一种井下固体防蜡技术的设计及应用

Design and application of solid paraffin inhibition technology in downhole

M油田在机采井上开展了井下固体防蜡技术设计与现场试验。其采用了蒙脱土纳米粒子技术,将化学药剂固化在承载器内,下入井下随着缓释与井内蜡质发生作用,延缓机采井结蜡,延长清蜡周期。通过室内实验,完善了药剂配方,确定试验井的药剂配方分别为Ⅰ型和Ⅱ型;研究了含蜡量与药剂浓度的关系,明确了试验井药剂浓度分别要达到2.9、 3、 2.8和3.3 ppm以上;研究了油层温度与缓释速率的关系,明确试验井条件下的缓释速率分别为10和13mg/min;依据各项数据,确定了设计药剂装入量,4口试验井的药剂装入量分别为11、11、14和15 kg。制造防蜡器单根装入药剂量为15 kg。因现场条件与实验室条件的差异,四口试验井现场实际用量分别为2根、2根、3根和3根。现场以上电流变化幅度相同所经历的时间为对比点,4口井均取得较好效果,平均清蜡周期由48 d延长至119 d,延长了1.48倍。在两年有效期内,4口井可累计节约柴油4 368 L、清水364 m^(3),节约费用约3.3万元。投入产出比为1∶3.2,且具有较好的社会效益。

The design and field test of solid paraffin inhibition technology have been carried out in mechanical production in M oilfield. The montmorillonite nano particle technology is adopted. The technology is solidified the chemical agent in the carrier and goes down the well to delay wax deposition in mechanical production well and prolong the wax removal cycle with the slow release and wax in the well.Even more to the point,through the indoor experiments,the reagent formula is improved and it is determined to be type Ⅰ and type Ⅱ.On one hand,the relationship between wax content and reagent concentration is studied. It is clear that the reagent concentration should be more than 2.9ppm,3ppm, 2.8ppm and 3.3ppm respectively. On the other hand, the relationship between reservoir temperature and slow-release rate is studied. It is clear that the slow-release rates under the conditions of test wells are 10mg/min and 13mg/min. According to the data, the designed reagent loading amount is determined. The chemical loading of the four test wells is 11kg, 11kg,14kg and 15kg respectively.The dosage of each wax preventer is 15kg.Thanks to the difference between field conditions and laboratory conditions, the actual consumption of the four test wells is 2,2,3 and 3 respectively. Most importantly, compared with the same amplitude of upstream current change, the field test shows that the four wells have achieved good results and the average wax removal cycle is extended from 48 days to 119 days. Within the two-years validity period, the four wells can save 4 368 liters of diesel and 364 cubic meters of clean water, saving about 33 000 yuan. The input-output ratio is 1∶ 3.2,which has better social benefits.