外加剂对矿渣-粉煤灰地聚合物固井水泥浆的影响

Effects of Admixtures on Slag-fly ash Geopolymer Cementing Slurry

针对地聚合物固井水泥浆凝结时间短、表观黏度及滤失量大等问题,基于凝结时间、表观黏度和滤失量等性能参数,研究了缓凝剂、分散剂和降失水剂对地聚合物固井水泥浆的影响。结果表明:缓凝剂氯化钡和硼砂仅起到微弱的缓凝作用,而氟硅酸钠缓凝效果很好,且具有提高水泥石抗压强度的能力;分散剂木质素磺酸钠和萘系减水剂具有一定程度的分散性能,且相同注入量下萘系减水剂比木质素磺酸钠降黏效果好,而聚羧酸减水剂表现为增稠效果;降失水剂CMC和CMS均具有明显降滤失能力,相同注入量下CMS降失水性能优于CMC,二者均能够提高凝结3 d的水泥石抗压强度。该研究为完井作业中水泥浆的选择提供了借鉴。

To address the problems of short setting time,high apparent viscosity and great filter loss of geopolymer cementing slurry,the effects of retarder,dispersant and fluid loss agent on geopolymer cementing slurry were studied based on the performance parameters such as setting time,apparent viscosity and filter loss.The results showed that,the retarders barium chloride and borax only had weak retarding effect,while sodium fluorosilicate had a good retarding effect and could improve the compressive strength of set cement;the dispersant sodium lignosulfonate and the naphthalene water reducer had a certain dispersibility,and the naphthalene water reducer had a better viscosity reduction effect than sodium lignosulfonate at the same injection rate,while the polycarboxylate water reducer showed a thickening effect;the fluid loss agents CMC and CMS were significantly effective in fluid loss reduction,CMS was superior to CMC in terms of fluid loss reduction at the same injection rate,and both of them could improve the compressive strength of cement set for 3 days,The study provides a reference for the selection of cement slurry used in well completion.