委内瑞拉Faja区块固井用耐高温增韧防窜水泥浆体系

分析了委内瑞拉Faja区块影响固井质量及后续稠油开发的地质因素:地层以砂岩为主，胶结疏松，井壁易垮塌；存在油田伴生气；地层非均质性强，不利于后续稠油开采；开发周期长，对水泥环的力学完整性要求很高。针对以上固井难题，形成了一套耐高温增韧防窜水泥浆体系。通过室内实验评价，该水泥浆在稠化时间、失水量、沉降稳定性等常规性能方面表现良好，UCA过渡时间在20min以内，防窜能力强；水泥石弹性模量能够大幅降低至2.6GPa，抗拉强度大于1MPa，热传导系数分别为0.65和1.13，水泥石的整体热力学性能良好；形成的水泥石在315℃条件下养护5d强度不衰退，性能满足蒸汽驱开发要求，具有推广应用前景。 

Cement Slurry Used in Block Faja Venezuela

Geological factors affecting the cementing job quality and heavy oil production in block Faja, Venezuela, include: unconsolidated sandstone formations that are easy to collapse, associated gases, formation, heterogeneity that is disadvantageous to subsequent heavy oil production, long production time that imposes rigorous requirements on the mechanical integrity of cement sheaths. A high temperature anti-channeling cement slurry with enhanced toughness has been developed to solve these problems. Laboratory evaluation demonstrated that the cement slurry had good thickening performance, filtration behavior and sedimentation stability. The cement slurry had UCA transition time that is less than 20 min, and good anti-channeling performance. The elastic modulus of the set cement was greatly reduced to 2.6 GPa, the tensile strength was greater than 1 MPa, and the coefficient of heat transfer is 0.65 and 1.13, meaning that the set cement had good thermodynamic property. The set cement, after aging 5 d at 315℃, was not decreasing. All in all, the cement slurry has the potential to satisfy the needs for steam flooding, and is worth applying in other areas.