ODP天然气水合物勘探方法研究
|
摘要
国内还没有发现实物天然气水合物样品,那么目前的水合物勘探需要更完备的理论指导,勘探方法的有效、可靠性也需要验证。
本文的研究目的是通过研究ODP航次中发现天然气水合物的站位的地质、地球物理和地球化学特征,提炼出水合物形成以及成藏的最佳地质条件,分析总结出其地球物理和地球化学特征,来指导国内的水合物勘探。
文中研究了ODP(大洋钻探项目)一些发现天然气水合物的航次的地质、地球物理和地球化学情况,比如164航次、204航次、308航次等,借此提出更合理、完善的水合物赋存模型,从而从更全面、详细的因素来约束我国天然气水合物的勘探。同时利用申请回来的ODP各航次样品进行酸解烃和甲烷同位素分析,来对比两种方法的优劣并检验这个模型的正确性。
首先研究了各航次的地质背景,得出这个模型的最佳地质条件组合:水深1000米左右的海域,最好有因大量气体转移而形成的塌陷或者滑坡,或因大量甲烷生物活动形成的海底烟囱,该地区沉积有新生代晚更新世沉积的富含微化石、有孔虫以及硅藻的岩层,如岩层中存在浊积岩,则很可能在附近存有水合物;
根据对BSR和浊积岩在ODP中的应用以及它们的优缺点分析,首次提出了BSR和浊积岩共同作为指标的天然气水合物赋存模型;
对这个模型的性质分析指出:浊积岩位于BSR上方,地震反射声速比BSR低,比环境岩层高;浊积岩密度、热传导率、未排水剪切强度、磁化系数和电阻率都比背景岩层高,孔隙率则减少近10%;水合物存在于浊积岩内或附近(特别是浊积岩间层内),甲烷在浊积岩内的往上渗透,浊积岩的层理结构为乙烷以及重烃提供了横向运移的通道;各种元素含量在浊积岩内的突变表明浊积岩内含有大量陆源碎屑;最后通过将该模型应用于164航次,对这个模型进行了验证,证实了这个模型的正确性和意义;
酸解烃方法测得的异常比顶空气法测得的异常明显,其它烃类测试结果说明甲烷在浊积岩中的渗透性比乙烷和其它烃类强,浊积岩成为重烃横向运移的自然通道;根据对164航次同位素的分析得出,布莱克区域的烃类有可能也是混合成因的。
Since no gas hydrate sample has been found in China and our sampling has been restricted in certain depth, the evaluation and development of the prospecting method we use in China relies on data from those areas in which gas hydrate samples have been found.
The purpose of the research in this paper is to summarize the geological conditions and geophysical、geochemical characteristics of gas hydrate zone in ODP Legs in which gas hydrate has been sampled, such as Leg164、Leg204 and Leg308, herein a new model of occurrence and distribution of gas hydrate has been brought forward to guide the gas hydrate prospecting in Qiong Dongnan Basin and Xisha Trough of South China Sea. And meanwhile the data of Site996 which were analyzed by acidolysis method were compared with the original ODP data which were mostly analyzed by headspace free gas method, therefore the feasibility and the validity of acidolysis method has been verified with the comparison between the data of acidolysis method and headspace free gas method.
Firstly the geological background of these Legs has been studied, such as the water depth of gas hydrate areas and the seafloor physiognomy, conformation and aggradations, the composing of formation, which have been compiled into a geological condition table later on, herein the primitive model has been brought forward, in which turbidite has been introduced;
After summarizing the function of BSR and turbidite in this model, it’s found out that BSR and turbidite have significant effect on this new model as the markers for gas hydrate.
The characteristics of this new model are as following: the velocity of turbidite is lower than that of BSR which is underlying turbidite; the density、heat conductivity、peak shear strength and resistivity are higher than these of background rock stratum while the porosity is lower by 10%; Gas hydrate is sampled in turbidite or in area adjacent to turbidite; methane infiltrates upwards through turbidite while other hydrocarbons move breadthwise along turbidite.
Then this new model has been proven valid again with those geochemical indexes of ODP Leg164;
I’ve requested 81 samples related to gas hydrate from IODP repositories and done some chemical testing with acidolysis method, compared with the original data of ODP, it’s indicated that acidolysis method’s a workable method to study anomaly and seek for gas hydrate which can show more distinctive anomalies than head space free gas method. And finally the cause of formation of hydrocarbon in Blake Region has been discussed in which a complex cause of formation was indicated.
本文的研究目的是通过研究ODP航次中发现天然气水合物的站位的地质、地球物理和地球化学特征,提炼出水合物形成以及成藏的最佳地质条件,分析总结出其地球物理和地球化学特征,来指导国内的水合物勘探。
文中研究了ODP(大洋钻探项目)一些发现天然气水合物的航次的地质、地球物理和地球化学情况,比如164航次、204航次、308航次等,借此提出更合理、完善的水合物赋存模型,从而从更全面、详细的因素来约束我国天然气水合物的勘探。同时利用申请回来的ODP各航次样品进行酸解烃和甲烷同位素分析,来对比两种方法的优劣并检验这个模型的正确性。
首先研究了各航次的地质背景,得出这个模型的最佳地质条件组合:水深1000米左右的海域,最好有因大量气体转移而形成的塌陷或者滑坡,或因大量甲烷生物活动形成的海底烟囱,该地区沉积有新生代晚更新世沉积的富含微化石、有孔虫以及硅藻的岩层,如岩层中存在浊积岩,则很可能在附近存有水合物;
根据对BSR和浊积岩在ODP中的应用以及它们的优缺点分析,首次提出了BSR和浊积岩共同作为指标的天然气水合物赋存模型;
对这个模型的性质分析指出:浊积岩位于BSR上方,地震反射声速比BSR低,比环境岩层高;浊积岩密度、热传导率、未排水剪切强度、磁化系数和电阻率都比背景岩层高,孔隙率则减少近10%;水合物存在于浊积岩内或附近(特别是浊积岩间层内),甲烷在浊积岩内的往上渗透,浊积岩的层理结构为乙烷以及重烃提供了横向运移的通道;各种元素含量在浊积岩内的突变表明浊积岩内含有大量陆源碎屑;最后通过将该模型应用于164航次,对这个模型进行了验证,证实了这个模型的正确性和意义;
酸解烃方法测得的异常比顶空气法测得的异常明显,其它烃类测试结果说明甲烷在浊积岩中的渗透性比乙烷和其它烃类强,浊积岩成为重烃横向运移的自然通道;根据对164航次同位素的分析得出,布莱克区域的烃类有可能也是混合成因的。
Since no gas hydrate sample has been found in China and our sampling has been restricted in certain depth, the evaluation and development of the prospecting method we use in China relies on data from those areas in which gas hydrate samples have been found.
The purpose of the research in this paper is to summarize the geological conditions and geophysical、geochemical characteristics of gas hydrate zone in ODP Legs in which gas hydrate has been sampled, such as Leg164、Leg204 and Leg308, herein a new model of occurrence and distribution of gas hydrate has been brought forward to guide the gas hydrate prospecting in Qiong Dongnan Basin and Xisha Trough of South China Sea. And meanwhile the data of Site996 which were analyzed by acidolysis method were compared with the original ODP data which were mostly analyzed by headspace free gas method, therefore the feasibility and the validity of acidolysis method has been verified with the comparison between the data of acidolysis method and headspace free gas method.
Firstly the geological background of these Legs has been studied, such as the water depth of gas hydrate areas and the seafloor physiognomy, conformation and aggradations, the composing of formation, which have been compiled into a geological condition table later on, herein the primitive model has been brought forward, in which turbidite has been introduced;
After summarizing the function of BSR and turbidite in this model, it’s found out that BSR and turbidite have significant effect on this new model as the markers for gas hydrate.
The characteristics of this new model are as following: the velocity of turbidite is lower than that of BSR which is underlying turbidite; the density、heat conductivity、peak shear strength and resistivity are higher than these of background rock stratum while the porosity is lower by 10%; Gas hydrate is sampled in turbidite or in area adjacent to turbidite; methane infiltrates upwards through turbidite while other hydrocarbons move breadthwise along turbidite.
Then this new model has been proven valid again with those geochemical indexes of ODP Leg164;
I’ve requested 81 samples related to gas hydrate from IODP repositories and done some chemical testing with acidolysis method, compared with the original data of ODP, it’s indicated that acidolysis method’s a workable method to study anomaly and seek for gas hydrate which can show more distinctive anomalies than head space free gas method. And finally the cause of formation of hydrocarbon in Blake Region has been discussed in which a complex cause of formation was indicated.
引文
[1] 朱秋格,天然气水合物-21 世纪潜在能源. 特种油气藏,2004,2,5～8
[2] 孙成年,朱岳年.21 世纪能源与环境的前沿问题—天然气水合物,地球科学进展,1994年,9(6):50～52
[3] 陈作义等,新世纪的新能源-天然气水合物. 辽宁化工,2001,10,422～425
[4] 方银霞等,天然气水合物的勘探与开发技术. 中国海洋平台,2002,02,11～14
[5] 樊栓狮等,天然气水合物的研究现状与发展趋势. 中国科学院院刊,2001,2, 106～110
[6] 程思海,陈道华,张欣.海底天然气水合物地球化学探测技术.海洋地质动态,2003 年,19(10):30～34
[7] 王维熙,孙春岩,牛滨华等,海洋油气勘探中高灵敏度气态烃现场探测系统的研制,北京:地球科学----中国地质大学学报,第 29 卷第 2 期,2004 年 3 月
[8] 王维熙,孙春岩,牛滨华。气态烃快速探测系统在海洋油气资源勘探中的应用,地质与勘查,2003,39(6):49～52
[9] 王宏语 孙春岩 黄永样等,海上气态烃快速测试与西沙海槽天然气水合物资源勘查,现代地质,Vol.16,No.2,Jun.,2002:180～186
[10] 地学前缘抽印本,中国地质大学出版社, 2004;
[11] H.布拉特等著,《沉积岩成因》翻译组译:《沉积岩成因》,科学出版社,北京,1978;
[12] 陈文山教授,国立台湾大学地质科学系,《海岸山脉地质解说》,摘自网络,2006;
[13] 陈多福,李绪宣,夏斌,南海琼东南盆地天然气水合物稳定域分布特征及资源预测,地球物理学报,2004;
[14] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 112, 1993;
[15] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 127, 1995;
[16] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 164, 1996;
[17] Trehu, A.M., Bohrmann, et al., Proceedings of the Ocean Drilling Program, Initial Reports Volume 204, 2003;
[18] Trehu, A.M., Bohrmann, et al., Proceedings of the Ocean Drilling Program, Initial Reports Volume 204, Leg 1250, Shipboard Scientific Party, 2003;
[19] Expedition 164 Scientists, Ocean Drilling Program Expedition 164 Preliminary Report No.64, 1996;
[20] Shipboard Scientific Party, Leg 204 Preliminary Report, Drilling Gas Hydrates on Hydrate Ridge, Cascadia Continental Margin, 2002;
[21] Shipboard Scientific Party, Leg 204 Preliminary Report, No.9 site 1250, 2002;
[22] Expedition 308 Scientists, Integrated Ocean Drilling Program Expedition 308 Preliminary Report, Gulf of Mexico Hydrogeology, 2005;
[23] Weimer, Paul and Slatt, Roger M. ,Sequence and seismic stratigraphy,Leading Edge (Tulsa, OK), v18, n4, p6 ,1999;
[24] Pettingill, Henry S., Turbidite plays' immaturity means big potential remains, Source: Oil and Gas Journal, v96, n40, p106-112O,1998;
[25] Von Huene,R., and Pecher,I.A., Vertical tectonics and the origins of BSRs along the Peru margin, Earth Planet.Sci.Lett,p47-55,1999;
[26] Sloan,E.D.Jr. Clathrate Hydrate of Natural Gases (second edition), New York, Marcel Dekker, p730, 1998;
[27] Andreassen, K.,K. Hogstad, and K.A.Berteussen, Gas hydrate in the southern Barents Sea, indicated by a shallow seismic anomaly, First Break,p235-245,1990;
[28] Collett,T.S., and J.Ladd, Detection of gas hydrate with downhole logs and assessment of gas hydrate concentrations and gas volumes on the Blake Ridge with electrical resistivity log data, Proc. Ocean Drill. Program, Sci. Results, p179-191,1999;
[29] Ginsburg, G.D. and A.V. Soloviev, Khutorskoy, Gas hydrate accumulation at the Haakon-Mosby mud volcano, Geo-Marine Letters,p57-67,1999;
[30] Edwards, R.N., On the resource evaluation of marine gas hydrate deposits using seafloor transient electric dipole-dipole methods, Geophysics,p62-74,1997;
[31] William Ussler Ⅲ and Charles K. Paull, Ion Exclusion Associated With Marine Gas Hydrate Deposits, Research and Development Division,2000;
[32] Keith A.Kvenvolden and Thomas Lorenson,The Global Occurrence of Natural Hydrate,U.S. Geological Survey,2000;
[33] Miriam Kastner, Gas Hydrate in Convergent Margins: Formation, Occurrence,Geochemistry, and Global Significance, Scripps Institution of Oceanography, 2000;
[34] William Ussler Ⅲ and Charles K.Paull, Ion Exclusion Associated With Marine Gas Hydrate Deposits, 2001;
[35] W.Steven Holbrook, Seismic Studies of the Blake Ridge: Implications for Hydrate Distribution, Methane Expulsion, and Free Gas Dynamics, Department of Geology and Geophysics, University of Wyoming, Laramie, WY, 2000;
[36] R.D.Hyndman1,2,G.D.Spence2, etc, Geophysical Studies of Marine Gas Hydrate in Northern Cascadia, 2000;
[37] Indonesia Saller, Arthur (Chevron ETC); Lin, Rui and Dunham, John,Leaves in turbidite sands: The main source of oil and gas in the deep-water Kutei Basin, American Association of Petroleum Geologists Bulletin, v90, n10, p1585-1608,2006;
[38] Sawyer, Derek E. and Flemings, Peter B.,Seismic geomorphology, lithology, and evolution of the late Pleistocene Mars-Ursa turbidite region, Mississippi Canyon area, northern Gulf of Mexico,American Association of Petroleum Geologists Bulletin ,v91, n2, p215-234, 2007;
[2] 孙成年,朱岳年.21 世纪能源与环境的前沿问题—天然气水合物,地球科学进展,1994年,9(6):50～52
[3] 陈作义等,新世纪的新能源-天然气水合物. 辽宁化工,2001,10,422～425
[4] 方银霞等,天然气水合物的勘探与开发技术. 中国海洋平台,2002,02,11～14
[5] 樊栓狮等,天然气水合物的研究现状与发展趋势. 中国科学院院刊,2001,2, 106～110
[6] 程思海,陈道华,张欣.海底天然气水合物地球化学探测技术.海洋地质动态,2003 年,19(10):30～34
[7] 王维熙,孙春岩,牛滨华等,海洋油气勘探中高灵敏度气态烃现场探测系统的研制,北京:地球科学----中国地质大学学报,第 29 卷第 2 期,2004 年 3 月
[8] 王维熙,孙春岩,牛滨华。气态烃快速探测系统在海洋油气资源勘探中的应用,地质与勘查,2003,39(6):49～52
[9] 王宏语 孙春岩 黄永样等,海上气态烃快速测试与西沙海槽天然气水合物资源勘查,现代地质,Vol.16,No.2,Jun.,2002:180～186
[10] 地学前缘抽印本,中国地质大学出版社, 2004;
[11] H.布拉特等著,《沉积岩成因》翻译组译:《沉积岩成因》,科学出版社,北京,1978;
[12] 陈文山教授,国立台湾大学地质科学系,《海岸山脉地质解说》,摘自网络,2006;
[13] 陈多福,李绪宣,夏斌,南海琼东南盆地天然气水合物稳定域分布特征及资源预测,地球物理学报,2004;
[14] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 112, 1993;
[15] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 127, 1995;
[16] PROCEEDING OF THE OCEAN DRILLING PROGRAM, SINECE RESULTS, Volume 164, 1996;
[17] Trehu, A.M., Bohrmann, et al., Proceedings of the Ocean Drilling Program, Initial Reports Volume 204, 2003;
[18] Trehu, A.M., Bohrmann, et al., Proceedings of the Ocean Drilling Program, Initial Reports Volume 204, Leg 1250, Shipboard Scientific Party, 2003;
[19] Expedition 164 Scientists, Ocean Drilling Program Expedition 164 Preliminary Report No.64, 1996;
[20] Shipboard Scientific Party, Leg 204 Preliminary Report, Drilling Gas Hydrates on Hydrate Ridge, Cascadia Continental Margin, 2002;
[21] Shipboard Scientific Party, Leg 204 Preliminary Report, No.9 site 1250, 2002;
[22] Expedition 308 Scientists, Integrated Ocean Drilling Program Expedition 308 Preliminary Report, Gulf of Mexico Hydrogeology, 2005;
[23] Weimer, Paul and Slatt, Roger M. ,Sequence and seismic stratigraphy,Leading Edge (Tulsa, OK), v18, n4, p6 ,1999;
[24] Pettingill, Henry S., Turbidite plays' immaturity means big potential remains, Source: Oil and Gas Journal, v96, n40, p106-112O,1998;
[25] Von Huene,R., and Pecher,I.A., Vertical tectonics and the origins of BSRs along the Peru margin, Earth Planet.Sci.Lett,p47-55,1999;
[26] Sloan,E.D.Jr. Clathrate Hydrate of Natural Gases (second edition), New York, Marcel Dekker, p730, 1998;
[27] Andreassen, K.,K. Hogstad, and K.A.Berteussen, Gas hydrate in the southern Barents Sea, indicated by a shallow seismic anomaly, First Break,p235-245,1990;
[28] Collett,T.S., and J.Ladd, Detection of gas hydrate with downhole logs and assessment of gas hydrate concentrations and gas volumes on the Blake Ridge with electrical resistivity log data, Proc. Ocean Drill. Program, Sci. Results, p179-191,1999;
[29] Ginsburg, G.D. and A.V. Soloviev, Khutorskoy, Gas hydrate accumulation at the Haakon-Mosby mud volcano, Geo-Marine Letters,p57-67,1999;
[30] Edwards, R.N., On the resource evaluation of marine gas hydrate deposits using seafloor transient electric dipole-dipole methods, Geophysics,p62-74,1997;
[31] William Ussler Ⅲ and Charles K. Paull, Ion Exclusion Associated With Marine Gas Hydrate Deposits, Research and Development Division,2000;
[32] Keith A.Kvenvolden and Thomas Lorenson,The Global Occurrence of Natural Hydrate,U.S. Geological Survey,2000;
[33] Miriam Kastner, Gas Hydrate in Convergent Margins: Formation, Occurrence,Geochemistry, and Global Significance, Scripps Institution of Oceanography, 2000;
[34] William Ussler Ⅲ and Charles K.Paull, Ion Exclusion Associated With Marine Gas Hydrate Deposits, 2001;
[35] W.Steven Holbrook, Seismic Studies of the Blake Ridge: Implications for Hydrate Distribution, Methane Expulsion, and Free Gas Dynamics, Department of Geology and Geophysics, University of Wyoming, Laramie, WY, 2000;
[36] R.D.Hyndman1,2,G.D.Spence2, etc, Geophysical Studies of Marine Gas Hydrate in Northern Cascadia, 2000;
[37] Indonesia Saller, Arthur (Chevron ETC); Lin, Rui and Dunham, John,Leaves in turbidite sands: The main source of oil and gas in the deep-water Kutei Basin, American Association of Petroleum Geologists Bulletin, v90, n10, p1585-1608,2006;
[38] Sawyer, Derek E. and Flemings, Peter B.,Seismic geomorphology, lithology, and evolution of the late Pleistocene Mars-Ursa turbidite region, Mississippi Canyon area, northern Gulf of Mexico,American Association of Petroleum Geologists Bulletin ,v91, n2, p215-234, 2007;