNG CHY DC THEO VNG B NN P

h SdP= L .N P

k R k R rdP k k ln r d P dP

h chiu dy tng cng ca va, ft Lp chiu di l bn, ft N: tng s l bn kR: thm va, md kdp: thm vng b nn p, md rP: bn knh l bn, in rdP: bn knh vng b nn p, inCng ngh khai thc du kh 178 PGS. TS. L Phc Ho

DNG CHY DC THEO VNG B NN P - Phn tn tht p sut ln nht dc theo l bn l do dng chy ri qua vng b nn p. Cc phng trnh: +i vi du:BP = + i vi kh: BP =

2 .3 10 . dP B . 0 rP2 .L2 . N 2 P 14 2 0

3 .161 10 12 dP . g .Z .T rP . L . N2 . 33 10 10 = 1 ., k dP 2179 PGS. TS. L Phc Ho

2 P

2

+ H s vn tc: dPCng ngh khai thc du kh

VA XI MNGPh thuc vo: Nhit tnh y ging khoan quy nh thi gian ng cng (thi gian c th bm phun xi mng) Nhit tun hon y ging khoan (s lm thay i thi gian ng cng) T trng ph thuc vo p lc a tnh ca mt s tng t khoan qua nht do ca va v c tnh lc ca n Cc thng s lu bin ca va Thi gian ng cng v gia tng bn chu nn bn ca xi mng v cc nhn t khc nhau c th lm h hi n (nc va n mn, nhit cao) - Va s dng ch yu gm xi mng v nc, c thm mt s cht ph gia - Chng loi xi mng s dng tu thuc vo chiu su v nht l nhit y ging khoan v c th tip xc vi nc va n mn - Cc loi xi mng v iu kin s dng (xem sch C s khoan v khai thc du kh)Cng ngh khai thc du kh 180 PGS. TS. L Phc Ho

HIN TNG NGM NC CA XI MNG- Qu trnh: bt u t thnh phn khan vi cc cht km n nh ri ti cc cht n nh hn. - Khi lng nc khng , cc thnh phn ny kt tinh li v to ra s ho tan mi ca cc thnh phn khan. Nh vy s xy ra s lin kt dn dn ca cc tinh th hnh kim cho n khi ng cng ton b h thng. - Mt s yu t tc ng n s ngm nc ca xi mng: Nhit : nh hng rt ln n vn tc ngm nc ca xi mng. Khi nhit tng s lm gim thi gian ng cng xi mng p lc: s ngm nc tng theo p lc

Cng ngh khai thc du kh

181

PGS. TS. L Phc Ho

S NHIM BN- Xy ra trong qu trnh trn vi nc dng hoc trn ln vi cc cht lng c trong ging khoan - Mi s thay i tnh cn bng trong pha c nc do b sung m khng kim tra cc nguyn t tan c hoc khng tan u tc ng n vic ngm nc ca xi mng nh NaOH, Na2CO3 Na2SiO3 lm tng nhanh qu trnh ng cng (kh c th d on c)

Cng ngh khai thc du kh

182

PGS. TS. L Phc Ho

CC CHT PH GIA- Cht lm ng nhanh: lm tng nhanh qu trnh ng cng xi mng nhit thp hoc khc phc hiu ng lm ng chm ca cc cht ph gia khc, cho php gim thi gian ch i trc khi khoan tip - Cht lm ng chm: lm chm qu trnh ng cng ca xi mng, tng thi gian bm va khi nhit y ging cao hoc hiu ng ca cht ph gia khc c nguy c lm gim ng k thi gian bm va vo ging - Cht lm nh: khi trn vi xi mng th gy hiu ng lm gim t trng va ng thi gim gi thnh nhng nh hng n thi gian ng cng v sc khng nn ca xi mng nn phi khc phc bng cc cht ph gia thch hp - Cc cht kim sot lc: lm va khng mt nc do lc qua cc tng thm nhng c th gy ra s ng cng khng ng lc hoc ng cng do thiu nc cn thit thu phn v kt tinh cc thnh phn ca xi mngCng ngh khai thc du kh 183 PGS. TS. L Phc Ho

C L NG CHNG TRONG GING C th s dng 1 trong 4 phng php sau: + n + Mn (n lm) + Tia xuyn + Tia thu lc - ct

Cng ngh khai thc du kh

184

PGS. TS. L Phc Ho

C BNG NLoi n c tc dng bn tng lot: to p lc 700KG/cm2 v nhit lm vic l 1270C Loi n c cha thuc n nhm gia tng kh nng c m v hiu qu bn va dy Loi n c tc dng bn ni tip: gim tc ng ca p lc ln ng chng v gi ng chng khi b bin dng v nt v Loi c c tc dng bn tch bit: ch bn tng vin theo th t nh. Loi n ny c s dng bn va sn phm mng v gia chng c xen k bi cc tng cha nc hoc cha st c bng n c s dng cho t khng qu cng v vnh xi mng xung quanh ng chng yuCng ngh khai thc du kh 185 PGS. TS. L Phc Ho

C BNG MN HAY N LM- Loi n lm khc vi cc loi n k trn l thay th u n bng u lm (ng li) c tc dng n chm - u n lm phng ra c ct ng chng v vnh trm xi mng ri tip tc i su vo va n v to thnh nhng khe rnh ph Bn mn nhng lp t cht st v c thm thp

Cng ngh khai thc du kh

186

PGS. TS. L Phc Ho

C BNG TIA XUYN- c bng tia xuyn, cht to n v c sc xuyn rt mnh - Vn tc ca nhng tia n khong 8000- 10000 m/s vi p lc khong 300 triu KG/cm2 - Loi tia xuyn cho php to nhng khe su vo va nn bo m tng thm S dng tt nht cho loi cng, thm km.

Cng ngh khai thc du kh

187

PGS. TS. L Phc Ho

C BNG TIA THY LC - CT- Nc trn ct c tnh mi mn cao c bm qua vi phun ca tht b vi p sut t 1500- 3000 KG/cm2 - Ming ca thit b phun ct c ch to t hp kim rt cng chng mi mn. ng knh ca vi phun khong 3 6 mm - Ct c ng knh t 0.2 1.2 mm - T l ct trong nuc t 50 200 g/l (lng ct khong 8 10 tn/ln x l) - Vn tc c l ct ng chng v t 0.6 0.9 mm/s - Khi bn thu lc ct, thit b ming ging khi lm vic phi t ti 70 MPa v my bm trm xi mng c cng sut ln p hn hp cht lng ct - Nhc im ca phng php bn tia thu lc ct l cn khi lng thit b k thut c cng sut ln v cng tc chun b v tin hnh trn quy m ln, s lng ngi tham gia nhiu nn chi ph rt cao (t c p dng)

Cng ngh khai thc du kh

188

PGS. TS. L Phc Ho

GI DNG SN PHM V QU TRNH KHI NG GING

Ph thuc vo cc yu t: + su ca ging v p sut ca va + Tnh cht ca du hoc kh c trong va + c tnh vt l ca t v mc bn vng ca chng v cu trc ging. + Thit b k thut sn c

Cng ngh khai thc du kh

189

PGS. TS. L Phc Ho

CC PHNG PHP+ Gim t trng ct dung dch trong ging bng cch thay dung dch nh hn nh nc, du, cht lng to bt, cht lng ngm kh + H mc cht lng trong ging: nh my nn kh hoc my bm su, pittng hoc gu mc + Kt hp c 2 phng php (xem C s khoan v khai thc du kh)Cng ngh khai thc du kh 190 PGS. TS. L Phc Ho