柴达木盆地石泉滩地区下侏罗统小煤沟组砂岩储层演化特征

doi:10.11743/ogg20070311

摘要/Abstract

摘要：

近几年柴达木盆地石泉滩地区下侏罗统小煤沟组厚层砂岩储层中油气的发现使人们对其储层特征和成因机理引起重视。通过该区7口井的储层岩石学研究,认为小煤沟组砂岩储层主要为大气水淋滤溶蚀形成的次生孔隙储层,溶蚀作用的程度决定了储集性质的优劣。储层经历了早侏罗世的弱压实阶段、中侏罗世至白垩纪的大气水淋溶阶段、古近纪的强压实阶段和新近纪的抬升保持阶段。弱压实阶段的成岩压实量约5.5%～6.5%;大气水淋溶阶段形成发育的溶蚀孔隙,其增孔量在4.6%～16.5%,同时伴随蒙脱石矿物的形成;强压实阶段使砂岩的成岩压实量达到19.0%～21.5%,此外有少量方解石析出,该阶段是砂岩原生孔隙的主要消失时期;新近纪储层发生抬升,储层特征基本保持不变。中侏罗世至白垩纪的大气水淋滤溶蚀和古近纪的强烈压实是该区储层成岩演化的两个重要阶段,它决定了储层的成因类型及储集性质。

关键词: 砂岩储层, 成因类型, 演化机理, 下侏罗统, 柴达木盆地

Abstract:

Recent oil and gas discoveries in the thick sandstone reservoirs in the Lower Jurassic Xiaomeigou Formation in Shiquantan area,Qaidam basin,attract attentions to their reservoir characteristics and genetic mechanisms.Detailed petrological study of the reservoirs of 7 wells in the area reveals that the sandstone reservoirs in the Xiaomeigou Formation are dominated by secondary pores dissolved by the leaching atmospheric water and that the intensity of leaching determine the poroperm characteristics of the reservoirs.The reservoirs went through the following stages: weak compaction during the Early Jurassic(with diagenetic compaction rate of 5.5%-6.5%),atmospheric water leaching during the Middle Jurassic and Cretaceous(with pore increase rate of 4.6%-16.5% and the generation of montmoirillonite),strong compaction during the Paleogene(with diagenetic compaction rate at 19.0%-21.5%,precipitation of small amount of calcite,and disappearance of primary pores),and uplifting and preservation during the Neogene with no significant changes in reservoir characteristics.The atmospheric water leaching during the Middle Jurassic and Cretaceous and the intensive compaction in the Paleogene are the two major stages in the evolution of the reservoirs,and determine the genetic types and characteristics of the reservoirs.

Key words: sandstone reservoir, genetic type, evolution mechanism, Lower Jurassic, Qaidam basin

中图分类号:

TE122.2

姚根顺,寿建峰,王少依,等. 柴达木盆地石泉滩地区下侏罗统小煤沟组砂岩储层演化特征[J]. 石油与天然气地质, 2007, 28(3): 377-383. doi: 10.11743/ogg20070311 Yao Genshun,Shou Jianfeng,Wang Shaoyi,et al. Evolution of sandstone reservoirs in the Lower Jurassic Xiaomeigou Formation,Shiquantan area,Qaidam basin[J]. Oil & Gas Geology, 2007, 28(3): 377-383. doi: 10.11743/ogg20070311

参考文献

[1] 刘云田,杨少勇.柴达木盆地北缘侏罗系砂岩孔隙发育特征[J].石油与天然气地质,2001,22(3):267～269
[2] 罗明高.定量储层地质学[M].北京:地质出版社,1998
[3] 寿建峰,张惠良,斯春松,等.砂岩动力成岩作用[M].北京:石油工业出版社,2005
[4] 寿建峰,斯春松,朱国华,等.塔里木盆地库车坳陷下侏罗统砂岩储层性质的控制因素[J].地质论评,2001,47(3):273～277
[5] 寿建峰,朱国华,张惠良.构造侧向挤压与砂岩成岩压实作用--以塔里木盆地为例[J].沉积学报,2003,21(1):90～95
[6] 寿建峰,斯春松,张达.库车坳陷下侏罗统岩石古应力场与砂岩储层性质[J].地球学报,2004,25(4):447-452
[7] 寿建峰,张惠良,沈扬,等.中国油气盆地砂岩储层的成岩压实机制分析[J].岩石学报,2006,22(8):2 165～2 170
[8] Maxwell J C.Influence of depth,temperature and geologic age on porosity of guartzose sandstone[J].AAPG Bulletin,1964,48(5):697-709
[9] Sehmoker J W.Gautier D L.Sandstone porosity as function of thermal maturity-an approach to porosity comparision and prediction[J].Geology,1988,16(11):1697-1703
[10] Soherer M.Parameters influencing porosity in sandstones:a modelfor sandstone porosity pridietion[J].AAPG Bulletin,1987,71(5):684-689
[11] 刘成林,朱筱敏,朱玉新,等.不同构造背景天然气储层成岩作用及孔隙演化特点[J].石油与天然气地质,2005,26(6):746～753
[12] 蔡进功,谢忠怀,田芳,等.济阳坳陷深层砂岩成岩作用及孔隙演化[J].石油与天然气地质,2002,23(1):84～88
[13] 李汶国,张晓鹏,钟玉梅.长石砂岩次生溶孔的形成机理[J].石油与天然气地质,2005,26(2):220～223
[14] 朱筱敏,王英国,钟大康,等.济阳坳陷古近系储层孔隙类型与次生孔隙成因[J].地质学报,2007,81(2):197～204
[15] 季汉成,徐珍.深部碎屑岩储层溶蚀作用实验模拟研究[J].地质学报,2007,81(2):213～218
[16] 刘建清,赖兴运,于炳松,等.成岩作用的研究现状及展望[J].石油实验地质,2006,28(1):65～72,77