复合压差激活密封剂的设计及其封堵性能  

Design and plugging property of composite pressure activated sealant

作　　者：许林 蒋孟晨 许洁[2] 许明标[3] 孟双 王东旭 XU Lin;JIANG Mengchen;XU Jie;XU Mingbiao;MENG Shuang;WANG Dongxu(College of Petrochemical and Energetic Engineering,Zhejiang Ocean University,Zhoushan,Zhejiang 316022,China;Institute of Exploration Techniques,Chinese Academy of Geological Sciences,Langfang,Hebei 065000,China;College of Petroleum Engineering,Yangtze University,Wuhan,Hubei 430100,China)

机构地区：[1]浙江海洋大学石化与能源工程学院 [2]中国地质科学院勘探技术研究所 [3]长江大学石油工程学院

出　　处：《天然气工业》2020年第3期107-114,共8页Natural Gas Industry

基　　金：国家科技重大专项“页岩气水平井钻井液与固井技术研究”(编号:2016ZX05060-015);浙江省基础工艺研究项目“海洋油气开发微泄漏压差激活密封剂及其自适应修复机理研究”(编号:LGG20E040002);浙江省教育厅科研项目“新型压差激活密封剂的微缺陷自适应修复行为研究”(编号:Y201840431);舟山市科技计划项目“海洋油气井密封损伤的压力控释靶向修复技术研发”(编号:2019C21006);浙江海洋大学创新计划项目“油气管线自适应堵漏剂及其作用机理”(编号:XJ2018082)。

摘　　要：压差激活密封剂是一种新型密封流体,可在漏点压差作用下对丝扣、管线等静密封的微缺陷损伤实施快速、自适应修复,但其密封性受漏点尺寸影响较大,因而在油气井生产及井筒完整性恢复中的应用受到了一定的限制。为了提高压差激活密封剂的适用性,基于密封流体在压差作用下的相态转变及密封行为特点,提出了固-液态密封材料协同增效强化大孔隙封堵的复合修复技术,通过两类固体密封材料("桥堵"刚性粒子与"拉筋"纤维)的联用,改变泄漏孔隙几何结构和流体迁移路径,促使压差激活密封剂形成有效固体屏障,充填大孔隙完成密封修复。室内实验结果表明:①制备的压差激活密封剂是一种多分散体系,其核心颗粒形状较规则,粒径集中分布于300~400 mm;②在评估压力范围内,海泡石纤维作为结构形成剂,提高了形成密封固体的完整性;③贻贝粉体作为孔隙结构修饰剂,改善了密封流体在泄漏受限空间的驻留能力,二者协同改善了形成固体屏障的结构,极大增强了复合压差激活密封剂的大孔隙封堵效果。结论认为,该研究成果可以为油气井新型多功能密封剂体系的开发与应用提供理论与技术支持。Pressure activated sealant(PAS),as a novel kind of sealing fluid,can provide rapid and self-adapting repair on the tiny damage of static seals(e.g.,screws and pipelines)while encountering pressure difference of leakage sites,but its sealing property is affected more by the size of leakage site,so it exhibits limited application in the production and wellbore integrity recovery of oil&gas wells.To extend PAS’s applicability,this paper put forward a composite PAS technology involving the cooperativity of solid and liquid sealing materials for enhancing large pore plugging based on the phase state transition and sealing behaviors of sealing fluid under the action of pressure difference.In this technology,two types of solid sealing materials(bridging rigid particle and tension reinforcing fiber)were used jointly to modify the geometries of leakage pores and the migration paths of fluids,which can promote the formation of effective solid barrier from the PAS to fill in large leaking pores,so as to perform sealing repair.And the following laboratory experimental results were obtained.First,the newly prepared PAS is a kind of polydisperse system,and the core particles are regular in shape with the size distribution mainly in a range of 300-400μm.Second,in the range of evaluation pressure,sepiolite fiber,as the structure promoter,reinforces the integrity of sealing solids.Third,mussel powder,as the pore structure modifer,improves the retention ability of the sealing fluid in the limited leakage space.These two sealing materials not only cooperatively improve the structure of solid barrier,but also markedly enhance the plugging effect of composite PAS in large pores.In conclusion,these research results can provide theoretical and technical support for the development and application of novel multifunctional sealants in oil&gas wells.

关 键 词：复合压差激活密封剂 密封材料 协同作用 液-固转化 结构形成剂 自适应密封 管柱泄漏 封堵性能 

分 类 号：TE358[石油与天然气工程—油气田开发工程] TE39