四川盆地东北部飞仙关组鲕滩储层地震预测技术

PREDICTION TECHNIQUE FOR THE OOLITIC BEACH RESERVOIR OF FEIXIANGUAN FORMATION IN THE NORTHEAST OF SICHUAN BASIN BY USING SEISMIC DATA

四川盆地东北部飞仙关组鲕滩储层是鲕粒灰岩云化后的碳酸盐岩储集体 ,孔洞缝发育 ,储层段中含有泥质、膏盐夹层 ,储层具有低速、低伽马、低阻抗的特征 ;泥质层具有低速、高伽马、低阻抗特征 ;而膏盐岩具有低速、低伽马、高阻抗特征。更重要的是 ,要如何通过地震预测的方法从复杂的围岩中检测鲕滩储层 ,进而指出天然气的高产区带。通过多年的攻关研究 ,终于寻找到了一套预测飞仙关组鲕滩储层行之有效的技术。即采用速度反演、辅以波阻抗和伽马反演有效地预测储层的有无 ;利用孔隙度反演和量化技术计算出储能系数 ,查明储层的厚薄和好坏 ;在储层段利用AVO技术得到的碳氢剖面可以判识储层是否含气。这套技术在实际应用中取得了明显的效果。

The oolitic beach reservoir of Feixianguan formation in northeast of Sichuan Basin is the carbonate pool of dolomized oolitic limestone. There are developed pore cave fracture,argillaceous bed and gypsum salt bed in the reservoir with the characteristics of low velocity,low gamma and low impedance The argillaceous bed is of the characteristics of low velocity,high gamma and low impedance,and the gypsum salt bed is of the characteristics of low velocity,low gamma and high impedance It is very important to find out the oolitic beach reservoir from the complex surrounding rocks by using seismic prediction data and furthermore to select the high yield belt Through investigating many years,a set of efficacious techniques for predicting the oolitic beach reservoir of Feixianguan formation has been carried out,i e :① efficaciously predicting if there is any reservoir by velocity inversion with acoustic inversion and gamma inversion;② calculating the reservoir coefficient by porosity inversion and quantum technique to clarify the thickness and quality of the reservoir;③ whether there is any gas or not in the reservoir could be determined with the hydrocarbon profile figure gained by AVO technique Evident results have been obtained by the set of technique in practice