1. Exploration & Production Institute, Southwest Oil & Gas Branch Co., SINOPEC, Chengdu, Sichuan 610041, China;
2. Key Laboratory of Multi Components Seismic Technology, SINOPEC, Chengdu, Sichuan 610041, China;
3. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
4. College of Geophysics, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
5. College of Earth Science, Chengdu University of Technology, Chengdu, Sichuan 610059, China
Abstract:Jinma-Yazihe nappe tectonic belt in Longmen Mountain is characterized by complicated surface and subsurface,and it is very difficult to predict reservoirs and fractures in this belt. According to geological background and geophysical features in the area,and logging responses of dolomite,limestone,and gypsolith,we calculate rock brittleness and fracture parameters based on seismic data,and obtain the following observations:①The spatial distribution of high-quality brittle reservoirs and fracture development characteristics are predicted based on brittleness differences between dolomite and limestone reservoirs and overlying mudstones,and between dolomite and limestone reservoirs and underlying gypsum rocks calculated on logging and seismic data. ②In the upper sub-Member of Leikoupo Formation,there are structural and non-structural fractures; their distribution has a close relationship with tectonic,sedimentation,and other factors; and fractures developed differently in gas traps. ③High-quality reservoir characteristics can be clearly identified based on rock brittleness differences and relationships between the brittleness and fractures; however the fractures in brittle reservoirs cannot quantitatively be predicted due to brittleness coefficient accuracy and seismic data resolution. ④In the upper sub-member of Member 4,Leikoupo Formation,dolomite and limestone reservoirs have high porosity,strong brittleness,and developed fractures,they should be key targets for the gas development. The above observations have been approved by the drilling results of Well PZ1 and Well YaS1.
Luo Xiaoquan,Tang Guibin.Conditions of hydrocarbon accumulation in the Leikoupo Formation,Longmenshan frontal margin,West Sichuan.Acta Geologica Sichuan,2012,32(1):32-35.
Xu Guoming,Song Xiaobo,Feng Xia et al.Gas potential of the Middle Triassic Leikoupo Fm in the western Sichuan Basin.Natural Gas Industry,2013,33(8):8-14.
Wu Shixiang,Li Hongtao,Long Shengxiang et al.A study on characteristics and diagenesis of carbonate reservoirs in the Middle Triassic Leikoupo Formation in western Sichuan Depression.Oil & Gas Geology,2011,32(4):542-559.
Xia Hongquan,Yang Shuangding,Gong Haohao et al.Research on rock brittleness experiment and logging prediction of hydraulic fracture height & Width.Jounlal of southwest Petroleum University (Science & Technology Edition),2013,35(4):81-89.
Feng Zengzhao,Bao Zhidong,Wu Shenghe et al.Lithofacies palaeogeography of the Early-Middle Triassic of Southern China.Scientia Geologica Sinica,1997,32(2):212-220.
Fan Zhuoyin,Lin Chengyan,Wang Tianxiang et al.Logging optimization modeling on brittleness index of tight formation rocks.Acta Petrolei Sinica,2015,36(11):1411-1420.
[11]
Leroueil S.Natural slopes and cuts:movement and failure mechanisms.Geotechnique,2001,51(3):197-243.
Xu Tianji,Yan Lili,Cheng Bingjie et al.Research of.anisotropy on shale gas in the fifth section of Xujiahe formation in the western Sichuan depression.Oil & Gas Geology,2015,36(2):319-328.
Kong Xuanlin,Li Jun,Xu Tianji et al.Research and application of 3D volumetric curvature.attribute extraction technology.Journal of Oil and Gas Technology,2011,33(5):71-75.
[17]
Crampin S.Seismic wave propagation through a cracked solid:polarization as a possible dilatancy diagnostic.Geophysical Journal of the Royal Astronomical Society,1978,53(3):467-496.
[18]
Chandra S R,Kenneth E H.Shear-wave velocity anisotropy in sedimentary rocks:A laboratory study.Geo-physics,1988,53(6):800-806.
[19]
魏建新.岩石横波分裂和各向异性的实验室观测.石油物探,1993,32(1):60-67.
Wei Jianxin.Laboratory observation for shear wave splitting and anisotropy in rocks.GPP,1993,32(1):60-67.
Li Yalin,He Zhenghua,Huang Deji et al.The experimental anisotropic analysis of P-wave and S-wave attenuations in cropping sandstone.OGP,1999,34(6):658-664.
Zeng Yunxian,Yang Yu,Liu Wei.The fracture characteristics of oolitic beach gas reservoirs in Feixianguan formation in the northeast of Sichuan basin.Natural Gas Exploration and Development,2003,26(4):14-18.
Zhang Xinhua,Zou Xiaochun,Zhao Hongyan et al.A new method of evaluation shale brittleness using X-ray fluorescence element logging data.Petroleum Drilling Techniques,2012,40(5):92-95.
[23]
刁海燕.泥页岩储层岩石力学特性及脆性评价.岩石学报,2013,29(9):3300-3306.
Diao Haiyan.Rock mechanical properties and brittleness evaluation of shale reservoir.Acta Petrologica Sinica,2013,29(9):3300-3306.
Li Qinghui,Chen Mian,Jin Yan et al.Rock mechanical properties and brittleness evaluation of shale gas reservoir.Petroleum Drilling Techniques,2012,40(4):17-22.
[25]
Rickman R,Mullen M,Erik P E et a1.
A practical use of shale petrophysics for stimulation design optimization:All shale plays are not clones of the barnett shale.SPE 115258,2008.
[26]
Thomsen L.On the use of isotropic parameters λ,E,ν,K to understand anisotropic shale behavior.SEG Technical Program Expanded Abstracts,2013,32:320-324.
[27]
宋惠珍.脆性岩储层裂缝定量预测的尝试.地质力学学报,1999,5(1):76-84.
Song Huizhen.An attempt of quantitive prediction of natural crack on brittle rock reservoir.Journal of Geomechanics,1999,5(1):76-84.