柴达木盆地狮子沟油田古近系异常高压成因GENESIS OF PALEOGENE ABNORMAL HIGH PRESSURE OF SHIZIGOU OILFIELD IN QAIDAM BASIN
李海,汤达祯,许浩,张君峰,申文敏
LI Hai,TANG Dazhen,XU Hao,ZHANG Junfeng,SHEN Wenmin
摘要(Abstract)：
实测地层压力资料显示,柴达木盆地狮子沟油田古近系异常高压明显,压力系数最高可达2.07。研究认为,异常高压的主要成因为不均衡压实、有机质生烃和构造挤压作用,3种因素产生的异常压力占现今剩余压力的比例分别为20%,~30%,30%~40%和35%~50%。此外,依据地质历史时期异常压力产生的主控因素和时间顺序,提出了研究区异常高压形成过程的概念模式:地层先因不均衡压实而出现弱超压,由于厚度较大的泥质岩、上覆膏岩层和断层在时空上的有效组合,在深部形成较好的封闭体系;随着地层的快速埋深,有机质逐渐成熟生烃,成为内部增压的主要来源;持续并且逐渐加强的构造挤压作用进一步提高了异常压力幅度。
The actually measured data of the formation pressure show that the abnormal high pressure is obvious for Paleogene system of Shizigou Oilfield in Qaidam Basin and the pressure coefficient can reach 2.07 at most.The studies prove that the main causes of abnormal high pressure are due to disequilibrium compaction,hydrocarbon generation from organic matters and tectonic compression.The contributions of the abnormal pressure induced by these three factors are 20%-30%,30%-40% and 35%-50% respectively of the present remained pressure.In addition,based on the main controlling factors and time order of the abnormal pressure generated in the geological history,the conceptual model of abnormal high pressure in the study area can be established as foUowings;(1) low overpressure initially appears in the formations resulted from the disequilibrium compaction,and later a much better closed system generated in the deep part just because of the effective combination of pretty thicker pelite,overlying gypsolyte and faults in time and space;(2) with the rise of fast buried depth of the formations,the organic matters gradually mature and generate hydrocarbon,and finally these conditions become the main source for inner supercharging;(3) the continuously increased and gradually strengthened tectonic compression have further en-hanced the degree of the abnormal pressure.
关键词(KeyWords)：
古近系;异常高压;成因机制;狮子沟油田;柴达木盆地
Paleogene;abnormal high pressure;genetic mechanism;Shizigou Oilfield;Qaidam Basin
基金项目(Foundation): 国家自然科学基金青年项目(40802027)
作者(Author):
李海,汤达祯,许浩,张君峰,申文敏
LI Hai,TANG Dazhen,XU Hao,ZHANG Junfeng,SHEN Wenmin
参考文献(References)：
- [1]华保钦,林锡祥.柴达木盆地异常地层压力及其成因探讨[J].石油学报,1983,4(4):66-74.
- [2]郭泽清,刘卫红,钟建华,等.柴达木盆地西部新生界异常高压:分布、成因及对油气运移的控制作用[J].地质科学,2005,40(3):380-384.
- [3]曹海防,闫林,夏斌,等.柴西南古近系和新近系异常压力与油气成藏[J].新疆石油地质,2007,28(3):283-284.
- [4]翟光明.青藏油气区[M]//青藏油气区石油地质志编写组.中国石油地质志:卷十四.北京:石油工业出版社,1985.
- [5]金之均,张明利,汤良杰,等.柴达木盆地中新生代构造演化[J].地球学报,1999,20(增刊):68-77.
- [6]徐凤银,尹成明,巩庆林,等.柴达木盆地中、新生代构造演化及其对油气的控制[J].中国石油勘探,2006,11(6):9-18.
- [7]李延钧,江波,张永庶,等.柴西狮子沟构造油气成藏期与成藏模式[J].新疆石油地质,2008,29(2):176-178.
- [8]Swarbrick R E,Osborne M J.Mechanisms that generation abnormal pressures;an overview[J].AAPG Memoir,70:13-34.
- [9]Magara.压实与流体运移[M].陈立荷,译.北京:石油工业出版社,1981.
- [10]Leach W G.New exploration enhancement in south Louisiana Tertiary sediments[J].Oil and Gas Journal,1993,91(9):83-87.
- [11]郭小文.含油气盆地生烃增压演化研究——以东营凹陷和白云凹陷为例[D].武汉:中国地质大学,2010.
- [12]唐振兴,苗洪波,李爱民,等.松辽盆地南部嫩江组—泉四段油气运移特征[J].大庆石油地质与开发,2007,26(6):40-41.
- [13]胡海燕.深部油气成藏机理概论[J].大庆石油地质与开发,2006,25(6):24-25.
- [14]罗晓容.构造应力超压机制的定量分析[J].地球物理学报,2004,47(6):5-12.
- [15]曾联波,刘本明.塔里木盆地库车前陆逆冲带异常高压成因及其对油气成藏的影响[J].自然科学进展,2005,15(12):1485-1491.
- [16]付志新.超压对断层垂向封闭作用的定量研究[J].大庆石油地质与开发,2008,27(2):17-18.
- [17]杨殿军.超压对泥岩盖层封闭各种相态天然气的作用研究[J].大庆石油地质与开发,2008,27(2):13-14.
- [18]孙宝珊,丁原辰,邵兆刚,等.声发射法测量古今应力在油田的应用[J].地质力学学报,1996,2(2):11-17.
- [19]王震亮,张立宽,施立志,等.塔里木盆地克拉2气田异常高压的成因分析及其定量评价[J].地质评论,2005,51(1):60-61.
- [20]张凤奇,王震亮,宋岩,等.库车坳陷构造挤压增压定量评价新方法[J].中国石油大学学报:自然科学版,2011,35(4):1-7.
- [21]张明利,金之钧,万天丰,等.柴达木盆地应力场特征与油气运聚关系[J].石油与天然气地质,2005,26(5)674-679.
- [22]王小凤,武红岭,马寅生,等.构造应力场、流体势场对柴达木盆地西部油气运聚的控制作用[J].地质通报,2006,25(9-10):1036-1043.