含天然气水合物储层衰减岩石物理研究进展
Review of rock-physics studies on natural gas hydrate-bearing sediment attenuation
摘要
Abstract
Attenuation is an essential reservoir property,and understanding its mechanism in gas hydrate-bear-ing sediments is important for predicting gas hydrate saturation.Natural gas hydrates mainly accumulate in coarse-grained sands or fine-grained clays with different morphologies,and the attenuation characteristics of these gas hy-drate-bearing sediments are inconsistent.Many rock-physics models have been proposed in recent years to elucidate the attenuation mechanisms of gas hydrate occurrence.There are two types of attenuation models for gas hydrates in sands.One of these models is based on the three-phase Biot theory and contains multiple mechanisms that de-scribe the contact effects between hydrate and sediment grains,such as grain cementation and squirt flows caused by microcracks.This model can reasonably reproduce the enhanced attenuation observed with increasing hydrate saturation in sonic-logging data.Attenuation described in the effective grain model is dominated by the viscous flow between the water in hydrate pores and free water.These types of models agree with the seismic attenuation observed in gas hydrates in sands.Moreover,the attenuation model of gas hydrates in clay is formulated by first es-tablishing an attenuation model for background sediments,which employs the effective grain model to characterize attenuation in clay minerals;then,the properties of pure gas hydrate and the effects of hydrate occurrence on sedi-ments are quantified.This model has also been successfully applied to seismic reflection data in the seismic fre-quency band.The above models have achieved significant progress in attenuation studies on gas hydrate-bearing sediments,and they have aided the quantitative interpretation of observed attenuation in field data and attenuation-related constraints for gas hydrate saturation.However,the application of these models is limited to certain extents:the attenuation predicted by the gas hydrate-bearing sands model failed to match that observed in the field data.Ad-ditionally,the gas hydrate-bearing clays model does not consider fracture shapes,and its performance has not been verified at the ultrasonic frequency band.To improve the accuracy and applicability of these models,the relation-ship between hydrate morphology and attenuation must be elucidated,and further rock-physics studies based on field data must be conducted.关键词
天然气水合物/衰减属性/岩石物理/水合物赋存形态Key words
natural gas hydrate/attenuation property/rock physics/hydrate morphology分类
地质学引用本文复制引用
刘涛,包雪阳,朱翔宇,李安昱..含天然气水合物储层衰减岩石物理研究进展[J].地球与行星物理论评（中英文）,2024,55(3):369-380,12.基金项目
国家自然科学基金资助项目(41976046) （41976046）
南方海洋与工程广东省实验室(广州)人才团队引进重大专项资助项目(GML2019ZD0203) （广州）
广东省地球物理高精度成像技术重点实验室资助项目(2022B1212010002) （2022B1212010002）
深圳市深远海油气勘探技术重点实验室项目(ZDSYS20190902093007855) （ZDSYS20190902093007855）
中国博士后科学基金项目(2021M701558)Supported by the National Natural Science Foundation of China(Grant No.41976046),the Key Special Project for Introduced Ta-lents Team of Southern Marine Science and Engineering Guangdong(Guangzhou)(Grant No.GML2019ZD0203),Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology(Grant No.2022B1212010002),Shenzhen Key Laboratory of Deep Offshore Oil and Gas Exploration Technology(Grant No.ZDSYS20190902093007855),and China Postdoc-toral Science Foundation(Grant No.2021M701558) （2021M701558）
