利用地震叠前数据预测火山岩裂缝的方法和效果分析——以松辽盆地北部徐家围子断陷营城组火山岩为例

The method and effect analysis of volcanic fracture prediction with prestack seismic data ——An example from the volcanic rocks of Yingcheng formation in Xujiaweizi fault depression,north of Songliao basin

裂缝问题是火山岩复杂岩性油气藏勘探开发中必须考虑的重要因素之一.火山岩储层裂缝预测的准确性直接影响着油气的产能、钻井工艺和增产改造措施等.本文主要根据等效HTI介质(扩容各向异性介质)的特性,立足地下介质各向异性理论,利用三维地震叠前P波在HTI介质中的属性分布特征来检测裂缝的发育情况.利用三维地震叠前P波裂缝检测技术在松辽盆地北部徐家围子断陷深层营城组火山岩中尝试开展了储层裂缝发育预测研究.通过研究建立了火山岩裂缝地震叠前预测方法,并对营城组火山岩裂缝发育情况进行预测,结果表明裂缝主要分布在工区中部构造高部位,发育方向以北北西向为主.最后利用测井资料和钻井产能资料等进行效果分析,证实该技术对于认识火山岩储层裂缝发育具有实际应用价值,说明应用地震资料开展储层裂缝预测具有横向分辨率高、实现井问分布描述和宏观空间分布规律清楚等特点.

Fracture is one of the most important factors that need to be considered in the oil and gas exploration and development of complicated lithologic reservoirs in volcanic rocks. The accuracy of fracture prediction in volcanic reservoir has influences on the oil and gas production, well drilling techniques and stimulation and reformation measures and so on. According to the characteristics of equivalent HTI media （anisotropic expansion） and the theory of subsurface anisotropy, we use the attribute distribution characteristics of prestack 3D P-wave to detect the development of cracks in HTI media. The fracture development prediction has been carried out with this technique in volcanic rocks of Yingcheng formation in deep layer of Xujiaweizi faultdepression, north of Songliao basin. The study establishes the volcanic fracture prediction method, forecasts the development of volcanic rocks in Yingcheng formation. The results show that the fracture mainly located in structural high position in the central work area with dominant development direction of NNW. Finally we make further effect analysis by the use of well logging and well production data. It shows that this technique has some value in practical application for fracture development in volcanic reservoirs, and further it illustrates that fracture prediction by seismic data presents a high lateral resolution, clear cross-well description and vivid macro-space distribution regularity.