疏松砂岩气藏管外窜槽的封堵实验研究

Plugging Experiment of Cement Channeling in Unconsolidated Sandstone Gas Reservoir

针对青海涩北气田在生产过程中由于套管外水泥环与储层接触面的胶结质量差而造成层间水容易窜至产层从而影响产能的情况,研制了低温水泥浆配方体系并进行了封堵模拟实验,评价了其固化后微观结构与抗压性能之间的关系及其在界面处的封堵效果。结果表明,添加剂的有效复配能够提高水泥浆中石英颗粒之间的联结强度,进而提高材料的固化强度;复合材料和水泥浆配方均能达到封堵的要求,但复合材料配方体系的封堵效果比水泥浆配方更好。

During the production of Sebei gasfield, Qinghai Province, poor cementing quality existing between cement sheath outside of tubing and reservoir interface will bring about interlay water easily channeling into payzone, which further affects deliverability. In this study, a low-temperature cement’s formula is developed to release this effect and an experiment on plugging simulation is implemented. In addition, a relationship between microstructure and compressive property of cement after its solidification is evaluated; meanwhile, a plugging effect at interface is also assessed. Results illustrate that (1) to effectively recompound an additive can increase a connection intensity of quartz particle among cement, and then to strength a solidification intensity; (2) compound material and cement formula can all meet the requirement of plugging, especially a better effect for the former.