莺歌海盆地LD10气田砂岩储层可动流体特征与天然气充注下限  

Movable fluid characteristics and lower limit of natural gas charging insandstone reservoirs of LD10 gas field in the Yinggehai basin

作　　者：范彩伟 黄志龙[3,4] 邓广君 侯静娴 赵静 FAN Caiwei;HUANG Zhilong;DENG Guangjun;HOU Jingxian;ZHAO Jing(Zhanjiang Branch of China National Offshore Oil Corporation Ltd.,Zhanjiang,Guangdong 524057,China;School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Hainan Branch of China National Offshore Oil Corporation Ltd.,Haikou,Hainan 570100,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司,广东湛江524057 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [3]中国石油大学(北京)地球科学学院,北京102249 [4]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [5]中海石油(中国)有限公司海南分公司,海南海口570100

出　　处：《地质学报》2022年第11期3994-4009,共16页Acta Geologica Sinica

基　　金：中海石油(中国)有限公司科技重点项目“南海西部油田上产2000万方关键技术研究”(编号CNOOC-KJ 135 ZDXM 38 ZJ 02 ZJ)资助的成果。

摘　　要：针对近海盆地低渗砂岩气藏含气量较低,物性下限不明显的难题,本文进行了莺歌海盆地LD10气田低渗砂岩储层流体可动性、天然气充注下限及充注过程的研究。结果表明:研究区发育3种类型储层,分别为:(1)强溶蚀-大孔粗喉可动型Ⅰ类储层,质量最好,大孔喉为优势运移通道;(2)弱溶蚀-中孔细喉部分可动型Ⅱ类储层,较高动力下储层可动流体占比高;(3)致密-微孔管束喉道束缚型Ⅲ类储层,发育极少大孔喉,含气饱和度差异较大。大孔喉分布、储层物性是控制低渗储层流体可动性的主要因素。综合考虑储层流体可动性的微观与宏观因素,认为LD10气田低渗砂岩储层气体可动性的孔喉半径下限为0.1μm,渗透率下限为0.125×10^(-3)μm^(2),Ⅲ类储层致密,可作为遮挡层。天然气充注动力较低或充注初期,Ⅰ类储层为气藏聚集的有利区;当天然气充注动力充足时,Ⅰ类储层既是优势运移通道,也是气藏的优势聚集区,Ⅱ类储层为有效储层。研究成果对低渗砂岩储层有效性的判别和气藏有利区的预测具有借鉴意义。Low-permeability sandstone gas reservoirs in offshore basins have low gas content and no obvious lower limit of reservoir physical properties, which is one of the difficult problems in the current exploration scenario. In this paper, the fluid mobility, the lower limit of reservoir physical properties and charging progress of natural gas in the low-permeability sandstone reservoir, LD10 gas field, Yinggehai basin are studied. The results show that three types of reservoirs are developed in the study area: characteristics of the movable type I reservoir is strong dissolution, large pore-throat with the best quality, which is the dominant migration channel. Weak dissolution, medium pore-throat with partially movable are the characteristics of type II reservoir, which has a high proportion of reservoir movable fluid under high power. Tight reservoirs with microporous tube bundle throat is the characteristics of the type III reservoir. Few large pore throats are developed, and the gas saturation varies greatly. The distribution of large pore-throat and reservoir physical properties are the main factors controlling fluid mobility in low-permeability reservoirs. Considering the micro and macro factors, the lower limit of pore-throat radius of low-permeability sandstone reservoirs in LD10 gas field is 0.1 μm. The lower limit of permeability is 0.125×10^(-3)μm^(2). Type III reservoir is tight and can be used as the shielding layer. Type I reservoir is a favorable area for gas accumulation when the natural gas charging power is low or at the initial stage. When the driving force is sufficient, type I reservoir is the dominant migration channel and the accumulation area of gas reservoirs, and the type II reservoir becomes an effective reservoir. The research results can be used for reference to distinguish the effectiveness of low-permeability sandstone reservoirs and predict the favorable area.

关 键 词：核磁共振 低渗砂岩储层 流体可动性 天然气充注下限 黄流组 

分 类 号：P618.13[天文地球—矿床学]