抗高温缓凝剂GH-ⅡB在中原油田固井中的应用

Application of high temperature cement retarder GH-Ⅱ B in Zhongyuan oilfield.

针对高温高压深井固井中发生的问题,中原油田采用了加有抗高温缓凝剂GH-ⅡB的水泥浆体系。该缓凝剂是有机多糖化合物经深度氧化后生成的液态物质,其羧基官能团能吸附在水化物表面形成保护膜,并抑制水化物与水接触,减缓水化物晶核的生成,从而降低水泥颗粒的水化速度。室内试验表明,抗高温缓凝剂GH-ⅡB具有较高的热稳定性,对水泥有良好的缓凝特性和一定的减阻能力,可适用于95-160℃的高温区域,稠化曲线近似呈直角;可形成早期强度,减少失重危害,并与其它外加剂配伍性良好。抗高温缓凝剂GH-ⅡB经在40多口探井和深井使用,效果良好,固井合格率达99%,优良率在80%以上。

To solve problems of HTHP deep wells, a cement slurry with high temperature cement retarder GH-Ⅱ B in was adopted by Zhongyuan Oilfield. As a polyhydroxyl compound, its hydroxyl group adsorbs on cement hydrate to form a protective membrane, stop the touching of water with cement hydrates, impedes the producing of hydrate core, and lowered the cement particles' hydration velocity. Lab tests indicated that GH-Ⅱ B possesses excellent thermal stability, making it effective at 95-160℃. It also provides delayed thickening and some drag reducing function, and the transient time is short on consistence curve. In addition, it is compatible with other cement additives in slurry. Application in 40+ wells illustrated its advantages, the cementing qualified ratio reached 99% , and the excellent ratio went up to 80%.