PETROVIETNAM
Md hinh mof v^ cac vung trur luvng cue bo duwc huy dong vao khai thac cua than ddu da mong mo Bach nd
TS. Pham Quang Ngoc
Xi nghiep Lien doanh Vietsovpetro
Bai bao trinh bay kit qua nghien cwu qua trinh khai thac than diu trong mdng mo Bach Hd, phit hien sw lien kit ngiu nhien eua cic vung trw Iwgng cue bd va de xuit sa do hinh re quat vi sw phan bd eac vung nay. Viec ip dung sa do hinh re quat cho phep giai thich sw can kiet trw Iwgng a mdt sd vung cue bd va dac trwng eua giing khi kit thue khai thac. Tren ea sa eac vung trir Iwgng cue bd, cd thi thwc hien dw bio kha nang thu hdi diu din cudi qua trinh khai thac eua than diu da mdng md Bach Hd.
1. SLF hinh thanh cac vung trD' luang cue bo
Than d i u da mdng md Bach Ho hien d giai doan g i n culi cua qua trinh khai thac. Doi tugng khai thac nay dugc chia thanh khoi Trung tam va cac khoi phia Bic. Cac khoi phia Bac cd mCpc dp bit dong nhit cao, phuang an khai thac chu y l u la gazlift vdi tong san lugng d i u khai thac chi chilm cd -6,2% lugng d i u eua toan da mdng (so lieu den hit 2008), vi vay trong nghien CCPU
nay tap trung d khoi Trung tam.
Qua trinh khai thac d khoi Trung tam than d i u mdng md
Bach Ho tCp 1988 d i n 2008 dat hieu qua r i t eao, tong san lugng d i u thu hoi dat -145 trieu t i n .
Than d i u mdng khoi Trung tam la mpt khoi thing nhit, vdi nhilu vung ed tru- lugng cue bp lien k i t vdi nhau. Dae trung b i t dong nhit eao v l dp rong, dp thim va nhilu thdng sd dja chit khac cua khdi Trung tam da tao thanh mdt than d i u trong da mdng nCpt ne granitoid hilm gap tren the gidi.
Hoat dpng khai thac va phat trien than d i u mdng md Bach Ho da huy ddng nhilu vung cd tru- lugng cue bd tham gia vao qua
trinh thu hdi d i u d khoi Trung tam; eac khoi phia B i c xem nhu mdt vung ddc lap. NhCpng vung cd tru' lugng cue bd k i t n l i vdi nhau mdt each ty nhien, hinh thanh hai day g i n nhu song song vdi nhau va tham gia vao qua trinh huy dpng d i u d khIi Trung tam (Hinh 1). K i t qua khoan d nhilu khu vyc khac nhau d khdi Trung tam, n i m xa hai day cho k i t qua ban c h i hoac khdng cd d i u , khang djnh dac trung hit SCPC ea biet sy phan b l cua nhu'ng vung cd trQ- lugng cue bd.
Tren co sd c i u true than d i u , sy phan b l cua eac gilng
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T H A M D 5 - KHAI THAC D A U KHi
khai thac d khoi Trung tam, ed the phan chia eac vung cd tru' lugng cue bd thanh hai day nhu sau:
• Day thCp I cd 6 vung tru' lugng cue bp, thCp ty tCp Nam len Bic:
+ Vung thCp nhit ed eac gilng 423, 438, 439, 9002, 9004 va 9005;
+ Vung thCp hai ed cac gilng 2, 402, 420, 422, 431, 440, 479, 442 va 2002;
+ Vung thCp ba ed cac gieng 1, 401, 430, 413, 7001, 7002, 491, 403, 2003, 428, 421, 2001, 409, 10001, 10003, 10004 va 10005;
+ Vung thCp tu cd cac gieng 407, 410, 411, 450, 7006 va 7010;
+ Vung thCp nam cd cac gilng910, 918, 923va924;
+ Vung thCp sau ed cac gilng 802, 803, 804 va 822.
• Day thCp II ed 4 vung tru- lugng cue bd, tCp Nam len Bac:
+ Vung thCp nhit cd cac gilng 415, 419, 429, 457, 462 va 476;
+ Vung thCp hai ed cac gieng 417, 426, 456 va 478;
+ Vung thCp ba ed eac gieng 406, 408, 432, 556, 7003 va 7007;
+ Vung thCp tu ed eac gilng 404, 412, 1111, 1116, 1117, 1118 va 7005.
NhCpng gilng khai thac boat ddng thdi gian dai, sau dd ehuyin len doi tugng khac va gilng mdi dugc khoan sau nay v l CO ban cung n i m trong hai day ehinh neu tren. Ngoai hai day ca ban I, II ton tai mdt so vung nhd ed tru- lugng nhung thyc t l khai thac cho thiy tru- lugng d i u dugc huy dpng tCp nhu-ng vung nay khdng Idn, chiem ty le nhd trong tong t h i tru- lugng huy ddng.
2. So- do phan bo tru> lu'O'ng cue bo hinh re quat
Tren ca sd sau vung tru lugng cue bd eua day thCp I va bin vung trO- lugng cue bd eua day thCp II nam g i n nhu song song vdi nhau va c i u true dja chit cua than diu mdng khoi Trung tam ed dang hinh ndn thoai dai, vi vay ed the de xuit so do phan bo cac vung trCJ- lugng cue bd dang hinh re quat (Hinh 2). Theo sa do nay, cae vung tru' lugng cue bd (theo mat c i t dCpng) ed dang hinh nem vdi chieu day xac djnh, Idn nhd khac nhau, phan bo khdng deu, tao thanh hinh re quat, lien k i t vdi nhau nhd he thong cae nCpt ne Idn. Sy lien kit giu-a eac vung tru- lugng cue bd vdi he thing nCpt ne da tao dilu kien cho chit luu djch ehuyin d l dang va ap suit ludn dupe tai phan b l trong suit qua trinh khai thac.
Sa d l hai day cac vung tru- lugng cue bd tao nen hai hinh re quat la hinh anh phan bo tru- lugng cua toan khoi Trung tam va vi cd hai day I, II n i m tua song song nen cd the gpi la sa do phan bo trCi- lugng hinh re quat kep. Mpt so gilng nam rai rac tuy khdng duge ghep vao eac vung cue bp nhung cd quan he thuy lye d mCpc dp nhit djnh vdi hai day nen cung nam trong he thing khai thac ehung eua toan khIi Trung tam.
3. Dac tru'ng phan bo trCi' lu'O'ng cue bo hinh re quat
Sy phan chia ngiu nhien thanh hai day cac vung trO" lugng cue bd duge huy ddng vao qua trinh khai thac mang tinh tuang ddi; cd su giao thoa tru lugng giu-a cac vung va cung chju tac ddng chung cua viec bam ep nudc (Hinh 3).
K i t qua boat dpng khai thac
cho thiy hai day tru- lugng cue bd tham gia vao qua trinh khai thac khac nhau; day I huy dpng dugc nhieu d i u vao qua trinh khai thac han day II (Hinh 3).
Qua trinh khai thac ban 20 nam d khoi Trung tam da lam syt giam nhieu trCi- lugng cue bp, tuy nhien cac gieng khai thac hien dang boat dpng d hai day vin phan anh moi tuang quan ve kha nang thu hoi d i u nhu ban dau, nghTa la day I v i n cho nhieu d i u ban day II nhung d mCpc dp thip han (Hinh 4).
Trong mdi day cac vung tru- lugng cue bd phan bo khdng dong d i u , khac nhau ve khoi lugng, ve ranh gidi dudi cua tCpng vung va kha nang tham gia vao qua trinh khai thac (Hinh 1,2, 3,4).
4. U'ng dung s a do phan bo trip lu'O'ng hinh re quat
4.1. Sw twang hgp giira sa do va thwc ti
Sa do phan bo tru- lugng cue bd hinh re quat duge xay dyng tren ca sd kit qua boat ddng khai thac thyc t l cua eac gieng, phan anh dugc qua trinh thu hdi diu tai nhO-ng vung cue bd cua toan khoi Trung tam, tuang hgp vdi sy phan bo he thong gieng khai thac.
Cae gilng khoan gap d i u va khai thac cd hieu qua lien kit ngiu nhien vdi nhau thanh hai day dai tCp Bic xuong Nam. Trong tCrng day, cac gilng phan b l khdng diu, nam tren eac vung cd tru- lugng cue bd.
4.2. GUI thich sw can kiet trir Iwgng cue bg
Mdt s l gilng khai thac d khoi Trung tam da chim dCpt boat ddng, cd nguyen nhan la do can kiet tru- lugng cue bd. Theo sa do hinh re qugt, cac vung tru' lugng cue bd n i m rieng re, khi mdt
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PETROVIETNAM
vung tru' lugng eye bd nao dd can kiet, cac nCpt ne ddng vai trd lien kit cac vung khep lai do ap suit via giam, d i u tCp cae vung khac khd djch chuyen den, mat khac nudc bom ep duge d i y tCp dudi len, vi vay cac gieng d thdi diem ngCfng boat ddng hoac khdng ed dau, hoac cd ty le nude trong san phim eao. Cd the d i n ra mpt so vung ed cae gieng phai chim dCpt hoat dpng vi can kiet trCJ' lugng nhu khu vyc gieng 412, 417, 450, 2001... ed nhCi-ng tinh chit vCpa neu.
4.3. Giii thich sw hoat dgng on djnh cua nhom giing 802, 803, 804 vi 822
Nhdm gieng nay nim d vung tru- lugng cue bd thCp sau eua day thCp I. Vung nay cd nde mdng nam tCp 3297-3443m, dp thim -1-224,5 mD, xen giu'a hai dCpt gay tya song song, lam tang tinh biet lap cua khu vyc. Vung nay chi cd bin gilng hoat ddng, luu lugng dau khai thac khdng Idn, cao nhit -600 tin/ngay/dem va suy giam nhanh trong thdi gian ngan (Hinh 1), trung binh xip xi 100 tin/ngay/dem. Ve mat nang lugng, vung nay chju sy tac ddng eua nude bam ep tCp gieng 804 (giai doan boat ddng bam ep), gieng 914 va mdt so gilng khac.
Vung tru- lugng cue bd nay ed nguon bo sung nang lugng via, luu lugng khai thac thip nhung on djnh, nhdm gilng 802, 803, 804 va 822 ve ca ban boat ddng khai thac d ehe dp gazlift (ed thdi gian ngan hoat ddng ty phun).
4.4. Giii thich sw hoat dgng on djnh cua cic giing tw phun
Cac gilng khai thac ty phun boat ddng on djnh vdi san lugng Idn la do nhO-ng vung cue bd cd tru- lugng Idn, sy lien thdng thuy lye theo phuang ngang va phuang thing dCpng tot, kha nang bo sung nang lugng via bing bom ep ed hieu qua (vung 2, vung 3 eua day I).
Cae vung tru' lugng cue bd 2 va 3 eua day I, than d i u cd gidi ban dudi kha sau (cd the xuong dudi -4700m), nam d khu vyc trung tam cua khoi Trung tam, vi vay kha nang huy ddng d i u vao khai thac Idn, nen ed the duy tri san lugng khai thac d i u d mu'c cao trong thdi gian dai.
Hinh 1. Sa do cac vung trw Iwgng cue bd a khoi Trung tam da mdng mo Bach Ho
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Hinh 2. Sa dd phan bd cic vung trir Iwgng dau cue bd hinh re quat d khdi Trung tam, mdng mo Bach Ho
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THAM DO - KHAI THAC DAU K H I
5. U'ng dung s a do hinh re quat d\r bao thu hoi dau tCr nhu'ng vung trCi' lu'gng cue bo
Ap dung sa dd hinh re quat eac vung tru- lugng cue bd cd the thyc hien dy bao kha nang thu hdi d i u cua mdi vung. Tren ca sd s l lieu khai thac eua eac gilng hoat ddng d tCpng vung, thyc hien dy bao san lugng d i u thu hii, ti le ngap nudc trong san phim. Viec dy bao thu hdi chit luu theo tu-ng vung cho phep khie phue dugc sy thay doi nhanh tinh trang khai thac (luu lugng, ngap n u d c . ) cua mdi gilng, k i t hgp vdi sy dang len cua ranh gidi d i u - nudc cho phep danh gia duge sy can kiet cua trCJ- lugng d tCpng khu vyc.
Ket luan
• So d l hinh re quat dugc xay dyng tren CO sd cac vung trO- lugng cue bd tham gia vao qua trinh huy ddng khai thac d khoi Trung tam da mdng md Bach Ho lien k i t ngiu nhien vdi nhau thanh hai day I, II tya song song va cd ranh gidi dudi khac nhau.
• Sy phan chia ngiu nhien thanh hai day cac vung tru- lugng cue bd mang tinh tuong d i i , cd su giao thoa tru- lugng d i u giu-a eac vung va cung chju tac ddng chung cua viec bom ep nudc.
• Hai day tru- lugng cue bd tham gia vao qua trinh khai thac khac nhau; day I huy dpng duge nhilu diu vao qua trinh khai thac ban day II.
• Ap dung sa d l hinh re quat cd the giai thich dac trung khai thac cua nhieu gilng hoac nhdm gilng, sy can kiet tru- lugng d mdt so khu vyc va du bao kha nang thu hoi chit luu cho tCpng vung.
Lai cam an
Tac gia xin cam an KS. Nguyen Hai Tiln va Trin Thj Lan Anh da giup xay dyng cae hinh ve.
Tai lieu tham khao
1. BbeTcoBnerpo, Hl^Fll^MopHectjTeraa AHanu3 meKyuj,ezo coemofiHUfi paspadomKu Meemopo)KdeHUfi BenbiCi Tuap u J^paKon Teivia H14PII.2 r. ByHrray 2009r.
2. XNLD Vietsovpetro, Vien NCKH&TK Diu khi bien. Sa dd cdng nghe khai thac vi xay dwng md Bach Hd. Tap 2, phin 1 Tp. Vung Tau 2003, 303 tr. m
Hinh 3. Diu thu hdi tw cac vung cd trw Iwgng cue bd (mau gaeh) va bam ep nwac (mau xanh) a khoi Trung tam da mdng mo Bach Hd din 11/2009
Hinh 4. Hoat ddng khai thac va bam ep cua cac gieng a khoi Trung tam thing 10/2009
40 DAU KHi-36 3/2010