超细水泥浆封堵技术的完善与应用

Improvement and Uses of Superfine Cement Plugging/Sealing Technology

报道了由G级油井水泥加工成的超细水泥的粒度分布、穿透能力及水泥石强度。讨论了超细水泥浆封堵施工中的影响因素,包括用量、滤饼形成、滤失量控制、稠化时间、流动性等。选用d90≤21μm的超细水泥,通过添加剂筛选,得到水基超细水泥浆的配方:缓凝剂HN Ⅱ1.0%,分散剂FS 11.0%,降滤失剂JS 11.0%,滤失量控制为100mL;以零号柴油为携带液,加入油溶和水溶混合表面活性剂、1.0%FS 1(按油相计),油灰水比为1∶2∶1,得到密度1.7～1.9g/cm3、流动度>30cm的油基水泥浆。介绍了超细水泥浆封堵工艺:地层预处理,水泥浆用量,封堵方法,封堵工具,封堵结果检测等。现河采油厂(地层温度60～120℃)2002年将密度1.6～1.8g/cm3的油基和水基超细水泥浆用于封管外窜、堵炮眼、油井堵水、修复套管,共施工48井次,成功率95.8%。介绍了封堵目的不同的4个井例。表6参6。

The particle size distribution, the permeating capacity in slurry, and the strength characteristics are presented for superfine cement (SFC) made of oilwell cement D. The influencing factors for SFC slurries as plugging/sealing agent are discussed, including slurry volume to be injected, cake formation, filtration loss control, thickening time, and fluidity. With SFC of d_(90)≤21 μm, a formula of water base SFC slurry of filtration loss ≤100 mL is obtained through additive screening experiments: 1.0% retarder NH-Ⅱ+1.0% dispersant FS-1+1.0% filtration loss reducer JS-1; with the same SFC an oil base SFC slurry of density 1.7—1.9 g/cm^3 and fluidity >30 cm is prepared at oil to cement to water ratio=1∶2∶1 with water- and oil-soluble mixed surfactant and 1.0% FS-1 added in oil (()~#0 diesel). The plugging/sealing technology covers formation pretreating, slurry volume, techniques and ways of slurry placement, tools, and job tests. At Xianhe factory in 2002, oil and water base SFC sulrries of density 1.6—1.8 g/cm^3 have been used 48 well-times for outer channellings and perforations plugging, water shutoff in oil wells, and case repairing with successfulness (95.8%). 4 examples with different job aim are described.