北部湾盆地稠油储层流体识别问题探讨  

Discussion on Fluid Identification of Heavy Oil Reservoir in Beibu Gulf Basin

作　　者：吴健 张恒荣 胡向阳 刘土亮 张恒 Wu Jian;Zhang Hengrong;Hu Xiangyang;Liu Tuliang;Zhang Heng(Zhanjiang Branch of CNOOC Ltd,Zhanjiang 524057,Guangdong,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

出　　处：《吉林大学学报（地球科学版）》2024年第3期1054-1067,共14页Journal of Jilin University：Earth Science Edition

基　　金：中国海洋石油集团公司“十四五”重大专项(KJGG2022-0301)。

摘　　要：南海西部北部湾盆地的稠油油藏分布在涠西南凹陷和乌石凹陷,主要以普通稠油和特稠油为主。此类稠油埋深范围较广,从浅层到中深层均有发现,物性较好,呈中—高孔渗和高阻特征,但常规气测往往仅有总烃和甲烷,气测值很低且无异常显示,录井岩屑在大部分区域未见任何荧光和含油显示,给地层流体识别带来很大困难。为此,针对本区不同类型的稠油进行分类并开展测、录井特征分析;在此基础上,以随钻测井曲线结合壁心含油性为主要手段,以气测图版和壁心三维定量荧光识别为辅助,提出了一套稠油快速识别方法。利用取样过程中对井下地层流体性质的监测和岩石热解分析结果,指出稠油本身典型的烃组分构成造就了其独特的气测特征;同时,认为强亲水的岩石润湿性以及沥青质稠油与砂岩骨架颗粒之间特殊的粘附性是造成部分稠油储层岩屑无荧光和含油显示的主要原因,壁心和取样流体的三维定量荧光能够真实反映地层流体的性质。The heavy oil reservoirs in Beibu Gulf basin of the western South China sea are mainly distributed in Weixinan sag and Wushi sag,It is mainly composed of ordinary heavy oil and extra heavy oil.This type of heavy oil has a wide burial depth unit and can be discovered from shallow to middle-deep layers,with good physical properties and characteristics of medium high porosity,permeability,and high resistivity.However,conventional gas logging often only includes total hydrocarbons and methane,the gas measurement value is very low and there is no abnormal display,no fluorescence or oil bearing indication is found in most areas during cutting logging,which brings great difficulties to formation fluid identification.Therefore,classification and logging characteristics analysis are conducted for different types of heavy oil in this area.On this basis,a fast identification method for heavy oil is proposed by combining logging curves while drilling with the oil content of the wall core as the main means,supplemented by gas logging maps and three-dimensional quantitative fluorescence recognition of the wall core.By utilizing the monitoring of fluid properties in underground formations and the results of rock pyrolysis analysis during the sampling process,it is pointed out that the typical hydrocarbon composition of heavy oil itself creates its unique gas logging characteristics.Meanwhile,the analysis suggests that the strong hydrophilicity of rock wettability and the special adhesion between asphaltene heavy oil and sandstone skeleton particles are the main reasons for the lack of fluorescence and oil content display in some heavy oil reservoir cuttings.It is also pointed out that the three-dimensional quantitative fluorescence of the wall core and sampling fluid can truly reflect the properties of the formation fluid.

关 键 词：稠油储层 重烃组分 润湿性 沥青粘附性 荧光录井 井下流体分析 北部湾盆地 

分 类 号：TE51[石油与天然气工程—油气田开发工程]