Main factors controlling accumulation of overpressured gas reservoir in Block D, Myanmar

Abstract

Abstract: Block D in Myanmar is located along the hydrocarbon-richest west deep depression zone in the Ayeyarwady Basin. Presently, high-yield gas flows have been obtained through testing of 3 wells drilled in Taben Formation of Eocene System, indicating that this block has a certain exploration potential. However, this block features a low overall degree of exploration, widespread presence of overpressure in major target layers of Eocene, complicated accumulation conditions and unclear main factors controlling enrichment of hydrocarbon within overpressure system, thus significantly increasing future exploration risks. Through statistical analysis of worldwide representative overpressure hydrocarbon reservoirs and correlated analysis carried out in adjacent counterparts according to the latest geologic knowledge and exploration results regarding Block D, it is believed that two sets of source rocks exist in Block D – Taben and Langshing. The autochthonously developed source rocks of Taben Formation are characterized by shallow buried depth and low degree of evolution. Accordingly, the hydrocarbon is supposed coming from genetic depressions adjacent to the block or the source rock of Langshing Formation deep down. Accumulation inside the overpressure zone in Block D is primarily controlled by reservoir and preservation conditions. The effective migration-transport system and spatiotemporal allocation are important factors for hydrocarbon enrichment. Block D is lack of high-quality reservoirs of Oligocene like in the south Salin depression and its major reservoirs feature medium-porosity, low-permeability sandstone of Taben Formation; therefore, high importance should be attached to secondary pore and fracture intervals in the overpressure system vertically. The lower wall of the fault in Block D is an important area of exploration due to its relatively good hydrocarbon preservation conditions.

Key words: Block D in Myanmar, accumulation conditions, overpressure, main factors controlling accumulation, area of exploration

Shi Lei, Li Fuheng, Yin Jinyin, Tian Naxin, Guo Jinrui, Zhu Weihua. Main factors controlling accumulation of overpressured gas reservoir in Block D, Myanmar[J]. China Petroleum Exploration, 2016, 21(2): 69-77.

References

[1] Friedich Bender. Geology of Burma [M]. Berlin: Gebruder Borntraeger, 1983:37-42.
[2] Krishnan. Geology of India and Burma [M]. New York: CBS, 1982:52-59.
[3] 叶德燎，王骏，刘兰兰，等. 东南亚油气资源及其评价[M]. 北京：石油工业出版社，2004:70-76 Ye Deliao, Wang Jun, Liu Lanlan, et al. Petroleum resources evaluation in Southeast Asia[M]. Beijing: Petroleum Industry Press, 2004:70-76.
[4] 叶德燎. 东南亚石油资源与勘探潜力[J]. 中国石油勘探，2005,10(1):55-64. Ye Deliao. Petroleum resources and exploration potential in Southeast Asia [J]. China Petroleum Exploration, 2005,10 (1):55-64.
[5] Wandrey C J. Eocene to Miocene composite total petroleum system, Irrawaddy-Andaman and North Burma geologic provinces，Myanmar[M]. Reston, Virginia: US Geological Survey, 2006:21-52.
[6] Cao Dinh Trieu, Nguyen Huu Tuyen, et al. Evolution of faulting tectonics in Southeast Asia[J]. Journal of Geodesy and Geodynamics, 2005,25(1):51-59.
[7] Chhibber, Haibans Lal. The geology of Buema [M]. New York: Macmillan and Co, 1994:35-56.
[8] Ramaswamy V, Birgit Gaye, et al. Distribution and sources of organic carbon, nitrogen and their isotopic signatures in sediments from the Ayeyarwady (Irrawaddy) continental shelf, Northern Andaman Sea [J]. Marine Chemistry, 2008, 111(1):137-150.
[9] 鲜志尧. 缅甸D区块烃源岩有机地球化学特征及油气源对比[D]. 成都理工大学，2012. Xian Zhiyao. Source rock organic geochemistry characteristics and oil-gas sources correlation of block D in Myanmar[D].Chengdu University of Technology, 2012.
[10] 李红，曹永斌，王新云.缅甸D区块石油地质特征及勘探潜力[J].石油与天然气地质，2011,32(2):265-272. Li Hong, Cao Yongbin, Wang Xinyun. Petroleum geologic characteristic and exploration potential of Block D in Burma [J].Oil & Gas Geology, 2011,32(2):265-272.
[11] 李娟.缅甸D区块始新统沉积体系研究[D]. 成都理工大学，2012. Li Juan. Sedimentary system study of Eocene for block D of Burma[D]. Chengdu University of Technology, 2012.
[12] 陈剑光，刘怀山，周军，等. 缅甸D区块构造特征与油气储层评价[J].西北地质，2006,39(1):105-113. Chen Jianguang, Liu Huaishan, Zhou Jun, et al. Structural feature and oil and gas reservoir analysis of block D, Myanmar[J]. Northwestern Geology, 2006,39(1):105-113.
[13] 赖生华，麻建明，廖林.缅甸中央沉降带Chindwin盆地油气勘探潜力[J]. 天然气工业，2005,25(11):21-24. Lai Shenghua, Ma Jianming, Liao Lin. The oil-gas exploration potential of Chindwin sag in the central basin in Burma[J]. Natural Gas Industry, 2005,25(11):21-24.
[14] 周新科.缅甸伊洛瓦底盆地D区块石油地质特征与勘探前景[J]. 江汉石油职工大学学报，2009,22(2)19-22. Zhou Xinke. Petroleum geologic characteristics and exploration prospects of Block D in Irrawaddy Basin of Myanmar[J]. Journal of Jianghan Petroleum University of Staff and Workers, 2009,22(2):19-22.
[15] 谢楠，姜烨，朱光辉，等. 缅甸Sagaing走滑断裂及对睡宝盆地构造演化的控制和影响[J]. 现代地质，2010,24(2):268-272. Xie Nan, Jiang Ye, Zhu Guanghui, et al. Evolution of the Sagaing strike-slip fault and its control of Shwebo Basin structural evolution, Myanmar[J]. Geoscience, 2010,24(2):268-272.
[16] 马启富，等. 超压盆地与油气分布[M]. 北京：地质出版社，2000:80-102. Ma Qifu, et al. Overpressure basins and the distribution of petroleum[M]. Beijing: Geological Publishing House, 2000:80-102.
[17] 郝芳，等. 超压盆地生烃作用动力学油气成藏机理[M]. 北京:科学出版社，2005:122-136. Hao Fang, et al. Overpressure basin hydrocarbon generation dynamics and petroleum accumulation mechanism [M]. Beijing: Science Press, 2005:122-136.
[18] 冯松宝. 库车坳陷克拉苏构造带超高压大气田形成机制研究[D].中国矿业大学（北京），2012. Fong Songbao. Accumulation mechanism of overpressured large gas field in Kelasu tectonic zone of Kuqa depression[D]. China University of Mining and Technology(Beijing), 2012.
[19] 钟大康，朱筱敏. 克拉2气田储层特征及优质储层形成机理[J]. 天然气工业，2007,27(1):8-11. Zhong Dakang, Zhu Xiaomin. Reservoirs characteristics and formation mechanism of high quality reservoirs in Kela-2 gas field[J]. Natural Gas Industry, 2007,27(1):8-11.
[20] 邹华耀，王红军，郝芳等. 库车坳陷克拉苏逆冲带晚期快速成藏机理[J]. 中国科学D辑，2007,37(8):1032-1040. Zou Huayao, Wang Hongjun, Hao Fang, et al. Late and rapid petroleum accumulation pattern in Kelasu tectonic zone of Kuqa depression[J]. Science in China(Series D), 2007,37(8):1032-1040.
[21] Flemings P B, Long H, Dugan B, et al. Pore pressure penetrometers document high overpressure near the seafloor where multiple submarine landslides have occurred on the continental slope, offshore Louisiana, Gulf of Mexico[J]. Earth and Planetary Science Letters, 2008,269(1):309-325.
[22] Scott L, Montgomery, Robinson John W. Jonah Field, Sublette County, Wyoming: gas production from over pressured upper Cretaceous lance sandstones of the Green River Basin [J]. AAPG Bulletin, 1997,81(7):1049-1062.
[23] Charles W Spencer. Hydrocarbon generation as a mechanism for overpressuring in Rocky Mountain region[J]. AAPG Bulletin, 1987,71(2):368-388.
[24] Caillet G, Judge N C, Bramwell N P, et al. Overpressure and hydrocarbon trapping in the chalk of the Norwegian Central Graben[J]. Petroleum Geoscience, 1997,3(1):33-42.
[25] 张伙兰，裴健翔，张迎朝,等.莺歌海盆地东方区中深层黄流组超压储集层特征[J]. 石油勘探与开发，2013,40(3):284-292. Zhang Huolan, Pei Jianxiang, Zhang Yingchao, et al. Overpressure reservoirs in the mid-deep Huangliu Formation of the Dongfang area, Yinggehai Basin, South China Sea[J]. Petroleum Exploration and Development, 2013,40(3):284-292
[26] 吕孝威，张哨楠，伏美燕,等. 莺歌海盆地东方区黄流组高温超压砂岩储集层发育机理[J]. 新疆石油地质，2014,35(1):52-57. Lv Xiaowei, Zhang Shaonan, Fu Meiyan, et al. The mechanism of high-temperature and overpressure sandstone reservoir development of Huangliu Formation in Dongfang area of Yinggehai Basin [J]. Xinjiang Petroleum Geology, 2014,35(1):52-57.
[27] 陈树光，任建业，吴峰，等.渤中坳陷沙北地区古地貌恢复及其应用[J].特种油气藏，2015,22(2):52-55. Chen Shuguang, Ren Jianye, Wu Feng, et al.Palaeogeomorphic recovery and its application in Shabei area, central Bohai depression [J].Special Oil & Gas Reservoirs, 2015,22(2):52-55.
[28] 刘爱群，周家雄，范彩伟，等. 莺琼盆地高温超压地层钻前压力预测面临的问题与对策[J].天然气工业，2015,35(2):21-26. Liu Aiqun, Zhou Jiaxiong, Fan Caiwei, et al. Pre-drilling pressure prediction problems and solutions in the HTHP strata of the Yinggehai-Qiongdongnan Basin [J].Natural Gas Industry, 2015,35(2):21-26.
[29] 梁顺军,雷开强,王静,等.库车坳陷大北—克深砾石区地震攻关与天然气勘探突破[J].中国石油勘探，2014,19(5):49-58. Liang Shunjun, Lei Kaiqiang, Wang Jing, et al.Seismic research and natural gas exploration breakthrough in DB-KS gravel zone in Kuqa depression[J].China Petroleum Exploration, 2014,19(5):49-58.
[30] 邱贻博.东营凹陷压力系统与油气成藏[J].特种油气藏，2015,22(3):58-61. Qiu Yibo.Pressure system and oil/gas reservoir forming in Dongying sag [J].Special Oil & Gas Reservoirs, 2015,22(3):58-61.