尖北气田高温深井堵塞物分析与解堵剂研究

Analysis of blockage and study on blockage removing agent in high temperature deep well of Jianbei gas field

关键词:  堵塞物  解堵剂  CaSO₄  高温深井 

Key words:  blockage  blockage removing agent  CaSO₄  high temperature deep well

摘要:

目的 为解决尖北气田高温深井的堵塞难题,开展了堵塞物组成分析和配套的解堵剂制备与性能评价。方法 采用原子吸收分光光度法测定堵塞物酸溶后的离子含量,采用X衍射对堵塞物组分进行分析,发现堵塞物以CaSO₄为主。以顺丁烯二酸酐(MA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酸(AA)和丙烯酸甲酯(MMA)为原料,合成了一种适合CaSO₄垢的解堵剂,红外光谱证实了目标产物中含有羧基与磺酸基,并对CaSO₄阻垢性能和以CaSO₄为主的堵塞物的溶垢性能以及腐蚀性进行了研究。结果 当解堵剂质量浓度为3.0 mg/L时,阻垢率高达97%以上；当温度为80 ℃,解堵剂质量分数为4%时,对CaSO₄的溶垢性能达到25.59 g/L,处理后的堵塞物粒径明显减小,粒径主要分布在5～30 μm；解堵剂投加前后采出水的腐蚀率分别为0.068 3 mm/a与0.045 9 mm/a,证明该解堵剂不具有腐蚀性,并且具有一定的缓蚀性。结论 该解堵剂具有较好的CaSO₄阻垢溶垢能力,对油气田管道不具有腐蚀性,可用于CaSO₄阻垢和除垢作业。 

Abstract:

Objective In order to solve the blocking problem of high-temperature deep wells in Jianbei gas field, the component analysis of blockage and the preparation and performance evaluation of matching blockage removing agent were carried out. Methods The ion content of the blockage after acid dissolution was determined by atomic absorption spectrophotometry, and the components of the blockage were analyzed by X-ray diffraction. It was found that the blockage was mainly CaSO₄. Taking maleic anhydride (MA), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), acrylic acid (AA) and methyl acrylate (MMA) as raw materials, a blockage removing agent suitable for CaSO₄ scale was synthesized. The target product contained carboxyl and sulfonic acid groups was confirmed by the infrared spectrum. The performance of inhibiting calcium sulfate scale and dissolving calcium sulfate scale as well as the corrosion of scale inhibitor were systematically studied. Results When the dosage of blockage removing agent was 3.0 mg/L, the scale inhibition rate was up to 97%. When the temperature was 80 ℃ and the amount of blockage removing agent was 4%, the best scale dissolving performance for CaSO₄ was 25.59 g/L, and the particle size of after-treatment field blockage decreased obviously, the particle size was mainly distributed in the range of 5-30 μm. The corrosion rates of produced water before and after adding blockage removing agent were 0.068 3 and 0.045 9 mm/a respectively. It was proved that the blockage removing agent has no corrosion and has certain corrosion inhibition. Conclusion sThe blockage removing agent has a good performance of scale inhibition and dissolving to CaSO₄. It has no corrosion to oil casing-pipes. It can be used as scale inhibition and removal to CaSO₄.