裂缝性碳酸盐岩储层气水识别的测井解释新途径--以四川盆地九龙山地区中二叠统为例  

A new log interpretation method for identifying water and gas layers in fractured carbonate reservoirs:A case study of Middle Permian in Jiulongshan area of northwestern Sichuan Basin

作　　者：杨华 张本健[2] 陈明江 孙志昀 田云英 杨迅 王宇峰 汤兴宇 胡欣 YANG Hua;ZHANG Benjian;CHEN Mingjiang;SUN Zhiyun;TIAN Yunying;YANG Xun;WANG Yufeng;TANG Xingyu;HU Xin(Northwest Sichuan Division,PetroChina Southwest Oil&Gasfield Company,Jiangyou,Sichuan 621700,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Geological Exploration&Development Research Institute,CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China)

机构地区：[1]中国石油西南油气田公司川西北气矿,四川省江油市621700 [2]中国石油西南油气田公司勘探开发研究院 [3]中国石油集团川庆钻探工程有限公司地质勘探开发研究院,四川省成都市610051

出　　处：《天然气工业》2021年第7期56-62,共7页Natural Gas Industry

基　　金：中国石油西南油气田公司科技专项“川西地区茅口组储层特征研究及勘探目标优选”(编号:20190301-07)。

摘　　要：四川盆地西北部九龙山地区有多口井在中二叠统茅口组、栖霞组测试获得了日产百万立方米的高产气流,预示着该区具有很大的天然气勘探开发潜力,但复杂的裂缝产状及普遍发育的非均匀岩石构造模糊了测井信息对流体的响应。为了建立该区有效的气、水层测井识别方法,首先开展了常规测井、成像测井资料与岩心分析、油气测试结果的对比分析,创建了识别裂缝和非均匀岩石构造的测井信息非相关性分析技术,形成了各类储层的非相关特征模式;然后对电阻率曲线进行高斯滤波,以降低裂缝对电阻率的影响,获得了反映基质岩块的电阻率信息;进而根据储层类型与孔隙结构指数m值的关系,建立了能够有效判别气、水层的孔隙度—高斯滤波电阻率交会图版。研究结果表明:①中二叠统气、水层电阻率界线随储层类型的变化而不同,表现为从裂缝型、缝洞型至孔洞型逐渐升高的趋势,变化范围介于80~300Ω·m;②利用上述图版对研究区L004-3井的气、水层进行了识别,其结果与实际测试结果吻合。结论认为,该研究成果可以为川西北九龙山地区中二叠统气、水分布规律的认识提供指导,同时也可以为其他区块裂缝性储层的气、水识别提供一条新的思路。A number of wells in the Jiulongshan area of northwestern Sichuan Basin have obtained high-yield gas flow(106 m^(3)/d)from the Maokou Formation and Qixia Formation of Middle Permian,which indicates great potential of natural gas exploration and development in this area.However,complex fracture occurrences and widely developed non-uniform rock structures obscure the response of log information to fluid.In order to establish an effective gas/water layer identification method based on well log for this area,this paper firstly compares conventional and imaging logs data with core observation and well test results,develops the non-correlation analysis technology of log information for identifying fractures and non-uniform rock structures,and establishes non-correlation characteristic modes for different types of reservoirs.Then,Gaussian filtering is applied to resistivity curve to reduce the influence of fractures on the resistivity,and the resistivity information reflecting matrix blocks is acquired.Finally,a porosity-Gaussian filtering resistivity crossplot which can effectively identify gas and water layers is prepared according to the relationship between reservoir types and pore structure indexes(m).And the following research results are obtained.First,as reservoir types vary,resistivity boundaries between gas and water layers of Middle Permian vary between 80Ω·M and 300Ω·M and present a trend of rising gradually from fractured reservoirs to fractured-vuggy reservoirs and vuggy reservoirs.Second,gas and water layers in Well L004-3 of this study area are identified by using this newly established crossplot,and its identification result coincides with the actual test result.In conclusion,the research results provide guidance for understanding the gas/water distribution in the Lower Permian of Jiulongshan area of northwestern Sichuan Basin,as well as a new idea for identifying gas and water layers in fractured reservoirs in other blocks.

关 键 词：碳酸盐岩 裂缝(岩石) 非均匀岩石构造 非相关性分析 气水识别 测井解释 四川盆地西北部 九龙山地区 

分 类 号：P631.81[天文地球—地质矿产勘探] P618.13[天文地球—地质学]