AVO属性在致密砂岩储层流体检测中的应用  

Application of AVO attribute to the detection of tight sandstone reservoirs

作　　者：巫芙蓉[1] 李亚林[1] 王聃[1] 陈浩凡[1] 姚明伟[2] 

机构地区：[1]川庆钻探工程有限公司地球物理勘探公司 [2]长江大学地球科学学院

出　　处：《天然气工业》2011年第5期55-57,117-118,共3页Natural Gas Industry

摘　　要：四川盆地WD区块低平构造上的WD7井在上三叠统须家河组二段获工业性气流并稳产了20多年,证实了该区具有巨大的勘探潜力。然而,依据该井地震响应模式相继钻探的WD8井、WD11井等测试产水,给后续钻探井位的部署带来了不确定性因素。因此,对该区砂岩储层的气水预测显得尤为重要。为此,利用流体替换、AVO正演模拟方法,提取了多种AVO属性,通过3种AVO属性分析,认识到截距*梯度属性可以区分须二段上部薄砂岩储层的含水和含气特征。进而采用三维叠前时间偏移获得的高质量CRP道集,提取截距*梯度属性数据体,预测了须二段上部致密砂岩储层的含气区分布,并提交了2口建议井位,经钻井检验,预测结果与实钻吻合。该方法对类似地区致密砂岩储层的气水识别具有一定的指导意义。Since achieving an industrial gas flow from the second member of the Upper Triassic Xujiahe Formation 20 years ago,the well WD7 drilled in the Block WD of the Sichuan Basin has been under steady production,verifying that great exploration potential exists in the study area.However,the following wells of WD8 and WD11 drilled according to the seismic responses from the WD7 well started to produce water,making it uncertain to emplace successive wells.Therefore,the accurate prediction of oil and gas distribution in the sandstone reservoirs in the study area is especially important.Fluid replacement and AVO forward modeling methods are used to extract several AVO attributes.Among three methods of AVO attribute analysis,the P + G attributes are proved to be effective in detecting the water-bearing and gas-bearing properties in the thin sandstone reservoirs in the upper part of the second member of the Xujiahe Formation.The high-quality CRP gathers obtained through 3D prestack time migration are used to obtain the P + G attributes,which is then applied to the prediction of gas-bearing zones.Two wells are proposed based on the prediction results,which are verified by the drilling data.This method can be popularized for the detection of water and gas zones in tight sandstone reservoirs in similar areas.

关 键 词：地震勘探 AVO 流体替换技术 气水识别 致密砂岩 储集层 四川盆地 

分 类 号：P618.13[天文地球—矿床学]