摘要
渤海湾QHD32-6海上油田两口油井酸化后返期期间，原油集输系统三相分离器和热处理器水相出口pH值下降。最低降至4．0，返排11小时后恢复正常值7．0。在此期间原油乳状液样稳定性增大，破乳剂（BH-09）的性能显著变差。考察了影响原油乳状液稳定性的3个因素。①显微观测表明pH=8．0时乳化水滴在油外相中分布较为均匀，而pH=2．0时乳化水滴出现凝聚倾向，使破乳剂不易进入油水界面；油水界面张力在pH≈7时最高，随pH值降低（7-1）而降低，随pH值升高（7-12）而迅速降低；注碱中和返排酸液引起pH升高，是原油乳状液稳定性增大的主要原因之一。②酸化产生的胶态金属氢氧化物和黏土颗粒使原油乳状液稳定化。③酸液中具有表面活性的添加剂使黏土颗粒亲油化或亲水化，导致原油乳状液稳定性增大。图2表3参8。
It was shown by in-situ monitoring data that in the course of backflow of acidizing fluids from 2 production wells at offshore oil field QHD-32-6, 13ohai Bay, the pH value of the produced water separated in triphase separator and thermal settler in oil gathering/pretreating system lowered gradually to 4.0 and recovered to its normal value of 7.0 after backflow over 11 hrs. In this period the crude oil emulsions （W/O emlsions） produced became more stable and the demulsifier used, BH-09, appeared less effective in laboratory tests. Three factors influencing the crude oil emulsion stability are investigated. （1） The dispersed water droplets emulsified in oil are distributed more evenly at a higher pH value of 8.0 and tends to aggregate at a lower pH value of 2.0, which impedes demulsifier molecules reaching to water/oil interfaces; the interracial tension between oil and water phases goes through a peak at pH≈7 and decreases fast with pH value lowering down from 7 to 1 and dramatically with pH value rising up from 7 to 12; the raise of pH value owing to introducing alkaline to neutralize the backflown acidizing fluids appears to be one of the important reasons for stabilization of the produced crude oil emulsions. （2） The colloidal metal hydroxides and clay particles created in acidization lead to stabilization of these emulsions, too. （3） The surface active additives in the acidizing fluids make clay particle surfaces more oleophilic or more hydrophilic and thus enhance the stability of these emulsions.
出处
《油田化学》
CAS
CSCD
北大核心
2008年第2期130-132,147,共4页
Oilfield Chemistry
关键词
酸化返排液
原油乳状液
油包水(W/O)乳状液
破乳脱水
稳定性
PH值
黏土颗粒
渤海湾海上油田
return acidizing fluids
crude oil ernulsions
water-in-oil （ W / O ） emulsions
demulsi fwation /dehydration
stability
pH value
clay particles
Bokai Bay offshore oil fields
