基于野外地质调查的构造裂缝体积及丰度估算方法探讨——以云南省澜沧县A区块为例  

Discussion on estimate method of structural fracture volume and abundance based on field geological survey:A case of Block A in Lancang County,Yunnan Province

作　　者：金文正[1] JIN Wenzheng(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083

出　　处：《非常规油气》2024年第4期21-28,共8页Unconventional Oil & Gas

基　　金：国家自然科学基金项目“龙门山冲断带构造分段变形机制研究”(41002072);云南省科技计划项目“云南省中深层地热能开发利用关键技术研究”(202302AF080001)。

摘　　要：构造裂缝的发育规律及预测是多种矿产和地热勘查的一项基础地质研究内容。为了探讨构造裂缝体积及丰度,针对地质勘探程度极低的区域,以澜沧县A区块为例,开展了野外地质调查和数据统计、计算及分析工作。结果表明:1)岩石类型可以影响构造裂缝密度,即相对于岩浆岩和变质岩,沉积岩中的构造裂缝密度较大,且空间分布较为规则;2)断层对构造裂缝的控制作用明显,即断层距离与构造裂缝密度表现为负相关特征;3)正断层、逆断层和走滑断层的构造裂缝横向影响范围不同,其中走滑断层的影响范围约为1 km;4)在理论计算过程中,一些复杂地质问题(包括不同层系之间的非均质性、多条断裂的复杂区域及断层在深部的产状变化等)的简化处理可能会造成计算结果存在一定的误差。在以上成果认识指导下,计算获得A区块内部构造裂缝数量约为7458×10^(7)条,构造裂缝体积约为7458×10^(4)m^(3),构造裂缝平面丰度为186.45×10^(4)m^(3)/km^(2),体积丰度为186.45×10^(4)m^(3)/km^(3),对该地区流体类(石油、天然气以及地热等)能源矿产勘探开发具有一定的借鉴价值。The development pattern and prediction of structural fractures are a fundamental research content for various mineral and geothermal exploration,and the development pattern of structural fractures is diverse and complex in outdoor outcrops.To explore the volume and abundance of structural cracks influenced by faults,the author carried out a field geological survey,data statistics,and calculation in Block A of Lancang County,and the geological exploration level was extremely low there.The author has reached the following conclusion:1)The rock type can affect the density of structural fractures,that is,compared with magmatic rock and metamorphic rock,the density of structural fractures in sedimentary rock is larger and the spatial distribution of structural fractures in sedimentary rock is more regular;2)The structural fractures is obviously controlled by faults,that is,there is a negative correlation between distance from faults and the density of structural fractures;3)There are different lateral influence ranges of structural fractures in normal faults,thrust faults and strike slip faults,of which the influence range of strike slip fault is about 1 km;4)In the process of theoretical calculation,the simplification of some complex geological problems(including heterogeneity between different layers,complex areas of multiple faults,changes in the occurrence of faults in the deep,etc.)may result in certain errors in the calculation results.Guided by the above achievements,the author calculated and obtained that the number of internal structural fractures in Block A is 7458×10^(7),the volume of structural fractures is 7458×10^(4)m^(3),the plane abundance of structural fractures is 186.45×10^(4) m^(3)/km^(2),and the volume aboundance is 186.45×10^(4)m^(3)/km^(3),which has certain reference value for the exploration and development of fluid energy minerals(such as oil,natural gas,geothermal,etc.)in this area.

关 键 词：构造裂缝 体积 丰度 野外地质调查 澜沧县 

分 类 号：TE132[石油与天然气工程—油气勘探]