nghien cuu su mon hong cua choong khoan

8/13/2019 Nghien Cuu Su Mon Hong Cua Choong Khoan

1/82

n tt nghip Trng i hc M - a cht

guyn Vn Hi

M U

Cng nghip du kh l ngnh kinh t mi nhn v non tr ca t

nc ta. Sn lng du th khai thc t m Bch H khng ngng tng, cngvi sn lng t cc m v ang c pht hin nh m i Hng, Rng,

Rng ng ng gp mt phn khng nh cho s pht trin ca nn

kinh t quc dn. Ngoi t thu v cho t nc t vic sut khu du th

t hn 1 t USD/nm. N hn vo nhng con s thng k ta thy c s pht

trin vt bc ca ngnh cng nghip du kh trong iu kin c s vt cht

v trang thit b phc v cho cng tc tm kim, thm d v khai thc du kh

cn nhiu hn ch so vi cc nc khc trong khu vc v trn th gii

khng nh c s trng thnh ca ngnh trong thi gian qua.

t c nhng mc tiu ra th nhim v cp bch ca ngnh

du kh l tip tc y mnh cng tc tm kim thm d cc b trm tch v

khn trng a cc m pht hin tr lng thng mi vo khai thc, y

l mt thch thc ln i vi ngnh, l biu hin tp trung cao v u t (

hng t USD) thc hin mt khi lng cng vic khng l m thc t

chng ta mi tin hnh c mt phn trong nhng nm va qua.

Mt khc do iu kin a cht c th ca vng m, ch yu du kh

c khai thc t tng mng su ln c nhit v p sut cao. Cho nn

vic tin hnh khoan cc l khoan thm d v khai thc du kh gp khng tkh khn phc tp, i hi phi c trnh khoa hc k thut cao cng vi

trang thit b hin i nng cao tc khoan nhm tng hiu qu v rt

ngn thi gian thi cng. Mt trong nhng dng c khoan quan trng quyt

nh n s thnh cng ca qu trnh khoan l chong khoan. Trong nhng

nm gn y bn v tui th ca chong khoan c tng ln ng k

do s dng ngy cng rng ri cc loi chong kiu mi c gn rng hp kim

cng v vt liu siu cng cho hiu qu khoan cao.

Chong chp xoay l loi dng c ph hy t ch yu thi cng

cc ging khoan tm kim, thm d v khai thc du kh, trong loi chongba chp xoay t ra hiu qu hn c, chim khong 86% - 95% khi lng cc

chong khoan c s dng trong ngnh du kh. Trc y ta thng dng

cc loi chong khoan do Lin X (c) sn sut, nhng nhng nm gn y


2/82


guyn Vn Hi

s dng rng ri cc loi chong khoan ca M, Php, N ht N hn chung

cc loi chong ca M t ra u vit hn chong khoan ca N ga song khng

n nh bng: C chong khoan c 600m n 800m, c chong ch khoan

c 50m n 70m. L do chnh l cc nh sn xut chong khoan cha c

nhng thit k ph hp vi iu kin a cht v thi cng ti vng m ca

nc ta, ng thi vic la chn chong khoan nc ta cng cha c c

s khoa hc v thc tin. V vy, vic nh gi hiu qu lm vic ca chong

khoan chp xoay c th s dng chng mt cch hp l l nhim v cp

bch hng u nhm nng cao hiu qu khoan, gim gi thnh khoan thm d

v khai thc du kh Vit N am.

L sinh vin thuc b mn Thit b Du kh v Cng trnh, khoa Du

Kh, trng i Hc M - a Cht H N i sau mt thi gian hc tp vnghin cu ti trng cng nh c thc tp ti X nghip khoan v sa

ging ca Vietsovpetro, c s hng dn nhit tnh ca thy N guyn Vn

Gip em quyt nh chn ti:

ghin cu s mn ca chong khoan trong khoan du kh.

Tnh ton s dng hp l chong khoan .

N him v ca ti trc ht l gii thiu s b v chng loi cng

nh cu to ca mt s loi chong . Tng hp, phn tch l thuyt v thc t

v chong chp xoay nh gi hiu qu lm vic ca chong , t lm c

s cho vic la chn chong khoan thch hp vi iu kin a cht v k

thut c th ca nc ta nhm t nng sut khoan cao, tit kim chi ph, h

gi thnh khoan.

Cu trc ti bao gm phn m u, 4 chng ni dung, phn kt

lun, ti liu tham kho, c trnh by trong 84 trang vi 14 bng biu, 42

hnh v. ti c hon thnh ti trng i hc M - a Cht di s

hng dn ca thy guyn Vn Gip- B mn Thit b Du kh v Cng

trnh.

Tc gi xin by t lng bit n su sc v li cm n chn thnh tithy gio guyn Vn Gip- B mn Thit b Du kh v cng trnh, cng

cc anh ch thuc x nghip khoan v sa ging ca Vietsovpetro, cc thy c

gio trong b mn Thit b Du kh v Cng trnh, b mn Khoan Khai

thc, b mn C kh, b mn My Thit b M trng i Hc M - a


3/82


guyn Vn Hi

Cht H N i cng ton th cc bn sinh vin gip tc gi hon thnh tt

ti ny.

Trong qu trnh lm ti, do mc tm hiu mi dng nguyn l,

ti liu cng cn hn ch v cha c trc tip s dng trong thc t nn

ti cn nhiu thiu st. Rt mong c s gp ca cc thy c v cc bn

ng nghip.

Xin chn thnh cm n !

H ni, thng 5 nm 2011

Sinh vin thc hin

guyn Vn Hi


4/82


guyn Vn Hi

CHG 1

TG QUA V S DG CHOG KHOA

VIETSOVPeTRO

1.1. Cc loi chong thng c s dng Vietsovpetro

1.1.1. Tng quan v chong khoan

Chong khoan l mt dng c khoan, l b phn c lp t di

cng ca t hp thit b y vi chc nng chnh l ph hy t to

thnh l khoan phc v cho cng tc tm kim thm d v khai thc cc

khong sn c ch trong v tri t.

Trong cng tc khoan thm d v khai thc du kh th chong khoan

ng 1 vai tr quan trng quyt nh n thnh cng ca qu trnh khoan.

Chnh v vy m vic la chn s dng chong khoan 1 cch hp l v c

hiu qu c quan tm ng mc trong cng tc khoan.

1. Chong khoan

2. Cn nng

3. Cn khoan

4. ng chng5. Gi ng cn

6. i p

7. Thp khoan

8. Sn khoan

9. Rng rc tnh

10. Cp khoan

11. Bn xoay

12. Ti khoan

13. My bm14.My pht in

Deleted: m


5/82


guyn Vn Hi

Hnh 1.1. V tr ca chong khoan trong t hp thit b khoan

V mt cu trc th chong khoan u gm 3 b phn chnh l : Phn

hot ng, b phn dn dung dch v phn lp ni. Ring i vi loi chong

chp xoay th cn c thm b phn c th l h thng ta ca chp xoay.

- Phn lp ni: L b phn ni chong khoan vi phn di ca ct

cn khoan v chuyn nng lng cn thit cho phn hot ng thng qua cc

u ni trc tip bng ren, c th l ren ngoi hoc ren trong ty theo kch

thc ca chong. N u chong c kch thc ln th ni bng ren trong cn

chong c kch thc nh th ni bng ren ngoi

- Phn hot ng: L phn tc dng trc tip vi t ph hy,

chng c th lm bng rng dng nm li ct, rng hp kim cng nh hnh,

hoc bng ht kim cngChng c b tr theo cc mt tip xc vi yv thnh l khoan nhm to cho l khoan c hnh dng v ng knh nht

nh. c tnh v nguyn tc ca phn hot ng ph thuc vo t .

- H thng dn dung dch: L khong trng gia cc thn chong cng

vi cc l dn cht lng xung y c b tr vi tc dng gii phng mn

khoan, lm sch y l khoan ng thi c tc dng lm mt chong khoan.

N u nh tc dng cht lng i qua khi vi di 70m/s c xem l h

thng ra thng, vi dn lin vi thn chong. Cn vi dng cht lng i

qua khi vi tng ln t 70-130m/s c gi l mi khoan kiu vi phun, lc

vi c ch to t vt liu bn mn nh hp kim gm, thp gi,thnhmt chi tit ring c th thay th c .

Trong thc t ca cng tc khoan hin nay ti Vietsovpetro ph bin nht

l 3 loi chong khoan c s dng l :

Chong khoan dng li ct: Dng khoan t mm do, lm

vic theo nguyn l ct - v.

Chong khoan dng hp kim cng hoc chong kim cng : Dng

khoan t t cng n rt cng, lm vic theo nguyn l mi-ct-v.

Chong khoan chp xoay: C th s dng vi nhiu loi t khc

nhau t mm n cng, lm vic theo nguyn l p-v.

Sau y ta s trnh by c th hn v tng loi chong.

1.1.2. Cc loi chong thng c s dng Vietsovptro


6/82


guyn Vn Hi

1.1.2.1. Chong khoan li ct

c ch to theo kiu 2 hoc 3 li ct, k hiu 2L, 3L. Chng gm

thn pha trn c u ni ren v phn di l cc li ct. Pha trc ca li

ct u c l thot cht lng ra sch y l khoan trong qu trnh khoan.

Thn v li ct c ch to t thp hp kim yu hoc trung bnh theo

phng php rn hoc dp. Ring mi khoan 2L c thn v li ct c ch

to lin nhau cn loi 3L thn c ch to ri sau li ct c hn vo

cch nhau 1200. tng cng bn cho li ct th mt trc v mt bn

c khm hp kim cng dng bt hoc dng tm kiu cc bt vonfram ti

mt chiu cao no .

N goi ra mi khoan li ct cn c h thng thot nc ra c tc dng

hng dng cht lng t cn khoan chy trc tip ln y khong cch 2/3bn knh t tm mi khoan vi mc ch m bo lch dng chy v mt

trc ca li ct ra sch y v lm mt li ct.

Loi mi khoan 2L cn c gi l mi khoan ui c thng c ng

knh t 76-161(mm ) hoc ln hn khoan trong t mm v thng

khng c dng trong khoan tua bin v m men ph hy ln.

4

3

2

1

Hnh v 1.2. Chong khoan 2 li ct

( 1- Thn chong; 2 - Cnh; 3 - Rng; 4 - Tm ct)


7/82


guyn Vn Hi

Loi mi khoan 3L (hoc nhiu hn) tuy c gi thnh ch to cao hn

loi 2L nhng c u vit hn do to s nh tm tt, c bn mn cao hn,

c th khoan vi cc cp ng knh ln hn t 120-750 mm. Chnh v vy

m mi khoan cn c gia c bng hp kim cng vi chiu dy c th ti

1,5mm. N goi ra cn ch to loi li khoan 3L dng trong cng tc khoan

ly mu vi cht lng m bo.

1.1.2.2. Chong khoan hp kim v chong khoan kim cng

*Chong khoan hp kim

c s dng khoan hiu qu i vi cc tng t c nhiu xen kp

cng v mi mn. N guyn l ph hy ca mi khoan l mi-ct, chnh s lm

vic c hiu qu ca loi chong khoan ny thc y qu trnh nghin cu

hon thin cu trc ca chong khoan hp kim. in hnh l loi DIR( caN ga ), t 1 thn c ngi ta hn vo 6 li ct c cc mp ct b tr chiu

cao khc nhau so vi y, do chng ln lt c tham gia vo qu trnh

ph hy t , khi cc mp di mn ht th c cc mp trn thay th. Cc

li ct c gn rng hp kim cng hnh tr, cc rng c p thnh tng

hng sao cho cc hng tip theo cao hn hng trc n khong 1/3 chiu cao

ca rng, mt sau v mt bn (phn doa thnh ) cng nh gia cc rng

phn trc u c gia c bng hp kim cng.


8/82


guyn Vn Hi

Hnh 1.3. Chong khoan hp kim

( 1- Thn c; 2- Khun u; 3- Rng ct )

Qu trnh lm sch y l khoan c tin hnh thng qua 4 vi phun

bng hp kim gm, trong c 1 vi phn b gia v 3 vi cn li c

phn b u gia cc li ct khong cch 2/3 bn knh t tm chong m

bo cho qu trnh lm sch y c hon ton.

N goi ra cn 1 s loi chong c cu trc c bit khi cc rng

c b tr thnh 3 hoc 4 mc chiu cao v t ra c hiu qu i vi t

mm v trung bnh.

* Chong khoan kim cng

Chong khoan kim cng lm vic theo nguyn l ct-v, c dng

khoan trong t t trung bnh n rt cng, c th khoan c c l khoanthng ng v nh hng. Dng c cho tt c cc phng php khoan c

bit l khoan tua bin v t c vn tc quay cao. N u s dng chong kim

cng 1 cch hp l th n cho nhng ch tiu khoan tt, c th l tin

khoan cao, gim c thi gian ko th, gim c cong trong khoan nh

hng. Tuy nhin, vic s dng chong ny ch yu ph thuc tnh cht ca

t v tnh ton kinh t.

Cu trc ca chong khoan kim cng gm phn thn, li thp, khun

u v kim cng.

- Thn c ch to t thp hp kim kt cu hoc l thp crom 40X vihm lng cc bon 0,3-0,4%, phn trn c tin ren ni vi cn khoan .

- Khun u l ni gn kt ca cc ht kim cng v b tr cc rnh

thot nc, n l b phn quan trng nht ca chong khoan. Vt liu v cht

lng ca khun u quyt nh n hiu qu hot ng ca chong kim

cng. Chnh v vy m khun u phi c gin n nhit ging nh kim

cng v c mn t l vi kim cng. N u khun u mm qu s mn

nhanh dn n hin tng kim cng d b trc, ri. N u khun u cng qu

s lm cho kim cng kh nh ln mt ca chong khoan tham gia vo

qu trnh ph hy.

Hin nay khun u c ch to t vt liu c s l bt cacbit volfam

v 1 cht chy, sau khi nung nng trong kh tr mt hp kim theo yu cu,


9/82


guyn Vn Hi

cc cht chy thng dng nht l N i, Mn, Co, Mo. Ty theo t l ca cht

chy m ta c th thay i c cng ca khun u.

1. u ni

2.Thn

3. Rnh thot

4. Khun u

5,7. Rng ct

6. Vi phun

8. Gc thot dungdch

Hnh 1.4. Cu to chong kim cng(PDC)Bng 1.1. Cc thng s thit k cho mt s loi chong kim cng ( Hughes

tool company)

M IADC M142 M342 M132 M133 M333 M433 M122

S li ct 4 6 5 4 8 10 4

S vi phun 4 4 4 - 6 4 6 8 4

ng knh 63/4 11-12 12-14 63/4

B mt ca khun u c hnh dng khc nhau to nn do cc rnh

thot nc c mt tip xc vi t , c th l rnh xon hoc rnh qut

hng tm. Thng qua cc rnh xon ny m cht lng c hng t cn

khoan ra khong khng vnh xuyn. Trong thi gian gn y ngi ta cn

Formatted:Centered


10/82


guyn Vn Hi

thit k cu trc rnh thot nc bo m lm sch, lm mt tt nhng khng

gy si l kim cng, chiu di v hnh dng phi la chn sao cho vi tc

chy nh th no vn m bo c 1 s gim p trn mi khoan khong 15-

30KG/cm2. N goi ra cn cc rnh chy qua thn hng trc tip cht lng ln

mt hot ng.

- Phn hot ng ca mi khoan l kim cng dng ht hoc dng bt.

S phn b kim cng trn khun u c th theo cc s khc nhau nh:

xon, bn c, hng tmTy theo tnh cht t , h thng dn nc, kch

thc hnh dng, loi kim cng m b tr nh ca ht trn mt khun l

1/3-1/8 kch thc ht. Vic sp sp ht kim cng trn 1 chong khoan cng

khc nhau, chng hn mt trc phn b cc ht c kch thc t 0,2-0,34

cara, cn cc mt bn v cn pha trong th c ht nh hn t 0,1-0,25cara.

Chong khoan kim cng c ch to theo cc phng php khc

nhau nh: khm, c v luyn kim bt

+ Khm l phng php luyn c in hin nay t c s dng, ch

yu dng ch to cc kiu mi khoan ly mu. Trn mt ca khun u

c c sn cc l sau khm ht kim cng v theo phng php th

cng.

+ Phng php c c s dng ch to chong khoan, nh cc

khun c c th bng than ch, khi cc ht kim cng s c sp sptheo s nht nhv rt hp kim nh vo sau c gn vi li v thn

chong.

+ Phng php luyn kim bt c tin hnh bng cch gn cc ht kim

cng theo s vo mt khun sau hn hp bt carbit volfram.

+ Phng php mi nht hin nay l thm nhim c tin hnh bng

cch t kim cng vo khun v hn hp bt carbit volfram vo, tip l

ph ln trn n bt hp kim lin kt c nhit nng chy thp hn ri tin

hnh p v nung, khi hp kim lin kt s chy v thm vo bt vt liu c

s ri lin kt chng li vi nhau to thnh khi thng nht.

Phm vi s dng ca chong kim cng c s dng trong nhiu loi

t khc nhau: mm, trung bnh, cng vi cng dng khc nhau: ph ton

y hoc ly mu. Cc ch tiu k thut ca mi khoan lin quan n tnh cht


11/82


guyn Vn Hi

ca t v ch khoan l: cng v bn mi ca khun u, ht,

s phn b v nh ca kim cng cng nh h thng thot nc ra.

+ i vi mm: S dng loi chong c gn ht kim cng ln.

Rnh thot nc kch thc ln, hng tm phn b xen k ng u gia

cc hng kim cng.

+ i vi trung bnh v cng nhng khng mi mn th s dng

loi chong c gn ht kim cng t 6 n 8 ht/cara v mt u c bc cho

php lm mt tt nht cc ht kim cng. Chong khoan loi ny c s

dng cho hiu qu tt nht trong cc va macma, dolomite, anhydrite, sa thch

mm

+ i vi cng mi mn th khun u cn phi rt cng, gm 6-9

rnh thot nc dng xon, ty theo yu cu m ch to nhiu kiu cu trckhc nhau.

Hn ch ca chong kim cng l s dng khng t hiu qu cao trong

t cng cng vi nt n, v chng c th lm cho ht kim cng b va p

mnh. Cc loi t cha la hoc pirit lm gim tui th ca chong

kim cng, v khi cc mnh vn bt ra s ln di chong v ph hng cc

ht kim cng.

Hnh 1.5. Cu to chong kim cng t nhin

( 1-u ni; 2-Thn; 3-Rnh thot dung dch;4-Khun u;


12/82


guyn Vn Hi

5- ng dn dung dch ra khi chong )

Hnh 1.6. Mt ct chong kim cng

Bng 1.2. Cc b phn chong khoan kim cng

STT Tn STT Tn

1 u mi khoan 9 ng ra ca dung dchkhoan

2 Cnh mi khoan 10 Rng ct

3 ng knh 11 Vi phun

4N i ghi cc s liu, ng knh,

ren, s l sn xut12 Li ct

5 Ren API 13 Rnh thot dung dch

6 u ni 14 Rnh thot dung dch

7 Thn 15 Khun u ( ni gn kimcng )

8 Matrix 16ng ra ca dung dch

khoan

1.1.2.3. Chong khoan chp xoay

Formatted:Centered


13/82


guyn Vn Hi

Chong khoan chp xoay l 1 dng c cng ngh thi cng cc

ging khoan tm kim thm d v khai thc cc khong sn c ch. Chong

chp xoay a vo s dng t nhng nm u th k 19 v c dng

rng ri trong cng ngh khoan du kh v cho hiu qu tt. Hin nay gn

95% s mt khoan du kh u s dng chong chp xoay. So vi cc loi

chong khoan khc th chong chp xoay c u im l:

Tuy c din tch tip xc vi y l khoan nh hn nhiu (so vi

chong cnh dt) nhng di mt lm vic li ln hn v vy hiu sut ph

hy cao hn.

Do c cu to c bit, cc chp xoay ln trn t trong qu trnh

ph hy nn rng chong t b mi mn hn.

ph hy t cn m men quay nh hn v vy hn ch c hintng kt chong trong qu trnh khoan.

c trng ca loi chong l s chuyn ng tng i ca phn hot

ng ( rng chong ) so vi thn to ra cho n c 3 bc t do l quay v

tnh tin theo trc mi khoan, ng thi cn thc hin cc chuyn ng quay

quanh trc ca chp xoay. Trong thc t c th ch to theo phng n

chong 1 chp xoay v nhiu chp xoay khoan ly mu hoc ph hy y.

Hnh dng ca chp c th l n cn hoc a cn, y l 1 c cu rt phc

tp gm nhiu khu c kch thc ng v gc lin quan cht ch vi nhau,

l 1 trong nhng mt hng c kh i hi cng ngh gia cng kh khn vphc tp nht.


14/82


guyn Vn Hi

Hnh 1.7. Chong khoan chp xoay

( 1- Chong rng phay, 2- Chong rng nh)

Bng 1.3. Cc thng s k thut c bn ca chong chp xoay

Loi chong AIDCTi trng cho php

( lb/in )

S vng quay

( vg/ph )

ATM-1 116 2000-5000 300-80

ATM-G1(S) 117 2000-5000 300-80

ATM-G3 137 2000-5000 300-80

ATM-05 417 2000-5000 280-70

ATJ-55A 637 3000-6000 70-35

ATJ-77 737 3000-6000 65-35

ATJ-99 837 4000-6500 55-30

MAX-G3 135 1000-4000 350-80

MAX-05 415 1000-3500 350-80

JG2 127 2000-5500 150-70

J3 136 2000-6000 120-60

JG3 137 2000-6000 120-60

JG4 217 3000-7000 90-50

J7 316 3000-7500 80-50

S80F 417 1000-5000 160-70

Hughes tool company)

1.1.2.4. Cc loi Chong c bit

Chong u nhn: Dng khoan chuyn ng knh t ln sang nh,

khoan ph nt xi mng trong ng chng, khoan cu s c.

Chong lch tm: Dng khoan m l nhnh trong trng hp cn c l

khoan ng knh ln hn ng knh cho.


15/82


guyn Vn Hi

Chong li xon: Dng khoan xin ging khoan trong trng hp

khoan bng phng php khoan roto c s dng mng nghing.

Chong doa rng: L chong dng m rng ng knh thn l

khoan. Thng c hai loi, loi c cnh doa trong t mm, loi c cu

to chp xoay doa trong t cng.

Chong khoan ly mu: L loi chong ph hy t y theo hnh

vnh khn st thnh l khoan li mu li gia. Chong ly mu c nhiu

kiu cu trc khc nhau, loi li ct kim cng, loi bn chp xoay c

cng khc nhau ph hp vi nhiu loi t khc nhau.

Hnh 1.8. Cc loi chong c bit


16/82


guyn Vn Hi

( 1- Chong u nhn; 2- Chong lch tm; 3- Chong doa

4- Chong xon; 5- Chong ly mu)

1.2. hng kt qu t c v 1 s tn ti

1.2.1. Kt qu

Vietsovpetro l X nghip Lin doanh u tin ca Vit N am vi nc

ngoi trong lnh vc du kh v l mt biu tng ca tnh Hu ngh Vit

N am - Lin Bang N ga.

X nghip Lin doanh du kh Vit -X c thnh lp trn c s cc

Hip nh Vit - X v hp tc thm d, khai thc du kh trn thm lc a

Vit N am k ngy 03/07/1980 v Hip nh Lin Chnh ph Vit N am - Lin

X k ngy 19/06/1981 v vic thnh lp Lin doanh du kh Vit - X.

Trong gn 30 nm hot ng, Viesovpetro kho st 115.000 kilmttuyn a chn, trong c 71.000 kilmt tuyn a chn khng gian 3

chiu.

khoan 368 ging, bao gm 61 ging khoan tm kim, thm d v 307

ging khoan khai thc.

Ti hai m Bch H v m Rng, xy dng trn 40 cng trnh bin

trong c cc cng trnh ch y nh: 12 gin khoan-khai thc c nh, 10

gin nh, 02 gin cng ngh trung tm, 02 gin nn kh, 04 gin duy tr p

sut va, 03 trm rt du khng bn.

Tt c cc cng trnh c kt ni thnh mt h thng ng ng ngmni m lin m di trn 400 killomet.

t c mc tiu ra th nhim v cp bch ca ngnh du kh

l tip tc y mnh cng tc tm kim thm d du kh cc b trm tch v

khn trng a cc m pht hin tr lng thng mi vo khai thc, y

l mt thch thc ln i vi ngnh, l biu hin s tp trung cao v u t

hng t USD thc hin mt khi lng cng vic khng l m thc t

chng ta mi tin hnh c mt phn trong nhng nm qua.

Mt khc do iu kin a cht c th ca vng m, ch yu du kh

c khai thc tng mng su c nhit v p sut cao. Cho nn vic

tin hnh khoan cc l khoan thm d v khai thc du kh gp khng t kh

khn phc tp, i hi phi c trnh khoa hc k thut cao cng vi trang

thit b hin i nng cao tc khoan nhm tng hiu qu v rt ngn thi


17/82


guyn Vn Hi

gian thi cng. Mt trong nhng dng c quan trng quyt nh n s thnh

cng ca qu trnh khoan l chong khoan. Trong nhng nm gn y

bn v tui th ca chong khoan c tng ln ng k do s dng ngy

cng rng ri cc loi chong kiu mi c gn rng hp kim cng v vt liu

siu cng cho hiu qu khoan cao.

N h gii thiu phn mt th c nhiu loi chong c s dng

ph hy t . N hng chong chp xoay l loi c s dng nhiu nht v

n c hiu qu hn c, chim khong 86%- 95% khi lng cc chong

khoan c s dng. Trc y thng s dng cc loi do Lin X sn xut,

nhng nhng nm gn y ta s dng rng ri cc loi chong khoan ca

M, Php, N htN hn chung cc loi chong ca M hiu qu hn ca N ga

nhng khng n nh: C chong khoan c 600m n 800m, c chong chkhoan c 50-70m.

T nhng mt khoan u tin n nay x nghip Vietsovptro khoan

thm d v khai thc hng ngn ki l mt di lng t. Khai thc hng triu

thng du v kh s dng cho ni a v sut khu thu v ngun ngoi t di

do, ng vai tr ln cho s nghip pht trin kinh t t nc.

Trong cng tc khoan th thi gian nng th b khoan c chim n 40%

tng thi gian khoan. V vy rt ngn thi gian nng th l yu t lun c

quan tm. n nay nhiu cng ngh mi c ci tin, cc loi chong

c sn xut vi cng ngh hin i hn tng bn nhit, mi mn gp phn rt ngn thi gian cht trong qu trnh nng th do t phi thay

chong. N h s ng dng ca mt s loi chong kim cng..vv..

S ng dng ca nhiu cng ngh mi trong thm dm kho st a cht

gip tm hiu ng hn v cu trc a tng t ti vng khoan. T c

th phn loi la chn chong khoan ph hp vi tng loi a tng c th

gip rt ngn thi gian khoan, gim ri ro cho chong, tng tui th lm vic.

Hin nay nhiu loi chong vi cu to v vt liu mi c ng dng

nhiu hn nng cao hiu qu cng tc khoan. Khoan cc ging su hn vi

cc loi chong c gia c bng cc loi vt liu cng, chu nhit chng mi

mn nh kim cng, gip rt ngn thi gian nng th.

1.2.2. hng tn ti


18/82


guyn Vn Hi

Hin ti cng tc khoan thm d v khai thc du kh ca Vit N am ch

yu c thc hin trong vng thm lc a tri di trong c nc. C rt

nhiu cc cng ty trong v ngoi nc tin hnh khoan cc ging khoan

thm d v khai thc du kh, c ging khoan t ti chiu su trn 5000m.

Tuy c nhiu s tin b trong cng tc khoan v thm d du kh nhng bn

cnh vn cn mt s tn ti.

Trong qu trnh thi cng cc ging khoan vic s dng chong khoan

cha c quan tm ng mc dn n hiu sut lm vic ca chong cha

cao, c rt nhiu nguyn nhn khch quan cng nh ch quan lm gim hiu

sut ca chong. Cho nn ti mt s cng trnh khoan xy ra s lng ph

ln trong vic s dng chong khoan lm cho gi thnh khoan tng cao.

Trc khi tin hnh khoan th cng tc la chn chong khoan cha ththp l, bi v bn thn chng ta cha ch to c chong khoan m phi

mua t cc cng ty ca nc ngoi cho nn cc chng loi ca chong khoan

cha tht ph hp vi c im a cht v iu kin lm vic ca Vit N am

v du ch yu c khai thc t tng mng c nhit v p sut cao, iu

kin lm vic ngoi bin rt phc tp v kh khn.

Trong qu trnh khoan th trc khi tin hnh th chong cha kim tra

k tnh trng lm vic ca chong dn n mt s chong c ko ln sm

v b s c. Sau khi ko chong ln th vic nh gi chat lng ca chong (

tnh trng mn, d v hng ) cha c quan tm ng mc. Cho nn victm ra nguyn nhn ti sao gy ra s c hng chong khng c thc hin

nghim tc lm c s khoa hc v thc tin trong vic la chn chong

khoan cho cc ging khoan tip theo.

t c v tn ti ci g? Chng ny ang ni v tng quan s dng

choong, vy, kt lun v vic s dng n ti Vietsov ch


19/82


guyn Vn Hi

CHG 2

CU TO V GUY L PH HY CA

CHOG KHOA

2.1. Phn loi chong Cu to v nguyn l ph hy th cn g phn loi?

Phn tng quan v s dng choong ti Vietsov c nu cc loi choong ri,

khng cn nu li phn loi na.

2.1.1. Phn loi chung

Do tnh cht a dng ca cng tc khoan, tnh cht c l ca t vcc yu cu trong qu trnh thi cng m chong khoan c ch to theo

nhiu cch khc nhau. Chnh v vy m vic phn loi chong khoan cng

da trn nhiu quan im khc nhau nh: mc ch khoan, nguyn l ph hy

t , hnh dng cu trc ca chong, tnh cht ca t tt c h thng

phn loi ny u ph thuc ln nhau v khng c 1 thang phn loi no

chim d c v tr ch o. Diu quan trng nht l ngi s dng phi

chn c loi chong khoan ph hp vi iu kin khoan c th p ng c

v mt kinh t cng nh k thut ca cng tc khoan. Hin nay c th phn

loi chong khoan theo 1 s quan im sau:2.1.1.1. Theo mc ch ca cng tc khoan

Li khoan ly mu: Dng cho cng tc khoan thm d kho st vi

mc ch ly c mu trong qu trnh khoan phn tch theo yu cu ca

cng tc khoan.

Chong khoan ph y: Ton b t y l khoan s b chong ph

hy hon ton to thnh ging khoan.

N hng loi chong khoan c cng dng c bit nh chong dng

doa rng thnh l khoan, chong dng khoan nh hng, chong dng

cu cha s c, ph cu xi mng

2.1.1.2. Theo nguyn l ph hy t

Di tc dng ca chong khoan t b ph hy theo nhng nguyn l

ph hy khc nhau v c cc loi chong tng ng:

Deleted:


20/82


guyn Vn Hi

Chong khoan kiu p - v: in hnh cho loi ny l chong khoan

chp xoay. t b ph hy di tc dng ca lc p v xoay.

Chong khoan kiu ct - v: t b ph hy di tc dng ch yu

ca lc ct v in hnh trong nhm ny l chong cnh.

Chong khoan kiu mi - ct: Ch yu trong nhm ny l li khoan

c gn hp kim cng hoc ht kim cng c kh nng chu mi mn cao.

2.1.1.3. Theo hnh dng cu trc

Chong cnh: c khoan trong t mm, b ri.

Chong chp xoay: c dng khoan trong t t trung bnh n

cng.

Chong kim cng: c dng khoan trong t cng.

2.1.1.4. Theo tnh cht c l ca t Do t c cng khc nhau cho nn ngi ta cng ch to ra cc

loi chong tng ng cho ph hp vi tng loi t nh: chong mm,

chong cng, chong trung bnh v cc loi chong trung gian k cn. N goi

ra cn c loi chong chu mi mn v chong t chu mi mn.

2.1.2. Phn loi theo IADC

c im cu to ca chong khoan chp xoay c trng bi ng

knh, hnh dnh, kiu dng, kiu rng, kiu v c cu bi trn. V vy,

cc hng ch to chong khoan cc nc u c cc k hiu ring cho

chong ca mnh v do i vi cng mt loi t m c nhiu kiu khiu chong khc nhau.

N m 1972 Hip hi Quc t cc nh thu khoan ( vit tt ting anh

IADC ) thng nht xy dng 1 bng phn loi i vi cc chong khoan.

N i dung ch yu ca bng phn loi ny l mi chong s c k hiu bng

3 ch s v mt ch ci. V d 123A.

- Ch s u tin c nh s t 1 n 8: Cung cp thng tin v kiu b

phn ct : kiu rng, cng, mi mn, v sc chu nn.

S 1,2,3 : Chong rng phay bng thp, c s dng khoan a

tng mm(1), trung bnh(2), n cng (3).

S 4,5,6,7,8 : Chong rng nh, rng cacbit vonfram, khoan trong t

c cng tng dn (t 4-mm n 8-rt cng ).


21/82


guyn Vn Hi

- Ch s th 2 : c nh s t 1n 4: Ch cng ca loi t

thch hp khoan c hiu qu, t mm(1) n rt cng(4).

S 1: t mm

S 2: t mm n trung bnh

S 3: t cng

S 4: t rt cng

- Ch s th 3 c nh s t 1 n 7: Quy nh loi v mc

bo v thn chp xoay.

S 1: bi a, h, khng bo v thn chp xoay, thng c ng

knh calip bng ng knh chong.

S 2: bi a, h, khng bo v. Dng c c thit k khoan

thi kh (trn thc t hu ht dng c khoan thi kh c bo v chng nmn nhng tr trng hp ny ).

S 3: bi a, h, c bo v calip chng n mn. Thng l

chong c ng knh 12.1/4.

S 4: bi a, kn, khng c bo v calip. Rt him gp loi ny,

khng thc t .

S 5: bi a, kn, c bo v calip (c s dng nhiu ).

S 6: trc ma st, kn, khng bo v calip (him gp, ko thc t,

c thit k khoan trong thi gian di )

S 7: trc ma st ,kn ,c bo v calip (ng dng thc t nhiu ).- K hiu cc ch ci: Cc ch ci quy nh cc chc nng m rng ca

chong khoan.


22/82


guyn Vn Hi

Bng 2.1. Bng cc ch ci trong h thng phn loi chong chp xoay

STTCh

ciCc chc nng m rng

1 A Thit k c bc v vi phun ra bng kh

2 B ln c bit

3 C Chong c vi phun trung tm

4 D Kim sot lch chong

5 E Vi phun ko di hn bnh thng

6 G Chng mi mn ng knh v thn chong

7 H Thit k dnh cho khoan nganh hoc khoan nh hng

8 M Chong thch hp dng cho ng c y

9 S Rng phay dng chun

10 T Chong hai chp xoay

11 W Rng chng mi mn

12 X Rng nh dng c

13 Y Rng nh dng nn

14 Z Rng nh dng khc

V d 1: C 1 chong khoan vi k hiu IADC nh sau 737Y . Yu cu

chng ta c v hiu ngha cc con s nh sau :

Ch s u tin 7 (7>3) : Chong kiu rng nh

Ch s th hai 3 : Chong c kh nng khoan nhng thnh h cng ,n

mn trung bnh v n mn .

Ch s th ba 7 : Dng trc ma st v c bo v calip

Ch ci Y : Rng nh dng nn

2.2. Cu to chung chong chp xoayChong chp xoay c cu to bng 3 phn chnh l: thn chong,

phn lm vic, h thng bi trn( nu c), b phn ta v h thng dn

nc ra:

Deleted:


23/82


guyn Vn Hi

- Thn chong c ch to bng thp hp kim theo hai kiu: thn ri v

thn lin:

Loi thn lin: Thn chong c c lin khi sau hn cc chn

vo( trn c np cc chp xoay, trong thn chong c hn 1 tm c cc

l hng dng nc ra theo yu cu, pha trn ca thn chong l phn u

ni c tin ren cn bn trong ni vi cn khoan, chong nhm ny

thng c ng knh 354 490mm.

Loi thn ri: Thn chong c hnh thnh bng cch hn cc chn

chong li vi nhau, trn c np cc chp xoay v c l thot nc ra,

u trn ca chong c tin ren ngoi ni vi cn khoan, loi thn ri

thng c ng knh 76 320mm.

- Phn lm vic ( bao gm chp xoay, cc rng ca chp xoay), bn trongl cc ng ln ngoi ca ta, cc rng c xp thnh tng hng vng

quanh cc chp xoay. Cc rng ca chp xoay ny xen k vi cc rng ca

chp xoay bn cnh. Cc rng bng thp c phay ngay trn chp xoay hoc

bng cacbua volfram nh vo cc l trn b mt cc chp.

1. Chp xoay 1

2. Chp xoay 2

3. Chp xoay 3

4. Hng rng ngoi

5. Sng rng nh

6. Hng rng nh

Hnh 2.1. B phn rng ct


24/82


guyn Vn Hi

Trong qu trnh lm vic th chp xoay va quay quanh trc ca

chong v t quay quanh trc ca chp ng thi b trt khi quay nn va

c tc dng p va c tc dng ct hu hiu vi t mm.

- B phn ta gm cc vng bi cu hoc bi a v vng trt. Ty

theo kiu chong v iu kin s dng m cu to ca chp xoay cng

khc nhau. Cc vng bi cu chu ti trng chiu trc l ch yu, cn cc vng

bi a chu ti trng hng tm l ch yu.

1. Tai mi khoan

2. bi a3. bi cu

4. Chp xoay

5. Rng ct

Hnh 2.2. B phn ta

- H thng cch ly v bi trn ln: H thng bi trn ln khng c

ng dng trong tt c cc loi chong. Ty thuc mc ch s dng v c

tnh cu to ca tng loi chong m ngi ta c hay khng ng dng h

thng bi trn thy lc ny. H thng bi trn thy lc thng c np t

trong cc c np vng m kn. H thng bi trn thy lc thng bao gm:

C cu b tr p sut bng mng cao su (1).

Hc m cha cht bi trn t ngay sau b b p sut (2)

ng dn dung dch: Rnh nh c thng t va du bi trn n

bi trn cho cc ln (3).N guyn tc lm vic: H thng bi trn lm vic di tc dng ca

p lc dung dch khoan trong y ging khoan. Thng qua c cu b tr (1)

c tc dng y lm p sut trong hc m lun bng vi p sut ca dung

dch khoan trong y ging. B b p sut nhn p lc t dung dch khoan


25/82


guyn Vn Hi

y ging, y cht bi trn trong va du (2) qua ng dn dung dch (3) ti

chn ln( du i theo hnh mi tn nh hnh v) v bi trn cho cc ln.


26/82


guyn Vn Hi

1. C cu b tr p sut

2. Hc m bi trn

3. ng dn

4,6. Cc bi

5. m kn

7. Chp xoay

8. Mng cn bng

9. Chn mi khoan

Hnh 2.3. B phn bi trn ln

- H thng dn nc ra ( h thng vi ra): c b tr thn chong

v cc b phn dn dung dch xung y nhm mc ch ra sch y l

khoan v lm mt chong khoan. C th phn ra 2 h thng ra l ra thng

v ra thy lc.H thng ra thng: L thot nc ra c thit k tm ca

chong thng c tit din trn. H thng ra thng thng c c trng

bi vn tc ca dng dung dch thot ra l thot l v < 70 m/s.


27/82


guyn Vn Hi

H thng ra thy lc: c trng bi vn tc dng nc ra thot ra

t 70-130 m/s c tc dng lm sch y tc bi 3 vi phun lm bng hp kim

gm s chng mi mn v c th thay th c.

Hnh 2.4. H thng vi phun (1)Kch thc ca cc chi tit cu thnh chong ph thuc vo loi t

cn khoan. Chong khoan trong t mm cn ti trng b th c cc ln

nh hn, cc chp xoay km dy hn v cc chn rng c tit din b hnchong khoan trong t cng. Cc chong khoan trong t cng cn

lm vic vi ti trng ln hn, c cc chi tit ct gt t hn, cc ln ln hn

v thn chong vng chc hn.


28/82


guyn Vn Hi

Hnh 2.5. H thng bi trn, ln, vi phun

1. Khe h dn du bi trn 6. u vi phun

2. Hc m bi trn 7. Vng chn

3. C cu b tr 8. chn

4. M bo v 9. bi cu

5. H thng vi phun

N goi ra chong chp xoay cn nhiu b phn nh khc. Di y l

hnh v m t chi tit cc thnh phn cu to ca mt loi chong chp xoay

rng nh.


29/82


guyn Vn Hi

Hnh 2.6. Cu to chi tit chong chp xoay


30/82


guyn Vn Hi

Bng2.2. Cc b phn ca chong chp xoay

STT Cc b phn STT Cc b phn

1 Vu nh tm 15 Thn chong

2 Vng 16 Vnh ngoi

3 Bc bng ng 17 Rng cc bt vonfram

4 Lp kim loi c bit 18 Vi phun

5 Giong hnh xuyn 19 G vi phun

6 C cu iu ha p lc 20 Mt chp xoay

7 B phn bo v 21 Hng rng gia8 Hc m 22 V bc chp

9 N i nghi nhn hiu 23 Hng rng nh

10 Ren ni 24 u rng

11 Vi phun 25 nh chp

12 Giong hnh xuyn 26 Hng rng gia

13 Vng gi vi phun 27 Hng rng ngoi

14 G vi phun 28 Cc loi rng

2.3. Quy lut ph hy t c bn ca chong chp xoay

Chong khoan chp xoay ph v t y ch yu nh 2 chuyn

ng chnh l chuyn ng tnh tin t trn xung di do tc dng ca p lc

chiu trc v chuyn ng quay ca chong do tc dng ca roto hoc tuc

bin. Trong qu trnh lm vic cc chp xoay va quay xung quanh trc ca

mnh va quay xung quanh trc ca chong khoan. Khi quay xung quanh trc

ca mnh cc chp xoay lc th t 1 rng lc th t 2 rng ln y lkhoan(hnh v), v vy trong qu trnh quay c s dch chuyn ln xung ca

rng chong, chnh s dch chuyn ny to ra qu trnh va p tng phn

ln y, cho nn cc chp xoay tc dng ln y l khoan c ti trng tnh

v ti trng ng. Ty theo hnh dng ca chp v v tr tng i gia trc


31/82


guyn Vn Hi

chong v trc chp m tc dng ca rng chong ln t l p thun ty

hay p cng vi ct trong qu trnh khoan v khi cc chp xoay thc

hin 1 chuyn ng rt phc tp c th hin trong hnh v sau.

Khi quay xung quanh trc ca chong ( trc OA ) theo chiu kim ng

h vi tc l OA, th cc chp xoay s ln v quay quanh trc OB ngc

chiu kim ng h, vi tc l OB (tc tng i). N h vy chuyn

ng tuyt i ca chp xoay ( tng hp ca 2 chuyn ng trn) l chuyn

ng quay quanh trc tc thi MN vi tc l MN . Trc MN i qua giao

im O ( ca trc chong v trc chp xoay ) v i qua im O1 l tip im

gia u rng chong vi mt y l khoan. Mi im nm trn trc quay tc

thi u ng yn, mi im nm ngoi trc quay tc thi MN u chuyn

ng trn ng trn, bn knh bng khong cch t im n trc MN .Khi chuyn ng quay quanh trc tc thi, cc chp xoay s ct t .

Hnh 2.7. Phn tch s chuyn ng ca chp xoay


32/82


guyn Vn Hi

Cng ct( trt )ca mt chong c nh gi bng h s trt K.

H s trt bng t l gia tng din tch trt trn t ca chong sau mt

vng quay v din tch y l khoan. Trong trng hp cc ng sinh ca

chp xoay nm trn trc quay tc thi th h s trt bng khng. H s trt

K c xc nh theo cng thc 2.1:

(2.1)

Trong : At - l tng din tch trt trn t ca chong sau 1

vng quay.Ad - din tch y l khoan

Trong s cc loi chong chp xoay c s dng trong cng tc khoan

th loi chong 3 chp xoay t ra c u vit hn c, n c th khoan c

nhiu loi t . Chnh v vy m loi chong ny c dng nhiu nht

trong khoan du kh chim khong 95% tng s chong c s dng.


33/82


guyn Vn Hi

CHG 3

GHI CU S M HG CA CHOG KHOA

3.1. Tnh cht a tng m Bch H

Bng3.1. Cu trc a cht m Bch H

Da vo cc c im thch hc, c sinh, ti liu Karota ging khoan ca

m Bch H, cc nh a cht phn chia v gi tn cc phn v a tng

Formatted:Font: Bold






34/82


guyn Vn Hi

theo tn a phng cho cc cu to a cht vng m Bch H. T trn

xung ct a tng tng hp ca m Bch H c m t nh sau:

3.1.1. Trm tch eogen v t* Trm tch Plioxen- T (ip Bin ng):Trm tch Bin ng

ph bt chnh hp ln trm tch Mioxen. Thnh phn thch hc gm ct, st

v st bt xen k si mu xm, mu vng v mu vng xanh. Thng gp

y nhiu mnh vi sinh vt bin. Ln trn thnh phn gm ct b ri xen k

vi st mu xm sng v xm xanh vi mt t mc n, c mt s lng ln

foraminifera. Chiu dy ca ip t 550- 600m.

* Ph thng Mioxen trn (ip ng ai):ip ng N ai gm cc lp

ct b ri v ct khng gn kt mu xanh ln xt nhiu mu. Chiu dy ip

t 600- 650m. B dy tng dn ra pha cnh ca lp cu to v ph dy lntrm tch ip Cn Sn.

* Ph thng Mioxen trung (ip Cn Sn): Phn di ca ip ny

c cu to bi cc lp ht th mu xm v xm trng vi st mu nu ,

trong st c lp kp than. y l nhng t lc nguyn dng khi, b ri.

Thnh phn chnh l thch anh chim 80%, Fenspat v cc phun tro, xi

mng st v st vi c mu loang l, b ri mm do. t ny to trong

iu kin bin nng, mui trung bnh, chu tc ng ca dng bin, ni

lng ng kh gn ca ngun vt liu. B dy ca ip t 800- 900m.

* Ph thng Mioxen di (ip Bch H):ip Bch H l s xen kp

cc lp ct, st v st bt, ct xm sng, xm, st mu sc s loang l kt dnh

do (c bit l tng trn ca ip- tng st Rotalia). bt xm, nu

phn di ca ip. y l tng chn mang tnh cht khu vc rt tt.

bt kt xm v nu . phn di ca ip chiu dy lp kp ct kt tng

ln, y l tng sn phm cha du 23, 24, 25. Cn c vo c im thch hc

v c sinh ngi ta chia ip Bch H ra thnh 2 ph ip: Ph ip Bch

H trn v ph ip Bch H di. Ph ip Bch H trn st chim u th,

ph ip Bch H di l s xen k ct kt v st kt, u th ct tng ln. Bdy ca ip l 600 700m.

3.1.2. Cc trm tch Paleogen

* Tp trm tch Oligoxen thng (ip Tr Tn):Trm tch ny bao

gm cc lp ct kt ht mn n trung, mu xm sng xen k vi cc tp dy


35/82


guyn Vn Hi

st kt mu nu chuyn dn sang en v pha di. c bit pht hin

trong tng trm tch ny cc thn phun tro c thnh phn thay i. dy

ca lp trm tch Tr Tn gim dn phn vm ca cu to m Bch H v

tng t ngt phn cu to. Trong ip Tr Tn c cc tng sn phm bo

ho du l: IB, IA, I, II, IV, V. Chiu dy trm tch ca ip thay i t 50 -

1400m.

* Tp trm tch Oligoxen h (ip Tr C):Trm tch ny bao gm cc

lp ct st xen k ht trung v ht nh mu nu xm ln vi bt kt mu nu

b nn nn cht nhiu v nt n. y ca ip gp si kt v cc mnh

mng to thnh tp lt y ca lp ph trm tch. B dy ca tp lt y

ny bin i trong cc ging khoan t 0 170m, tng dn theo hng ln

chm ca mng cn vm th vng mt hon ton. N gi ta nhn cdu tp lt ny. N goi ra cn pht hin lp kp phun tro mt s ging

khoan. Tng a chn phn x 11 trng vi nc ip Tr C. Cc tng ct kt

cha du cng nghip (t trn xung): VI, VII, VIII, IX, X c xc nh.

l cc tp ct kt mu xm sng, ht t trung bnh n mn, chn la

tt, c rng bin i t 10 20%.

3.1.3. mng trc Kainozoi

mng trc Kainozoi ch yu l cc th xm nhp granitoit, granit

v granodiorit. Thnh phn khong vt ch yu l thch anh (10 30%),

Fenspat (50 80%), Mica v Amphibol (t him ti 8,9%) v cc khong vt

ph khc. Tui ca mng l Jura mun v Kreta sm (tui tng i l t

107 - 108 triu nm). mng c b dy phn b khng u v khng lin

tc trn cc a hnh. B dy lp phong ho c th ln ti 160m. Kt qu phn

tch khng gian rng trong mng cho thy rng trong phn b khng

u, trung bnh t 3- 5%. Quy lut phn b rng rt phc tp. Hin nay

mng l ni cung cp du th rt quan trng ca m Bch H. Du t phun

vi lu lng ln t mng l mt hin tng c o, trn th gii ch gp

mt s ni nh: Bombay (n ), High (Libi). Ging khoan su 900m vo mng kt tinh m Bch H vn cha tm thy ranh gii du - nc.

gii thch cho hin tng tr du th trong mng kt tinh, ngi ta tin

hnh nhiu nghin cu v u ra kt lun s hnh thnh khng gian rng cha


36/82


guyn Vn Hi

du trong mng granitoit m Bch H l do tc ng ca nhiu yu t a

cht khc nhau.

3.2. Cc dng mn ca chong khoan, nguyn nhn v cch nhn bit

3.2.1. S mn hng do qu trnh sn xut, vn chuyn

Chong b hng hc khuyt tt trong qu trnh ch to, ( lng rng, chp

b mo, chp xoay b kt trong , cc li v ln ). Cc s c i vi

chong khi hot ng nh b v chong, t thn, v vng bi, tut u ni. S

c xy ra nhiu nht vn l ri chp y l khoan, do mn bt thng ta

hay ngng trc..

Do c li trong qu trnh gia cng vt liu, cc vt liu c gia cng

khng ng quy trnh k thut dn n khng m bo cc yu cu v

cng, chu mi mnca vt liu lm chong.Hoc chong c th b st m, cong vnh do va p trong qu trnh vn

chuyn hoc kim tra.

3.2.2. Cc dng mn hng do qu trnh s dng v vn hnh

3.2.2.1. Mn chong

- Mn rng: Cc rng b mn theo dng trn, phn mi b mn, khng

cn kch thc nh bnh thng nhng phn lng c th vn nm trong kch

thc bnh thng. Chong vn khoan c bnh thng nhng kh nng

m xuyn b gim mnh do cm su ca rng chong vo t b hn

ch. Mi ca rng chong b mi trn nguyn nhn ch yu l khi khoan vot mi mn cao, vi tc vt qu cho php hay khoan m rng di

y ging.

Hnh 3.1. Mn rng


37/82


guyn Vn Hi

- Mn chp xoay: Chp xoay b mi mn trong mn khoan tc cao.

Do tc ng ca dng xoy nn bn khoan c th lm mn v chp xoay t b

mt tip xc trc tip vi dng dung dch i ra t vi phun. Trn chong c

gn cacbua vonfram, v chp xoay b mn c th dn n lm mn chn rng,

l nguyn nhn ch yu dn n mt rng ct. Xi mn thng l vn lin

quan n thy lc. Vi cc thng s thy lc khng ph hp bn khoan c th

lm xi mn v chp xoay nhanh hn mc bnh thng. Mt khc vic d

tha nng lng thy tnh c th dn n xi mn cht lu cao. Kt hp vi

vic mi mn do tip xc vi va dn n xi mn cc rnh ca chp xoay.

- Mn calip (vt chong): Chong b vt khi n b p nh hn kch c

ban u bng cc lc c hc. Cc lc p c th b gy ra bi s b hp ca

thnh ging khoan khi khoan vo thnh h mm, d st l. Khi chong b pnh hn kch thc ban u, hu ht cc g ca rng s b mn theo hnh

vng trn. Bnh thng n b ph hy theo ng vung gc vi lc gy mi

mn.

Hnh 3.2. Chong b vt

N guyn nhn khc ca chong b vt l do p chong vo ging nh hn

kch thc chong, a chong chp xoay vo lm vic trong vng ging

khoan m thch hp khoan vi chong kim cng, hoc chong b vt do thit

b g hc chong khoan.Chong b vt c th dn n rng b t gy, vt rng, chp xoay b dnh

vi nhau, khi chp s trt (ko lt) lm cc b phn ct b mi mn nhanh

chng.


38/82


guyn Vn Hi

- Xi l mi hn: Xy ra bt k lc no trong qu trnh hot ng ca

chong. N u mi hn ca chong xp, rng hay khng kn, chong s bt u

b xi l mi hn ngay khi bt u qu trnh vn hnh.

Thng thng mi hn kn nhng s nt gy trong qu trnh hot ng

do cc va chm vi y ging khoan hoc cc mu trong qu trnh nng

th. V khi xy ra nt v bt u tun hon dung dch, qua vt nt s xi mn

xy ra nhanh hn.

Xi l mi hn c th do dng chy ca dung dch khoan trong y

ging hoc do p lc thy tnh ngay trong ct cn khoan.

Hnh 3.3. Xi l mi hn

3.2.2.2. Hng cc b cc b phn chong

- Hng rng: N hng cnh sc ca nhng vt m trn nn xoay cho thy

s mn hng ca rng vo thi k cui ca chong khoan.

Hnh 3.4. Hng rng


39/82


guyn Vn Hi

mt vi thnh h rng b hng l do c dim mi mn bnh thng

ca rng cacbua vonfram gn vo chong, khng phi l vn do hot ng

ca chong. Vi chong gn rng cacbua vonfram, iu ny cng xy ra

thng xuyn khi bn nn ca t ln hn ca rng ct. Cn i vi

rng thp th n khng c coi l hin tng mn bnh thng. N l do s

ng dng hay cc thng s hot ng ca chong khng thch hp. V d nh

khi khi khoan vi ti trng vt qu mc l nguyn nhn dn n hng ch

yu vi cc hng rng gia. Cn khoan vi s vng quay vt qu mc th

ch yu lm hng hng rng ngoi cng.

N goi ra rng c th b t gy do y ging cn ln ph phm hoc va

chm vi cc mu trong qu trnh nng th( cc mu thng sut hin

trong thnh h mm, do s chnh lch v trng lng nn b nh ra khi thnhging), hoc do chong t ngt chm vo y, hay cc c tnh ca chong

khng thch hp s dng ph hy t trong mi trng . V d nh

khoan vo va qu cng i vi cng ca chong ang c s dng cng

c th lm t gy rng.

- N t chp xoay: Xut hin vt nt trn quanh chp xoay( nh hnh v)

Cc vt nt sinh ra do v chp b mn, lm gim dy ca v c bit

l rnh ca chp. Hoc nhit lng pht ra do s mi mn va trong qu

trnh hot ng c bit l qu trnh khoan hoc nng th lch tm cng l

nguyn nhn gy ra vt nt. N goi ra chp xoay cng c th b nt do phphm di y ging khoan, hay chong va chm vo cc mu , hoc ct

cn b ri, hoc nn xoay c th b nt gy b dn do hidro sunfua.

Hnh 3.5. Chp xoay b nt


40/82


guyn Vn Hi

- V chp xoay: Chp xoay b v mt phn nhng vn cn kh nng xoay

nhng km hiu qu, cn phi kim tra va c bin php khc phc ngay v khi

mt phn chp xoay b v s ri xung y ging v va chm vi cc rng ct

trong qu trnh khoan lm mn rng nhanh chng.

Chp xoay b hng c th do b gin bi hidrosunfua, mt loi kh c

c cng thc ha hc H2S c th t sinh ra trong du th v khi gp nc to

thnh axit c kh nng n mn cc hp cht kim loi.

Hnh 3.6. Hng chp xoay

Chp xoay cng c th b hng do gp phi mu trong khi ko th. Sva chm vi cc mu c cng cao c th lm nt,v chp xoay. Hay cc

chp xoay b dnh hoc va chm vo nhau khi trc cc chp xoay b vnh hay

b mt ng knh trc.

- Hng tai mi khoan: Mn tai mi khoan c th dn ti hng b phn bt

kn trong cc ta, c th lm ph hy ta. N guyn nhn chnh l do ph

phm vn trong ging, hay trong qu trnh khoan m rng y ging c

ng knh nh hn ng knh ca chong khoan, do cc va t gy lm

tn hi n tai mi khoan phn ngoi cng ca chong. l mt vi

nguyn nhn gy hi n tai mi khoan.

- Chong tr li ra ngoi: Chong tr li ra ngoi khi phn mi b hng.

Khi phn mi b mi mn qu mc do cng ca t va ln hn sc chu

mi mn ca chp xoay.

Deleted:


41/82


guyn Vn Hi

Hnh 3.7. Chong tr li ra ngoi

3.2.2.3. Mt cc b phn chong khoan- Mt rng: Ch xy ra vi chong rng nh khi c b phn rng ct b

bt ra ngoi.

N guyn nhn ch yu do s ni lng ca vng kp cc rng ca chp

xoay, do lm mt 1 vi rng ca chp xoay, hoc c th do v chp xoay b

mn lm tr chn rng ra ngoi.

i vi chong c gn rng cacbua vonfram, s mt rng thng xy

ra vi hng rng gia ca chp xoay. N guyn nhn ny lin quan trc tip n

cc loi ph phm cn li trong y ging khoan.

Hnh 3.8. Mt rng

Mt rng xy ra nhanh hn khi cc rng quay quay vi tc cao, cng

vi vic xi mn chp xoay. N goi ra vic sut hin cc vt nt chp xoay


42/82


43/82


44/82


guyn Vn Hi

- T mi nhn: T mi nhn l hin tng rng chong b mi nhn u

v c v nh vn gi c hng dng nh ban u thm tr c sc bn hn.

Khi t mi nhn gip duy tr tc m xuyn tt hn t u n cui

qu trnh hot ng nhng rng s yu hn. c tnh ny thng cho thy s

la chn chong ph hp vi cc thng s hot ng. C chong rng nh

cacbon vonlfram v chong rng phay thp u c hin tng t mi nhn.

Hnh 3.12. T mi nhn


45/82


guyn Vn Hi

0

Vch

G

A

B

G GA B

C

C1

2

C3

Q

Q

Q

1

2

3

CHG 4

CC BI PHP G CAO TUI TH

CA CHOG

4.1. nh hng ca cc thng s ch khoan n cc ch tiu lm vic

ca chong

4.1.1. nh hng ca ti trng y n cc ch tiu lm vic ca chong

S ph hy t y l khoan l kt qu n t ca rng chong vo

t v s chuyn di trn mt phng y ca chong khoan ( chuyn ng

quay). ngp ca rng chong ph thuc vo ti trng ln chong,

cng ca t , hnh dng v mn ca rng. Ti trng cng ln th chiu

su ngp ca rng cng ln. N h vy ti trng cng tng th vn tc c hccng tng.

Ti trng ring: Gr = ; (4.1)Atx: Din tch tip xc ca rng chong vi t .

xt s nh hng ca ti trng n ch tiu lm vic ca chong ta

gi cho s vng quay( n ) khng i.

Hnh 4.1. th nh hng ca ti trng y n

cc ch tiu lm vic ca chong


46/82


guyn Vn Hi

+ Gr< (on O-A)

N u ti trng ging nh hn cng ca t ( ), t b ph

min b mt ph hy. Trong min ny s tng ca vn tc c hc V chv tng

ti trng y theo mt ng thng rt thp. Hiu qu ph hy t thp,

chong b mi mn nhanh chng.

+ Gr> ( on B-C)

t b ph hy trng phm vi ca min ph hy th tch. Trong phm

vi ny gi tr vn tc c hc Vchtng ln rt nhanh cng vi s gia tng ca ti

trng theo ng BC. Trong min ny nng lng ph hy t cng t

hn, vn tc mi mn cng b hn.

+ on A-B

Gia hai min ny l min ph hy do hin tng mi ng cong AB.N u nh theo di ti trng ring ti im C, dng cho mi lu lng Q.

Vn tc c hc s tng ln rt chm v c xu hng gim. N guyn nhn l khi

tng G, lng mn khoan s nhiu hn v lu lng khng ra sch y

l khoan. t b ph hy s li y lm gim kh nng m xuyn ca

rng chong vo va. Do vn tc c hc s khng tng ln c v c xu

hng gim.

4.1.2. nh hng ca s vng quay n ch tiu lm vic ca chong

Kt qu nghin cu ch ra rng : Khi khoan bng chong chp xoay,

nu tng s vng quay n th s gim ngp su ca rng chong vo t .

N gc li khi tng s vng quay s tng s ln va p ca rng chong v t

. Do ty thuc vo yu t ny hay yu t khc n s lm tng hiu sut

lm vic ca chong, nhng li lm gim tui th ca n rt nhiu. N h vy

khi tng tc vng quay ca chong chp xoay th tc c hc khoan c

th tng hoc gim xung ty theo yu t no ( trong cc yu t ni trn ) c

u th hn trong iu kin cho.

Khi khoan trong t gin hoc gin - do, m h s do khng ln

lm th tc khoan cc i c th t c vi s vng quay ln nht ( hngnghn vng trn mt pht).

Cn i vi t do, c bit l t khng b ph hy gin th tc

khoan cc i c th t c vi s vng quay nh.


47/82


guyn Vn Hi

cT

ch

cTch

n

Hnh 4.2. th nh hng ca s vng quay n cc ch tiu

lm vic ca chong

4.1.3. nh hng ca cc thng s thy lc n cc ch tiu lm vic cachong

Hai chc nng quan trng nht ca dung dch khoan l:

- Ra sch y l khoan.

- Vn chuyn t ph hy y l khoan ln mt t.

Qua ra sch y l khoan chng ta hiu rng cn phi thc hin mt

tun hon dung dch khoan vi lu lng, vn tc vi phun v tnh cht ca

dung dch m bo tch v cun sch mn khoan y ging mt cch nhanh

chng.. Trong trng hp ny vn tc c hc s l cc i. Trng hp ngc

li di y l khoan s tch ly mn khoan gy ln hin tng bt chong

khoan, lm gim chiu su ngp ca rng v vn tc c hc s gim. Tm li

chng ta phi s dng mt lu lng v vn tc vi phun ln m bo vic

sch y l khoan.

4.1.3.1. nh hng ring bit ca lu lng v vn tc vi phun

*nh hng ca lu lng

Gi s vng quay n v ti trng Gckhng i. Chng ta nhn thy rng

vn tc c hc tng vi s tng ca lu lng Q. Vi mt gi tr no th

vn tc (v) khng tng c na bi v chng tha mn vi mt ti trngv s vng quay khng i.

Bin thin gia vn tc c hc v lu lng theo cng thc sau y:


48/82


guyn Vn Hi

ch V

Q

(m/s)j

V70 130

ch V

(4.2)

Trong : V: vn tc c hcQ: lu lng dung dch khoan

a,b l hai hng s ph thuc vo cc tnh cht c l ca

t, v cc i lng Q,n v tng loi cu trc ca chong.

Hnh 4.3. th nh hng ca lu lng n cc ch tiu

lm vic ca chong

*nh hng ca tia dung dch khi ra khi chong khoan

Qua vic tng vn tc ca dung dch ra khi vi phun chong, ngay ctrong lc gi Q khng i, vn tc c hc cng tng khi vj = 70 - 80 m/s, n

c tc dng tch cc mng b ph hy y l khoan. Tng vjc hiu

lc tt hn tng Q bi v vjcn c tc dng khng cho mn khoan bt chong.

Chng ta thy rng tng vjqu ln th Vchtng v dn n tn tht p sut ln

chong.


49/82


guyn Vn Hi

3

2

1

H

T

Hnh 4.4. th nh hng ca vn tc dng chy n cc

ch tiu lm vic ca chong

4.1.3.2. nh hng phi hp gia lu lng v vn tc vi phun

Cng sut thy lc chong:

N t=Q.Pc (4.3)

Pc: tn tht p lc chong khoan. (4.4)

.h s lu lng vi ( = 0,42 0.48).

Vy ta c: (4.5)

N h vy chng ta thy rng vn tc c hc s tng cng vi s tng ca N tdo tng vi tch Q.vj

2.

4.1.4. nh hng ca cht lng dung dch khoan n cc ch tiu lm

vic ca chong

*Trng lng ring ca dung dch

Chng ta nhn thy rng nu khoan vi dung dch khoan c khi lng

ring . Vn tc c hc s ln, thi gian khoan s gim. nh hng ca i

vi Vch c gii thch bng p sut chnh lch y lm mn khoan kh

tch ra v t y cn b nn cht hn nht l t mm

1.Khoan bng dung

dch st

2. Khoan bng nc l

3. Khoan bng thi kh

Hnh 4.5. th nh hng ca trng lng ring dung dch

n cc ch tiu lm vic ca chong


50/82


guyn Vn Hi

p sut chnh lch y: P = Ptt - Pv (4.6)

Ptt- p sut thy tnh do ct p ca dung dch khoan trong l khoan.

Pv- p sut va.

H,T l su thc t ca ging v thi gian thc t khoan.

p sut chnh lch c nh hng n tc c hc khoan theo hai yu t.

- Thay i cng ca t

cng ca t y l khoan c xc nh bng cng thc:

= o + k( Ptt - Pv) (4.7)

o : cng ca t iu kin kh quyn

K l h s ph thuc vo tng loi chong khoan

Chong chp xoay K= 5,5

Chong kim cng K = 6,5Chong khoan li ct K=5


51/82


guyn Vn Hi

Hnh 4.6. nh hng ca cng t n

cc ch tiu lm vic ca chong

- Thay i lc gi gia mng t b ph hy y ging khoan

N u mt rng ca chong cm vo . Bn cnh phn b v pha di

rng chong phn a n cn ko theo mt th tch b ph hy xung quanh n

phn b ln hn th tch phn a rt nhiu ln.

p sut chnh lch gia dung dch khoan v cht lng trong va c xuhng gi mng t b ph hy. trong thi gian tc ng ca rng, t

y ln rt kh do lc ma st. p sut chnh lch cng ln bao nhiu, lc

ma st cng ln by nhiu. Sau khi rng chong ri ra khi chng, mng b

ph hy cun i di tc dng ca dng dung dch li cng kh do lc ma st

v lc vung gc vi n nh ni trn. mng b ph hy d dng

cun i di tc dng ca dng dung dch hay ca rng, p sut b mt trt

phi tng ln v cn bng vi p sut thy tnh ca ct dung dch. Cn bng

p sut xy ra do:

Dung dch khoan thm vo l hng, khe nt ca mng b ph hy, ni

tm li gim ti trng ring ca dung dch khoan tc l gim p sut chnh

lch Ptt - Pvcn gi l p sut gi. Lm tng hiu qu ph .


52/82


guyn Vn Hi

Hnh 4.7: Biu phn b lc quanh vngph hy ca rng chong.

* thot nc ca dung dch

N h ta bit thot nc ca dung dch cng ln th p sut chnh

lch Ptt - Pvcng b. Bi v vn tc cn bng p sut cng ln. Do dng

nc l khoan ta thu c vn tc ln Vch.

N hng dung dch c thot nc b n s li mt mng st c

thm b v n s gy mt gradient p sut ln trong chiu su ngp ca rng

chong. Hn na mng st y s lm chm s tip xc gia rng v v

chng hn hp vi mn khoan to nn mt hn hp do gy kh khn cho sra ca dung dch. Do nu t thnh l khoan n nh c th nn

khoan vi dung dch c thot nc ln.

*Hm lng cht rn

Hm lng cht rn bao gm st, barit, ct v mn khoan trong qu trnh

khoan. Tng hm lng cht rn tc l tng t trng ca dung dch a n

tng p sut chnh lch Ptt=Pv, hu qu l gim Vch. Hm lng cht rn s

gy mi mn cc b phn trong h thng tun hoan. Bm, ct cn khoan,

chong khoan v.v..

4.2. La chn chong khoan ph hp vi a tng

4.2.1. Cc c im ca chong

4.2.1.1. Chong khoan chp xoay


53/82


guyn Vn Hi

Chong khoan chp xoay ph hy t theo nguyn l p-v. C hai

loi c bn l chong rng nh v chong rng phay.

Chong khoan rng phay, nn c c lin khi ri phay thnh cc

rnh rng, nh vy vt liu ch yu lm t thp cc bon c cng cao, cng

loi vt liu vi thn chong. N goi ra trn b mt c ph mt lp hp kim

cng chng mi mn.

Chong rng nh c rng lm t hp kim cc bon vonfram c cng

v chng mi mn cao. Rng c ch to v c nh vo chp xoay theo

mt quy trnh cng ngh ring. Do c tnh ca vt liu rng chong m

chong rng nh thng c dng khoan trong t c cng t

trung bnh n rt cng.

Kch thc, hnh dng, dy tha ca rng chong ph thuc phn lnvo tnh cht ca t va.

+ Trong t mm, yu cu ti trng nh, chong thng c kch

thc ln nh, chp xoay nh hn, s lng rng t i, khong cch cc

rng ln, hnh dng rng nhn hn d m xuyn vo t v ct mt

lng ln t trong mt vng quay.

+ N gc li trong t cng kch thc ln s ln hn chu ti

trng ln, v vy m chp xoay cng ln hn. S lng rng trn mt chp

xoay s nhiu hn gim ti trng ln rng dng thi khong cch rng s

dy hn, rng t hn gim kh nng b mi mn.

Hnh 4.8. Cc c im ca rng chong cho tng loi a tng

( hm 1- t mm; nhm 2- t cng)


54/82


55/82


guyn Vn Hi

mi li ct c nh s lng rng ct nhiu hn va kch thc rng ct

nh hn. Cc chong ny thch hp cho khoan va t cng dn t 2 n 4.

Hnh 4.10. Cc loi chong kim cng (PDC)

4.2.2. guyn tc la chn chong khoan

la chn chong khoan ph hp cho tng khong khoan nhm nng

cao hiu qu ph hu t v y nhanh tin thi cng ging khoan ngi

ta thng la chn chong khoan da vo cc yu t sau:

* cng ca t : Cc loi chong khoan khc nhau c c ch ph

hu t khc nhau. Chong chp xoay ph hu t theo c ch p-v

v mi mn, chong cnh dt ph hu t theo c ch ct-v, chong kim

cng ph hu t theo c ch mi-ct. Chnh v vy, i tng t

s dng cc loi chong khoan ny cng khc nhau.

t c cng cao s khng thch hp cho c ch ph hu ct, do

chong kim cng c s dng khoan qua cc tng t cng n rt

cng.

t mm do s thch hp cho c ch ph hu ct-v nn chong

cnh dt thch hp khoan qua cc tng t ny.

Chong chp xoay ph hu t theo c ch p-v v mi mn nn

i tng ph hu ca loi chong ny a dng hn. Loi chong chp xoayc th c la chn ph hu t t mm do n cng hoc rt cng.

Tuy nhin, vi t rt cng th hiu qu s dng chong chp xoay khng

bng chong kim cng.


56/82


guyn Vn Hi

* H dung dch: Loi dung dch khoan v cc c tnh ca n c nh

hng n tc khoan nh kh nng ra sch y ging khoan. Mt khc p

sut y do ct dung dch to ra lun ln hn p sut thnh h, iu ny lm

gim hiu qu ph hu t ca chong khoan. V vy la chn mt chong

khoan ng thi ph hp vi cc c tnh ca t va v h dung dch

khoan l rt quan trng.

* Phng php khoan: Cc phng php khoan khc nhau s c cc

thng s ch khoan khc nhau, v d nh: khoan r to hay khoan bng

ng c chm, cc ch ti trng v s vng quay, cc c tnh khoan

nghing hay thngDo tu thuc vo tng phng php khoan m ta la

chn chong khoan cho ph hp.

Khi la chn chong khoan cn la nhng c im sau:Chong kim cng, do c tnh ca kim cng cng nhng gin nn

chu lc ct v va p thp, do khi khoan bng chong kim cng phi

khoan vi ti trng thp. Tin khoan ca chong kim cng ln lm gim

thi gian ko th khi phi thay chong l mt nhn t tch cc khi s dng

chong khoan kim cng.

i vi chong PDC: Khi s dng phng php khoan bng ng c

y nn dng chong c s rng nhiu hn trung ho s mi mn do tc

quay ln, khi khoan bng phng php khoan roto (hoc Top Drive) nn dng

chong c h thng vi phun nhm m y ging v mt chong.

4.2.3. Chn chong khoan cho Ging khoan 10003 BK10

4.2.3.1. Mt ct a cht ging khoan 10003 v cc tnh cht


57/82


guyn Vn Hi

a

cht

chi

usu

c t a t ng

tng

phn

x

g r a d ien p

sut v a v p

sut v v a

tr-c

kainozoi

a

cht

Plioxenv

t

mioxen

n2+q

N1

2

N1

1

mz

N1

3

c 1

c 2

c 3

cr-oligoxen

p23

pv pv v

pv = ptt

pv v =1,3Ptt

c 5

c 7

Hnh 4.11. S mt ct a cht ca ging 10003 BK10

* Ranh gii a tng

T 85- 700m l trm tch T v N eogen.

T 700- 1280m l trm tch Mioxen trn.T 1280- 2170m l trm tch Mioxen trung.

T 2170- 2980m l trm tch Mioxen di.

T 2980- 3190m l tng Oligoxen.

T 3190m tr xung di l tng mng.


58/82


guyn Vn Hi

* hit va

Gradien nhit ca va: 2,50C/100m.

* cng ca t

T su 85 2170m: t mm v b ri, c cng t I II

theo khoan.

T su 2170 2980m: t tng Mioxen h mm v trung bnh

cng. cng t III IV theo khoan.

T su 2980 3190m: t tng Oligoxen trung bnh cng n

cng. cng t V VIII theo khoan.

T su 3190m tr xung di: t mng kt tinh t cng n

rt cng. cng t VIII IX theo khoan. t n nh v bn vng.

4.2.3.2. La chn cu trc ging khoanDa vo cc c im phn tch v iu kin a cht trn ta c th la

chn cu trc ging 4 ct ng l:

Ct ng chng nh hng: Da vo kinh nghim khoan ca cc ging

m Bch H, ta thng s dng ct ng cch nc loi 72016D. Thi

cng bng phng php ba my ng ng xung su 120m di y

bin.

Ct ng chng dn hng: Theo kinh nghim th lp t t b ri

mi hnh thnh, c gn kt km nn thnh ging khoan d sp l khi tathay i ch khoan. V vy ta thng chn chiu su ca ct ng ny ti

chiu su 400 m, trm xi mng ton b chiu di ct ng.

Ct ng trung gian th nht: Do khoan qua vng bin ng t l ct

st ht trung t mm n trung bnh, c hin tng mt dung dch nh nn ta

tin hnh chng ng chng trung gian n chiu su 2170m, trm xi mng

ton b chiu di ct ng.

Ct ng trung gian th hai: trnh hin tng sp l thnh ging

khoan t su 2170 - 2980m khi khoan qua tng Mioxen ta cn tin hnh

chng ct ng trung gian th hai n ht su 2980m, tin hnh trm ximng mt phn, t su 1970 2980m.

Ct ng trung gian th ba (ct ng chng lng): T on 2980m -

3190m c hin tng sp l thnh ging khoan mnh nn ta tin hnh chng

ct ng chng lng on ny, t su 2970 3190m.


59/82


guyn Vn Hi

Khi khoan m va on mng phong ho, t su 3190m do t

y cng v n nh nn ta tin hnh khoan qua v khng chng ng

chng on ny nhm khai thc ging thn trn vi chiu dy 1850m.

4.2.3.3. La chn ng knh chong cho qu trnh khoan

Chn ng knh ca chong khoan ch yu da vo ng knh mufta

ca ng chng (Dm) v khong h trm xi mng gia mufta v thnh ging

khoan ().

ng knh ca chong khoan (Dc) c tnh theo cng thc sau:

Dc= Dm+ 2.= Dm+ (4.8)

Trong : Dc: ng knh chong khoan

Dm: ng knh mufta.

: khong h gia mupta v vnh ging khoan.Sau khi xc nh c ng knh chong khoan ngi ta tin hnh

xc nh ng knh ca ng chng pha trn trc n. Hiu s gia ng

knh trong ca ng chng (dtg) v ng knh chong khoan th qua n khng

c vt qu 6 8 mm:

dtg= Dc+ ( 6 8 ) mm. (4.9)

Da vo cc s liu tnh ton ta la chn ng knh chong v ng

knh ng theo kch thc gn nht.

Chng c tra theo bng 1.2 v 1.3 sau:

Bng 4.1.Bng qui chun tnh theo cp ng knh ng chng ca Gost

ng knh ng chng

(mm)

- khng ln hn

(mm)

114, 127 10 - 15

140, 146 15 - 20

168, 178, 194 20 - 25

219, 245 25 - 30

273, 299 30 - 35

324, 340, 351 35 - 45

377, 407, 426 45 - 50


60/82


guyn Vn Hi

Bng 4.2. Bngkch thc ng chng v ng knh Mufta tong ng

Muftang knh ng

chng

(mm) ng knh (mm) Chiu di (mm)

114 127 159

127 142 165

140 154 171

146 166 177

168 188 184

178 196 184

194 216 190

219 245 197

245 270 197

273 299 203

299 324 203

324 351 203

340 365 203

351 376 229

377 402 229

407 432 228

426 451 229

508 533 228


61/82


guyn Vn Hi

Cn c vo lu lng khai thc v c tnh cu to tng sn phm l

mng. Do ging c thit k l dng thn trn. ng knh chongkhoan m va sn phm l chong c ng knh 165,1mm.

N h vy ta tnh ton cho cc khong khoan nh sau:

*Tnh ng trung gian th 3(ng chng lng)

dtg3= 165,1 + (6 8 mm) = 171,1 173,1 mm,

Cn c vo b dy ng trung gian ta c D tg3= 194mm, tra bng ta c:

Dm(tg3)= 216mm.

Tnh ng knh chong cho on khoan ng trung gian th 3:

Ta c: Dc(tg3)= Dm(tg3)+ = 216 + 25 = 241 mm

Theo qui chun chong ta c Dc(tg3)= 243mm.

N hng thc t s dng loi chong 215,9mm khoan qua on

ny v s dng loi ng chng c ng knh 194mm.

*Tnh ng trung gian th 2

Ta c: dtg2= 215,9 + (6 8 mm) = 221,9 223,9mm,

Cn c theo b dy ca ng ta c D tg2= 245 mm, suy ra Dm(tg2)= 270mm.

Tnh ng knh chong khoan on ng trung gian th 2:

Ta c Dc(tg2)= Dm(tg2)+ = 270 + 35 = 305 mm

Theo qui chun chong ta c Dc(tg2)= 311,1 mm.*Tnh ng trung gian th nht

Ta c: dtg1= 311,1 + (6 8 mm) =317,1 319,1mm

Cn c theo b dy ca ng ta c D tg1= 340mm.

Tnh ng knh chong khoan on ng trung gian th nht:

Ta c: Dc(tg1)= Dm(tg1)+ = 340 + 45 = 395mm

Theo qui chun chong ta c Dc(tg1)= 444,5 mm.

* Tnh ng dn hng

Ta c ddh= 445 + (6 8 mm) = 451 453mm

Cn c theo b dy ca ng ta c Ddh=508 mm.Theo qui chun ta chn c chong Dc(dh)= 660,4 mm.

N h vy ta c bng cu trc ging khoan nh sau:


62/82


63/82


guyn Vn Hi

Bng 4.3.Bng cu trc ging khoan 10003

Loi ng chngchiu su th

(m)

ng knh

ng (mm)

ng knh chong

(mm)nh hng 120 720 ng ba my

Dn hng 400 508 660,4

Trung gian1 2170 340 444,5

Trung gian2 2980 245 311,1

ng lng 3190 194 215,9

on ging thn trn 165,1

4.2.3.4. Phn chia khong khoan

Da trn cc s liu v a cht v dng thn ging khoan ta c cc

khong khoan cho ging 10003 nh sau:

Bng 4.4. Phn chia khong khoan ca ging khoan 10003

STTKhong khoan theo chiu su thng

ng (m)

Khong khoan theo chiu su

thn ging (m)

1 0 400 0 400

2 400 710 400 7143 710 2170 714 2237

4 2170 2351 2237 2430

5 2351 2980 2430 3072

6 2980 3190 3072 3281

7 3190 5040 3281 5131

4.2.3.5. La chn chong khoan cho tng khong khoan

* T 0 400 m

ng knh ng chng l 508mm, ng knh chong theo tnh ton l

660,4mm.


64/82


guyn Vn Hi

t thuc h t v N egoxen, t mm v b ri, c cng t I

II theo khoan.

T cc d liu trn ta chn chong cho khoan tng ny l chong 660,4

3S. Chong c ng knh 660,4mm, chiu di 800mm, trng lng 617kg,

m AIDC l 121. T m hiu chong ta thy chong thuc loi rng phay c

cng trung bnh, thch hp khoan vi cc tng t mm n trung bnh,

b ri. Chong c trang b bi a, khng bo v thn chp xoay.

*T 400 714m

ng knh ng chng l 340mm, ng knh chong theo tnh ton l

444,5mm.

t thuc h t v N egoxen, phn t gm ct, st v st bt xen

k si mu xm, mm v b ri, t tng ny c cng t I II theo khoan, d ph hy nhng n nh km d sp n thnh ging khoan.


3SK. Chong c ng knh 444,5mm, chiu di 520mm, trng lng 225kg.

M hiu chong l 126. T m hiu chong cho thy chong thuc loi rng

phay c cng v mi mn trung bnh. Thch hp khoan t mm n

trung bnh, t mi mn. Chong c trang b trc ma st, kn.

* T 714 2237m

ng knh ng chng trong khong khoan ny l 340mm, ng knh

chong theo tnh ton l 444,5mm.t thuc tng Mioxen trn v trung, gm cc lp ct b ri, ct khng

gn kt, d gy sp n thnh ging khoan gy kt mt b khoan c. Trong xt

i khi c ln kp than. cng ca t t I II theo khoan.


3SK. Chong c ng knh 444,5mm, chiu di 520mm, khi lng 225kg.

M hiu chong l 126. T m hiu chong cho thy chong thuc loi rng

phay c cng v mi mn trung bnh. Thch hp khoan t mm n

trung bnh, t mi mn. Chong c trang b trc ma st, kn.

* T 22372430m

ng knh ng chng l 245mm, ng knh chong khoan theo tnh

ton l 311,1mm.


65/82


guyn Vn Hi

t l trm tch Mioxen di, kt cu ch yu l s xen kp cc lp

ct, st v st bt, ct xm sng, xm, st mu sc s loang l kt dnh do

(c bit l tng trn ca ip). bt xm, nu phn di ca ip. y

l tng chn. cng ca t t III IV theo khoan.


ATX G3. Chong c ng knh 311,1mm, chiu di 350mm, khi lng

l 100kg. M hiu chong l 135, t m hiu chong cho ta thy chong

thuc loi rng phay ,c cng kh cao, c th khoan trong t cng v

mi mn tng i. Chong c trang b bi a kn, c bo v calip gip

chng mi mn.

*T 2430 3072m

ng knh ng chng l 245mm, ng knh chong khoan theo tnhton l 311,1mm.

t l trm tch Mioxen di, kt cu ch yu l s xen kp cc lp

ct, st v st bt, ct xm sng, xm, st mu sc s loang l kt dnh do

(c bit l tng trn ca ip). bt xm, nu phn di ca ip. y

l tng chn. cng ca t t III IV theo khoan.


ATX G3 . Chong c ng knh 311,1mm, chiu di 350mm, khi lng

l 100kg. M hiu chong l 135, t m hiu chong cho ta thy chong

thuc loi rng phay ,c cng kh cao, c th khoan trong t cng vmi mn tng i. Chong c trang b bi a kn, c bo v calip gip

chng mi mn.

* T 3072 3281m

ng knh ng chng l 194mm, ng knh chong khoan theo tnh

ton l 215,9mm.

t l tng Oligoxen. Thnh phn thch hc bao gm cc lp ct kt

ht mn n trung, mu xm sng xen k vi cc tp dy st kt mu nu. c

bit pht hin trong tng trm tch ny cc thn phun tro c thnh phn

thay i. i su xun gp si kt v cc mnh mng to thnh tp lt y

ca lp ph trm tch. cng t V VIII theo khoan. Vi cc c im

v a cht cho thy y l a tng kh cng, cc thnh phn ct kt d gy


66/82


guyn Vn Hi

mi mn chong khoan. Thnh phn mng c cng cao c th gy va

p ph hy hoc kt mt chong khoan.


GT G1 chong c ng knh 215,9mm, chiu di 350mm, trng lng

40kg. M hiu chong l 116, t m hiu chong cho ta thy chong thuc

loi rng phay, c cng cao, b mt rng v thn chong c gia c bng

vt liu chng mi mn.

* T 3281 5131m

y l tng cui cng ca ging, ging c thit k l dng thn

trn. ng knh chong khoan m va sn phm l chong c ng knh

165,1mm.

Tng sn phm l mng, t mng kt tinh t cng n rt cng. cng t VIII IX theo khoan. t n nh v bn vng.

T cc d liu trn ta chn chong cho khoan tng ny l chong chong

165,1 ATJ 22, chong c ng knh 165,1mm, chiu di 310mm, trng

lng 21kg. M hiu chong l 517, t m hiu chong cho thy chong

thuc loi rng nh. Rng c lm t vt liu cac bon vonfram c cng

v chng mi mn cao. Chong c trang b trc ma st, kn, c bo v

calip, thch hp khoan trong a tng cng, mi mn.

N h vy ta c bng tng kt la chon chong cho cc khong khoan.

Bng4.5. Bng chong chn cho cc khong khoan

Khong khoan (m) Loi chong

0 400m 660,4 - 3S

400 714m 444,5 3SK

714 2237m 444,5 3SK

2237 2430m 311,15 ATX G3

2430 3072 311,15 ATX G3

3072 3281m 215,9 GT G1

3281 5131 165,1 ATJ 22


67/82


guyn Vn Hi

N h vy ta c cu trc ging s dng chong cho cc a tng nh sau:

Hnh 4.13. Cc loi chong cho khoan tng a tng


68/82


69/82


guyn Vn Hi

4.2.4. Tnh cng sut ph hy t ca chong chp xoay cho cc

khong khoan

Cng thc tnh cng sut ph hy t cho chong chp xoay:

N = (3 4).10-4.P.n.Dc (4.10)

Trong : P: ti trng y (tn)

n: s vng quay chong (vg/ph)

Dc: ng knh chong (mm)

Xc nh cng sut ph hy cho khong khoan t 0 400m

* Xc nh ti trng y cho khong khoan t 0 400m

- Ti trng nh nht chong ph hu t trong min ph hu th tch

c tnh theo cng thc:

G1= F. (4.11)Trong :

: Gii hn bn nn ca t .

F: Din tch tip xc ca rng chong vi t y l khoan

2

.. KDnF ct=

(4.12)

nt: H s ph ca rng chong. n t= 1,05 2

K: H s mn ca chong. K = 11,5

Dc: ng knh chong khoan. Dc= 660,4 mm

Tra bng cc thng s ta c:

Gii hn bn nn ca t : = 10 kG/mm2

Chn nt = 1,5; K = 1,1

Thay cc thng s trn vo cng thc tnh F ta c:

283,5442

1,1.4,660.5,1mmF ==

Vy ta tnh c ti trng: G1= 10. 544,83 = 5448,3 kG = 5,4483 Tn

- Xc nh ti trng lm vic nh mc ca chong khoan G2:

G2= GT. Dc (4.13)

Trong :

GT: Ti trng ring (ti trng n v).

Tra bng ta c:

Ti trng ring: GT= 200 kG/cm


70/82


71/82


guyn Vn Hi

c: H s ph thuc vo cong ca ging. Vi ging c gc

nghing 30th: c = 18,8.10-5

d: Trng lng ring ca dung dch khoan. d= 1,03 T/m

3

Dc: ng knh chong khoan. Dc= 0,6604 m

L: Chiu di thn ging. L = 400 m

+ N c: Cng sut tiu th chong

N c= 34,2.10-4.K.Gc.Dc.nmax

K: H s mn ca chong. K = 1,1

Gc: Ti trng y.Gc = 8 tn = 8000 kg.

Thay cc s liu trn vo cng thc ta c:

- Cng sut tiu th b mt:

N bm= a1.nmax+ a2.nmax2

= 25.10-3

.nmax+ 0,12.10-3

.nmax2

- Cng sut quay ct cn khng ti:

N kt= 21,11. 10-3. nmax

1,7

- Cng sut tiu th chong:

N c= 34,2.10-4.K.Gc.Dc.nmax = 34,2.10

-4.1,1.8000.0,6604. nmax= 19,87. nmax

- Tc quay cc i ca chong l nghim ca phng trnh:

N max= N bm+ N kt+ N c (4.17)

1395 = 25.10-3.nmax+ 0,12.10-3.nmax

2+ 21,11. 10-3.nmax1,7+19,87. nmax

Gii phng trnh trn ta c: nmax= 68,5 v/p- T tc quay nmax tm c kt hp vi kinh nghim ca cc ging

khoan trc ta chn tc quay hp l ca chong khoan trong khong

khoan ny l: n = 50 60 v/p.V thc t cng chn tc d quay ny cho

khong khoan trn.

*h vy cng sut ph hy t cho khong khoan ( tnh cho s vng

quay v ti trng ln nht):

N = (3 4).10-4.P.n.DcN

= 3,5.10-4.8000.60.0,6604 = 111 (KW).

* Tng t nh trn, ta tnh c ti trng y, s vng quay v cng sut

ph hy t cho cc khong khoan khc, kt qu tnh ton ny c th

hin trong bng sau:


72/82


73/82


guyn Vn Hi

N u khng c mt ch thit lp ph hp c th dn n ph hy

chong trong khi khoan ( nh trong trng hp vi phun ko di ), hoc

chong c th b kha li trong bn r to do thit b g hc chong khoan b

bin dng.

Bng km theo ch ra yu cu v vic thit lp m men xon cho mt s

ch ni v cc loi chong, trng hp vn khng cht hoc qu cht c

th dn n vt nt sm v phi tin hnh sa cha kp thi.

Bng 4.8. Bng thng s m men xon cho cc loi chong kim cng

Bng 4.9. Bng thng s m men xon cho chong chp xoay

ng knh

chongim ni M men xon

(in) (in) (daN .m) ( Lb.ft)3 3/4 2 3/8 400-480 3000-3500

4 5/8 2 7/8 800-950 6000-7000

5 1/8 - 7 3/8 3 1/2 950-1200 7000-9000

7 1/2 - 9 3/8 4 1/2 1600-2200 12000-16000

9 1/2 - 14 1/2 6 5/8 3800-4300 28000-32000

14 5/8 - 18 1/2 7 5/8 4600-5400 34000-40000

18 5/8 8 5/8 5400-8100 40000-60000

ng knh

chongim ni M men xon

(in) (in) (Da.n) (Lb.ft)

3 11/16 - 4 1/2 2 3/8 400 - 480 3000 - 3500

4 17/32 - 5 2 7/8 800 - 950 6000 - 7000

5 1/32 - 7 3/8 3 1/2 950 - 1200 7000 - 9000

7 13/12 - 9 3/8 4 1/2 1600 - 2200 12000 - 160009 13/12 - 14 1/2 6 5/8 3800 - 4300 28000 - 32000

14 9/16 - 18 1/2 7 5/8 4600 - 5400 34000 - 40000

18 9/16 & > 8 5/8 5400 - 8100 40000 - 60000


74/82


guyn Vn Hi

N h chng ta thy thng s m men xon c chng bng mt phn hai

ch ni bnh thng( tng ng 70% i vi ch ni nh v 40% i vi

ch ni ln).

N u mt chong c c a vo khoan tip th phi ch cc im

sau:

- Kim tra k ren ni, ren ni phi m bo theo tiu chun ca API

- Bi trn li chong nu n khng c trang b m lm kn ln.

-Kim tra hot ng trc v chp xoay, c th xoay bng tay ( bi

a) hoc s dng cha vn( trc ma st), nu chng khng quay th phi

loi b.

- Kim tra m lm kn v h thng p sut b tr p sut, gip khc

phc cc ch mn gn np hoc cc l thng gi b bt do ht st hay mnkhoan.

- Cn ch n cc thng s chong ( kiu chong, s lp rp, s seri,

kch c vi phun) trn bn ghi ca chong trc khi a chong vo hot

ng, v cc thng tin lun c trn u ni ca chong v c th b ty

i do n mn.

- Trong h dung dch mn khoan gc nc v thnh h nhiu st, c s

bi trn hon ton i vi b mt chong cng vi s bi trn a nng trc

khi h xung ging c th gip vic hot ng c trn chu v h s an ton

cao hn.4.3.2. H xung

trnh nhng s c vi chong trong khi h xung:

Th chm b khoan c qua on ging cong gp, qua cc tng khng

bnh thng ca ging.

Khng cho php chong va mnh vo y, cn thn on ni cui cn

khoan. C b khoan c c di chuyn xung di mt cch t t vi s

vng quay thp v lu lng mn khoan ln. Sau tng dn ti trng v

s vng quay mt cch t t n gi tr tnh ton.

N u trc chong mt mt s ng knh cn thit, ta cn phi khoan

m rng thnh ging trn mt vi chiu di trc khi tip tc th xung y

mt ln na( thng khoan bng cc chong chuyn dng cho khoan m rng

thnh ging). Trong sut qu trnh khoan m rng, cc trc phi chu lc p


75/82


guyn Vn Hi

bt thng t thnh ging, do khng nn khoan m rng lin tc trong mt

thi gian di.

N n s dng chong PDC khoan m rng. N hng ch vng calip

ngoi chong PDC s chu ti trng ln v rung cao, do c tnh ca

chong trong trng hp khoan m rng vi chiu di ln ( 500m hoc hn)

vi chong PDC, tt hn l loi ra khi ging v thay bng chong ba chp

xoay.

S dng chong PDC khoan m rng ch nn s dng nhng loi

c thit k c bit, hay c gia cng chuyn dng nh calip gn rng cc

bon vonfram c chng mi mn cao, hoc mt s loi chong c cu to

c bit gip chng s mi mn calip.

Hnh 4.15. Chong PDC c gia c calip chng mi mn

( 1- Calip c gia c rng PDC )

Trong hu ht cc trng hp khoan m rng c thc hin vi ti

trng thp v tc quay chm gim mn hng cho chong v hao ht

kch c calip( v ngay c khi ti trng nh nhng din tch y l khoan thu

hp cng s to ng sut ln).

4.3.3. Chm yTrc khi khoan phi lm sch y ging khoan. Lm sch cc ph

phm, vn cng sinh ra trong qu trnh khoan. V nu chong khoan tip

xc trc tip vi cc ph phm khi quay s nhanh chng mi mn chong c

bit l i vi chong kim cng.


76/82


guyn Vn Hi

Trong giai on u ca qu trnh khoan mt chong mi s to ra khun

mu ca ging khoan nhng n y ging hnh dng s rt khc so vi khun

m ban u, do c s thay i v hnh dng ca chong lm cho hnh dng

y ging khng ging nhau. V vy khi bt u tip tc khoan khng c s

dng ti trng ln chong v s vng quay ln nht.

Khi chm n y:

- iu chnh my bm t lu lng yu cu cho ch khoan tnh

ton v kim tra p sut ng dng bn.

- Tun hon y ging lm sch y trong khong 30s.

- Chm n y mt cch nh nhng vi tc quay chm v kim tra

m men xon.

- t chong v tr cch y 30cm bng cch trng lng nhln chong( khng nh s lm chong ny ln) sau tng c tc quay v

trng lng ln chong.

- T y s tm c cc thng s kt hp gia ti trng ln chong v

tc quay hp l trong mt thnh h nht nh.

* i vi chong PDC

Vi t mm, c th tng thm mt tn ti trng ln chong ti

u tc quay.

N u va cng, khi chm y cn gim ti trng ln chong v tc

quay( khong 70 vg/ph). Sau s tng ti trng n gi tr ti u( trnhph hy u ct do va chm vi cc ph phm rn y ging khoan).

Chong nn c t ln y ging trc khi cho chong quay bnh thng.

4.3.4. Khoan

Cn thit s dng ti trng khng i trong qu trnh khoan, nu khng

c th gy ra ng sut khng cn thit ln b phn

Mt chc nng quan trng ca lu lng mn khoan l lm sch v

lm mt chong. N u v mt vi l do no m lu lng bn khoan khng

th duy tr mc thch hp, tt hn l dng khoan v sa cha. S dng cc

thng s khoan thp hn hoc thay i chong.

N n s dng ch khoan t ng cng nhiu cng tt, c bit l th

khoan khng nn iu chnh ti trng ln chong. iu ny rt quan trng v


77/82


guyn Vn Hi

cc s liu ch ra khi ch khoan t ng c s dng th tui th ca

chong tng 40%, ch yu l do ti trng ln chong c gi n nh.

Vi chong PDC v m rng thm vi chong ba chp xoay, m men

xon v tc quay chong thay i bt thng, hin tng ny c gi l

stick and slip. Hin tng ny sut hin kh thng xuyn thnh h

mm. Ct cn khoan hot ng nh mt l xo khi chong cm vo va, nng

lng xon c tch tr trong ct cn khoan( lc ny tc ca chong gn

nh bng khng) v c gii phng mt cch mnh lit khi m men xon

chong tri hn va. Ti thi im ny chong v b khoan c y ging

c tc quay/pht ln nht sau t ngt dng li khi chong chun b

m vo va mt ln na. S cng hng ny c th b ph v do cch s

dng cc s kt hp khc nhau gia ti trng ln chong v s vng quay(gim ti trng,

Trong qu trnh khoan phi ch cn thn khi khoan qua cc on a

tng cha c o c, p dng ti trng v s vng quay nh phng

cc s c khng mong mun.

Mt hin tng thng xuyn xy ra trong qu trnh khoan l chong

khoan b kt mt, do t va km bn vng, hoc do sp l thnh ging.

Kt mt dn n gim m men xon, gim tc khoan v lm tng p sut

ng dng bn. Chnh v vy trong qu trnh khoan lun lun theo di xt sao

cc thng s hot ng ca chong nh s vng quay, ti trng, lu lng, psut dung dch qua vi phun. N u c s thay i bt thng cn c phn tch

ng n v c gii php khc phc.

Hin tng kt mt chong c th hn ch bng cch ko chong ln

khi vng kt mt vi tc chm, gim ti trng sau tng ng thi s

vng quay v lu lng dung dch.

4.3.5. Th nghim khoan y mn

- Th nghim khoan y mn i lc c tin hnh gip tm ra s kt

hp tt gia ti trng v tc quay.

- Th nghim khoan y mn c tin hnh trong nhng trng hp sau:

Tin hnh khoan ln u tin.

Khi va thay i.

Khi tc ct gim.


78/82


79/82


guyn Vn Hi

- Trc khi khoan phi la chn, nh gi chong khoan ph hp. Thc

hin cc bin php an ton m bo hiu qu qu trnh khoan ng thi

gip nng cao tui th ca chong.

Trc khi khoan th phi c cc hot ng khoan thm d kho st t

trc hoc da vo cc s liu ca cc vng ging k cn c cc hiu bit

y v cu to a tng ca vng t cn khoan. T phn loi cng,

mi mn, sp l, kt xt... ca t .Vi mi loi a tng c dy v

c tnh ring m ta la chn chong cho ph hp tng loi a tng. V d

nh vi a tng mm, nhiu xt, d xp n ta thng dng chong khoan

chp xoay kiu rng nh cng trung bnh. Vi a tng cng, mi mn,

nhit va cao ta c th s dng chong khoan hp kim cng hoc chong

kim cng a tinh th..vv..Xc nh cc hin tng bt thng c th xy ra trong khi khoan nh

hin tng sp l thnh ging khoan, kt mt c cc bin php bo v

chong khoan nh khoan doa, gia c thnh ging trc khi khoan tip.

Lm sch y l khoan trc khi khoan: m bo l y l khoan c

sch s, khng cn cc mnh vn, ph phm rn. Cc ph phm rn c th

ph hy chong khoan trong khi khoan.

- Trong khi khoan: S dng cc thit b khoan, cc thit b ph tr ph

hp. C ch khoan vi cc thng s khoan ph hp tng loi thit b.

Vi mi loi chong khoan c th c cc nh sn xut quy nh ccthng s lm vic hiu qu nh s vng quay trn pht, ti trng ln chong,

nhit , p sut lm vicCng vic ca ngi k s khoan l kt hp cc

thng s c mt ch khoan ph hp vi tng loi a tng. Trnh vt

qua cc thng s gii hn ca chong c th ph hy chong hoc lm gim

tui th.

S dng b lc bn lc tch cc ht c kch thc kh ln, ngn

chn hin tng bt vi phun, m bo lu thng dung dch c thng sut

qu trnh khoan.

Theo di st xao qu trnh khoan, pht hin cc hin tng bt thng

khi khoan nh cc thay i v ti trng ln chong, tc

nghien cuu su mon hong cua choong khoan

Documents