A.C. DRILLING - TRAND OR NECESSITY

Authors:

ph. d. eng. Ion POTARNICHE - general manager

dipl. eng. Sergiu ROZENBERG – technical directordipl. eng. Cornelia POPESCU

ICPE ACTEL Privately joint-stock company with 100% Romanian capital

Producer of : customized turnkey solution and products of power electrical drives

Exporter

Member of chambers of commerce, professional associations ( ACFR)

ICPE ACTEL – the single Romanian supplier of power electricaldrives system for offshore and onshore drilling rigs

ICPE ACTEL’s expertise 40 years in offshore and onshore drilling

Offshore drilling rigs:

•GLORIA•FORTUNA •PROMETEU •ORIZONT •ATLAS•SATURN •JUPITER

1976 –GLORIA

(ICPE ACTEL’s Archive photo)

Drilling electric drives systems

A brief history D.C. main motors

•Ward –Leonard systems

•Magnetic amplifiers

•Converters with thiristors

A.C. main motors

•Frequency converters electric drillings

Main motors

Converter typeControl

typeCommand

type

D.C. SCRA.C./D.C.SIMOREG DC MASTER

Controlled speed

PLC

A.C. VFD

A.C./A.C. SINAMICS G150

A.C./A.C. SINAMICS S120,with D.C. current bus-bar

for all main motors

~=

~~

The Drilling electric drives systems - today

~=

~=

~=

~=

~= ~=

D.C. Drilling- Principles- DisadvantagesUm= k x Ua x cos α

Um = motor’s voltage

k= converter’s constant

Ua = supply voltage

α = firing angle of converters thyristors

Um= kem x Φ x n + RIkem = rotorical electromagnetic constantΦ = statoric flown= motor speedR= rotoric resistanceI = rotoric current

If RI ≅ 0, then n ≅ cosα, cosα med = 0,4...0,5

For medium speed nmed

P = Ua x Ia x cosϕQ = Ua x Ia x sin ϕ

For cos ϕ = 0,4 and sin ϕ = 0,92cos ϕ = 0,5 and sin ϕ = 0,866

~=

M=

Um

NUa

D.C. Drilling - Conclusions

Machine work at medium speed

Consumes:

•P active power

•2 x Q reactive power

•P loss active power along the transport lines

A.C. Drilling – Principle- Disadvantages

PrincipleUm = kη x Ua

kη = conversion factor,

kη = < 1, (usually kη = 0,96)

Machine work at medium speedConsumes:

P active power

≅ ½ Q reactive powerP loss active power along the transport lines

~~ ==

M=

Um

NUa

=L Ui

C

LC filter If cos ϕ = ct = 0,86, then sin ϕ = 0,5

DisadvantageThe bigger price of A.C./A.C. converter (P =ct )Recompensed by resulted economies in few months

JUPITER offshore rig SATURN offshore rig

(2009)

Main motors 11 x D.C. motors of 850 kW

2 x draw works

3 x 2 pumps

1 rotary table

2 x lifting pumps

11 x A.C. motors of 850 kW

2 x draw works

3 x 2 pumps

1 rotary table

2 x lifting pumps

Power supply: 5 x motor-generator sets x 1500 kVA

5 x motor-generator sets x 1500 kVA

Fuel consumption /hour

FC D.C. 0,8 x FC D.C.

CONCLUSIONS - Comparative example

Advantages of using of A.C./A.C. converters for drilling

Apply to all types of supply : Lines of 6 kV, 10 kV, 20 kV Diesel motor –generator sets Both of themFast and efficiently communication by PROFIBUS interface Easily parameters setting by graphic control panels: Local On the drilling chief deskLow THD factor by: line reactors on the rectifiers input rectifiers supplied by 2 transformers with 30° displacement of phaseHigh efficiency (η)Saved energy by power management High power factor ( cos ϕ = 0.86…0,92)Diagnosis, monitoring, failures memory, short dead times A.C. motors advantages: strong, simply, safety, high dynamical performances

INTERNAL REFERENCES

ONSHORE DRILLING

UPETROM 1 Mai Ploiesti, UPET Targoviste, UZTEL, DAFORA Medias, FOSERCO Tg. Ocna, FORAJ SONDE Tg. Mures, etc.

OFSHORE DRILLING RIGS:

GLORIA, ATLAS, FORTUNA, JUPITER, HORISONT, PROMETEU, SATURN, jackets on Black Sea

ICPE ACTEL is member of ACFR - Romanian Drilling Contracting Association.

EXPORT:

FranceIndonesiaIraqLibya

KazakhstanRussiaUkraine

United Arab Emirates

ICPE ACTEL’s ADVISE:

Use the A.C. DRILLING !

ROMANIA, BUCHAREST

313 Splaiul Unirii , District 3, OP 77

Tel: 0040-021-346.86.90, 0040-021-346.86.91

Fax: 0040-021-346.72.67

E-mail: office.actel@icpe-actel.ro

http://www.icpe-actel.ro

CONTACT:

Thanks for your attention!

www.icpe-actel.ro