摘要
出砂是制约当前天然气水合物长效开发的关键因素之一。基于水合物分解区地层松散沉积物球形颗粒堆积假设,分析了水合物分解前缘和分解区内部地层砂微粒的受力情况,基于力矩平衡条件建立了松散沉积物中地层砂颗粒启动运移临界流速的计算模型,并进行模型敏感性分析。结果表明,水合物分解前缘和分解区内部微粒的临界流速均随着粒径、排布角度、颗粒摩擦系数的增加而增加,胶结物性质、流体中的电解质类型以及浓度等参数均对临界出砂流速产生一定的影响。本文建立的砂粒启动运移临界流速模型能够为水合物开采储层出砂评价提供支撑。
In the mining process of natural gas from a hydrate reservoir,sanding is one of the major factors restricting the development of natural gas hydrate.In this paper,based on the assumption that hydrate cemented sediment is composed of tightly squeezed balls in equal size,we analyzed the stress conditions of such sand particles on the leading edge and in the decomposed zone.A critical velocity model for sand migration in decomposed hydrate-cemented sediment is built then on account of torque balance conditions.The results indicate that critical velocity of particles on the leading edge and in the decomposed zone increases with the increase in particle diameter,arrangement angle and coefficient of friction,and the properties of cement and the type and concentration of electrolyte in the fluid also influence the critical velocity of sand migration.The model proposed in this paper can provide a theoretical basis for evaluation of hydrate sanding.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2017年第5期166-173,共8页
Marine Geology & Quaternary Geology
基金
国家自然科学基金项目(41606078)
泰山学者特聘专家项目
中国地质调查专项(DD20160216)
青岛海洋科学与技术国家实验室开放基金(QNLM2016ORP0203,QNLM2016ORP0207)
关键词
天然气水合物
出砂
水合物分解区
松散沉积物
启动运移
临界流速
natural gas hydrate
sand Production
hydrate cemented sediment
loose sediments
sand initiating model
critical velocity
