杭锦旗地区致密气藏石英砂替代陶粒可行性实验研究

Feasibility study on quartz sand replacing ceramsite in Hangjinqi Area tight gas reservoir

为了满足鄂尔多斯盆地杭锦旗地区低成本压裂改造的需要,根据杭锦旗地区不同区块闭合压力特点,开展了不同岩板对长期导流能力的影响、不同粒径对长期导流能力的影响、石英砂铺砂浓度的界定以及石英砂替代陶粒导流能力分析等实验研究工作。结果表明:1)在相同的闭合压力加载条件下,长期导流能力大小与石英砂所占支撑剂比例呈负相关;2)随着闭合压力加载时间的延长,支撑剂破碎和嵌入程度逐渐严重,30 h以后,人工裂缝导流能力损失明显;3)石英砂与陶粒的混合比例为2∶8,3∶7和4∶6时,其导流能力均满足闭合压力为35~50 MPa的要求,能够实现用石英砂替代陶粒而达到降低压裂成本的目的。以上成果认识,对杭锦旗地区石英砂替代陶粒压裂改造及实现低成本战略具有一定指导意义。

In order to meet the needs of low-cost fracturing reconstruction in Hangjinqi Area of Ordos Basin, according to the characteristics of closing pressure in different blocks in Hangjinqi Area, experimental studies were carried out on the influence of different rock slabs on long-term conductivity, the influence of different particle sizes on long-term conductivity, the definition of sand spreading concentration of quartz sand, and the analysis of conductivity of quartz sand replacing ceramsite. The results show that: 1)Under the same closed pressure loading conditions, the long-term conductivity is negatively correlated with the proportion of quartz sand in proppant;2)With the extension of the closing pressure loading time, the proppant embedment and fragmentation become more and more serious. After 30 h, the long-term conductivity loss of the artificial fracture is obvious;3)The mixing ratio of quartz sand and ceramsite is 2∶8,3∶7 and 4∶6, and its conductivity meets the requirements of closure pressure of 35~50 MPa, which can realize the purpose of replacing ceramsite with quartz sand and reduce the fracturing cost. The above results have a certain guiding significance for the transformation of quartz sand replacement ceramite fracturing and the realization of low-cost strategy in Hangjinqi Area.