摘要
裂缝是火山岩形成有利储层的重要因素,裂缝发育有利于储层改造,从而提高油井产能。选用合适的地球物理方法预测裂缝是火山岩油藏储层研究的重点和难点。基于叠前方位各向异性的裂缝预测方法,经过NMO道集分析、分方位角道集叠加和偏移、频谱分析、各向异性计算等步骤,利用5组方位角道集数据完成目标区3个油层的火山岩裂缝发育强度和裂缝走向预测。预测结果显示,裂缝发育强度主要为1.10~1.5,强度大于1.25的裂缝发育区主要分布在研究区中部,裂缝走向以近东西向为主,符合火山机构控制裂缝发育程度的区域地质认识。实践表明,叠前方位各向异性预测技术能够定量描述高角度裂缝预测的分布,且效果明显优于常规的曲率或相干等叠后地震不连续性检测结果。叠前方位各向异性技术突破了主体围绕叠后地震资料定性预测火山岩裂缝的局限,有效地解决了准噶尔盆地西北缘石炭系火山岩裂缝定量预测的难题。
Fracture is an important factor of favorable reservoirs in volcanic rock,and the development of fracture is conducive to reservoir reconstruction,so as to improve oil well productivity.Choosing appropriate geophysical methods to predict fractures is the focus and difficulty of volcanic reservoir research.Based on pre-stack azimuthal anisotropy fracture prediction method,through NMO gather analysis,azimuthal gather stack and migration,spectrum analysis,anisotropy calculation and other steps,five groups of azimuth gather data are used to complete the prediction of volcanic rock fracture development strength and fracture trend of three oil layers in the target area.The prediction results show that the value of fracture intensity is between 1.10 and 1.50,and the fracture development area with fracture intensity greater than 1.25 is mainly distributed in the middle of the study area.The fracture trend is mainly in the east-west direction,which is consistent with the regional geological understanding.The practice shows that the pre-stack azimuthal anisotropy prediction technology can quantitatively describe the distribution characteristics of high angle fracture prediction,and the effect is obviously better than the conventional detection results of curvature or coherence.The pre-stack azimuthal anisotropy technology breaks through the limitation of qualitative prediction of volcanic rock fractures based on post stack seismic data,and effectively solves the problem of quantitative prediction of fractures in Carboniferous volcanic rocks in northwestern margin of Junggar basin.
作者
任涛
秦军
周阳
华美瑞
REN Tao;QIN Jun;ZHOU Yang;HUA Meirui(School of Geophysics and Information Technology,China University of Geosciences(Beijing),Beijing 100083,China;Exploration&Development Research Institute of Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)
出处
《石油地质与工程》
CAS
2021年第1期1-7,共7页
Petroleum Geology and Engineering
基金
中国石油重大科技专项“火山岩油藏效益开发关键技术研究与应用”(2017E-0405)
中国石油科技项目“准噶尔盆地石炭系火山岩分类评价与规模效益建产关键技术研究及工业化应用”(KT2017-18-05)。
关键词
准噶尔盆地西北缘
火山岩
方位各向异性
裂缝预测
裂缝发育强度
northwest margin of Junggar basin
volcanic rock
azimuthal anisotropy
fracture prediction
fracture development strength
