【摘要】 川西上三叠统须家河组气藏为致密裂缝性气藏,储层为低孔低渗致密砂岩,裂缝尤其是高角度裂缝预测是获得高产的关键因素。由于储层与围岩波阻抗叠置,而且裂缝预测复杂,常规地震勘探技术难以适应气藏勘探开发的需要。为此,利用三维三分量地震勘探技术进行储层预测、裂缝检测和含气性预测。以储层岩石物理参数敏感性分析为基础,利用多波联合反演、多波属性分析和多属性交会方法,更好地预测相对优质储层的分布,分析储层含气性;利用纵波及转换波振幅特征,识别规模网状裂缝形成的高效储渗区;利用相干、曲率、循环重褶积、PS波方位各向异性、横波分裂等技术可靠预测裂缝,特别是高角度裂缝的分布及发育程度。形成了一套有效的适用于川西深层致密裂缝性气藏的地震综合识别模式。更多还原

【Abstract】 Upper Triassic Xujiahe Formation gas reservoirs in Western Sichuan Basin are tightly fractured with low porosity and low permeability tight sandstone.Fracture prediction,especially the high-angle fracture prediction is the key for high production of gas.The conventional seismic exploration technologies cannot satisfy the requirements of gas exploration and development because of the superimposition of impedance of the reservoirs and the surrounding rock,as well as the complexity in fracture prediction.Therefore,we adopted 3D3C seismic exploration technique for reservoir prediction,fracture prediction and gas-bearing prediction.On the basis of sensitivity analysis of petrophysical parameters,by using multi-wave joint inversion,multi-wave attribute analysis and multi-attribute cross plotting,the distribution of relative high-quality reservoirs was well predicted and the gas-bearing was analyzed.The high-efficiency storage and permeability zone formed from scale network fractures was recognized by using the amplitude characteristics of P-wave and PS-wave.The fractures were identified by coherence,curvature,loop convolution,anisotropy of PS-wave,S-wave splitting,especially for recognizing the distribution and development of high-angle fractures.A set of seismic comprehensive identification pattern effective for the prediction of deep tight fractured gas reservoirs in Western Sichuan Basin was gained.更多还原