| 摘要: |
| 库车山前高温高压气井井筒堵塞物多为垢样,不动管柱酸化解堵作业是目前常用的解堵手段。但在高温条件下,常规酸液解堵易在井筒产生二次沉淀,同时会对13Cr不锈钢材产生严重的腐蚀。为此,研制了一种能够代替盐酸体系的新型氨基羧酸类低伤害螯合酸液体系,典型配方为6%(w)有机酸+5%(w)SA-3+2%(w)SA-701。室内评价表明,该配方具有良好的溶垢、高温缓速、抑制二次沉淀能力,其鲜、残酸在130 ℃时腐蚀速度均低于45 g/(m2·h),满足SY/T 5405-2019 缓蚀剂行业标准。模拟井筒堵塞动态驱替解堵实验表明:该配方酸液能有效疏通堵塞井筒,井径越大、温度越高、关井时间越长,解堵效果越佳；井筒温度为110 ℃时,关井4 h的溶垢率超过90%。室内实验证实,该新型解堵体系能够满足高温气井不动管柱井筒解堵作业的要求。 |
| 关键词: 高温 高压 井筒堵塞 螯合酸 不动管柱解堵作业 |
| DOI：10.3969/j.issn.1007-3426.2021.05.013 |
| 分类号: |
| 基金项目:中国石油塔里木油田分公司科技项目“克深储层改造技术潜力评价及地下自生支撑剂可行性研究”( 201019081016) |
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| Development and performance evaluation on wellbore plugging removal system of fixed string in high temperature gas well |
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Liu Ju1, Luo Zhifeng2, Ren Dengfeng1, Wu Hongjun1, Xie Yaozeng2
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1. Research Institute of Oil and Gas Engineering, PetroChina Tarim Oilfield Company, Korla, Xinjiang, China;2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan, China.
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| Abstract: |
| Aiming at the characters of compound plugging of sand and scale in the wellbore of Kuqa piedmont high temperature gas well and the characters of unplugging operation with fixed pipe string, most of the plugging materials in high temperature and high pressure gas wells in Kuqa piedmont are scale samples, and acidizing unplugging operation of immovable pipe string is a commonly used plugging removal method. However, the conventional acid solution is easy to produce secondary precipitation in the wellbore and seriously corrode 13Cr stainless steel under the condition of high temperature. Therefore, a new amino carboxylic acid chelating acid system with low damage is developed, which can replace hydrochloric acid system, with a typical formula of 6%(mass fraction) organic acid + 5%(mass fraction) SA-3 + 2%(mass fraction) SA-701. The laboratory evaluation show that the formula system has good scale dissolving capacity, high temperature retarding and secondary precipitation inhibiting ability. The high temperature corrosion rate of fresh and residual acid at 130℃ is lower than the national first-class standard. The simulation of dynamic displacement unplugging experiment shows that:the bigger the diameter of the well, the higher the temperature and the longer the shut in time, the better the plugging removal effect; the scale dissolution rate is more than 90% after 4 hours of shut-in at 110℃. The laboratory tests show that the new plugging removal system can meet the functional requirements of wellbore plugging removal in high temperature gas wells with fixed pipe string. |
| Key words: high temperature high pressure wellbore blockage chelating acid unplugging operation of fixed pipe string |
