摘要
在油田开发初期,裂缝能大幅度提高油井产量,但是在注水后期却成为水窜的主要通道。出现裂缝性水窜后,如何高效封堵裂缝通道,成为了裂缝性油藏高效开发的关键。文章以强亲水性纤维素和强黏附性阳离子单体二甲基二烯丙基氯化铵为主剂研发出了一种强力封堵剂,其最佳配方为:0.8%纤维素+2%二甲基二烯丙基氯化铵+0.12%交联剂+0.05%引发剂。该体系初始黏度低、可注入性强、成胶时间可控,成胶后具有半固体的性质,凝胶黏度可达17×10^4m Pa·s,是以弹性为主的强凝胶。在闭合裂缝、70目开度裂缝和40目开度裂缝中封堵后的突破压力梯度均超过21.7 MPa/m,能将两块断裂的岩心牢固粘结。所研发的堵剂在温度60℃~80℃、矿化度0~100 g/L、p H值8~10的范围内具有良好的适应性。实验说明纤维素凝胶能够有效封堵裂缝性油藏中的窜流通道,为该类油藏的高效开发提供重要技术支撑。
At the early stage of oilfield development,fracture can greatly increase oil production.However,at the later stage of water injection,it can become the main channel of water channeling.How to effectively plug the fracture after the occurrence of fractured water channeling has become the key to the efficient development of the fractured reservoirs.To this end,in this paper,a strong plugging agent has been developed by using the cellulose with strong hydrophilicity and cationic monomer dimethyldially lammonium chloride with strong adhesion as the main agent.The optimum formulation is:0.8%ultrafine cellulose+2%dimethyldiallyl ammonium chloride+0.12%crosslinker+0.05%initiator.The gelling solution with a low initial viscosity has a good inject ability.Its gelation time is controllable.After gelation,the formed gel has a high viscous modulus and the viscosity can reach 17×10^4 m Pa.s,which has semi-solid properties.The breakthrough pressure gradients are all more than 21.7 MPa/m after plugging in the closed fracture,70 mesh opening fracture and 40 mesh opening fracture,respectively.The formed gel can firmly cement the two fractured cores together.The developed plugging agent is suitable for use at a temperature range of 60~80℃,a salinity range of 0~100 g/L,and a p H range of 8~10.The experiment can provide an important technical support for the efficient development of the fractured reservoirs.
作者
梁甲波
刘波
陈楠
LIANG Jiabo;LIU Bo;CHEN Nan(Iraq Limited Oil Well Operation Center of China National Offshore Oil Corporation,Tianjin 300192,China;China National Offshore Oil Corporation EnerTech Technology&Services Oil Production Co.,Tianjin 300450,China;China National Offshore Oil Corporation EnerTech Safety&Environmental Protection Company,Tianjin 300450,China)
出处
《钻采工艺》
CAS
北大核心
2020年第2期103-106,I0022,共5页
Drilling & Production Technology
基金
中海油支持项目“智能控释型调—堵—驱复合EOR体系研究”(编号:E-23197022)。
关键词
裂缝水窜通道
改性纤维素
凝胶
黏弹性
突破压力
fracture water channeling
modified cellulose
gel
viscoelasticity
breakthrough pressure
