煤粉对支撑裂缝导流能力的影响特征及其防控

发布时间：2018-10-16 11:13

【摘要】：针对煤层气井的煤粉伤害问题,运用LD-1A导流能力测试系统模拟了煤层气井变排量、恒排量及间抽过程中煤粉在支撑裂缝中的运移沉积情况,分析了不同流速下煤粉对支撑裂缝导流能力的影响特征及伤害机理。实验表明:煤粉易滞留沉积在支撑裂缝底部严重影响导流能力,导流能力伤害率可达90%以上;在没有煤粉持续进入支撑裂缝的情况下,有效排出煤粉导流能力有增大的趋势;排采制度、煤粉质量含量、煤粉粒径对导流能力的影响特征存在明显差异;煤粉随水运移时对支撑剂窄口的疏通作用和聚集堵塞作用共同影响支撑裂缝导流能力。压裂前期使用小粒径支撑剂,尾追大粒径支撑剂,合理控制排采速度,使排采速度略小于煤粉运移的临界流速,并使用煤粉分散剂,有利于适量排出煤粉减小导流能力伤害。
[Abstract]:In order to solve the problem of pulverized coal damage in coalbed gas wells, this paper simulates the migration and deposition of coal powder in supporting fractures by using LD-1A flow conductivity test system. The influence characteristics and damage mechanism of pulverized coal on the conductivity of supporting crack under different velocity of flow are analyzed. The experimental results show that coal powder is easy to be deposited at the bottom of the supporting crack, and the damage rate of the conductivity can reach more than 90%, and the effective discharge capacity of pulverized coal increases when the coal does not continue to enter the supporting crack. There are obvious differences in the characteristics of the influence of coal quality content and coal particle size on the flow conductivity and the channeling effect of pulverized coal on the narrow mouth of proppant and the aggregation blockage effect on the conductivity of the supporting crack when the pulverized coal moves with water. In the early stage of fracturing, small particle size proppant and large particle size proppant are used in the early stage of fracturing, the production speed is controlled reasonably, the extraction speed is slightly less than the critical velocity of coal powder migration, and the coal powder dispersant is used, which is beneficial to the proper discharge of pulverized coal to reduce the damage of flow conductivity.
【作者单位】：中国石油华北油田公司勘探开发研究院;中国矿业大学(北京)地球科学与测绘工程学院;中国石油大学气体能源开发与利用教育部工程研究中心;
【基金】：国家科技重大专项资助项目(2011ZX05061,2011ZX05062)
【分类号】：TE377

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