碳酸盐岩储气库盖层动态密封性评价研究  

Study on dynamic sealing evaluation of carbonate gas storage cap rock

作　　者：滕振超[1] 张品金 贾善坡 徐萌 张广权[4] 贾跃玮[4] TENG Zhenchao;ZHANG Pinjin;JIA Shanpo;XU Meng;ZHANG Guangquan;JIA Yuewei(School of Civil Engineering and Architecture,Northeast Petroleum University,Daqing,Heilognjiang,163000,China;Institute of Unconventional Oil&Gas,Northeast Petroleum University,Daqing,Heilongjiang,163000,China;School of Earth Sciences,Northeast Petroleum University,Daqing,Heilongjiang,163000,China;Sinopec Petroleum Exploration and Production Research Institute,Beijing,100089,China)

机构地区：[1]东北石油大学土木建筑工程学院,黑龙江大庆163000 [2]东北石油大学非常规油气研究院,黑龙江大庆163000 [3]东北石油大学地球科学学院,黑龙江大庆163000 [4]中国石油化工股份有限公司石油勘探开发研究院,北京100089

出　　处：《天然气与石油》2022年第4期98-107,共10页Natural Gas and Oil

基　　金：国家自然科学基金项目“气藏型储气库泥岩盖层的疲劳效应及密封性动态演化机理研究”(42072166);黑龙江省自然科学基金项目“地下储库泥岩盖层损伤及其渗透性演化机制研究”(LH2020D004);深部岩土力学与地下工程国家重点实验室项目“热—力耦合条件下泥岩损伤、自愈特性及其与渗透性的关联性研究”(SKLGDUEK2001)。

摘　　要：注采扰动会导致碳酸盐岩储气库盖层微观孔隙结构发生不同程度的弹塑性变形,甚至会使盖层发生宏观破坏,从而导致盖层泄漏。针对储气库高速往复注采的特点,从地质特征、毛细管物性密封和宏观力学完整性三个方面出发,开展了注采条件下的盖层动态密封性评价。以Q储气库碳酸盐岩盖层为背景,通过开展注采条件下的动态密封性试验,明确了交变力学对于盖层动态密封性的影响,发现交变荷载下渗透率和突破压力呈现出下降—稳定—上升的趋势,当围压较大时,规律主要表现为下降—稳定;通过研究应力—应变曲线及声发射特征,明确了盖层疲劳破坏风险及声发射特征,表明注采条件下交变疲劳破坏风险较低;综合运用AHP和可拓学理论,对碳酸盐岩储气库盖层动态密封性进行综合评价,Q储气库评价为盖层动态密封性极好。评价体系的建立为碳酸盐岩储气库盖层动态密封性评价提供了科学依据。Injection-production disturbance will lead to varying degrees of elastic-plastic deformation of micro-pore structure of carbonate gas storage caprock, and even macro damage of the cap rock, resulting in cap rock leakage. According to the characteristics of high-speed reciprocating injection-production in gas storage, the dynamic sealing evaluation of caprock under injection-production conditions was carried out from geological features, capillary physical sealing and macro mechanical integrity. Taking the carbonate caprock of Q gas storage as the background, the influence of alternating mechanics on the dynamic sealing of caprock was clarified through the dynamic sealing test under injection-production conditions. It was found that under alternating load, the permeability and breakthrough pressure showed the trend of first decline-stability-rise. When the confining pressure was large, the law is mainly in the decline-stability stage;Through the stress-strain curve and acoustic emission characteristics, the fatigue failure risk and acoustic emission signal characteristics of caprock were defined, which showed that the alternating fatigue failure risk was low under injection-production conditions;Using AHP and extension theory comprehensively, the dynamic sealing of carbonate gas reservoir cap was evaluated. Q gas reservoir cap is evaluated as excellent dynamic sealing. The establishment of the evaluation system provides a scientific basis for the dynamic sealing evaluation of carbonate gas reservoir caprock.

关 键 词：碳酸盐岩 储气库 盖层 动态密封性评价 声发射 

分 类 号：TE972[石油与天然气工程—石油机械设备]