Numerical study on the effect of reservoir heterogeneity and gas supply on hydrate accumulation in subsea shallow formations  

作　　者：Liang Zhang Rong Feng Songhe Geng Xin Li Fangping Yan Shaoran Ren 

机构地区：[1]School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,266580,China [2]Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)),Ministry of Education,Qingdao 266580,China [3]Zhongyuan Oilfield,Sinopec,Puyang,457000,China [4]Lusheng Company,Shengli Oilfield,Sinopec,Dongying,257000,China [5]Department of Petroleum Engineering,Chengde Petroleum College,067000,China

出　　处：《Petroleum Research》2021年第2期91-115,共25页石油研究（英文）

基　　金：This research is supported by the Fundamental Research Funds for the Central Universities(No.15CX05036A,18CX05009A);the National Key Basic Research Program 973 project(No.2015CB251201);It is also partially financed by the National Major S&T Project(No.2016ZX05056004-003);the General Project of Shandong Natural Science Foundation(ZR2020ME090);the National Natural Science Foundation of China(No.51974347)。

摘　　要：Seepage-type gas hydrate accumulation in subsea shallow formations involves complicated thermohydro-solid coupling processes and matching problem between various accumulation elements.Theformation physical properties control local natural gas migration pathway and thus the final reservoircharacteristics of hydrates.In this paper,a novel mixed-flux model for gas hydrate accumulation isestablished and then used to simulate the process of methane gas migration into the shallow stratum toform a hydrate reservoir.The effects of reservoir heterogeneity and gas source conditions on the distribution of pore fluid and hydrate accumulation are examined.The simulation results show thatreservoir heterogeneity is conducive to the retention and lateral migration of CH4 in a hydrate stabilityzone.CH4 can contact more pore water to form a large hydrate reserve,but the formed hydrate is oftendispersed.Low-permeability layers enhance the trapping of CH4 and form a uniform and large hydratesaturation.Besides,gas source conditions have an important impact on the hydrate accumulation inreservoirs.Large gas flux,small pore water flux,continuous gas supply,high content of heavy components in natural gas,and numerous gas source points contribute to large amounts of hydrates generationin a certain time period.The presented work will deepen our understanding of the controls of natural gashydrate systems in subea shallow formations.

关 键 词：Hydrate accumulation Mixed-flux model Reservoir simulation Reservoir heterogeneity Gas source condition 

分 类 号：O62[理学—有机化学]