Calculadora de Sistema de Energia para Campos de Petróleo
Dimensionamento da distribuição elétrica para um campo de petróleo remoto — cargas de bombas de cavalo mecânico, bombas de injeção e motores ESP, configuração de subestação tipo caixa pré-fabricada, verificação de queda de tensão na partida do motor e opção off-grid.
As cargas em campos de petróleo são amplamente distribuídas e frequentemente off-grid, portanto a arquitetura correta é uma subestação pré-fabricada (tipo caixa) por agrupamento, com alimentadores BT curtos. Esta calculadora agrega bombas de cavalo mecânico, bombas de injeção e motores ESP, aplica um fator de demanda, verifica a queda de tensão na partida do maior motor e configura a subestação tipo caixa — apenas o lado elétrico.
ESP soft-start + speed control · downhole pump protection
5
📐 Single-line diagram
⚙️ Electrical schematic (protection & metering)
⛳ Grounding grid layout
🔌 Cable schedule & routing
🗄 Switchgear arrangement
🛡 Protection configuration
📋 Protection settings
Circuit
Protection
Setting
Time
Standard
HV incoming 10 kV
50 instantaneous
924 A
inst
IEC 60255-151 / IEEE 242
HV incoming 10 kV
51 overcurrent
139 A
0.5 s
IEC 60255-151 / IEEE 242
HV incoming 10 kV
51N earth-fault
23 A
0.5 s
IEC 60364-4-41
Transformer 2000 kVA
87 differential
23 A
inst
IEEE C37.91 / GB/T 14285
Transformer 2000 kVA
49 thermal overload
86% of rated
alarm 90%
IEC 60076-7 / IEEE C57.91
LV incoming 0.4 kV
50 instantaneous
23094 A
inst
IEC 60947-2
LV incoming 0.4 kV
51 overcurrent
3464 A
0.3 s
IEC 60947-2 / IEC 60255
LV incoming 0.4 kV
51N earth-fault
577 A
0.3 s
IEC 60364-4-41
Beam pump 1
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
Beam pump 2
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
Beam pump 3
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
Beam pump 4
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
Beam pump 5
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
Beam pump 6
50/51/51N (MCCB)
Ir 141 A - Im 1026 A - Ig 26 A
0.1 s (grading)
IEC 60947-2 / IEC 60255
+23 more feeders
50/51/51N (MCCB)
per feeder load
0.1 s (grading)
IEC 60947-2
Settings are illustrative starting points — confirm with a protection coordination study per IEC 60255 / IEEE 242.
📚 Calculation book
CALCULATION BOOK
2000 kVA - 10kV/0.4kV - single - illustrative
1. Load calculation
Standard: IEC 60076 - IEC 60364-5-52
Parameter
Formula
Value
Connected load
P = sum(kW)
2,190 kW
Demand factor
Kd
0.75
Demand power
Pd = P x Kd
1,643 kW
Power factor
cos(phi) before -> after
0.85 -> 0.95
Design apparent power
Sd = Pd / cos(phi)
1,729 kVA
Transformer loading
Sd / Srated
86%
2. Short-circuit calculation
Standard: IEC 60909
Parameter
Formula
Value
System impedance (pu)
Zs = S / Ssc
0.80% (on 2000 kVA base)
Transformer impedance
Zt = Z%
4%
Total impedance
Z = Zt + Zs
4.80%
LV prospective Isc
Isc = In / Z
60.1 kA
HV prospective Isc
Isc = Ssc / (sqrt(3) x V)
14.4 kA
Breaking check
Icu >= Isc
LV 65 kA (1.1x margin) PASS
3. Voltage drop
Standard: IEC 60364-5-52 Annex G
Parameter
Formula
Value
Main feeder
dU = sqrt(3) x I x L x R / V
240 mm2 - dU 2.01% @ 120 m
Limit
max 3%
within limit
Transformer volt. reg.
dU ~ loading x Z% x sin(phi)
1.1% at full load
4. Reactive power / harmonics
Standard: IEC 61921 (PFC) - IEEE 519 (harmonics)
Parameter
Formula
Value
Required compensation
Qc = Pd x (tan1 - tan2)
478 kvar
PFC bank
standard step
500 kvar
Detuned reactor
p = 6%
30.0 kvar @ 6% (anti-resonance)
5. Grounding
Standard: IEC 60364-5-54 earthing arrangements and protective conductors LV earthing target 10 ohm (TN systems); 4 ohm used as a conservative design target - target 4 ohm
Parameter
Formula
Value
Single rod resistance
R1 = rho/(2 x pi x L) x ln(4L/d)
39.6 ohm
Rods required
n = R1 / (target x 0.8)
13 rod(s) <= 4 ohm
Rod spec
dia x length
20 mm x 2.5 m
This calculation book is illustrative it consolidates the computed values with the referenced standards. A licensed engineer must verify and seal final design documents for construction.
Cable & grounding pricing:Cable conductors and grounding are priced from the confirmed cables-trays-grounding price reference (per-metre copper YJV; aluminium remains POA). The main copper busbar is POA — its length is project-specific.
Busway (high-current feeders):LV current 2887 A exceeds the 2500 A busbar limit — a 4000 A busway trunking system is specified instead of parallel cables.
Motor starting:Largest motor 250 kW started Soft starter draws a 2.3% bus dip (within the 15% limit).
Distributed load:Oilfield loads are widely distributed — an oil-immersed transformer substation per cluster keeps LV feeders short and reduces cable cost.
Off-grid:Grid-connected: supply via 10 kV overhead/feeder line.
Injection pump & ESP drives:High-pressure injection pumps use soft starters with overload/underload protection; ESP motors use variable-frequency drives for soft starting and production-rate control — quoted per project.
Scope:Electrical power side only — mechanical/petroleum engineering (API wellhead/rod-pump specs) is outside this calculator.
Como foi calculado
Como funciona o dimensionamento
Carga conectada = Σ (unidades × kW por unidade). Demanda P = conectada × fator de demanda. kVA de partida do maior motor = P ÷ (η·cosφ) × kst; a queda de tensão resultante no barramento = Sstart ÷ (Sstart + Ssc), verificada contra um limite de 15%. O transformador da subestação tipo caixa é então dimensionado no fator de potência alvo.
Normas aplicáveis
O dimensionamento segue GB/T 17467 e IEC 62271 (subestações pré-fabricadas), IEC 60034 (máquinas rotativas) e GB 50052 (projeto de alimentação de energia).
Perguntas frequentes
What voltage do oilfield beam-pump motors run at?
Beam-pump (pumping unit) motors are typically 0.4 kV for units under 45 kW and 0.66 kV or 1.14 kV for larger units to cut cable losses across widely dispersed wells. A 37 kW unit uses 0.4 kV; wells spread over 1-2 km favour a 10/0.66 kV or 10/1.14 kV distribution with a pad-mounted Substation per cluster.
Why do oilfield motors need soft-start?
Direct-on-line starting draws 5-7 times rated current and can dip the weak, long feeder voltage below 85%, stalling adjacent pumps. Soft starters limit starting current to 2.5-3.5 times and ramp torque over 10-30 seconds. This matters on off-grid or long radial oilfield feeders; the calculator checks motor-starting voltage dip and recommends soft-start or VFD.
What is an ESP and how is it powered?
An electrical submersible pump (ESP) is a downhole centrifugal pump driven by a submersible motor, fed from a step-up Transformer and VFD at surface. A typical 90 kW ESP runs on a dedicated 10/0.66-3.3 kV feed through a variable-speed drive that matches pump speed to well inflow. ESPs are sensitive to voltage quality, so harmonic and dip control matter.
When is an off-grid power system right for an oilfield?
Off-grid (diesel or gas generator plus storage) suits remote wells where a grid connection would cost more than roughly $20,000-50,000 per km of line. Typical off-grid oilfield loads are 50-500 kW. Gas-driven generation using associated gas can cut fuel cost 60-80% versus diesel; the calculator prices an off-grid option alongside the grid-fed case.
What demand factor applies to a multi-well oilfield?
A multi-well oilfield with 20 pumping units rarely runs all motors simultaneously at full load; a demand factor of 0.7-0.8 is typical. Injection and ESP loads are more continuous, running 0.8-0.9. The calculator uses 0.75 by default and lets you adjust per site, preventing a 25-35% transformer oversize.
What standards govern oilfield box substations?
Pad-mounted and box-type substations for oilfields follow GB/T 17467 (prefabricated substations) and IEC 62271-202 (high-voltage/low-voltage prefabricated substations), with explosion-proof or weatherproof enclosures per the hazardous-area classification. Transformers follow IEC 60076; the calculator's BOM cites the applicable standard basis for each selected item.
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Os resultados são estimativas de engenharia para referência. O dimensionamento final deve ser confirmado por um engenheiro local licenciado, de acordo com as condições do local e os códigos aplicáveis. Os preços são FOB Qingdao (EXW) e não incluem frete, direitos aduaneiros ou instalação.
Design the complete system
Move to the full Power System Configurator — 4 layers, 13 drawings, protection schedule, BOM and price.