Troubleshooting Methods for Rising Pressure Difference of Coalescing Filters in Wellhead Crude Oil Purification

1. Product Overview & Failure Hazards

Aite Wellhead Crude Oil Coalescer & Separator Cartridge is a high-performance filtration component designed for wellhead crude 

oil purification systems – undertaking the dual functions of solid impurity interception and micro-water coalescence separation 

to guarantee qualified crude oil output. Wellhead crude oil contains mixed impurities including formation sand, pipeline rust, 

scaling particles, emulsified water droplets, light hydrocarbon condensate, and trace asphaltene colloid. Medium temperature 

fluctuates greatly with seasons, and the medium presents alternating gas-liquid-solid three-phase impact during intermittent 

pumping.

Aite Wellhead Crude Oil Coalescer & Separator Cartridge is engineered as a fully interchangeable substitute for original coalescer

 elements, delivering reliable separation performance, extended service life, and consistent contaminant control under 

demanding wellhead conditions.

Sustained abnormal rise of filter cartridge pressure difference brings multiple operation risks:

· System pipeline load increases, pump unit power consumption rises, and equipment energy consumption increases 

significantly

· Excessive pressure difference causes flow channel compression inside filter media, fluid shear force surges, coalesced large 

water droplets are broken again into micro-emulsions, and outlet crude oil water content exceeds the standard

· Long-term high differential pressure operation leads to pleat collapse, fiber delamination, and skeleton deformation – resulting 

in bypass leakage of unpurified crude oil and downstream equipment scaling and corrosion

· Severe blockage triggers overpressure interlock shutdown of the wellhead metering and purification system, interrupting 

continuous crude oil collection

According to field operation data, pressure difference faults of Aite Wellhead Crude Oil Coalescer & Separator Cartridge are 

divided into three categories:

· Slow and gradual rise: Regular pollutant accumulation under normal conditions – prepare spare cartridges for periodic 

replacement

· Rapid short-term surge: Abnormal sudden increase of inlet pollution load or system parameter mismatch

· Irregular fluctuating pressure: Caused by unstable gas cut, liquid level disorder, or pipeline flow fluctuation

2. Step-by-Step Troubleshooting Process

Aite Wellhead Crude Oil Coalescer & Separator Cartridge troubleshooting follows a systematic sequence:

Step 1: Instrument Calibration

Before checking filter cartridges, eliminate measurement deviation caused by instrument failure:

· Close sampling valves, drain condensate and solid dirt blocked in pressure guiding tubes

· Disassemble and inspect pressure measuring components; calibrate against standard gauges

· After dredging and calibrating, if the value returns to normal baseline, the fault source is instrument blockage

Step 2: Check Front-End Pre-Separation Equipment

· Inspect the bottom ash hopper of the inlet cyclone separator; open blowdown valve to discharge accumulated sand and rust

· Disassemble the secondary 20–50μm metal pre-filter screen; observe surface dirt accumulation and mesh breakage

· Judgment standard: If pre-filter pressure difference exceeds 0.05MPa, rapid pressure difference rise is induced

Step 3: Inspect Liquid Level and Exhaust Condition

· Check liquid level of bottom collecting bin; if exceeding 2/3 of bin body, emulsified water will backwash filter pleats – manually 

open drain valve for full drainage

· Operate automatic exhaust valve at tank top to discharge trapped gas

· Record gas volume fraction; when instantaneous gas cut exceeds 20%, high-speed gas-liquid mixed flow scours media and

 pushes up pressure difference

3. Root Cause Classification & Disposal Schemes

Category 1: Slow Gradual Rise (Daily ΔP ≤ 0.006MPa)

· Root Cause: Continuous accumulation of conventional trace solid impurities and emulsified droplets under stable

 conditions – normal consumption of dirt holding capacity

· Disposal: Perform standardized timed blowdown; reduce system flow by 10%; record daily pressure difference curve; 

arrange replacement before reaching 0.15MPa threshold

Category 2: Rapid Surge (Daily ΔP ≥ 0.012MPa)

· Root Cause 1: Sudden high pollution load – well washing, well overhaul, or stratum water breakthrough

  · Disposal: Open bypass to reduce load; increase cyclone blowdown frequency; replace blocked pre-filter screen

· Root Cause 2: Long-term overload operation with excessive flow

  · Disposal: Adjust pump frequency; open bypass valve for flow division; add spare coalescing tank if permanently high

· Root Cause 3: Front pre-separation device failure – cyclone blocked or pre-filter screen broken

  · Disposal: Fully clean cyclone ash hopper; replace damaged pre-filter screens; increase daily inspection frequency

Category 3: Irregular Fluctuating Pressure

· Root Cause 1: Unstable gas cut – intermittent gas surging causes periodic gas wrapping of cartridges

  · Disposal: Increase exhaust valve opening frequency; install buffer tank; reduce single-tank flow

· Root Cause 2: Uncontrolled liquid level – automatic drain valve jamming causes intermittent backwashing

  · Disposal: Overhaul drain valve; set high liquid level interlock alarm

· Root Cause 3: Unstable pumping flow – reciprocating pump pulse flow impacts cartridges

  · Disposal: Install pipeline flow stabilizer; adjust pump operating parameters

Category 4: Permanent Irreversible High Pressure (Remains above warning value after back-blowing)

· Root Cause: Sticky asphaltene sludge and compact sand cake embedded deep into fiber pores; pleat collapse and skeleton 

deformation

· Disposal: Safe shutdown and tank opening; replace all cartridges in batches; thoroughly clean tank inner wall and tube plate 

before installing new cartridges

4. Standardized Back-Blowing Operation Specification

Aite Wellhead Crude Oil Coalescer & Separator Cartridge allows limited back-blowing only under specific conditions:

· Applicable Restrictions: Only when pressure difference reaches 0.10–0.12MPa (early warning), outlet water content is qualified, 

and no pleat collapse observed – maximum twice per service cycle

· Procedure:

  1. Switch system to bypass operation to ensure continuous crude oil collection

  2. Close inlet/outlet cut-off valves; open exhaust and drain valves to reduce tank pressure

  3. Use dry oil-free compressed air (dew point ≤ -20°C), back-blowing pressure at 0.25–0.30MPa, single blowing duration 0.18s, 

6–10 times per operation

  4. After completion, close valves, slowly inject crude oil, exhaust air, and restore to rated flow

  5. Record pressure difference drop; if pressure rebounds to warning threshold within 3 working days – arrange replacement

Strictly Prohibited Operations:

· Washing with water or organic solvent – sludge solidifies into hard blocks; coalescing film is damaged permanently

· Long-term high-pressure back-blowing – tears composite media and causes fiber shedding

· Continuous overload operation after pressure warning – accelerates pleat deformation and shortens service life by more than 

half

5. Preventive Control Measures

· Shift regular blowdown: Discharge accumulated sand and liquid every shift to reduce pollutant accumulation baseline

· Weekly pre-filter maintenance: Disassemble, clean, and inspect secondary metal pre-filter screen weekly

· Real-time flow monitoring: Limit maximum processing flow; open bypass division when instantaneous flow exceeds standard

· Seasonal parameter adjustment: In winter, reduce operating flow to lower surface flux and extend dirt holding cycle

· Well working condition linkage: After well washing/perforation, reduce single-tank load and increase inspection frequency

· Instrument daily maintenance: Dredge pressure guiding tubes weekly to eliminate false pressure difference data

6. Post-Fault Handling Acceptance Standards

After completing fault disposal, continuous stable operation for more than 4 hours is required:

· Filter cartridge operating pressure difference drops below 0.08MPa

· Outlet crude oil water content stable below design index

· Wellhead pump power consumption returns to daily average normal level

· No abnormal flow fluctuation, gas surging, or liquid level alarm

7. Frequently Asked Questions (FAQ)

Q1: What is the Aite Wellhead Crude Oil Coalescer & Separator Cartridge designed for?

A: Aite Wellhead Crude Oil Coalescer & Separator Cartridge is designed for wellhead crude oil purification – undertaking solid

 impurity interception and micro-water coalescence separation to guarantee qualified crude oil output.

Q2: Is the Aite Wellhead Crude Oil Coalescer & Separator Cartridge fully interchangeable with the original?

A: Yes. Aite Wellhead Crude Oil Coalescer & Separator Cartridge is precision-engineered to match original dimensions, thread

 interfaces, sealing groove sizes, and installation parameters – enabling direct drop-in installation without any housing 

modifications.

Q3: What are the common causes of rapid pressure difference rise?

A: Common causes include: (1) sudden high pollution load from well washing or stratum water breakthrough; (2) long-term

 overload operation with excessive flow; (3) front pre-separation device failure (blocked cyclone or broken pre-filter screen). 

Follow the step-by-step troubleshooting flow to locate the root cause.

Q4: Can the Aite Wellhead Crude Oil Coalescer & Separator Cartridge be cleaned and reused?

A: Limited back-blowing is permissible only at early warning stage (0.10–0.12MPa), maximum twice per service cycle. Washing

 with water or organic solvent is strictly prohibited – this permanently damages the coalescing film and fiber structure. Replace

 when pressure difference reaches 0.15MPa.

Q5: What is the recommended replacement interval for the Aite Wellhead Crude Oil Coalescer & Separator Cartridge?

A: Replacement interval depends on operating conditions and contamination levels. Monitor pressure difference daily – replace 

when ΔP reaches 0.15MPa (alarm) or 0.20MPa (mandatory), or when back-blowing cannot reduce pressure difference to normal 

levels.

Q6: What sealing materials are available for the Aite Wellhead Crude Oil Coalescer & Separator Cartridge?

A: Aite Wellhead Crude Oil Coalescer & Separator Cartridge is available with standard NBR seals for general applications and FKM 

(Viton) seals for high-temperature conditions – ensuring leak-proof sealing across the full operating temperature range.

Q7: What documentation is provided with the Aite Wellhead Crude Oil Coalescer & Separator Cartridge?

A: Each shipment includes EN 10204 material certificates, ISO 16889 filtration performance test reports, dimensional inspection 

records, and factory quality certificates – ensuring smooth customs clearance worldwide.

Q8: What industries is the Aite Wellhead Crude Oil Coalescer & Separator Cartridge most suitable for?

A: Aite Wellhead Crude Oil Coalescer & Separator Cartridge is widely used in oilfield crude oil gathering systems, wellhead

 metering and purification stations, and upstream oil production facilities – covering all crude oil dehydration and solids removal

 applications.

Q9: Can the Aite Wellhead Crude Oil Coalescer & Separator Cartridge handle gas-liquid-solid three-phase flow?

A: Yes. Aite Wellhead Crude Oil Coalescer & Separator Cartridge is specifically engineered to handle alternating gas-liquid-solid 

three-phase impact during intermittent pumping – with reinforced construction that maintains structural integrity under

 challenging conditions.

Q10: Can I order samples of the Aite Wellhead Crude Oil Coalescer & Separator Cartridge before bulk purchase?

A: Yes. We support paid sample orders with production lead time of approximately 7–10 days. Sample costs are fully deductible

 from your first bulk order upon approval.

Aite Wellhead Crude Oil Coalescer & Separator Cartridge – engineered for crude oil purification, precision interchangeability, 

proven separation performance at competitive factory-direct pricing. Contact us today for a free compatibility check and 

quotation within 24 hours.