基于PIV系统的支撑剂运移铺置规律及参数优化

Proppant migration and placement law and parameter optimization based on PIV system

李恋,吴亚红,王明星,王佳,陈小璐,郭皓男,曹耐

中国石油大学（北京）石油工程教育部重点实验室，北京 102249 中国石油新疆油田分公司工程技术研究院，新疆 克拉玛依 834099 中国石化石油工程技术研究院，北京 100101

MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Engineering Technology Research Institute, Xinjiang Oil Field Company, PetroChina, Karamay 834099, China Research Institute of Petroleum Engineering, SINOPEC, Beijing 100101, China

滑溜水体积压裂是非常规致密储层的主要经济增产措施，支撑剂的运移与分布规律决定着复杂裂缝网络内支撑剂的最终分布形态和导流能力。文中采用PIV（粒子成像测速）系统捕捉支撑剂颗粒在主裂缝中的瞬时运移状态，研究了不同压裂液黏度、排量、砂比和支撑剂筛目条件下支撑剂铺置后的砂堤平衡状态，揭示了砂堤前缘与末端流场的变化规律。结果表明：随着排量、砂比和支撑剂筛目的增大，以及压裂液黏度的降低，支撑剂颗粒在砂堤前缘入口处和离开砂堤峰部时的运移速度更快，湍流强度更大，形成的有效裂缝更长；砂堤处于平衡状态时的高度和时间随着排量增加而减小，砂堤整体形态变得平缓；砂比越大，砂堤峰部出现位置越靠近裂缝入口处；优化的排量为10~12 m3/min、砂比控制在20%以下、压裂液黏度在6~16 mPa·s、支撑剂筛目为40/70目时，形成的砂堤高度和长度最大。该研究成果可以为滑溜水体积压裂设计和施工提供有效的技术指导。

 Slickwater volume fracturing is the main economic stimulation measure for unconventional tight reservoirs. The migration and distribution of proppant determine its final distribution pattern and conductivity in the complicated fracture network. In this paper, a PIV（particle image velocimetry） system was used to capture the transient transport state of proppant particles in the main fracture. The equilibrium state of the sand embankment after proppant placement was studied under different fracturing fluid viscosity, displacement, sand ratio and proppant mesh number, and the change law of the flow field at the front and end of the sand embankment was revealed. The results show that, with the increase of displacement, sand ratio and proppant mesh, as well as the decrease of fracturing fluid viscosity, the migration speed of proppant particles is faster at the leading edge of the sand embankment and away from the peak of the sand embankment, the turbulence intensity is stronger, and the effective fracture is longer. The balance height and balance time of sand embankment decrease with the increase of displacement, and the overall shape of sand embankment becomes gentle. The larger the sand ratio is, the closer the position of sand embankment peak is to the crack entrance. When the displacement is 10￣12 m3/min, the sand ratio is controlled below 20%, the viscosity of fracturing fluid is 6￣16 mPa·s, and the number of proppant mesh is 40/70, the height and length of the sand body are the largest. The results can provide effective technical guidance for slickwater volume fracturing design and construction.

10.6056/dkyqt202105022