A coupled microscopic simulation method was implemented to investigate the bond breakage behaviour during perforation and sand production in a weak cemented sandstone. A new contact bond model was implemented in the open-source program CFDEM to simulate a large cylindrical sample of one hundred thousand numerical particles using a high-performance computer (HPC) system. The coupled simulation of the particle–fluid phases and the information exchange between them required intensive computational power and highly efficient parallelization algorithms, yet it provided the detailed information on the distribution of bond and bond breakage, new contact formation, particle migration and the associated change in the internal porosity across the sample. The perforation process was found to create a damage zone that contained a compacted core of unbonded particles. The compacted core expanded quickly under fluid flow condition and released its particles to migrate towards the perforation tunnel. Small particles were produced first from the perforation damage zone, while fewer particles of larger sizes were produced later in an overall transient sand production phenomenon.

采用耦合显微模拟方法研究了弱胶结砂岩射孔和出砂过程中的粘结断裂行为。在开源程序 CFDEM 中实施了一种新的接触键模型，以使用高性能计算机 (HPC) 系统模拟包含十万个数值粒子的大型圆柱形样品。粒子-流体相的耦合模拟以及它们之间的信息交换需要强大的计算能力和高效的并行化算法，但它提供了关于键分布和键断裂、新接触形成、粒子迁移和相关变化的详细信息在整个样品的内部孔隙度中。发现穿孔过程会产生一个损坏区域，其中包含一个压实的未粘合颗粒核心。压实的岩心在流体流动条件下迅速膨胀并释放其颗粒向射孔隧道迁移。小颗粒首先从射孔损伤区产生，而较大尺寸的颗粒在整个瞬态产砂现象中随后产生。