Focused fluid flow in the Baiyun Sag, northern South China Sea: implications for the source of gas in hydrate reservoirs
文献类型：CNKI期刊论文
| 作者 | Chen DX(陈端新); Wu SG(吴时国); Dong DD(董冬冬); Mi LJ(米立军); Fu SY(付少英); Shi HS(施和生) |
| 发表日期 | 2013-01-15 |
| 出处 | Chinese Journal of Oceanology and Limnology
 |
| 关键词 | gas hydrate thermogenic gas biogenic gas Dongsha Movement focused fluid flow South China Sea |
| 英文摘要 | The origin and migration of natural gas and the accumulation of gas hydrates within the Pearl River Mouth Basin of the northern South China Sea are poorly understood. Based on high-resolution 2D/3D seismic data, three environments of focused fluid flow: gas chimneys, mud diapirs and active faults have been identified. Widespread gas chimneys that act as important conduits for fluid flow are located below bottom simulating reflections and above basal uplifts. The occurrence and evolution of gas chimneys can be divided into a violent eruptive stage and a quiet seepage stage. For most gas chimneys, the strong eruptions are deduced to have happened during the Dongsha Movement in the latest Miocene, which are observed below Pliocene strata and few active faults develop above the top of the Miocene. The formation pressures of the Baiyun Sag currently are considered to be normal, based on these terms: 1) Borehole pressure tests with pressure coefficients of 1.043-1.047; 2) The distribution of gas chimneys is limited to strata older than the Pliocene; 3) Disseminated methane hydrates, rather than fractured hydrates, are found in the hydrate samples; 4) The gas hydrate is mainly charged with biogenic gas rather than thermogenic gas based on the chemical tests from gas hydrates cores. However, periods of quiet focused fluid flow also enable the establishment of good conduits for the migration of abundant biogenic gas and lesser volumes of thermogenic gas. A geological model governing fluid flow has been proposed to interpret the release of overpressure, the migration of fluids and the formation of gas hydrates, in an integrated manner. This model suggests that gas chimneys positioned above basal uplifts were caused by the Dongsha Movement at about 5.5 Ma. Biogenic gas occupies the strata above the base of the middle Miocene and migrates slowly into the gas chimney columns. Some of the biogenic gas and small volumes of thermogenic gas eventually contribute to the formation of the gas hydrates. |
| 文献子类 | CNKI期刊论文 |
| 资助机构 | Supported by the National Natural Science Foundation of China (Nos.40930845 and 41006031) ; the International Science & Technology Cooperation Program of China (No. 2010DFA21740) ; the National Science and Technology Major Project (No. 2011ZX05026-004-06) |
| 卷 | v.31期:01页:180-191 |
| 语种 | 英文; |
| 分类号 | P618.13 |
| ISSN号 | 0254-4059 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/191018]  |
| 专题 | 中国科学院海洋研究所 |
| 作者单位 | 1.GuangzhouMarineGeologySurvey 2.KeyLaboratoryofMarineGeology&Environment,InstituteofOceanology,ChineseAcademyofSciences 3.GraduateUniversityofChineseAcademyofSciences 4.ExplorationDepartment,ChinaNationalOffshoreOilCorporation(CNOOC) 5.ShenzhenBranchofCNOOC |
| 推荐引用方式 GB/T 7714 | Chen DX,Wu SG,Dong DD,et al. Focused fluid flow in the Baiyun Sag, northern South China Sea: implications for the source of gas in hydrate reservoirs. 2013. |
入库方式： OAI收割
来源：海洋研究所
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