During production and transportation, crude oil, water, and fine solids may form highly stable emulsions.

These emulsions commonly result in:

• Difficult oil-water separation
• Increased water cut
• Lower export crude quality
• Higher dehydration load
• Reduced separator efficiency

Emulsion problems are particularly severe in heavy oil and high-solids systems.

Case Study 1

PROJECT BRIEF

• Block II, East of No.2 Area, Some Oilfield Located in North China, ASP Flooding
• Emulsion stability increased significantly which makes the breaking more difficult
• OIW significant high in discharging water from Free Water Knockout
• EB optimization work needed

CHALLENGE

• ASP concentration getting higher in the produced fluid from Nov. to Dec., 2014 (Surfactant 70-80mg/L , Polymer 500-600mg/L, pH 9.6-9.8 )
• The breaking of ASP combined with oil & water emulsion is getting more difficult
• 35ppm dosage of 2 kinds EB which were using at that time
• OIW is about 11,000mg/L in the discharging water

The Optimizaton of EB

• When Z-EMUL 150 dosage is 35-40 ppm, OIW is about 1,000 mg/L
• 20 ppm Z-EMUL 150 dosage and OIW is about 2,500 mg/L for better cost-effectiveness

Case Study 2

CHALLENGE

• X-1 Process Station at an oilfield in North China
• 30,000m3/d (90% is water), which includes about 7,000 ~ 8,000m3/d liquid from ASP flood
• ASP flooding operation started from May, 2015
• Electric current of EDD was running higher continuously as the quality of produced fluid became unstable
• EDD overloading trips frequently, or shutdown and maintenance needed
• BS&W and OIW of disqualified sometimes
• Liquid level of Emergency Tank running too high
• EB optimization work needed

RESULTS

• OIW and suspended solids in the discharged water reduced significantly
• The frequency of trips reduced to the lowest of the latest 2 years, all 4 EDD in operation and current & voltage running smoothly
• Only 2 overloading trips and restored in very short time after Z-EMUL 140 injected
• Z-EMUL 140 could be used as routine Emulsion Breaker as well as EB for oil from emergency tanks, without any affection to the normal production
• OIW of discharged water is about 0.116% (from 0.06 to 0.18%)