Abstract:

Secondary cementing of small casing is a new type of cementing technology. At present, due to the brittleness of cement itself, it is easy to gas channeling and water channeling, and it is an alkaline solidified body, which is easy to produce cracks under pressure, and it is also easy to be damaged by acidic medium. An unsaturated polyester resin was synthesized by using D-33 diol and maleic acid as raw materials and styrene as dispersant. The introduction of fillers in the resin system improved the toughness and compressive strength of the product. The resin was characterized by FTIR. The performance of the resin system was evaluated by universal testing machine. The results indicated that the target product contained the characteristic peaks of aldehyde group, carbon-carbon double bond and p-benzene ring structure. The curing system was dibenzoyl peroxide / N,N-dimethylaniline, and its dosage at 50℃, 60℃ and 70℃ was 0.2%/0.02%, 0.1%/0.02% and 0.1%/0.01%, respectively. The test results of universal testing machine showed that the compressive strength after curing at 50℃, 60℃ and 70℃ for 24h was about 50MPa, 70MPa and 90MPa, respectively. A cementing material with adjustable polymerization time, low viscosity, high pressure resistance, acid and alkali resistance was obtained in the experiment, which was expected to be widely used in horizontal well refracturing.

Key words: secondary cementing, unsaturated resin, low viscosity and high pressure resistance, catalyst, curing agent, filler

摘要：

小套管二次固井是一种新型的固井工艺，针对目前由于水泥自身脆性大易气窜和水窜且为碱性固化体、易受压产生裂缝、易受酸性介质破坏的问题，以D-33二元醇和顺丁烯二酸为原料，苯乙烯作为活性稀释剂合成了一种不饱和型聚酯树脂。在树脂体系中引入填料，提高产品韧性及抗压强度。采用傅里叶变换红外光谱仪对树脂进行表征；通过万能试验机对树脂体系进行性能评价。结果表明，目标产物包含羰基、碳碳双键和苯环对位取代结构的特征峰，固化体系为过氧化二苯甲酰/N,N-二甲基苯胺，其在50℃、60℃和70℃条件下的添加量分别为0.2%/0.02%、0.1%/0.02%、0.1%/0.01%，万能试验机测试结果显示，在50℃、60℃和70℃下养护24h后的抗压强度分别约为50MPa、70MPa、90MPa。实验获得了一种聚合时间可调、黏度小、抗压强度高且耐酸耐碱的固井材料，有望在水平井重复压裂改造中大规模使用。

关键词: 二次固井, 不饱和树脂, 低黏高抗压, 催化剂, 固化剂, 填料