【摘要】 鄂尔多斯盆地SG气田是我国典型的低孔,低渗,致密砂岩气藏的代表.该区地震勘探开发面临着两大难题:一是含气砂岩和围岩的声波阻抗存在较大范围叠置,利用声波阻抗预测储层存在明显的多解性;二是SG气田局部地区气、水关系复杂,地质上不存在统一的气、水层分界面,产水井严重影响产能建设,流体类型的识别是面临的又一难题.为了降低声波阻抗预测砂岩储层的多解性,提高有效储层预测精度,定量识别储层中流体的类型,本文提出了叠前地震弹性参数交会定量解释技术,从横波测井资料不同岩性、流体的岩石物理参数分析入手,优选了能够区分岩性和流体的最佳敏感弹性参数,制作了敏感弹性参数交会模板,通过地震叠前反演获得反映储层物性和含气性的地震弹性参数体,最后进行地震弹性参数交会定量解释预测有效储层和识别流体.勘探实例证实了该技术方法在SG地区对有效储层的预测是有效的,能够为井位优选提供可信的依据.地震弹性参数交会技术将纵向分辨率较高的测井岩石物理分析和横向分辨率较高的地震叠前反演结合在一起,使用了多个弹性参数交会,减少了以往单一弹性参数预测储层的多解性,最终获得比较可靠、更量化的反映储层物性和含气性的地震弹性参数交会体,为有效储层预测和流体识别探索出了新的途径,这一技术的应用和推广可以降低地震解释的风险,提高储层预测精度.更多还原

【Abstract】 The SG gas field in China belongs to a low-porosity and low-permeability,tight sandstone gas reservoir.There is a large overlap in the acoustic impedance of the gas-bearing sandstone and the surrounding rocks,with no unified interface of gas bearing layers and water bearing layers,restricting the gas productivity construction.Therefore,it is difficult to distinguish between gas-bearing sandstone and shale by the acoustic impedance and it is hard to identify fluids.It has multisolutions to use the conventional single acoustic impedance parameter to predict effective reservoir.In order to reduce the ambiguity of reservoir prediction by the conventional single acoustic parameter,improve the accuracy of the effective reservoir prediction,and identify fluids,this paper starts with shear wave logging data,selects the best sensitive elastic parameters to distinguish gas reservoir and shale and different fluids,according to the cross plots analysis of the elastic multiparameter,and obtains seismic acoustic parameter data from pre-stack seismic inversion,and finally it predicts the effective reservoir and identifies fluids by cross-plotting technique between the sensitive elastic parameters of the shear wave logging data and seismic acoustic parameter data based on prestack seismic inversion.The technique for quantitative interpretation of seismic elastic multi-parameter cross plot on effective reservoir prediction in SG gas field has been proven to be effective and practical.Elastic multi-parameter cross-plot technology based on well and seismic data rendezvous longitudinal resolution higher shear wave logging data and lateral resolution higher seismic prestack inversion.It reduces the ambiguity of effective reservoir prediction by the conventional single acoustic parameter.The application and popularization of the elastic multi-parameter cross-plot has improved the accuracy of effective reservoir prediction.更多还原