Experimental study on solid particle migration and production behaviors during marine natural gas hydrate dissociation by depressurization  

作　　者：Yan-Long Li Fu-Long Ning Meng Xu Min-Hui Qi Jia-Xin Sun Alireza Nouri De-Li Gao Neng-You Wu 

机构地区：[1]Key Laboratory of Gas Hydrate,Ministry of Natural Resources,Qingdao Institute of Marine Geology,Qingdao,266237,Shandong,China [2]Laboratory for Marine Mineral Resources,Laoshan Laboratory,Qingdao,266237,Shandong,China [3]Faculty of Engineering,China University of Geosciences-Wuhan,Wuhan,430074,Hubei,China [4]MOE Key Laboratory of Petroleum Engineering,China University of Petroleum,Beijing,102249,China [5]School of Mining and Petroleum Engineering,University of Alberta,Edmonton,AB,Canada

出　　处：《Petroleum Science》2023年第6期3610-3623,共14页石油科学（英文版）

基　　金：supported by the Laoshan Laboratory(No.LSKJ LSKJ202203506);the Taishan Scholars Program,and the National Natural Science Foundation of China(Grant No.41976074).

摘　　要：Sand production is one of the main obstacles restricting gas extraction efficiency and safety from marine natural gas hydrate(NGH)reservoirs.Particle migration within the NGH reservoir dominates sand production behaviors,while their relationships were rarely reported,severely constrains quantitative evaluation of sand production risks.This paper reports the optical observations of solid particle migration and production from micrometer to mesoscopic scales conditioned to gravel packing during depressurization-induced NGH dissociation for the first time.Theoretical evolutionary modes of sand migration are established based on experimental observations,and its implications on field NGH are comprehensively discussed.Five particle migration regimes of local borehole failure,continuous collapse,wormhole expansion,extensive slow deformation,and pore-wall fluidization are proved to occur during depressurization.The types of particle migration regimes and their transmission modes during depressurization are predominantly determined by initial hydrate saturation.In contrast,the depressurization mainly dominates the transmission rate of the particle migration regimes.Furthermore,both the cumulative mass and the medium grain size of the produced sand decrease linearly with increasing initial methane hydrate(MH)saturation.Discontinuous gas bubble emission,expansion,and explosion during MH dissociation delay sand migration into the wellbore.At the same time,continuous water flow is a requirement for sand production during hydrate dissociation by depressurization.The experiments enlighten us that a constitutive model that can illustrate visible particle migration regimes and their transmission modes is urgently needed to bridge numerical simulation and field applications.Optimizing wellbore layout positions or special reservoir treatment shall be important for mitigating sand production tendency during NGH exploitation.

关 键 词：Natural gas hydrate Solid particle migration Sand production Sand control SANDING Hydrate exploitation 

分 类 号：TE53[石油与天然气工程—油气田开发工程]