摘要
数字岩心技术起源于储层岩石微观孔隙结构建模研究,基于岩石的二维统计特征信息或三维扫描成像,是利用一系列图像处理算法或数学方法实现三维数字岩心的模型重构,并在此基础上进行岩心微观表征及物理特性分析的方法。目前常用的三维数字岩心数学建模方法分为随机法和过程法两大类,其中马尔可夫链蒙特卡洛法(MCMC法)是一种随机方法,其以计算速度快、适用范围广和可体现各向异性等优势被广泛使用。以碳酸盐岩为研究对象,利用MCMC法建立了不同图像尺寸的碳酸盐岩三维数字岩心,并对建模结果进行了分析。结果表明,由于MCMC法中选取用于计算转移概率的邻域模板的长度有限,重构结果受其图像尺寸影响较大;当图像尺寸较小时,重构三维数字岩心模型切面的孔隙度与原始二维图像切面的孔隙度符合度较高,建模结果较为理想;图像尺寸较大时,重构三维数字岩心模型切面的孔隙度与原始二维图像切面的孔隙度差异较大,建模效果不佳。因此,利用MCMC法重构三维数字岩心模型时,应选择合适的图像尺寸,尽可能建立最接近真实岩心的三维数字岩心模型。
Digital core technology,originating from the study of micro pore structure modeling of reservoir rock,is based on two-dimensional statistical characteristic information or three-dimensional scanning image of rocks.It is also a method through the use of a series of image processing algorithms or mathematical methods to achieve 3D digital core model reconstruction,and on this basis to carry out core microscopic characterization and physical characteristics analysis.At present,the commonly used 3D digital core modeling methods are divided into two categories:random method and process method.Among them,Markov chain-Monte Carlo(MCMC)is a random method,which is widely used due to its advantages such as fast calculation speed,wide application range and reflectable anisotropy.Taking carbonate rock as the research object,the 3D digital core of carbonate rock with different image sizes was established by MCMC,and the modeling results were analyzed.The results show that because the length of the neighborhood template selected to calculate the transition probability is limited in the MCMC method,the reconstruction results are greatly affected by the image size;When the image size is small,the porosity of the section of reconstructed 3D digital core model is in good agreement with that of the original 2D image section,and the modeling result is relatively ideal;If the image size is large,the porosity of the section of reconstructed 3D digital core model is greatly different from that of the original 2D image section,and the modeling effect is poor.Therefore,when the MCMC method is used to reconstruct the 3D digital core model,the appropriate image size should be selected to build the 3D digital core model that is closest to the real core as far as possible.
作者
聂昕
胡俊强
万宇
张超谟
张占松
NIE Xin;HU Junqiang;WAN Yu;ZHANG Chaomo;ZHANG Zhansong(Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education(Yangtze University),Wuhan 430100,Hubei;Hubei Cooperative Innovation Center of Unconventional Oil and Gas(Yangtze University),Wuhan 430100,Hubei;China Petroleum Logging Co.Ltd.,Xi’an 710077,Shaanxi)
出处
《长江大学学报（自然科学版）》
CAS
2021年第2期28-35,共8页
Journal of Yangtze University(Natural Science Edition)
基金
国家自然科学基金项目“页岩油储层岩石物理特性数值模拟研究”(41504094)
国家科技重大专项“复杂碳酸盐岩储层测井评价关键技术研究与应用”(2017ZX05032003-005)。
