海域天然气水合物地层的弹性波特征及井孔多频数据研究  

Elastic wave characteristics of natural gas hydrate formations and study of multi-frequency data from borehole

作　　者：王文浩 李盛清[1,2,3] 陈鸣 毛锐[5] 苏远大[1,2,3] 唐晓明 WANG WenHao;LI ShengQing;CHEN Ming;MAO Rui;SU YuanDa;TANG XiaoMing(State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao Shandong 266580,China;School of Geosciences,China University of Petroleum(East China),Qingdao Shandong 266580,China;Laoshan National Laboratory for Marine Science and Technology,Qingdao Shandong 266071,China;CNOOC China Limited,Zhanjiang Branch,Zhanjiang Guangdong 524057,China;Research Institute of Exploration and Development,Xinjiang Oilfield Company,Petro China,Karamay Xinjiang 834000,China)

机构地区：[1]中国石油大学(华东)深层油气全国重点实验室,山东青岛266580 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [3]崂山实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071 [4]中海石油(中国)有限公司湛江分公司,广东湛江524057 [5]中国石油新疆油田公司勘探开发研究院,新疆克拉玛依834000

出　　处：《地球物理学报》2024年第11期4417-4431,共15页Chinese Journal of Geophysics

基　　金：深层油气全国重点实验室课题资助(SKLDOG2024-ZYTS-04);国家自然科学基金(42174145,42074137,41804124);国家重点研发计划(2019YFC0605504);山东省自然科学基金(ZR2019BD039);中石油重大科技项目(ZD2019-183-004);中央高校基本科研业务费专项资金资助(20CX06077A)联合资助。

摘　　要：弹性波的声速和声衰减对沉积物的组成和孔隙流体性质具有较高的敏感性, 是反映水合物饱和度和赋存方式的重要参数.针对弹性波预测水合物形态及其赋存方式的评价问题, 基于均质砂岩的水合物岩石物理模型, 分析水合物的四种能量损失机制.数值模拟了亚微尺度挤喷流、微尺度挤喷流、甲烷气泡阻尼以及"Biot"型整体流动这四种波动机制的对弹性波的影响.数值模拟发现, 水合物地层的声速和声衰减主要受亚微尺度挤喷流控制, 微尺度挤喷流出现于超声频段, 甲烷气泡阻尼以及"Biot"型整体流动对水合物声速和声衰减的影响较小.对海域水合物洋脊的声波测井(高频, 10^(4)Hz)和地震VSP(低频, 约10^(2) Hz)数据进行分析, 结合岩石物理模型对该地区井下水合物的形态及其赋存方式进行预测, 结果表明胶结型水合物为该地区水合物的主要赋存状态.本文工作为准确估算水合物饱和度及其赋存差异评价提供指导.Elastic wave velocity and attenuation are sensitive to the composition of sediments and the properties of pore fluids, and is an important parameter relating to the saturation of hydrates and hydrate occurrence. To understand the effects of hydrate morphology and its occurrence mode on elastic waves, four energy loss mechanisms of hydrate were considered using a hydrate-saturated homogeneous sandstone model, for which the sub-micro squirt flow, micro squirt flow, bubble damping, and inertial movement of pore fluid relative to the frame were numerically analyzed. Numerical simulation results show that the sub-micro squirt flow plays a major role in affecting the acoustic velocity and attenuation of hydrates, while the micro squirt flow is effective mainly in the ultrasonic frequency band;the bubble damping and inertial movement of pore fluid relative to the frame have negligible effects on the acoustic velocity and attenuation of hydrates. The hydrate petrophysical modeling results were applied to the 10^(4) Hz acoustic logging data and the 10^(2) Hz VSP data acquired in an oceanic ridge region, to predict the morphology and occurrence of hydrate in the study region. The predicted results show that cement hydrate is the main occurrence state of underground hydrate in the research area. The analysis results of this work provided a guideline for estimating hydrate saturation and evaluating hydrate occurrence differences.

关 键 词：水合物 岩石物理 声衰减 声波测井 VSP数据 赋存规律 

分 类 号：P631[天文地球—地质矿产勘探]