粉煤灰——漂珠复合低密度水泥浆固井试验与应用

针对吴起地区固井中一些低压地层由于破裂压力低，不能承受常规水泥浆液柱压力，出现固井水泥浆漏失、水泥返高达不到设计要求的问题，开展了低密度水泥浆体系研究。通过室内试验，对减轻材料粉煤灰、漂珠及二者复合体系进行了较系统的研究，确定了适合的配方。研究选用增稳剂ZW 加入低密度体系，提高了低密度水泥的强度。实验结果及现场实践表明: 用减轻材料配制低密度水泥浆及降低水泥浆液柱压力，是确保低压易漏地层固井水泥浆返高的有效途径，对提高固井质量和延长油井寿命都将起到积极作用。

Experiment and application of composite low-density slurry cementing with fly ash and floating bead

The authors studied the low-density slurry system,because the fracture pressure of some strata in cementing was low,the well walls could not bear the high pressure by slurry columns,leading to the leak of slurry and the cement return height could not reach engineering designation in Wuqi oilfield.Through the laboratory experiment,the lightening materials of fly ash,floating bead and the composit system of both were analyzed and the proper mixture ratio was decided.In order to improve the intensity of low-de...