Controlling of cements and physical property of sandstone by fault as observed in well Xia503 of Huimin sag,Linnan sub-depression  

作　　者：GAO LiHua HAN ZuoZhen HAN Yu HAN Chao WEI FeiFei QIN Zhen 

机构地区：[1]State Key Laboratory of Mining Disaster Prevention and Control, Key Laboratory of Depositional Mineralization & Sedimentary Minerals in Shandong Province, Shandong University of Science and Technology [2]College of Geological Science and Engineering, Shandong University of Science and Technology [3]School of Earth Sciences and Resources, China University of Geosciences

出　　处：《Science China Earth Sciences》2013年第11期1942-1952,共11页中国科学（地球科学英文版）

基　　金：supported by National Basic Research Program of China(Grant No.2012CB723104);National Natural Science Foundation of China(Grant Nos.41372108,41372134);Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province,and SDUST Research Fund(Gant No.2010KYTD103)

摘　　要：Cement content of carbonate in tight sandstone near section is much the fault of well Xia503, in the Huimin sag in Linnan sub-depression higher than that of the normal sandstones far away from In order to understand the origin and its impact on fault sealing, analyses of the whole-rock minerals, casting thin sections, cathodoluminescence, isotope and physical properties are conducted on cores from well Xia503. It is found that c~ L3C varies from 0.1%o to 0.6%o with the average value of 0.42%o, c~ LSO varies from -13.5%o to -12.3%c with the average of-13.1%~., and C-O isotope plotting points are distributed in the low to moderate temperature area of the hydrothermal dolomite. According to the occupied relationship, cathodoluminescence, and C-O isotope feature, the carbonate cementation could be divided into four stages： calcites, dolomite, ankerite, and ferrocalcite. It is discovered that the carbonate cementation is negatively related to reservoir physical property, with the porosity of 4.8%, permeability of 0.37 roD, and displacement pressure of 1.97 MPa in the tight sandstone, which have increased by almost one order of magnitude compared to the porosity of 14.3%, permeability of 3.73 mD, and displacement pressure of 0.27 MPa in the normal sandstone, which is far away from the fault. Regardless of the lithology of the counterpart wall of the fault, only the displacement pressure difference caused by carbonate cementation between the tight sandstone and the normal sandstone could seal 41 m high oil column.Cement content of carbonate in tight sandstone near section is much higher than that of the normal sandstones far away from the fault of well Xia503,in the Huimin sag in Linnan sub-depression.In order to understand the origin and its impact on fault sealing,analyses of the whole-rock minerals,casting thin sections,cathodoluminescence,isotope and physical properties are conducted on cores from well Xia503.It is found that 13C varies from 0.1‰to 0.6‰with the average value of 0.42‰,18O varies from 13.5‰to 12.3‰with the average of 13.1‰,and C–O isotope plotting points are distributed in the low to moderate temperature area of the hydrothermal dolomite.According to the occupied relationship,cathodoluminescence,and C–O isotope feature,the carbonate cementation could be divided into four stages:calcites,dolomite,ankerite,and ferrocalcite.It is discovered that the carbonate cementation is negatively related to reservoir physical property,with the porosity of 4.8%,permeability of 0.37 mD,and displacement pressure of 1.97 MPa in the tight sandstone,which have increased by almost one order of magnitude compared to the porosity of 14.3%,permeability of 3.73 mD,and displacement pressure of 0.27 MPa in the normal sandstone,which is far away from the fault.Regardless of the lithology of the counterpart wall of the fault,only the displacement pressure difference caused by carbonate cementation between the tight sandstone and the normal sandstone could seal 41 m high oil column.

关 键 词：carbonate cementation genetic mechanism ANKERITE low to moderate temperature hydrothermal fault sealing ability 

分 类 号：P575[天文地球—矿物学]