接触变质带中冷凝收缩缝裂缝参数定量研究  

Quantitative Study on Parameters of Condensate Contraction Joint Fracture of in Contact Metamorphic Belt

作　　者：王军[1,2] 崔红庄[1] 戴俊生[2] 季宗镇[3] 

机构地区：[1]中国石化集团胜利油田西部新区研究中心,山东东营257015 [2]中国石油大学地球资源与信息学院,山东青岛266555 [3]中国石化集团国际石油勘探开发有限公司,北京100083

出　　处：《吉林大学学报（地球科学版）》2012年第1期58-65,共8页Journal of Jilin University：Earth Science Edition

基　　金：国家科技重大专项(2011ZX05042-001)

摘　　要：模拟岩浆侵入时期的温度场及应力场获取围岩中温度及应力的分布,综合应用应变能及表面能理论,建立热应力与冷凝收缩缝参数之间的定量关系,对裂缝参数作出定量预测,进而总结变质带中冷凝收缩缝的发育规律。对GY凹陷北斜坡接触变质带研究发现:变质带厚度随侵入岩厚度增大而增大,侵入岩厚度小于20m时无变质带;热应力随着距离侵入岩距离的增大而减小。冷凝收缩缝主要靠近侵入岩体分布,裂缝线密度最大值约为13条/m;远离侵入岩体裂缝线密度迅速变小,至变质带外边缘,裂缝线密度降为3～6条/m。整体上,上变质带孔渗性能稍好于下变质带孔渗性能。冷凝收缩缝孔隙度最大值位于侵入岩厚度最大部位;短轴方向裂缝渗透率与铅直方向渗透率分布相似,两者值均大于长轴方向渗透率。岩心统计资料验证了模拟计算结果的可靠性。Temperature and stress of country rock are obtained by the simulation of the temperature and stress when magma emplaced.The quantitative relationship between heat field and condensation contraction joint are established by integrated application of strain energy and surface energy theory.The fracture parameters are assessed quantitatively.Consequently,the development law of contraction joint is concluded in metamorphic belt.The metamorphic thickness increases when the intrusive thickness increases,while no metamorphic belt forms when the intrusive thickness is less than 20 m,by the study of the contact metamorphic belt in north slope of Gaoyou sag.Thermal stress decreases with the increasing distance from the intrusive rocks.Condensation contraction joints are chiefly extensive near the intrusive rock and the maximum of crack linear density is about 13 cracks/m.Away from the intrusive rock,the density of fracture line rapidly decreases,especially 3-6 linear density of cracks/m in the metamorphic belt edge.Overall,the upper metamorphic permeability is slightly better than that of the lower one.The maximum porosity of condensation contraction joints lies in the most thickness of the intrusive rocks,and short axis direction of crack penetration is similar to vertical direction,while its permeability is greater than that of the long axis.The validity of this simulation is testified by rock core statistics.

关 键 词：冷凝收缩缝 热应力 应变能 表面能 孔隙度 渗透率 

分 类 号：TE112.222[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]