基于TOUGH+的水合物藏降压开采过程中气体运移规律数值模拟研究  

Numerical Simulation Study of Natural Gas Transport Law from Hydrate Decomposition by Depressurization Based on TOUGH+

作　　者：刘丽强[1] 徐军[2] 李雁[3] 

机构地区：[1]广州海洋地质调查局,广州510760 [2]河海大学,南京210098 [3]中山大学,广州510006

出　　处：《南海地质研究》2015年第1期26-37,共12页Gresearch of Eological South China Sea

基　　金：海洋地球科学及勘探技术发展调研(课题编码:GZHJK2014001)

摘　　要：天然气水合物的特征是优质、洁净、储量巨大，主要蕴藏在陆域的永久冻土或海洋沉积物中，被认为是人类在21世纪最重要的替代能源，对水合物开采的基础研究受到世界各国政府的高度重视。数值模拟技术作为一种重要的预测和评估手段，近年来被应用于水合物开采的研究中。TOUGH＋HYDRATE模型是国际上较为先进的水合物数值模型，基于该模型对水合物竖井降压开采进行数值模拟，研究海底沉积物中的水合物藏在开采中的气体运移、产量规律等是天然气水合物开发领域的热点和前沿问题。本文利用TOUGH＋HYDRATE，以南海神狐海域为研究对象，建立水合物竖井降压开采模型，研究气水产量的演化规律。在降压分解过程中设置3种不同的井筒压力（11．5MPa、12．46MPa和13MPa），模拟结果显示，井筒压力为12．46MPa时，储层内的累计产气总量大，效益显著，水合物分解产气速率也较为适中，开发潜力优于其他两种情况。Natural gas hydrate has the characteristics of high quality, clean and enormous reserves. It is mainly located in terrestrial permafrost or the deep sea sediments, and considered to be the most important alternative energy sources in this century. As a kind of important mean of prediction and assessment, numerical simulation technology is applied in the study of hydrate mining method. TOUGH＋HYDRATE （T＋H） is one of the advanced softwares widely used in the simulation of the hydrate production. In this paper, TOUGH＋HYDRATE is applied to simulate the hydrate dissociation and gas production process in the South China Sea with the vertical well depressurization, and to study the production rule of the hydrate in the sediments during the production process. These are hot issues in the field of natural gas hydrate development. The study area is Shenhu which is located in the South China Sea. Based on the TOUGH＋HYDRATE model,we build a model which is conform to the actual situation. In the simulation, we set three different cases of wellbore pressure （11.5 MPa,12.46 MPa and 13 MPa） during the dissociation process by depressurization. The simulation results indicate that when the wellbore pressure is set 12.46 MPa, CH4 production rate of hydrate dissociation and total CH4 production rate in the reservoir both show moderately, and the economic benefit is remarkable.

关 键 词：天然气水合物 数值模拟 TOuGH+HYDRATE(T+H) 竖井降压 

分 类 号：P744.4[天文地球—海洋科学]