【作者】 王超；

【导师】 蒋官澄；

【作者基本信息】 中国石油大学 ， 油气井工程， 2010， 硕士

【摘要】 随着目前钻井过程中复杂情况的增加和对钻井环境保护要求的提高,降滤失剂等钻井液添加剂,面临高温、高矿化度及环保性能等方面的挑战。本文以羧甲基淀粉CMS为合成基体,在过硫酸钾和亚硫酸钠氧化还原体系的引发下,以接枝非离子单体AM和阴离子单体AMPS,合成了改性羧甲基淀粉共聚物。并使用Design-Expert软件进行数据分析,通过响应面法确定了最佳聚合条件为:CMS的取代度为0.29,AM/AMPS摩尔比为3:1,单体与羧甲基淀粉加量比0.38:1,反应温度为65℃,引发剂加量为0.22g/L。并采用物理改性的方法,即将共聚物与成膜剂按质量比2:1进行复配,制备得到性能更加优良的改性羧甲基淀粉降滤失剂。室内评价结果表明,该降滤失剂在淡水基浆和盐水基浆中均有很好的降滤失能力。在降滤失剂加量为1%时,在淡水基浆老化前后API降滤失率分别达到81.3%、82.1%;在降滤失剂加量为2%时,盐水基浆、饱和盐水基浆及海水基浆中老化前后API降滤失率分别达到90.5%、91.9%、90.8%、90%、93.3%、93%。该降滤失剂还具有优良的耐温抗盐能力,抗高温可达150℃,抗NaCl至饱和,抗钙侵达2.5%,降滤失效果也优于与常用降滤失剂OCL、CMS,同时,新型降滤失剂可生物降解,毒性低,对环境影响小。更多还原

【Abstract】 With the increasing of complex situations in the process of drilling, Filtration reducing agents have to face the challenges of high temperature, high salinity and environmental protection. The graft copolymer intermedium which used potassium peroxodisulfate and sodium sulfite as the initiator system was prepared by carboxymethyl starch(CMS) and 2-acrylamide-2-methyl propanesulfonic acid (AMPS) and acrylamide (AM). Operation conditions were optimized with the Design-Expert 8.0 software, The optimum reaction conditions were that the degree of substitution of CMS was 0.29, the molar ration of AM:AMPS was 3:1, the mass ratio of monomer and CMS was 0.38:1, reaction temperature 65℃, reaction time 2h, pH value 7.0. The modified carboxymethyl starch as filtration control agent was formulated with the graft copolymer and film forming agent at the mass ratio of 1:2.Laboratory experiments were done on the evaluated of the new type of filtration control agent, which showed that it has very good abilities of depressing the filter loss at both fresh mud and salty mud. With the additive of 1% filtration control agent, the API filter loss rate of pre and post aging could be controlled at 81.3% and 82.1% at the fresh mud. At salty mud, saturated salty mud and sea water mud, the API filter loss rate of pre and post aging could be controlled at 90.5%, 91.9%, 90.8%, 90%, 93.3%, 93%. The agent also has very good abilities of saturated brine, 2.5% calcium and 150℃temperature-resistant. Compared with filtration control agent OCL and CMS, and the ratio of performance and cost is relatively high. The environmental protection of experiment results showed that the new agent was degradable and will not pollute the environment.更多还原