摘要
建南气田长兴组碳酸盐岩储层由于前期对酸岩反应规律的认识严重不足,酸压改造效果并不理想。因此开展了旋转圆盘、岩心驱替、扫描电镜等相关实验,以揭示其酸岩反应规律。实验结果表明,岩石成分变化以及晶粒成熟度对酸岩反应速率影响显著,生屑灰岩与胶凝酸的反应速率约为生物灰岩的1.3倍,为灰质云岩的1.4倍,为普通灰岩的1.9倍,20%胶凝酸与4种岩心反应,表面均能形成非均匀刻蚀;溶孔云岩过酸后,由于压实、颗粒运移作用,易造成二次污染,渗透率降低;生物灰岩和生屑灰岩过酸时,胶凝酸更易与方解石充填物发生反应,且优先在晶间孔、晶间缝进行溶蚀,但形成的酸蚀蚓孔较少。针对不同类型储层,分别提出了前置液酸压、加砂酸压、小型酸化。
The Changxing Formation in Jianxing Gas Field has two sedimentary types,bioclastic beach and biogenic reef,and different minerals in the reservoir formations react differently with acids.Lack of understanding of the reaction patterns of rocks and acids resulted in poor stimulation job quality.Laboratory study on rock samples showed that composition and maturity of crystal grain of the rocks greatly affected the reaction rate of rocks and acids,the reaction rate of bioclastic limestone and gelled acid was 1.3 times that of biolithite,1.4 times that of limy-dolomite,and 1.9 times that of common limestone.The four rock samples,after reaction with acids,all produced non-uniform corrosion on their surfaces.Dolomite with erosion pores,after reaction with acids,will experience further permeability impairment because of compaction and particle migration.After reaction with acids,the calcitc fillings of biolithite and bioclastic limestone reacted much easily with gelled acid,with erosion first formed in the inter-crystalline pores and inter-crystalline cracks,but acid wormholes were rarely seen.
出处
《钻井液与完井液》
CAS
北大核心
2015年第2期85-88,103-104,共4页
Drilling Fluid & Completion Fluid
基金
四川省青年科技创新研究团队资助计划"储层增产改造"(2011JTD0018)
