基于三维激光扫描技术的裂缝...：以库车坳陷库车河剖面为例_唐永.pdf

地球科学 Earth Sciencehttp:/第 48 卷 第 2期2 0 2 3 年 2 月Vol.48 No.2Feb.2 0 2 3https:/doi.org/10.3799/dqkx.2022.371基于三维激光扫描技术的裂缝随机模拟：以库车坳陷库车河剖面为例唐永1，肖安成2，唐文军3，王珂4，曾凡成51.长江大学非常规油气湖北省协同创新中心，湖北武汉 4301002.浙江大学地球科学学院，浙江杭州 3100273.中国石油新疆油田公司准东采油厂，新疆阜康 8315114.中国石油杭州地质研究院，浙江杭州 3100235.吉林油田公司川南天然气开发事业部，吉林松原 138000摘要：库车坳陷是塔里木盆地重要的天然气勘探开发目标区，其大北克深地区含气层系下白垩统埋深超过 7 500 m，岩性致密孔隙度平均为 4.8%，但仍然获得高产工业气流，岩层内所发育的裂缝成为天然气高产的核心要素.因此利用合理技术对裂缝数据进行有效表达是明确深层致密砂岩裂缝发育特征及空间分布规律的关键，是有效开发裂缝型气藏前提.利用三维激光扫描能够获得大数据的优势，运用点数据拼接、去噪、切割处理方法，直接识别点云数据中的有效裂缝信息，并结合野外剖面实测获得的裂缝数据对所识别的裂缝信息进行修正处理，建立目标区域裂缝信息地质知识库.确定目标区域裂缝发育的空间范围，裂缝密度发育规律，裂缝方位分布状态，为后期随机模拟确定约束条件.在三维激光扫描点云处理数据的约束下，应用随机模拟技术的 fisher函数能够较好的表现裂缝发育区域单条裂缝之间方位偏转现象，体现自然裂缝的随机发育特征.利用裂缝开度信息，应用 Oda计算方法对对每条裂缝的渗流能力进行了计算分析，定量确定裂缝发育区对围岩流体渗流影响的大小.库车坳陷库车河剖面计算结果显示：右侧裂缝簇导致的渗流带宽度可达 3.1 m，延伸长度平均为 2.6 m；中间区域所展现裂缝簇渗流带宽度 1.2 m，延伸长度平均为 1.4 m；左侧裂缝簇渗流带宽度约 0.9 m，延伸长度仅仅为 0.33 m 左右，这与野外数据吻合.与人工对比显示：数据处理面积是人工测量的 25倍，所消费的时间仅仅是人工处理的 1/10，大大提高了工作效率.由此可见裂缝簇内裂缝密集程度越高，对流体渗流影响就越大，流体在裂缝簇渗流扩展的宽度，影响的范围就越广，较好的表达了库车深层裂缝致密气藏的特征.说明基于激光扫描技术的裂缝随机模拟技术能够真实的表达裂缝三维空间展布状态，以及对流体渗流的贡献.关键词：裂缝；三维激光扫描；随机模拟；库车坳陷；定量；石油地质.中图分类号：P618.13 文章编号：1000-2383(2023)02-640-17 收稿日期：2022-11-17Stochastic Fracture Simulation Based on ThreeDimensional Laser Scan Technology:a Case Study of Kuqa River Outcrop in Kuqa DepressionTang Yong1，Xiao Ancheng2，Tang Wenjun3，Wang Ke4，Zeng Fancheng51.Hubei Cooperative Innovation Center of Unconventional Oil and Gas，Yangtze University，Wuhan 430100，China2.School of Earth Sciences，Zhejiang University，Hangzhou 310027，China3.Cainan Operation District of Xinjiang Oilfield Company CNPC，Fukang 831511，China基金项目：国家十三五重大专项（Nos.2017ZX05008001;2017ZX05008005）；湖北省教育厅科学研究计划项目（No.T201905）.作者简介：唐永（1981-），男，讲师，主要从事裂缝地质分析及数值模拟的研究.ORCID：0000000247105243.Email：water_引用格式：唐永，肖安成，唐文军，王珂，曾凡成，2023.基于三维激光扫描技术的裂缝随机模拟：以库车坳陷库车河剖面为例.地球科学，48（2）：640-656.Citation：Tang Yong，Xiao Ancheng，Tang Wenjun，Wang Ke，Zeng Fancheng，2023.Stochastic Fracture Simulation Based on ThreeDimensional Laser Scan Technology：a Case Study of Kuqa River Outcrop in Kuqa Depression.Earth Science，48（2）：640-656.第 2 期唐永等：基于三维激光扫描技术的裂缝随机模拟4.Hangzhou Institute of Petroleum Geology，PetroChina Exploration and Development Research Institute，Hangzhou 310023，China5.Natural Gas Development Department in Southern Sichuan Basin of Jilin Oil Field Company，PetroChina，Songyuan 138000，ChinaAbstract:The Kuqa Depression is an important natural gas exploration target area in the Tarim Basin.Although the gasbearing layer from the lower Cretaceous in the DabeiKeshen area is buried deeper than 7500 m,and the average lithologic tight porosity is 4.8%,the area is still getting highyield industrial gas stream.Fractures developed in rock formations have become the key factor for high natural gas production.Therefore,using reasonable techniques to effectively express fractured atais the key to clarifying the development characteristics and spatial distribution off ractures in deep tight sandstone,and is the premise for the effective development off ractured gas reservoirs.The advantages of big data can be obtained by using 3D laser scanning.Using point data splicing,denoising,and cutting methods,directly identifying the effective fracture information in the point cloud data,and analyzing the identified fracture information in combination with the fracture data obtained from the field profile measurement are incredibly useful to establish a geological knowledge base of fracture information in the target area.Identifying the spatial extent of fracture development in the target area,the development law of fracture density,and the azimuthal distribution of fractures helps to determine the constraints for the later random simulation.Under the constraints of 3D laser scanning point cloud processing data,the fisher function using stochastic simulation technology can better represent the azimuthal deflection phenomenon between single fractures in the fracture development area,reflecting the random development characteristics of natural fractures.Using the fracture opening information,the Oda calculation method is used to calculate and analyze the seepage capacity of each fracture,and the influence of the fracture development area on the surrounding rock fluid seepage is quantitatively determined.The calculation results of the Kuqa River section in the Kuqa Depression show that the vadose zone caused by the fracture cluster on the right side can reach 3.1m in width and 2.6m in extension;The vadose zone of the fracture cluster in the middle area is 1.2m wide and the extension length is 1.4 m;The width of the fracture cluster vadose zone on the left is about 0.9m,and its extension length is only about 0.33m.Itisconsistentwithfielddata.It can be seen that the higher the density of fractures in the fracture cluster,the greater the impact on fluid vadose zone.The wider the width of the fluid vadose zone expansion in the fracture cluster,the scope of influence wider.This better expresses the characteristics of deep fractured tight gas reserv