深井小间隙尾管固井水泥浆体系研究与应用

Study and Application of Cement Slurry for Deep-Narrow Clearance of Liner string

针对塔河油田深井尾管固井由于环空间隙小,导致固井时漏失和顶替效率低、水泥环薄耐冲击能力弱且易破碎的问题,优选出了高强低密度度水泥浆和非渗透抗高温常规密度水泥浆,并优选出一种化学冲洗液和加重隔离液组成的复合前置液。塔河油田深井φ177．8 mm尾管固井采用高强低密度水泥浆和复合前置液、φ127．0 mm尾管固井采用非渗透抗高温常规密度水泥浆和复合前置液,固井合格率达到100%,重叠段封固质量优。这表明深井小间隙尾管固井采用高强低密度水泥浆、非渗透抗高温常规密度水泥浆和复合前置液能提高重叠段的固井质量。

The narrow annulus of deep liners in the Tahe Oilfield will cause circulation loss, inefficient mud displacement, fragile cement sheath, etc. Regarding such scenario, a high-strength low-density cement slurry, a non-permeable high temperature cement slurry with conventional density, a chemical flush fluid, and a compositive lead fluid made up of weighted spacer are optimized. A Ф177.8 mm liner in the Tahe Oilfield is tested with high-strength low-density slurry and compositive spacer, a Ф127.0 mm liner is cemented with non- permeable high temperature normal density slurry and compositive spacer, both well achieves successful ratio of 100%, especially gets good cementing quality at overlapped section. Field applications indicate that cementing quality can be improved considerably for intercross sections and narrow annulus via high-strength low density, non-permeable normal density slurry, and compositive lead fluids.