摘要
川南地区五峰组—龙马溪组海相页岩储层大量发育有机质孔隙,有机质孔隙是页岩气的重要存储空间,所以有机质孔隙的表征具有重要意义。文中依据扫描电镜和核磁共振等实验资料,采用Otsu阈值分割算法对扫描电镜图像(SEM)进行分割,获取图像中有机质与有机质孔的阈值范围。为解决SEM图像中存在的无机质孔与有机质孔边缘高亮区域对实验的影响,将灰度变换增强、改进Canny算法与Otsu算法相结合,对SEM图像进行处理,计算了研究区的面孔率均值。基于改进Canny-Otsu算法,计算得出川南地区某2口井的有机质孔面孔率均值(15.55%),并以此构建有机质孔隙度计算模型,用于计算该研究区的实际有机质孔隙度。结果表明,该计算模型基本适用于研究区五峰组—龙马溪组海相页岩储层有机质孔隙度的计算。
The marine shale reservoirs of Wufeng-Longmaxi Formation in southern Sichuan region develop a large number of organic matter pores,which is an important storage space for shale gas,so the characterization of organic matter pores is of great significance.Based on experimental data of scanning electron microscopy and nuclear magnetic resonance,the Otsu threshold segmentation algorithm was used to segment the scanning electron microscopy(SEM)image and obtain the threshold range of organic matters and organic pores in the image.In order to solve the influence of edge highlights of the inorganic and organic pores in the SEM image on the experiment,the grayscale transformation enhancement,improved Canny algorithm and Otsu algorithm are combined to process the SEM image and calculate the average surface porosity of the study area.Based on the improved Canny-Otsu algorithm,the average surface porosity of organic matter porosity of two wells in southern Sichuan was calculated to be 15.55%,and an organic matter porosity calculation model was constructed to calculate the actual organic matter porosity in the study area.The results show that the calculation model is basically suitable for the calculation of organic matter porosity of marine shale reservoirs of Wufeng-Longmaxi Formation in the study area.
作者
欧发辉
赖富强
夏小雪
李娇
马麒
李慧
OU Fahui;LAI Fuqiang;XIA Xiaoxue;LI Jiao;MA Qi;LI Hui(Chongqing Key Laboratory of Complex Oilfield Exploration and Development,Chongqing University of Science and Technology,Chongqing 401331,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2023年第5期705-714,共10页
Fault-Block Oil & Gas Field
基金
国家自然科学基金项目“基于成像测井的泥页岩储层可压裂性评价方法研究”(41402118)
页岩气勘探开发国家地方联合工程研究中心开放课题“川渝地区页岩气储层脆性成因机理实验及评价方法研究”(YYQKTKFGJDFLHGCYJZX-201901)
重庆市基础研究与前沿探索项目“页岩储层多组分多尺度数字岩心构建及脆性微观成因机理模拟研究”(cstc2018jcyjAX0503)。
