一种耐温的油井水泥缓凝剂的制备

Preparation of a Temperature Resistant Oilwell Cement Setting Retarder

由二甲胺、亚磷酸、丙烯醛合成了3-(二甲胺基)烯丙基膦酸DMAAPA,再在硫酸亚铁铵/过氧化氢体系引发下与衣康酸共聚,得到了DMAAPA/IA共聚物。介绍了合成过程。通过红外光谱分析确认了DMAAPA的化学结构。在水灰比0.44,加有0.25%分散剂的基础D级水泥中加入0.5%共聚物,水泥浆室温和90℃下的流型指数n值和K值(五次平行测定平均值)分别由3.376降至3.000,由0.0276Pa.sn降至0.0262Pa.sn;118℃、50 MPa下的稠化时间由74 m in延长至124 m in,稠化曲线趋于直角化;加剂量为0.5%和1.0%时,90℃养护24 h的抗压强度(三次平行测定平均值),由19.8 MPa分别降至18.4和15.5 MPa。讨论了该共聚物的缓凝机理。

3-（Dimethylamino）allyl phosphoric acid,DMAAPA,was synthesized by reacting dimethylamine,phosphorous acid,and acrolein and was copolymerized with itaconic acid at the presence of ferrous ammonium sulfate/hydrogen peroxide redox system to give DMAAPA/IA copolymer.The synthetic procedures were dipicted.The chemical structrue of DMAAPA was identified by IR spectormetric analysis.For an experimental slurry of class G oilwell cement of WCR=0.44 with 0.25% dispersant SXY-2 and 0.5% this copolymer added,the rheologic parameters n and K,averaged over 5 determinations,decreased from 3.376 to 3.000 and 0.0276 Pa·sn to 0.0262 Pa·sn,respectively;the thickening time at 118℃and 50 MPa elongated from 74 min to 124 min with the thickening curve becoming one of rectangular form;the compression strength of set cement cured at 90℃ in 24 hrs,averaged over 3 determinations,decreased from 19.8 MPa to 18.4 MPa and,at the copolymer dosage raised to 1.0%,further to 15.5 MPa.The mechanisms involved in setting retardation of cement slurry by the phosphoric acid copolymer were discussed.