柴达木盆地西部地区古近系—新近系油气资源丰富,但天然气勘探程度相对较低,为了推进研究区天然气勘探新局面,以源-盖控烃、构造-储层-圈闭控藏的选区评价思路为指导,综合运用实验分析、盆地模拟及地质评价技术,研究气源岩、储集层、圈闭、盖层及保存条件等特征,并提出有利勘探目标。研究结果表明:柴西地区气源岩(Ro≥0.8%)有5套,主力气源岩为E32和N1,具有明显晚期生烃特征,主要分布在柴西北及靠近茫崖凹陷的柴西南局部地区,面积约为4 743.40 km2,生烃总量约为1.17×1012m3;柴西地区储层分为碎屑岩和碳酸盐岩两大类,岩性致密,物性变化较大;柴西地区存在2套区域性盖层,深层盖层保存条件好,浅层盖层保存条件差;有效气源岩区深层主要以E31、E32晚期(断)背斜及断鼻等构造圈闭为主,与生气期、成藏期及保存期时空匹配一致。在此基础上,优选了狮子沟-干柴沟、咸水泉-油泉子-黄瓜峁和南翼山3个天然气有利勘探区带,明确了12个有利圈闭和3个较有利圈闭。研究结果对柴西地区天然气的深入勘探具有一定借鉴意义。
There are abundant Paleogene-Neogene oil and gas resources in the western Qaidam Basin, but the natural gas exploration level is relatively low. In order to promote future exploration of natural gas in the study area, the study area was selected and evaluated by ideas of source-cap rock controlling hydrocarbon accumulation and structure-deposit-trap controlling reservoir, secondly, experimental analysis, basin simulation and geological evaluation technologies are used to study the characteristics of gas source rock, reservoir stratum, trap, caprock and preservation conditions, and finally, favorable exploration targets were proposed. The findings show that there are 5 sets of gas source rocks (Ro ≥ 0.8%) taken from the western Qaidam Basin, the primary gas source rocks are E32 and N1, with significant late hydrocarbon generation characteristics, mainly distributed in the northwest Qaidam Basin and locally in the southwestern Qaidam Basin near the Mangya depression, with an area of about 4 743.40 km2 and a total hydrocarbon amount generated of about 1.17×1012 m3; the reservoirs in the western Qaidam Basin are classified by two types: clasolite and carbonatite, with tight lithology and petrophysical changes; there are 2 sets of regional caprocks in the western Qaidam Basin; the deep caprock is properly preserved while the shallow caprock is poorly preserved; the deep layers of the effective gas source rock area are dominated by structural traps such as late E31 and E32 (fault) anticlines and fault noses, and consistent in time and space in gas generation period, accumulation period and preservation period. Based on above findings, three favorable natural gas exploration zones, namely Shizigou-Ganchaigou, Xianshuiquan-Youquanzi-Cucumbermao and Nanyishan were selected, and 12 favorable traps and 3 more favorable traps were identified. There is much for reference of the results of the study to the further exploration of natural gas in western Qaidam Basin.
[1] 甘贵元,尹成明,张冰清,等.柴达木盆地油气资源战略调查成果与下步工作重点[J].地质通报,2006,25(9/10):1068-1073.
GAN Guiyuan,YIN Chengming,ZHANG Bingqing,et al.Outcomes of strategic investigation of oil-gas resources in the Qaidam Basin, northwest China and focus of future work[J].Geological Bulletin of China,2006,25 (9/10):1068-1073.
[2] 刘军,刘成林,董清源,等.柴达木盆地西部地区古近系—新近系天然气成藏期次研究[J].地学前缘,2016,23(5):127-134.
LIU Jun,LIU Chenglin,DONG Qingyuan,et al.A study on the period of gas accumulation of Paleogene-Neogene in western Qaidam Basin[J].Earth Science Frontiers,2016,23 (5):127-134.
[3] 刘军,刘成林,孙平,等.柴达木盆地西部地区咸化湖盆天然气地球化学特征及成因类型判识指标——以古近系—新近系为例[J].地质通报,2016,35(2/3):321-328.
LIU Jun,LIU Chenglin,SUN Ping,et al.Geochemical characteristics of natural gas in saline basin of western Qaidam Basin:a case study of Paleogene-Neogen strata[J].Geological Bulletin of China,2016,35 (2/3):321-328.
[4] 曹国强,陈世悦,徐凤银,等.柴达木盆地西部中—新生代沉积构造演化[J].中国地质,2005,32(1):33-40.
CAO Guoqiang,CHEN Shiyue,XU Fengyin,et al.Ceno-Mesozoic sedimentary and tectonic evolution in the western Qaidam Basin[J].Geology in China,2005,32 (1):33-40.
[5] 方向,张永庶.柴达木盆地西部地区新生代沉积与构造演化[J].地质与勘探,2014,50(1):28-36.
FANG Xiang,ZHANG Yongshu.Cenozoic sediments and tectonic evolution in the western Qaidam Basin[J].Geology and Exploration,2014,50 (1):28-36.
[6] 马雪,伊海生,夏国清.柴达木盆地西部新生代砂岩碎屑组分变化记录的沉积转型事件[J].地质通报,2010,29(9):1294-1303.
MA Xue, YI Haisheng, XIA Guoqing.Cenozoic sedimentary transformation event record by detrital components in western Qaidam Basin[J].Geological Bulletin of China,2010,29 (9):1294-1303.
[7] 李婷,夏志远,刘小平,等.柴达木盆地东坪地区基岩气藏成藏条件分析[J].特种油气藏,2015,22(5):69-73.
LI Ting,XIA Zhiyuan,LIU Xiaoping,et al.The bedrock gas reservoir forming conditions in Dongping Area of Qaidam Basin[J].Special Oil & Gas Reservoirs,2015,22 (5):69-73.
[8] 孙秀建,阎存凤,张永庶,等.柴达木盆地阿尔金山前基岩气藏成藏条件分析[J].特种油气藏,2015,22(1):75-78.
SUN Xiujian,YAN Cunfeng,ZHANG Yongshu,et al.The bedrock gas reservoir forming conditions in the front of Altun Mountain, Qaidam Basin[J].Special Oil & Gas Reservoirs,2015,22 (1):75-78.
[9] 赵凡,贾承造,袁剑英,等.柴达木盆地西部走滑相关断裂特征及其控藏作用[J].地质评论,2012,58(4):660-670.
ZHAN Fan,JIA Chengzao,YUAN Jianying,et al.Study on strike-slip fault and its control effect on oil and gas accumulation in western Qaidam Basin[J].Geological Review, 2012, 58 (4): 660-670.
[10] 方向,江波,张永庶.柴达木盆地西部地区断裂构造与油气聚集[J].石油与天然气地质,2006,27(1):56-61.
FANG Xiang,JIANG Bo,ZHANG Yongshu.Faulted structure and hydrocarbon accumulation in western Qaidam Basin[J].Oil & Gas Geology,2006,27(1):56-61.
[11] 孙国强,郑建京,胡慧芳,等.关于压陷型沉降拗陷盆地的讨论——以柴达木盆地为例[J].天然气地球科学,2004,15(4):395-400.
SUN Guoqiang, ZHENG Jianjing, HU Huifang, et al. Discussion of the down-warped setting basin: taking Qaidam Basin as an example [J].Natural Gas Geoscience,2004,15 (4):395-400.
[12] 董清源,刘小平,张盼盼,等.孔南地区孔二段致密油生烃评价及有利区预测[J].特种油气藏,2015,22(4):51-55.
DONG Qingyuan,LIU Xiaoping,ZHANG Panpan,et al.Assessment on hydrocarbon-generation potential of tight oil and prediction of favorable zones in Kong-2 Member of the Kongnan Area[J].Special Oil & Gas Reservoirs,2015,22 (4):51-56.
[13] 郭泽清,马寅生,易士威,等.柴西地区古近系—新近系含气系统模拟及勘探方向[J].天然气地球科学,2017,28(1):82-92.
GUO Zeqing,MA Yinsheng,YI Shiwei,et al.Simulation and exploration direction of Paleogene-Neogene gas system in the western Qaidam Basin[J].Natural Gas Geoscience,2017,28(1):82-92.
辽公网安备 21110002000031号 辽ICP备18011648号-1
