油井伴热循环水系统缓蚀处理技术  

Corrosion Control of Circulating Thermoinsulating Water for Oil Gathering Pipelines

作　　者：郭鹏[1] 陶剑清[1] 殷玉平[1] 

机构地区：[1]中国石化江苏油田分公司试采一厂,江苏江都225265

出　　处：《油田化学》2008年第3期232-234,260,共4页Oilfield Chemistry

摘　　要：江苏油田SN区块由油井口到集油站的集输管线用伴热水保温,伴热水管线腐蚀严重。根据水质检测数据,伴热水基本上不含细菌,预测结垢量不大,而现场挂片测定的腐蚀速率,来水中为0.8646 mm/a,回水中为0.4298mm/a,89.3%挂片垢物为铁垢(以Fe2O3计)。用Na2SO3除氧的缓蚀效果差。从10种商品中选出了A剂(主要成份为改性咪唑啉、有机磷及非离子表面活性剂)为伴热水缓蚀剂。用KSCN示踪剂法测定了伴热水系统总水量、循环水量、代谢时间、流程总长及流量。由85℃下A剂缓蚀率与加剂量关系,确定采用冲击方式加药,首次加剂量300 mg/L,循环水量420 m3,每隔14天按100 mg/L加剂量加药一次。46天现场挂片监测结果表明,来水和回水腐蚀速率分别降至0.2412 mm/a和0.1507 mm/a。The oil gathering pipelines from the production wells to the gathering station in district SiN, Jiangsu, are thermally insulat- ed by using a circulating water system, which suffers from severe corrcsion. There are practically no bacteria growing in the circulating thermoinsulating water （CTIW） as shown by water quality data, the scale creation predicted is not notable in the CTIW meanwhile the corrosion rate of A3 steel specimens in the CTIW is rather high with in-line determinations in flowing in and back streams of the system being of 0. 8648 and 0. 4298 mm/a, respectively, and the scaled substances on the test specimens comprise 89.3 % ferric compounds （as Fe2O3）. The corrosivity of the CTIW can not be inhibited effectively by using Na2SO3 as oxygen scavenger. A corrosion inhibitor, A, composed of modified imidazolines, organophosphorus ingredient, and nonionic surfactant（s） is selected experimentally for the CTIW from 10 commercial inhibitors. The flow characteristics of the circulating water system, such as total water volume, volume of effectively circulating water, whole loss time duration, total flow line length, and flowing rate are determined by KSCN tracering method. Based on a relationship between corrosion inhibition and dosage of inhibitior A at 85℃, a working scheme of inhibitor introduction into the circulating water system is ascertained as follows： inhibitor A to be introduced by the way of shock feed at dosage 300 mg/L at first time and 100 mg/L in every 14 days, suggesting water volume in circulation being of 420 m^3. The field monitoring data of corrosion rate determined with test specimens suspended in flowing in and back streams of the system in 46 days show that the corrosion rate has decreased notably to 0.2412 and 0. 1507 mm/a, respectively, as a result of corrosion inhibition.

关 键 词：伴热水 缓蚀剂 缓蚀处理 工艺参数 原油集输管线 江苏SN油田 

分 类 号：TE988.2[石油与天然气工程—石油机械设备] TE984