固井工程中耐高温高效隔离液的研制及抗污染机理
发布时间：2018-10-05 10:29
【摘要】：固井工程中的注水泥作业是极为重要的一道工序,为达到避免钻井液和水泥浆两种理化性质差异较大的流体产生接触污染现象,隔离液通常会先于水泥浆被注入到井段中,并在钻井液和水泥浆之间形成分隔。但是,现有的隔离液体系大多耐温性差、与水泥浆、钻井液不相容、抗污染机理研究尚不成熟。为此,本文在合成PIAS、流型调节剂HS和优选其他添加剂的基础上,研制成了耐高温的高效PIAS/HS隔离液。 首先通过分子结构设计,根据自由基聚合原理,以衣康酸、丙烯酰胺、对苯乙烯磺酸钠、过硫酸钾等原料合成了PIAS,并采用FTIR和TG对合成PIAS的结构和热性能进行了表征。通过设计三因素三水平正交试验得到其最佳合成条件为：控制体系的pH6-7、反应时间5hr,单体的质量比IA:AM:SSS=1:4:3、反应温度55℃、引发剂加量3%。180℃×115MPa条件下,含PIAS水泥浆体的稠化实验和水泥石的早期抗压强度测试证实PIAS对水泥浆具有良好的缓凝效果并且不会产生水泥浆超缓凝现象。通过SEM、 XRD、EDS、升降温稠化试验等表征分析,探讨了PIAS的缓凝机理和自适应机理。 采用自由基接枝聚合法获得羟乙基纤维素／对苯乙烯磺酸钠接枝共聚物流型调节剂HS,并采用FTIR和TG对流型调节剂HS的结构和热性能进行了表征。通过控制变量的方法分别设计了质量比、引发剂加量及反应温度三组单因素变量合成实验,并以所得流型调节剂HS的粘度为评价指标,从而得到流型调节剂HS的最佳合成条件,即：质量比HEC:SSS=1:2;过硫酸铵引发剂加量0.5%；反应温度50℃；反应时间8hr。 对隔离液其他添加剂进行复配、优选后,配置成耐高温的高效PIAS/HS隔离液,并依照标准SY/T5374-2000测定了PIAS/HS隔离液的悬浮稳定性、流变性以及与水泥浆、钻井液的相容性等工程性能。实验表明,该隔离液在60-180℃内能保证浆体良好的悬浮稳定性,密度在1.2-2.4g/cm3范围内可调节,并且能有效隔离钻井液和水泥浆,明显改善水泥浆-隔离液两相混浆体系以及水泥浆-隔离液-钻井液三相混浆体系的流变性,防止了混浆絮凝、闪凝等现象的产生。此外,通过XRD等分析手段解释了隔离液的悬浮机理、对固井二界面的冲刷机理及其抗污染机理。
[Abstract]:Cementing is a very important process in cementing engineering. In order to avoid contact pollution of drilling fluid and cement slurry, the isolating fluid is usually injected into the well section before cement slurry. A separation is formed between the drilling fluid and the cement slurry. However, most of the existing isolated liquids have poor temperature tolerance, incompatible with cement slurry and drilling fluid, and the study of anti-pollution mechanism is not mature. Therefore, based on the synthesis of PIAS, flow regime regulator HS and other additives, a high-temperature and high-efficiency PIAS/HS isolating solution was developed. Firstly, PIAS, was synthesized from itaconic acid, acrylamide, sodium styrene sulfonate and potassium persulfate by molecular structure design, according to the principle of free radical polymerization. The structure and thermal properties of synthesized PIAS were characterized by FTIR and TG. By designing three factors and three levels orthogonal test, the optimum synthesis conditions were obtained as follows: the reaction time of pH6-7, was controlled at 5hrs, the mass ratio of monomer to IA:AM:SSS=1:4:3, was 55 鈩，
本文编号：2253043
[Abstract]:Cementing is a very important process in cementing engineering. In order to avoid contact pollution of drilling fluid and cement slurry, the isolating fluid is usually injected into the well section before cement slurry. A separation is formed between the drilling fluid and the cement slurry. However, most of the existing isolated liquids have poor temperature tolerance, incompatible with cement slurry and drilling fluid, and the study of anti-pollution mechanism is not mature. Therefore, based on the synthesis of PIAS, flow regime regulator HS and other additives, a high-temperature and high-efficiency PIAS/HS isolating solution was developed. Firstly, PIAS, was synthesized from itaconic acid, acrylamide, sodium styrene sulfonate and potassium persulfate by molecular structure design, according to the principle of free radical polymerization. The structure and thermal properties of synthesized PIAS were characterized by FTIR and TG. By designing three factors and three levels orthogonal test, the optimum synthesis conditions were obtained as follows: the reaction time of pH6-7, was controlled at 5hrs, the mass ratio of monomer to IA:AM:SSS=1:4:3, was 55 鈩，
本文编号：2253043
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