822 Cac ygu td anh hudng va giai phap nang cao chat luong tram ximang gieng khoan d bg Cisu Lon^ CAC YEU TO ANH HlTOOVG VA GIAI PHAP NANG CAO C H A T LirONG TRAM XI MANG GIENG KHOAN 6 BE CUtJ LONG Ngu[.]
822 Cac ygu td anh hudng va giai phap nang cao chat luong tram ximang gieng khoan d bg Cisu_Lon^ C A C Y E U T O A N H HlTOOVG VA GIAI PHAP N A N G C A O C H A T L i r O N G T R A M XI M A N G GIENG K H O A N B E C U t J L O N G Nguyin Xuan Hoa Viin Ddu Khi Dinh Huu Khang, Nguyin Van Toan Tdng cdng ty Ddu Viet Nam Hoang Qu6e Khanh XNLD Vietsovpetro Hoang Ba Cuang Cong ty Thdm - Khai thde Ddu TOM TAT Cdc sd lieu tdng hgp vi trdm xi mdng giing khoan bi Cim Long cho thdy chdt lugng trdm xi mdng chua cao, khdng ddng diu, cdn xdy phuc tgp, su cd, dge biit Id xudt hiin dp sudt gida cdc cdt dng chdng qud trinh khai thde, ldm gidm tudi thg giing khoan, tdng chi phi sira chira vd hiiu qud khai thde bi gidm sut Trong bdo cdo, cdc tdc gid da phdn tich chi tiit cdc yiu td dnh hucmg din chdt lugng trdm xi mdng giing khoan nhu: diiu kiin dia chdt - ky thudt, vgt lieu, cdng nghi trdm vd th&i gian ldm vlic ciia giing khoan, trin ca s& di xudt mdt sd gidi phdp cdp thiit nhdm ndng cao chdt lugng trdm xi mdng giing khoan trin khu vuc nghien cim MO DAU Be Ciru Long la khu vue eo nhieu mo dau duge phat hien va dang giai doan phat trien, khai thae nhu Bach H6, R6ng, Rang D6ng, H6ng Ngge, Su Tir Den, Su Tir vang, v.v Dae biet, viee phat hien va khai thac dau d6i tugng da m6ng dang dat kha nhieu birc xue d6i voi viee thi c6ng gieng khoan, co c6ng tac tram xi mang gieng khoan Tren be Ciru Long them lue dia Nam Viet Nam hang tram gieng khoan tham va khai thae da duge thi c6ng vai hang ngan cot 6ng va hang trieu met 6ng da dugc tram xi mang Cac s6 lieu thuc te [1] cho thay c6ng tac tram xi mang gieng khoan eon nhieu bat cap, chat lugng tram chua eao, kh6ng duge d6ng deu, c6n xay sir c6 va phirc tap, nhat la xuat hien ap suat gitra eae cot 6ng eh6ng qua trinh khai thac dan den giam tu6i thg gieng khoan, chi phi t6n kem eho c6ng tae eiru chtra su c6 va sira chtra Ket qua la hieu qua khai thae bi giam sut Chinh vi vay, viec phan tich cac yeu t6 anh huang de tim cae giai phap nang eao chat lugng tram xi mang gieng khoan be Ciru Long la mot van de cap thiet d6i voi e6ng tac khoan tham d6 va khai thac dau Tuygn tap bao cao Hdi nghj KHCN "30 nam DSu Viet Nam: Cff hdi mdi, thach thuc mdi" 823 CAC YEU TO ANH HU-ONG DEN CHAT UTONG TRAM XI MANG GIENG KHOAN Yeu to dja chat - ky thuat fl Anh hw&ng cua dp suat via vd dp sudt v& via be Cim Long, trim tieh tu6i Pliocen va Miocen dae trung bai set, bgt, eat xen ke, gradient ap suit via tuong duong - l,ls.g va ap suat vo via tuong duong 1,3-1,8 s.g Cac nha thau da thi6t kk cac cot 6ng 324mm; 340mm; 245mm; 133/8" va 9ys" vai ty trgng vtra xi mang 1,48 - l,58s.g ea tang hoae lieu dau la tuong d6i phii hgp Chinh vi vay, chat lugng lien ket xi mang dat muc trung binh (lien ket t6t chiem tren 40%)), nhien, van xay mot s6 phuc tap mat dung dieh vao via cac tang cat kem lien ket hoae bi nirt ne Tram tich Oligocen c6 gradient ap suat via tuong d6i cao tuong duong vai ty dung dieh 1,25 - l,65s.g va ap suat vo via tuong duong 1,7 - 2,0s.g thuang duge chan boi cot 6ng cbbng limg 194mm hoae cot 6ng 9Vs'\ Cac nha thau thiet ke ty trgng viia khoang tram khoang 1,72 - 1,91 s.g la tuong d6i phii hgp voi dieu kien dia tang Tuy nhien, m6 Bach H6 thi c6ng tram xi mang, d6i van xay phirc tap mat dung dich vao via o phan chan de 6ng ch6ng limg 194mm noi tiep giap voi mong eiing nhu hieu qua thay the dung dich khoan kem nen chat lugng tram cot 6ng limg 194mm m6 Bach H6 dat thap (lien ket t6t chiem duoi 40%o) Trong mong nut ne ap suat via chi tuong duong ap suat thuy tTnh, tham chi thap hon nen khoang tram gap nhieu phuc tap mat dung dich vao via Cac nha thau da giam ty trgng vti'a xi mang xu6ng 1,48 - l,53s.g, ap dung c6ng nghe tram tang, tram phan doan, ca giai phap dtmg cau each ly eo hgc ngan each cot dung dich khoan phia tren nham giam ap suat thuy tTnh, v.v nhung chat lugng tram mong van thap (6 m6 Bach H6 lien ket t6t chiem duoi 40%)) Ngoai ra, ap suat duoi gieng khoan co anh hu6ng den chat lugng ciia vanh da xi mang, thuong thi anh huong mang tinh tich cue Ap suat day nhanh qua trinh hydrat boa, CO vai tro tich cue hinh cau true da xi mang lam tang ben va giam tham cua da xi mang giai doan dau dong ran Do qua trinh hydrat hoa dugc day nhanh duai tac dgng cua ap suat nen thai gian dong ket cua vtra xi mang giam di Vi vay, can tinh den yeu t6 thiet ke don vtra xi mang, tranh su c6 viia xi mang bi d6ng ket truoc thoi gian du kien duoi tac dgng ciia ap suat b Anh hw&ng cua nhiet giing khoan Nhiet CO anh huong hai mat den qua trinh thuy boa ciia xi mang va tinh chat ciia da xi mang.Truac bet, t6c hydrat boa ciia cac khoang xi mang tang nhiet tang vi vay thoi gian d6ng kit giam Nguyen nhan chinh ciia hien hrgng la nhiet lam tang kha nang hoa tan, tang he s6 khuyech tan ciia cac phan tir tham gia phan ung va lam tang boat tinh eua nuac De keo dai thoi gian d6ng ket ciia xi mang nguoi ta phai sir dung cac chat cham dong nham tranh sir co vtra xi mang d6ng ket fruoc k§t thuc qua trinh tram, d nhiet duoi 60°C, nhiet co anh huang tot toi tinh chit ciia da xi mang khoang nhiet tren 60°C nhiet lam suy giam bSn va tang tham ciia da xi mang phan buy cac mu6i phirc va sir tai ket tinh chuyen pha eua khoang a-CzSH nhiet tren 120°C 120°C da xi mang mit tren 80% cuong sau khoang thang Trong thuc te, vanh da xi mang gilng khoan phai lam viec dilu kien nhiet cao hon 824 Cac ygu td anh hudng va giai phap nang cao chat luoTig tram ximang gieng khoan ff bl Cuu_Lon£ nen bi giam cuong va tang nhanh tham Do vay, cac gilng khoan co nhiet cao (> 120°C) nguoi ta phai sir dung xi mang ben nhiet tren co sa xi-mang gilng khoan dat tieu chuan API hoae GOST va dilu ehinh ty le CaO/Si02 = 0,8-1 bing each pha trgn them cat nghien Tai be Cim Long, khoang tram eiia cac cot Ing 324mm, 340mm; 13 3/8" va phin tren eiia cac cot Ing 245mm va 9^%" nhiet thuang duoi 100°C (40°C - 100"C) Tuy nhien, tai m6 Bach H6, mgt s6 gieng khoan eo luu lugng khai thac Ion, nhiet mieng gieng co the len tren 100°C, d6 can xem xet sir dung eat nghien ca d6i voi phan tren ciia cot 6ng D6i vai cae khoang tram phan duoi eae cot 6ng 245mm, 9%" va cac cot 6ng khai thae den mong, nhiet day gieng deu tren 100°C c Anh hw&ng cua tinh chdt ca ly vd thdnh phdn thach hoc ddt dd cae tao nirt ne, hang h6e, bo roi kem lien ket thuang co gradient ap suat vo via thap, vi vay tram xi mang thuong xay mat dung dich vao via ap suat thuy tTnh cot xi mang Ion hon ap suat vo via ciia he Trong mat eat cae gieng khoan ciia be Cim Long, cac tap tram tich kem lien kit tu6i Pliocen, cac tap eat tu6i Mioeen, Oligocen va dac biet la mong nirt ne truac De tam la cae tao eo nhieu nguy co xay phire tap mat dung dich vao via Tren bl mat cac tap cat (thim t6t) thuong tao cac v6 set, c6n tren be mat cac tap set (thim kem) thuong e6 mgt lop set bi truang no, day v6 set phu thuge nhieu vao chat lugng dung dieh khoan Khi xi mang dong ran, xay qua trinh giam ap, eo ng6t va hut nuoc dan den lam mat nuoc lap vo set va giam the tieh lop v6 set Ket qua la m6i lien ket gitra xi mang va he bi pha vo, hinh cac vi khe nirt, tao dieu kien cho sir xam nhap va dieh chuyen tren ranh gioi xi mang - dat da [4] Chinh vi vay, truac bom xi mang vao gieng khoan, nguoi ta thuang diing cac dung eu nao vo set hoae rira vo set bang eae dung dich rira dac chiing Cac khoang tram co m6i lien ket xi mang - he kem thuang gap cac tap set, set ket, tu6i Miocen ehira nhieu khoang vat nhom montmorilonit Cac khoang tram co m6i lien ket xi mang - he t6t thuang lien quan vai cac tap cat, cat ket, v.v (Bang 1) Bang 1: Anh huong phan ciia he den chai lu'ong lien ket xi mang Khodng Cdt dng Thanh phdn chinh Chdt lugng lien ket v&i thdnh he Gieng khoan trdm (m) ciia thdnh hi (inch) Kem Tdt 598- 1880 nyg 32,29% Cat kit 61,1 Wo 1,38% 15-2-RD-lX Set kit 98,62% 9Vz 1785-3028 0,00% Cat kit 100,00% f 15-2-GD-lX 1688-2322 nys 2303 - 2992 9y8 680-2144 i3y8 1897-2943 9y8 2111 -3541 9y8 15-2-RD-5X 15-2-RD-3X cat kit Set ket Set kit Cat kit 71,38% 23,29% 81,17% 88,67% 28,62% 76,71% 18,83% 11,33% Set kit 59,02% 40,98% Set kit 85,54% 14,46% Cat kit 93,00% 7,00% Set kit 87,30% 12,70% cat kit 92,44% 7,56% Tuygn tap bao cao Hdi nghj KHCN "30 nam Phu Viet Nam: Cff hdi mdi, thach thuc mdi" 825 Nhu vay, phan tich anh huong ciia cac ylu t6 dia chit - ky thuat den chat lugng tram xi mang gilng khoan tai bl Cim Long, co the di din mgt so nhan dinh sau: • Dilu kien dia chit - ky thuat (ap suat, nhiet do, phan thach bgc, v.v.) co anh huong dang kl din chit lugng tram xi mang cae cot 6ng • Khi tram cac cot Ing din Pliocen, Miocen va Oligocen tren co gradient ap suat va via khoang 1,5 - l,7s.g thi viec sir dung ty trgng vtra xi mang khoang 1,5 l,56s.g va e6ng nghe tram phan doan, tram tang la hgp ly • Khi tram cac cot 6ng den mong nirt ne co gradient ap suat vo via thap, nguy co mat dung dieh vao via cao can phai giam ty trgng xi mang xu6ng duoi l,5s.g bang each sir dung xi mang ngam hoae xi mang nhe tren co so vi hat r6ng, sir dung vat lieu bit nhet hoae cac giai phap c6ng nghe kbac nham giam ap suat thuy tTnh cot xi mang len via (diing cau each ly co hgc, chi tram phan duoi va phan tren cua 6ng ch6ng) • Khi tram xi mang phan duai cac cot 6ng ky thuat va cot 6ng khai thae eo nhiet cao can chu y den su anh huong eiia nhiet den thai gian d6ng ket va nang cao tinh ben nhiet ciia xi mang • Su CO mat ciia v6 set tren gieng khoan anh hu6ng dang ke den lien ket xi mang va he Vi vay, truoc tram xi mang can nao rira v6 set hoae rira sach bang dung dich rira Yeu to vat lieu va cong nghe tram a Xi mdng, phu gia, hod phdm r \ w r r cac s6 lieu thu thap dugc ve tram xi mang cac cot 6ng ch6ng gieng khoan be Ciru Long [1] cho thay cac nha thau sir dung vat lieu va don viia tram eo mgt s6 diem khae (Bang va 3) Do xi mang PCG va OCG ma XNLD Vietsovpetro sir dung ehi dat tieu chuan xi nghiep nhung chua dugc danh gia theo tieu chuan API nen ehua the so sanh voi xi mang "G" dugc cac nha thau Dowell va BJ sir dung Tuy nhien, neu chi xet ve phan khoang thi ham lugng khoang tricanxi silieat xi mang PCG thap ban so voi xi mang "G" ben sunphat (C3S ciia PCG la 50 ± 2%), C3S cua G.HSR la 65%)) ham lugng khoang Tricanxialuminat cao hon so voi xi mang "G" co bin sunphat cao (C3A ciia PCG la ± 1%, C3A ciia G.HSR < 3%)) va tong ham lugng khoang Tricanxialuminat + Tetraeanxialuminat ferit nam tieu chuan ciia xi mang "G" (t6ng C3A + C4AF cua PCG la 22%); t6ng C3A + C4AF cua G < 24%) Tuy thuge vao dieu kien dia chat - ky thuat ciia gieng khoan (ap suat via va ap suat vo via) va c6ng nghe tram (tram tang, tang, lieu, v.v.) cac nha thau da thiet ke ty trgng vQa nam khoang 1,48 - l,9s.g D6i vai cac khoang tram hay xay mat dung dich (thuang la cae via mong) ty trgng vtra xi mang ehi nam khoang l,5s.g, ty le nuoc/xi mang la cao (0,9 - 1) lam cho chat lugng lien kit xi mang thuang kem (d6i voi vtra xi mang tieu chuin thuong ty le nu6e/xi mang phii hgp la 0,44) Vi vay, can phai sir dung cac loai xi mang nhe co ty le nuac/xi mang thip hon nhu xi mang ngam hoae xi mang nhe tren co so vi hat (voi ty 1,15 - 1,54s.g; ty le nuoc/xi mang ehi 0,5 - 0,54) 826 Cac ygu td anh hudng va giai phap nang cao chdt iuoTig tram ximang gigng khoan ff bg CuuJ^tHig Thuc trang tram xi mang tai cac gilng khoan bl Cim Long cho thiy: • Sir dung phu gia cat nghien cac khoang tram e6 nhiet cao chua duge thuong xuyen din din giam nhanh chat lugng vanh da xi mang sau thai gian gieng dua vao khai thae • Sir dung cae phu gia dae biet nhu xi mang ngam (gilng khoan 822 XNLD Vietsovpetro tram) va vi hat LW6 (GK 15.1-SD-IX BJ tram) d6i voi cac khoang tram co nguy co mat dung dich eao la nhtrng huong di eo trien vgng de nang cao chit lugng tram xi mang gieng khoan Bang 2: Xi mang, vija tram va phuong phap tram cac gieng khoan be Ciru Long Tyle nu&c/xi mdng Phuang phdp trdm 1,48-1,9 0,5-1 Thuan, thuan nghich, phan doan tang, tang, cau each ly co hoc OCG, PCG 1,48- 1,72 0,5-1 Thuan, thuan nghich, phan doan, tang, tang 15.2 G 1,5-1,9 0,5 - 0,9 Thuan, tang, tang Khae G 1,5-1,9 0,5- Thuan, tang, tang Md Logi xi mdng Bach H6 OCG, PCG, G Rong Ty trgng vda Bang 3: Phu gia, hoa pham da su' dung de tram cac gieng khoan tai be Cun Long Nhd thdu Cham ddng/nhanh ddng VSP FCl, NTF (NazCOs) BJ Dowell R-15LS, R-21LS D081,D110 Chdng tgo bgt Chdt n& Gidm thdi nu&c Phdn tdn Khdc Set, Diatomit CMC FCl Silica, FP-9LS A-3L FL-45LS CD-31LS A300L Silica, LW6 D047 D075, D020 DUO D064 Silica b Phwong phdp trdm Thuc te tram xi mang cac gieng khoan tai be Ciru Long cho thay cac nha thau thuang sir dung eae phuong phap tram truyen th6ng va mgt s6 phuong phap dac biet nhu: - Phuong phap tram thuan ian - Phuong phap tram tang - Phuong phap tram 6ng ching lung va tram phan doan - Phuong phap tram nghich - Phuong phap thuan nghich Tuygn tap bao cao HQi nghj KHCN "30 n5m Pdu Viet Nam: Cff hdi mdi, thach thuc mdi" 827 - Phuong phap diing clu each ly co hgc - Phuong phap tram diing packer ngoai 6ng ch6ng (ECP) c Dinh tdm Theo danh gia ciia mot s6 nha nghien ciiu ciia XNLD Vietsovpetro [2] thi ke tir nam 1991 blu hit cac cot 6ng ch6ng XNLD Vietsovpetro deu kh6ng dugc dinh tam hoae dinh tam kh6ng dang ke Thieu dinh tam, cot 6ng se tua vao gieng tao nhtrng vimg kh6ng chay lam hieu qua thay the dung dieh khoan bang viia xi mang kem Mgt ly it sir dung 16ng dinh tam o XNLD Vietsovpetro la khe ho khong gian vanh xuyen hep, nhat la d6i vai cot 6ng 194mm va 140mm tren thi truang kh6ng CO I6ng dinh tam tieu chuan Viec sir dung qua it dinh tam XNLD Vietsovpetro (Bang 4) la mgt nhtrng nguyen nhan lam cho chat lugng tram xi mang cac cot 6ng 194mm va 6ng khai thae thap Trong do, chit lugng tram xi mang cac cot 6ng khai thac 16 15.2 cao ban ban nha thau sir dung tuang d6i diy dii dinh tam qua trinh tram.Vi vay, can phai sir dung I6ng dinh tam mgt each diy dii, nhit la dinh tam co kha nang tao dong chay xoay nham nang cao kha nang thay thi dung dich khoan Neu thieu I6ng dinh tam tieu chuan dilu kien ky thuat dae biet ciia XNLD Vietsovpetro, khe ho vanh xuyen hep can thilt phai cbl tao I6ng dinh tam nuoc dam bao tieu chuan Bang 4: Thirc trang sn dung dinh tam gieng khoan mo Bach Ho va 16 15.2 Bgch Hd Cot ong Ld 15.2 Sd lugng Sd lugng Sd lugng Max Min TB/cdt dng 245 80 194 50 194x168x140 87 10 mm Cdt dng Sd lugng Sd lugng Sd lugng TB/ cdt dng inch Max Min 13 3/8 35 20 5/8 187 10 56 d Tdc bom day Cimg voi cac bien phap co hgc nhu dinh tam cot 6ng, xoay va dao 6ng tram, viec lira chgn che d6ng chay day xi mang phii hgp la rat quan trgng Vila xi mang hoae chat 16ng dem a che chay r6i hoae chay nut se tao duge su phan b6 ap suat d6ng deu len kh6i dung dieh khoan khoang kh6ng vanh xuyen do dugc lira chgn de thiet ke che bom ep xi mang Ket qua t6ng hgp ve t6c bom day xi mang qua trinh tram cac gieng khoan be Ciru Long (Bang 5) cho thiy: Tai cac gieng khoan XNLD Vietsovpetro tram, luu lugng bom diy thip hon so voi cac gieng khoan 16 15.2 Dowell tram Tai XNLD Vietsovpetro [2] tram voi eae loai vtra th6ng thuang, cbl chay rli chi dat dugc luu lugng bom diy cao ban 25l/s c6n d6i voi cae loai vtra eo nhot cao thi luu lugng phai cao hon 351/s Tuy nhien, dilu kien thue tl eiia mo Bach H6 thi viec tri luu lugng 828 Cac yeu td anh hudng va giai phdp nang cao chht luong tram ximang gieng khoan d bg CuuJ^^ong^ bom cao nhu vay la kh6ng cho phep nguy co pha va via rit ion Nhu vay tai cac gilng khoan mo Bach H6, luu lugng bom diy thuc tl ehua cho phep tao dong chay rli ngoai khoang kh6ng vanh xuyen, vay chic chin lam giam kha nang thay the dung dich khoan va anh huong den chat lugng tram cac cot Ing Dilu chi c6 the giai quyet tang khe ho vanh xuyen bang each thay dii clu true gilng khoan Bang 5: Liru lirong bom day xi mang tram cac cot Ing Bgch Hd Ld 15.2 Cot ong, mm Luu lugng bom ddy, l/s 245 17,7-22,2 194 9,6-13,9 194x178x140 9,7 - 22,2 Cdt dng, inch Luu lugng bam ddy, l/s 13,25-53 9'A 13,25-47,7 e Dung dich dim vd dung dich rira De dam bao chat lugng tram xi mang truoc bom viJa xi mang, nguoi ta thuong bom dung dich dem hoae dung dich rira Viec sir dung dung dich dem va dung dich rira gieng kh6ng ehi ngan dung dich khoan lam ban vtra xi mang ma lam sach be mat 6ng ciing nhu he kh6i lap vo set va lam thay d6i tinh dinh uot nuoc eiia cac be mat Thuc te tram xi mang tai cac gieng khoan be Cim Long cho thay, cac nha thau da sir dung dung dich dem va dung dich rira co phin khae nhau, c6 thi chi la nuoc biin, nu6c de tron viia xi mang (co chua cac boa pham), nuoc ky thuat pha cbl them chit boat dong be mat, cac chit ire chi, v.v co thi la cae dung dich pha cbl dac biet (CW7, CWIOO, MCS, v.v ) voi kh6i lugng chii ylu tir - lOm^ Ngoai ra, sir dung cac loai dung dich khoan kbac ciing anh buong dang kl din lien ket xi mang - he Khi khoan, gieng khoan xay hai qua trinh nhu: dung dich khoan tuong tac vai da set tren gieng lam biin d6i ham lugng nuac ciia ehiing va hinh v6 set cac khoang co thim cao Cac kit qua nghien cuu [4] voi cac he dung dich khoan khae cho thiy da set bi truong no tilp xiic voi dung dich PHPA va GLYCOL, nguge lai co ngot tilp xuc voi dung dich silieat va dung dich glc dau Tuy nhien, bin lien kit be mat xi mang - set lai cao nhit set tilp xiic vai dung dieh silieat va thap nhat set tilp xuc voi dung dich glc diu Mgt s6 c6ng trinh nghien ciiu khae [3] cho rang, chat lugng tram xi mang gilng khoan tang len sau sir dung dung dich khoan silieat Nhu vay, de nang cao chat lugng lien ket xi mang can thiet phai lira chgn he dung dich khoan phii hgp, nhat la khoan qua cac ting set day co chiia nhieu phin set truang no mat cit gilng khoan bl Cim Long Anh huong cua thoi gian lam viec ciia gieng khoan den chat luong vanh da ximang Theo bao cao ciia XNLD Vietsovpetro [5] thi s6 gieng khoan eo ap suit gitj-a cac cot 6ng ch6ng cang tang, din da chiem gan 50%o t6ng s l cac gilng khoan ciia XNLD Vietsovpetro (Hinh 1), dac biet la cac gilng khoan khai thac eho san lugng khai thac diu eao Su gia tang ve so lugng gieng khoan co ap suit gitra 829 Tuygn tap bao cao Hdi nghj KHCN "30 nam D5u Viet Nam: Cff hdi mdi, thach thuc mdi" cac cot Ing va gia tri ciia ap suit chirng t6 chit lugng vanh da xi mang ngoai Ing ching cang bi suy giam bi pha buy ban via, xir ly via va phai lam viec dieu kien khic nghiet eua via (nhiet cao, ap suat eao, m6i truong an mon, V.V.) cae so lieu danh gia chit lugng lien ket xi mang eae cot 6ng khai thac a XNLD Vietsovpetro duge lap lai sau nhthig khoang thai gian kbac cung da phan anh ro net xu thi giam chit lugng ciia vanh da xi mang theo thai gian lam viec cua gieng khoan Khoang tram eo chat lugng lien ket t6t giam di ro ret va thay vao d6 khoang tram co chat lugng trung binh hay kem tang len S6 lieu t6ng hgp eho thay khoang tram co chat lugng lien ket t6t giam xu6ng gitra hai ian dau tien va ian cu6i tir 2,1% den 100%, t6e suy giam mgt nam khoang tir 0,2% den 90%o 140 100 Hinhl: Tinh hinh ap suat giua cot ong khai thac va cot ong ky thuat ff XNLD Vietsovpetro (Theo bdo cdo cua Vien NIPI) M6i lien quan gitra t6c suy giam chat lugng lien ket eiia vanh da xi mang cot ong khai thac voi nam thi c6ng tram xi mang gieng khoan (Hinh 2) eho thay xu the tang din t i c suy giam tir nam 1987 din nam 1999, dac biet tir sau nam 1994 830 Cac ygu td anh hudng va giai phdp nang cao chit luong tram ximang gieng khoan d bg C u u J ^ n g 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 /, X Hinh 2: Toe suy giam chat lu'ong xi mang cot ong khai thac cac gieng khoan ciia XNLD Vietsovpetro (1987 -1999) (Tinh tren ca s& sd lieu ciia Xi nghiep Dia vdt ly giing khoan) Nhu vay, danh gia anh huong ciia thai gian lam viec cua gilng khoan din chit lugng lien ket vanh da xi mang co the di din kit luan va dl xuit sau: - Chat lugng lien ket ciia vanh da xi mang suy giam theo thoi gian - Can dinh ky danh gia mirc suy giam dk lap k l hoach sira chua gilng MOT SO GIAI PHAP N H A M NANG CAO CHAT LlTOfNG TRAM XI MANG GIENG KHOAN Nhom giai phap phong ch6ng cac phirc tap, sy c6 thircmg xay tren khu vu-c nghien ciru • Khi thilt kl clu true gilng khoan, cin dam bao khe ho vanh xuyin du dl lip dat cac thilt bi e6ng nghe (dinh tam, nao v6 set, packer, v.v.), gia tri cu thi dilu kien dia chit - ky thuat gilng khoan, nhung kh6ng nen duoi 25mm • Lira chgn don vtra xi mang theo thoi gian d6ng kit dilu kien nhiet va ap suit day gilng cho thai gian d6ng kit vugt thai gian thi c6ng tram kh6ng duoi 25%) • Kiem tra nghiem ngat kha nang lam viec ciia cac thiet bi dau treo Ing ching lirng, packer, dau tram phan ting, v.v truoc tha xulng gilng • Thiet ke c6ng nghe va vat lieu tram phii hgp voi dieu kien ap suit vo via thip nhu: sir dung packer ngoai 6ng ch6ng, dimg clu each ly co hgc, tram phan doan hoae tram tang, thiet ke vira tram co ty trgng thip duoi l,5s.g bang xi mang ngam hoae xi mang nhe tren eo so vi hat, v.v Tuygn tap bao cao Hdi nghj KHCN "30 nam Phu Viet Nam: Cff hdi mdi, thach thuc mdi" 831 Nhom giai phap nang cao chat luong lien kit cua xi mang vol cot ong chong va he • Su dung dung dieh khoan co kha nang lie cbl cao khoan qua cac tap set, it gay cho cac tap set bl truang no, khuyin khich sir dung he dung dich silieat • Sir dung diy dii dinh tam ong eh6ng, dac biet dinh tam tao r6i • Sir dung diy du dung dich dem, dung dich rira kh6ng lam thay d6i tinh chat viia xi mang va eo kha nang nia, phan tan v6 set, dung dich khoan • Thiet ke che bom day hgp ly tao dugc dong chay r6i ngoai khoang kh6ng vanh xuyen ma kh6ng gay vo via Nhom giai phap nang cao chat luong vanh da xi mang • Sir dung xi mang dat tieu chuan (GOST, API, v.v ) co ben sulfat cao • Sir dung phu gia cat nghien voi ty le hgp ly nham nang cao tinh ben nhiet eiia xi mang dieu kien nhiet tren 100°C • Sir dung cac phu gia nang cao tinh deo, chiu bien dang, eh6ng xam nhap nhu latex, gasblock, khi, v.v KET LUAN Phan tich cac so lieu t6ng hgp c6ng tac tram xi mang gieng khoan be Cim Long cho thay, chat lugng tram xi mang gieng khoan kh6ng d6ng deu, khong 6n dinh va kh6ng cao phu thuge vao cac dieu kien dia chat - ky thuat m6, vat lieu va c6ng nghe ap dung Tren co so danh gia day dii vai tro ciia cac yeu t6 anh huong, de co giai phap hoan thien hgp ly can thiet phai: • Dinh ky lap lai CBL, VDL cac cot 6ng khai thac de danh gia sir suy giam chat lugng nham kip thai sira chtra gieng • Don gian va tieu chuan boa cau true cot 6ng de de dang sir dung cac thiet bi va dung cu tram cua phuang Tay san co va hgp ly boa chieu cao dang ciia cot vtra xi mang ngoai vanh xuyen cho van dam bao an toan cho gieng khoan boat dgng ma thuan lgi hon sira chtra va t6n chi phi thu dgn m6 sau (d6i voi XNLD Vietsovpetro) • Tiep tuc nghien ciiu hoan thien c6ng nghe va vat lieu tram dieu kien ap suat thap, nhiet cao (trong mong) Tiep tuc nghien ciiu hoan thien de sir dung rgng rai eae loai xi mang dac biet nhu xi mang nhe tren co so vi hat, xi mang ngam khi, xi mang c6 tinh each ly cao ch6ng xam nhap khi, xi mang no, nang cao tinh deo va giam gi6n ciia da xi mang TAI LIEU THAM KHAO Nguyen Xuan Hoa va n.n.k., 2004 Tdng hgp vd ddnh gid kit qud trdm xi mdng cdc giing khoan ddu bi Cim Long giai dogn 1994 - 2001 Bao cao ting kit dl tai nghien cim khoa hgc cap nganh Ha Ngi 832 Cac yeu td anh hudng va giai phap nang cao chat luong tram ximang gilng khoan d bg CuiiJ^j>n£ Hoang Qu6c Khanh, 2002 Hodn thien cdng nghi gia cd gieng khoan & XNLD Vietsovpetro Luan an Tien sy Ha Ngi D.G Cardno, D Ripley, B.W Mud, J.W Crawford, 1997 The use of silicate WBM facilitates successful primary cementation operation SPE/IADC 37611 Ladva J., B Craster, J Jones, G Goldsmith, D Scott, 2004 The cement to formadon Interface in Zonalisolation lADC / SPE 88016 Coeepuieucmeoeauue u euedpenue uoetix Memodoe u mexHO.no2uii no npedynpejicdeuuK) u miKeudaifuu MK/J CKeaDieunax, Koumpojib sa ux euedpemie OxHeTbi, HHHH 2001,2003 ... phan khoang thi ham lugng khoang tricanxi silieat xi mang PCG thap ban so voi xi mang "G" ben sunphat (C3S ciia PCG la 50 ± 2%), C3S cua G.HSR la 65%)) ham lugng khoang Tricanxialuminat cao hon... phap nang cao chdt iuoTig tram ximang gigng khoan ff bg CuuJ^tHig Thuc trang tram xi mang tai cac gilng khoan bl Cim Long cho thiy: • Sir dung phu gia cat nghien cac khoang tram e6 nhiet cao chua... ty trgng vtra xi mang ehi nam khoang l,5s.g, ty le nuoc /xi mang la cao (0,9 - 1) lam cho chat lugng lien kit xi mang thuang kem (d6i voi vtra xi mang tieu chuin thuong ty le nu6e /xi mang phii