áp dụng hệ dung dịch khoan polime ít sét để thi công các giếng khoan có góc nghiêng lớn qua địa tầng oligoxen dưới và tầng đá móng mỏ bạch hổ

Hoi nghj KHCN 2000 "Nginh Dad khi Viet Nam trifdc them theky2r AP DUNG HE DUNG DICH KHOAN POLIME IT SET e^ THI CONG CAC GIENG KHOAN CO GOC NGHIENG LON QUA DIA TANG OLIGOXEN W(^\ Vk TANG DA MONG MO BAC[.]

Hoi nghj KHCN 2000 "Nginh Dad khi Viet Nam trifdc them theky2r

AP DUNG HE DUNG DICH KHOAN POLIME IT SET e^ THI CONG CAC GIENG KHOAN CO GOC NGHIENG LON

QUA DIA TANG OLIGOXEN W(^\ Vk TANG DA MONG MO BACH HO

TS Ngo Van Tu

KS Nguyen Trong Nghiem

XNLD Vietsovpetro

TOM TAT

He dung dich khoan polime phi set ANCO - 2000 da dugc chinh thirc dua vao ap dung thanh cong dethi cong nhUng gieng khoan ngang a mo Bach Ho Tuy nhien, ben canh nhdng uu diem co dugc, ANCO - 2000 con boc lo mot

so nhugc diem, nhu do anh huang cua nhiet do cao, cau true dung dich tra nen kem ben vUng De on dinh cac thdng

so luu bien da phai tieu ton mot lugng iOn hoa pham polime tao cau triic de xir ly trong qua trinh khoan Ngoai ra, khi khoan qua cac iOp dat da phi set (da granit) do khong du kha nang tao ra igp vd set ngan each ben vUng co do tham nho tren thanh gieng khoan nen dung dich de" tham mat vao via, dac biet la khi gap tang da mong nui ne, tu do gay nen hien tugng bit via, lam anh huang den qua tnnh ggi dong va giam san lugng khai thac ban dau ciia gieng

De khae phuc nhCtng han che noi tren, Vien NCKH&TK Dau khi bien da nghien cdu va dua vao ap dung he dung dich khoan mgi - he polime it set He dung dich khoan mdi co cac thong so ky thuat toi uu, cau true ben vCrng, on dinh a nhiet do cao, va dae biet phii hgp cho thi cong qua dia tang Oligoxen duOi va tang da mong nut ne ke ca trong trugng hgp co goc nghieng iOn (ign han 45°) He dung dich polime it set khong gay nhiem ban va lam hu hai doi vgi cac tang chda trong qua trinh khoan

M6OAU

Cdng tac thi cdng gieng khoan cd gdc xien Idn (gieng khoan ngang) da dugc ehinh thirc dua vao hoat

ddng tai md Bach Hd ke ttr nam 1995 Mpt trong nht/ng yeu td dac biet quan trpng gdp phan vao thanh cdng

trong thi cdng cac gie'ng khoan ngang la viec ap dung dung cdng nghe dung djch khoan He dung djch

polime phi set ANCO - 2000 da dugc dua vao sir dung thanh cdng de thi cdng mdt sd gie'ng khoan cd gdc

nghieng Idn han 45° qua cac dja tang Mioxen va Oligoxen md Bach Hd (GK 815,1010, 917, 919, v.v )

Tuy nhien, ben canh nhUng uu diem cd dugc, he polime phi set ANCO - 2000 cdn cd mpt sd mat han

che, dd la:

• d nhiet dp cao, cac polime bj phan hiiy nhanh, vi vay, de duy tri dn djnh cau true, he polime sir dung de

xir ly trong qua trinh khoan se tieu tdn nhieu han, ttr dd dan den tang gia thanh chi phi dung dich khoan

• Khi thi cdng qua tang da mdng nirt ne, dung djch polime phi set khdng cd kha nang tao Idp vd set ngan

each tren thanh gie'ng khoan, do do dung djch de bj tha'm mat vao via, mat khae, do anh hudng rat

manh bdi nhiet dp cao nen Idp vd bun xi mang hda tren thanh gieng ed tinh tai xdp khdng dii kha nang

han che, ngan ngira su xam nhap ciia dung djch hoae nude thai vao via, dan den hau qua anh hudng

xau den tinh chat tham chira tu nhien ciia tang san pham

Oe giai quyet nhiem vu dat ra cho viec thi cdng cac gieng khoan cd gdc nghieng Idn d tang da mdng

va tang Oligoxen dudi, Vien NCKH&TK Dau khi bien da nghien ciru va dua vao ap dung he dung djch khoan

mdi - he polime it set cd ham lugng pha ran thap

Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky2r

T H A N H P H A N P H A C H E V A C A C OAC TINH KY THUAT CUA HE DUNG DjCH POLIME IT bET

He dung dich polime it set cd cac thanh phan: set bentonit API, xanthanbiopolime, polimesihc hiru ca (KOR), caeboxyl metyl xenluld (CMC - HV), chat bdi tran, chat diet khuan Set bentom' API va xanthanbiopolime cd tac dung tuang hd lam tang dp ben cau true va dn dinh d nhiet dp cao, dan; bao cho dung dich cd tinh chat chay loang tdt, Caeboxyl metyl xenluld lam giam dd thai nude va lam tang do nhdt bieu kien ciia dung dich khoan Phu gia bdi tran de giam ma sat giua bd khoan eg, dng chdng va thanh gieng khoan Chat diet khuan nham ngan ngira va han che su phan rCfa do vi khuan doi vcri cac hap chat gdc polime Tinh kiem va dd mdm cua nude dugc dam bao nhd KOH va NaHCO, Khae vdi he dung dich polime phi set, trong he dung dich polime it set, hgp chat polime silic huu ca ngoai tac dung ire che set con tang tinh ky nude be mat dat da thanh he, miin da khoan va cac pha trong dung dich,

Cdng thirc hda hpc ciia polime silic huu ca dugc neu dudi day:

R R

Na 0 [ Si 0 Al 0 ] , Si 0

-R ONa -R

N = 9-15, R=CH3, C2H5hoacOC,H, Nhd su cd mat cua cac nhdm hydrocacbua no ma khi hao thu len be mat dat da hoae cac pha, Idp mang hap phu dugc tao ra cd be day khoang 3.10-^cm mang tinh ky nuoc [11, Ca che hap phu ciia cac phan tir polime silic huu ca len be mat vat the dugc md ta theo cac Hinh 1 va 2 Odng thdi, cung vdi cac nhom hydrocacbua no, cae nguyen tir silic va nhdm cua hgp chat polime silic hCru ca trong mang hap phu lam tang tinh ben nhiet ciia cac thanh phan trong he dung dich, lam cho he dn djnh d nhi^t dp CEO den 200°C

Hirh 1

Hpi nghi KHCN 2000 " Nganh Dau khi Viet Nam trifdc them theky 21'

Hinh 2 Ben canh nhtrng uu diem ndi tren, lap vd set duac tao ra tren thanh gieng rat mdng, dai, chac, cd dp tham nhd va hoan loan ky nude, Dac tinh nay ddng vai trd rat quan trong nhim gop phan han che su xam nhap cua nude thai dung dich hoae chinh dung dich khoan vao via do dd giam thieu anh hudng xau den cac tinh chat tham ddi vdi dau eiia via, dac biet la ddi vdi cac tang dat da granit nirt ne, phi set Nhd cd tinh ky nude ciia polime silic hti'u ca va tinh ua nude tU trung binh trd len ciia cac mao dan thudc tang da granit nirt

ne md Bach Hd [2] nen khi bj nuac thai xam nhap tren thanh cac d'ng mao dan se duac phii bdi Idp mang ky nude, ngan ngira sutao nhO tuong dau - nude, Oieu nay rat quan trong trong qua tnnh goi ddng san pham, Cac dac tinh ky thuat nhan duac trong dieu kien phdng thi nghiem cd so sanh vdi he ANCO - 2000,

he dung djch set va dung dich \ic che ky nude KR - 22 dugc neu d Bang 1 Ket qua d Bang 1 cho thay, cac

thdng sd dung djch dat dugc, dae biet la tinh chat luu bien (irng luc cat tinh, luc cat ddng Yp, dp nhdt deo, v.v.,.) hoan toan phti hgp vdi yeu cau thiet ke dung dich cho thi cdng cac gie'ng khoan cd gdc nghieng Idn, Ngoai ra, dieu dd dang nhan thay d day la, he dung djch polime it set cd ty trpng rat thap: y = 1,01 ^ 1,03g/cm^ va chi sd doc d toe dd Gvong/phut (do bang may FANN - 35A) dat dugc tu 8 -10 d nhiet dd 150°C trong thdi gian nung 3 gid, Oay la thdng sd luu bien cd tam quan trpng dae biet, gdp phan lam sach gieng, ngan ngua hien tuang tao ldp miin set d cac khoang chieu sau cd gdc xien lan

KET QUA AP DUNG DUNG DjCH POLIME IT SET TAI THLfC DjA

Tren ca sd phan tich va danh gia cac ket qua nghien ciru thi nghiem, he dung djch polime it set da dugc dua vao ap dung thir nghiem de thi edng GK 428 md Bach Ho Mae dii dac diem dia chat va dieu kien thi cdng GK 428 rat phirc tap nhu qua tang da mdng nirt ne, thudng xuyen xay ra mat dung dieh tu ro ri den tram trpng nhiet dd day gieng cao den 160°C, gdc nghieng rat lan, d chieu sau 4448m gdc nghieng dat tdi 84° Song, vai cac thdng sd dung djch phii hgp va dn dinh nen qua trinh thi cdng da didn ra an toan va gieng khoan da dat den chieu sau thiet ke sdm han thdi ban so vdi du kien Cac thdng sd ky thuat ciia dung dich polime it set duoc neu 6 Bang 2

Hoi nghi KHCN 2000 "Nganh Dad khi Viet Nam trifdc them theky 21'

Bang 1: Cae thdng sd ky thuat cua dung djch thu nhan dugc trong qua trinh khoan

Ten cac chi tieu

Trpng lugng rieng, g/cm^

Op nhdt tuang ddi, s

Op thoat nude API, ml

Cfng luc cat tinh, dyn/cm^

Sau 1 phut

Sau 10 phut

Op nhdt deo, eps-PV

D'ng luc eat dpng, YP,Lbf/100ft^

Ham lugng keo, % (theo the tich)

He sd ma sat

Chi sd dpc d tdc dp 6 vdng/phut

(theo may FANN - 35A - API)

Theo yeu cau thiet ke

-40-80 4-8

5-15 15-20

*CNCT

-<2,5

*CNCT

**

Thirc te

GK1011 1,04-1,05 35-50 4-5

9-15 13-20 25-30 17-20 2,9 0,15-0,18 3-4

GK1010 1,2-1,3 40-50 3,5-4,5

30-80 50-100 30-40 40-45 1-1,3 0,12-0,15 10-12

GK428 1,02-1,04 40-60 4-6

7-15 12-28 10-20 30-40 1-1,5 0,10-0,12 8-10

GK1016 1,10-1,70 50-80 4-6

7-15 15-30 30-40 40-45 1,0-1,3 0,03-0,08 10-12

Ghi chii: *CNCT - Cang nhd cang tdt

" C h i sd dpc a tdc dp 6 vdng/phtit ciia dung djch de khoan cac khoang chieu sau cd gdc nghieng Idn han 45° phai Idn han 8

Bang 2: Cac chi tieu ky thuat ciia he dung djch polime it set cd so sanh vdi cac he da ap dung d XNLD Vietsovpetro

TT

1

3

4

5

6

7

8

9

Chi tieu ky thuat

Trpng lugng rieng, g/em^

Op nhdt tuang ddi, s

Dp thoat nude API, ml

CTng luc cat tinh, dyn/cm^

Sau 1 phut Sau 10 phiit

Dp nhdt deo, (PV), cps

Op nhdt ddng, YP,Lbf/100ft2

Ham lugng keo, (col) % (tinh

theo the tieh)

He sd ma sat

Chi sd dpc d tdc dp 6 vdng /

phiit (theo may FANN 35A

-API)

Yeu cau

thiet ke cho khoang khoan

-40-60 4-8

7-15 15-25

*CNCT 25-35

<2,5

*CNCT

**

Cac he dung djch sir dung cr XNLD

Dung djch set lignosulfonat

1,05-1,06 25-35 4-5

9-15 13-20 25-30 17-20 2,9 0,25-0,3 3-4

Dung djch \sc

che ky nude KR-22 1,05-1,06 25-35 4-5

9-15 13-20 30-40 40-45 1,7-2 0,2-0,25 3-4

Dung djch polime phi set ANCO-2000 1,01-1,02 40-60 4-5

7-15 15-25 10-20 30-40 1-1,3 0,1-0,2 8-10

Dung dich polime it set 1,01-1,02 40-60 4-5

7-15 15-25 25-35 35-40 1-1,3 0,08-0,12 8-10

Ghi chu: * CNCT - Cang nhd cang tdt

" Chi sd dpc b tdc dp 6 vdng/phut ciia dung djch de khoan cac khoang chieu sau cd gdc nghieng

Idn han 45° phai Idn han 8

Hoi nghj KHCN 2000 "Nganh Dad khi Viet Nam trifdc them theky 21'

Qua phan tich cac thdng sd ky thuat ciia cac he dung djch khoan khae nhau dugc ap dung de thi cdng cac gieng khoan qua dja tang Oligoxen dudi va mdng d XNLD Vietsovpetro d Bang 2 chiing ta nhan thay, he dung djch polime it set cd cac tinh chat dae trung (tinh luu bie'n, bdi tran, v.v ) tuang tu nhu ciia he dung djch ANCO - 2000 Oieu khae biet d he dung djch polime it set la trong thanh phan ciia nd cd chira hgp chat polime silic hiru ca nen he cd tinh dn djnh nhiet tdt han so vdi he ANCO - 2000 Oieu nay da duge khang dinh qua thue te thi cdng d mdt sd gieng khoan d md Bach Hd (GK 428,1016, 477, v.v ) Nhd nhu'ng dac tinh uu viet dat dugc ma he dung djch polime it set da ap dung thanh cdng khdng nhtrng cho cac gieng khoan xien ma cdn cho ca cac gie'ng khoan ed gdc nghieng Idn

HIEU QUA KINH TE - KY THUAT CUA VIEC AP DIJNG HE DUNG DjCH POLIME IT S f T KHI THI CONG QUA CAC OIA TANG OLIGOXEN DLTOI VA TANG MONG CO GOC NGHIENG LON 6 M 6 BACH HO

Hieu qua kinh te - ky thuat ciia viec ap dung he dung djch polime it set cd the dugc danh gia can cir vao nhu'ng yeu td sau day:

• Gia thanh chi phi dung djch tren mpt met khoan hoae gia thanh chi phi de dieu che va xir ly 1m^ dung djch khoan

• Tang van tdc ea hpc va van tdc thuang mai do ngan ngira cac su cd hoae tinh hudng phirc tap trong qua trinh khoan

• Anh hudng den chat lugng md via san pham, dac biet la luu lugng khai thac ban dau ciia gie'ng

Qua thue te thi cdng GK 428 va GK 1016 md Bach Ho bang he dung djch polime it set, ddng thdi qua tinh toan gia thanh chi phi eho tieu hao hda pham de dieu che va xir ly 1 m^ dung djch khoan va gia thanh ehi phi dung djch cho 1m khoan (Bang 3) cho thay, gia thanh chi phi cho 1m^ ciia he dung djch polime it set trung binh nhd han hai lan so vdi he polime phi set (ANCO - 2000) va khdng khae xa so vdi sir dung dung djch set ire che ky nude

Bang 3: Chi phi gia thanh khi ap dung he dung djch polime it set de thi cdng eae gieng khoan d md Bach Ho

Ten gieng

khoan

1011BH

1010BH

428BH

1016BH

He dung djch sir dung

DD ire che ky nude

DD polime phi set

DD polime it set

DD polime it set

Chi phi theo thiet ke

USD/1 m'DD 100,0 220,0 110,0 110,0

USD/lm khoan

-Chi phi theo thirc te

USD/1 m^DD 69.60 175,7 92,0 67,27

USD/lm khoan 68,60 181,2

*235 67,6

* Gieng khoan xay ra mat dung djch tram trpng

Hieu qua kinh te - ky thuat cua viec ap dung he dung djch polime it set edn dugc khang djnh khi thi cdng GK 428 Bach Hd Oay la gieng khoan cd dae diem dja chat phirc tap va dieu kien thi edng khd khan nhu gap dj thudng ap suat thap, thudng xuyen gay ra mat dung djch ttr rd riden tram trpng, gie'ng khoan cd gdc nghieng Idn (den 28°) Song he dung dich polime it set da la mpt trong nhtrng yeu td quan trpng gdp phan nang cao dang ke cac ehi tieu kinh te - ky thuat thi cdng khoan Cu the la theo thiet ke, de dat den chieu sau 4526m, thdi gian djnh muc la 102,5 ngay dem va tdc dp thuang mai la 1323m/thang/may Nhu vay, so vdi thdi gian hoach djnh, thdi gian thi cdng thuc te rut ngan 7 ngay, hieu qua kinh te dem lai xap xi bang 107.290USD

Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky 21'

Anh hudng cua he dung djch polime it set den van tdc ea hpc khoan cdn dugc chirng minh khi thi edng GK 1016 Bach Hd ed so sanh vdi mot sd gieng khoan ke can trong ciing dieu kien dia chat va dieu kien thi cdng nhung sir dung he dung djch khae Van tdc ca hpc khi md via Oligoxen dudi ciia GK 1016 dat tdi 2,4m/h, nhanh han so vdi van tdc ca hpc trung binh khi khoan cac gieng 1009, 1014, 1003, 1013 (Vmex.tb = 2,2m/h)

Ben canh lgi ich tren, khi dua gieng khoan vao thir gie'ng gpi ddng, luu lugng ban dau ciia gie'ng dat den 900 tan/ngay dem (Bang 4)

Bang 4: Ket qua thir gie'ng gpi ddng ciia cac gie'ng khoan dugc xir ly bang cae he dung djch khoan khae

nhau d XNLD Vietsovpetro

STT

1

3

4

Ten gieng khoan

438 Xakhalin

436 Xakhalin

437 Xakhalin

428 Ciru Long

Doi tugng khoan

Tang mdng

-nt-Hedung djch sir dung

Set lignosulfonat -nt-Polime it set

Liru lirgng khai thac ban dau

720 tan/ngay dem

470 tan/ngay dem

650 tan/ngay dem

900 tan/ngay dem K^T LUAN

He dung djch khoan it set ed ham lugng pha ran thap ndi chung va he dung djch khoan polime it set dugc xir ly bang hgp chat polime silic hti'u ca (KOP) ndi rieng cho den thdi diem hien tai ngay cang khang djnh y nghla thue tien va khoa hpc cao eua nd, dd la:

1 0am bao an toan eho qua trinh thi cdng, dac biet la khoan qua cac doan chieu sau cd gdc nghieng Idn, nhiet dp day gieng cao, ke ca cac he tang chura set hoat tinh (Oligoxen dudi) va he tang phi set ed tinh nurt ne Idn (tang da mdng)

2 Ap dung he dung dich khoan polime it set dugc xir ly bang hgp chat polome silic hQu eg (KOP) da gdp phan lam tang van tdc thuang mai khoan

3 He dung djch khoan polime it set (KOP) it gay nhidm ban via vi vay khoan md via san pham bang dung djch ndi tren se gdp phan tang kha nang bao tdn eae tinh chat tham chira tu nhien ddi vdi dau khi, tU dd dan den tang kha nang khai thac ban dau ciia gie'ng

4 Cdng nghe dieu che va xir ly he dung djch khoan polime it set rat dan gian va thuan tien, vi vay ed the dugc cho phep sir dung trong mpi dieu kien thiet bj va dac thii thi cdng d XNLD Vietsovpetro

KpCMHMM opraHM^ecKMc nOJIHMepbl H MX

TAI LIEU THAM KHAO

npHMCHeHHe, MocKBa, I960

2 Tran Le Odng, Pham Anh Tuan, Martyntsiv O.F Tinh dinh udt va cac tinh chat mao dan cua collector

da mong nirt ne mo Bach Ho Tap chi Dau khi, sd 4/1993