| The modern oil industry has been born for more than 160 years,and the exploitation of oil has entered the middle or late period.In order to ensure the oil production,polymer flooding and other tertiary oil recovery technologies have emerged.Since the polymer flooding field experiment was carried out in 2003,Bohai oil field has achieved significant production increase effect.In 2018,it has achieved an annual output of 30 million tons of crude oil,becoming the third largest oil and gas field in China after Changqing oil field and Daqing oil field,making great contribution to energy security in China.With the development of oil recovery technology,the treatment of produced fluid becomes more difficult than before.This is especially true for the demulsification of the produced liquid on the offshore platform.It is urgent to develop new demulsifiers for oil production.In this paper,the following work has been carried out for demulsification of produced liquid from offshore platform:(1)A series of modified HM demulsifiers were synthesized with bisphenol A-based demulsifier as a single agent and PM200 as a modifier.The modified demulsifier performance was excellent,and the dehydration ratatio of HM41F-2.5%reached 97.6%in 60 minutes,which was much higher than HM1 and HM2(71.5%,85.7%),and still performed well in the field evaluation of the platform.According to laboratory evaluation and field evaluation,small scale pilot produce was carried out on HM41F-2%.The pilot product has performed well in the simulation application of crude oil land terminal treatment plant,and the dehydration rate can reach 95.7%within 40 min.(2)A series of polyether demulsifiers for treating aging oil emulsion on offshore oilfield were prepared from procyanidin phenolamine resin precursor which was synthesized by proanthocyanidin(PC),formaldehyde and tetraethylpentamine(TEPA).Their structures and properties were characterized by GPC,1H NMR,FTIR,hydrophobicity and interfacial activity.The demulsification test results showed that the PC demulsifiers had excellent demulsification performance for the aging-oil emulsion in Bohai oilfield,and the dehydration ratio can be reaches 94.4%at the dosage of 100 mg/L and 70℃ within 120 min.In addition,the demulsification mechanism was proposed by combining partition coefficient,rheological properties of emulsion,demulsifier properties and demulsification data.To confirm the practical applicability on offshore platforms,this kind of demulsifier has been pilot produced on a ton scale and the pilot-product has been proved to be excellent as laboratory sample in demulsification performance(3)Based on the natural polyphenol epigallocatechin gallate(EGCG)extracted from green tea,a series of novel EA demulsifiers were prepared using mature synthetic process.Their structures and properties such as NMR,GPC,dynamic interfacial tension and RSN value were characterized.The demulsifier was used for demulsification of three kinds of crude oil emulsions,namely,Bohai oilfield aging oil emulsion,Bohai oilfield normal crude oil emulsion,and Nanhai oilfield aging oil emulsion.The results of demulsification showed that the dehydration ratios of the three kinds of crude oil emulsions can be reaches 91.7%,91.9%and 94.3%respectively at the dosage of the dosage of 100 mg/L and 70℃ within 100 min. |
PDF Full Text Request