Distributive characteristics of reservoirs and exploration potential associated with intrusive rocks of Yingcheng Formation in Yingtai rift depression, NE China  

作　　者：TANG Huafeng KONG Tan ZHAO Hui GAO Youfeng 

机构地区：[1]College of Earth Sciences, Jilin University, Changchun 130026, China [2]Exploration and Development Research Institute of Jilin Oilfield, Songyuan 138000, Jilin, China [3]Research Center of Palaeontology & Stratigraphy of Jilin University, Changchun 130061, China

出　　处：《Global Geology》2016年第1期13-25,共13页世界地质（英文版）

基　　金：Supported by Projects of the National Natural Science Foundation of China(41002038);the National Major Fundamental Research and Development Projects(Nos.2012CB822002,2009CB219304)

摘　　要：Petroleum geologists have paid great attentions to the volcanic reservoirs of Songliao Basin in NE Chi- na. There are plenty of subvolcanic rocks in the Songliao Basin accompanying the Early Cretaceous Yingeheng Formation. The logging data show the good reservoir potential of these intrusive rocks but the distribution char- acteristics and formation mechanisms of these reservoirs are not clearly understood. Based on the previous stud- ies by using coring, cuts and logging data of Yingtai rift depression, the reservoirs＇ characteristics of intrusive rocks are presented. There are two types of intrusive rocks namely the syenodiorite-porphyrite and diabase which occur as laccolith and/or sill, both having the characteristics of low gamma and high density with little primary porosity and permeability. The prevalent reservoir porosity is the secondary porosity, such as spongy/cavernous pore, tectonic fracture. The laboratory data of porosity of diabase can reach 6.7%, but the permeability is less than 0.6 x 10-3μm2, median pressure is high, indicating that the pore throat of this kind reservoir is small. The maximum logging porosity is about 12%. The change of porosity does not correlate to the buried depth. It is the major significant differences in the distributive characteristics compared to the normal sedimentary rock reservoirs. Most of intrusive rocks underwent alteration diagenesis whilst some were subjected to precipitation diagenesis. The spongy and cavernous pore can be formed during the alteration processes of plagioclase to illite and pyroxene to chlorite. The secondary porosity is greatly correlated with the alteration intensity of matrix, pla- gioclase and pyroxene. There are pyroxenes and more plagioclases in diabase, which cause the higher alteration intensity than the syenodiorite-porphyrites in the same acid fluid. So the porosity of diabase is higher than that of syenodiorite-porphyrites. The top or/and bottom part of intrusive rocks develop the higher porosity. Because those parts are easy to coPetroleum geologists have paid great attentions to the volcanic reservoirs of Songliao Basin in NE China. There are plenty of subvolcanic rocks in the Songliao Basin accompanying the Early Cretaceous Yingcheng Formation. The logging data show the good reservoir potential of these intrusive rocks but the distribution characteristics and formation mechanisms of these reservoirs are not clearly understood. Based on the previous studies by using coring,cuts and logging data of Yingtai rift depression,the reservoirs' characteristics of intrusive rocks are presented. There are two types of intrusive rocks namely the syenodiorite-porphyrite and diabase which occur as laccolith and / or sill,both having the characteristics of low gamma and high density with little primary porosity and permeability. The prevalent reservoir porosity is the secondary porosity,such as spongy / cavernous pore,tectonic fracture. The laboratory data of porosity of diabase can reach 6. 7%,but the permeability is less than 0. 6 × 10^(-3)μm^2,median pressure is high,indicating that the pore throat of this kind reservoir is small.The maximum logging porosity is about 12%. The change of porosity does not correlate to the buried depth. It is the major significant differences in the distributive characteristics compared to the normal sedimentary rock reservoirs. Most of intrusive rocks underwent alteration diagenesis whilst some were subjected to precipitation diagenesis. The spongy and cavernous pore can be formed during the alteration processes of plagioclase to illite and pyroxene to chlorite. The secondary porosity is greatly correlated with the alteration intensity of matrix,plagioclase and pyroxene. There are pyroxenes and more plagioclases in diabase,which cause the higher alteration intensity than the syenodiorite-porphyrites in the same acid fluid. So the porosity of diabase is higher than that of syenodiorite-porphyrites. The top or / and bottom part of intrusive rocks develop the higher porosity. Because those parts are easy to contact fo

关 键 词：Songliao Basin Yingcheng Formation intrusive rocks porosity alteration diagenesis 

分 类 号：P618.13[天文地球—矿床学]