Characteristics and origin of low porosity and low permeability sandstone reservoir of Wenchang Formation in HZ25-7 structural belt of Huizhou Depression

  • LIU Aiqun ,
  • HAO Jianwei ,
  • CHEN Dianyuan ,
  • WANG Lijun ,
  • LU Tongxiang
Expand
  • 1. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China; 2. College of Geosciences, China University of Petroleum, Beijing 102249, China;3. Shengzhen Branch, CNOOC, Guangzhou 510240, China

Online published: 2014-08-15

Abstract

Huizhou Depression is an important oil and gas-rich region of Pearl River Mouth Basin. HZ25-7 structural belt is an important area designed for seeking oil and gas of Wenchang Formation in Huizhou Depression. The research of reservoir characteristics and mechanism of Wenchang Formation is the foundation of oil exploration breakthrough. Based on comprehensive analysis of various data such as drilling, casting thin sections, scanning electronic microscope, physical properties analysis and mercury penetration test, this paper analyzed the reservoir characteristics and mechanism of Wenchang Formation of HZ25-7 structural belt. The results show that sandstones are mostly litharenite and feldspathic litharenite, and are generally immature both texturally and compositionally. The average porosity and permeability of the sandstones are 12% and 7.1 mD respectively, and it is emphatically defined as the low porosity and low permeability reservoir. Pore types are mainly intragranular dissolved pores and primary intergranular pores, and its micro-pore structure is typical medium-micro pore and fine throat, with poor pore connectivity. Such low porosity and permeability reservoir of Wenchang Formation is controlled by depositional conditions and diagenesis. Braided fluvial deltaic depositional environment characterized by near provenance determined the large quantity of ductile grains in detrital composition and the infilling of part of primary pores by resulting matrix. Strong compaction results in primary porosity loss significantly. Due to low content in soluble grains, the improvement of physical properties mediated by organic acid is not obvious. Clay and carbonate cementations lead to continued worsening of reservoir properties and tightening, but abnormal overpressure is constructive to the preservation of reservoir porosity.

Cite this article

LIU Aiqun , HAO Jianwei , CHEN Dianyuan , WANG Lijun , LU Tongxiang . Characteristics and origin of low porosity and low permeability sandstone reservoir of Wenchang Formation in HZ25-7 structural belt of Huizhou Depression[J]. Lithologic Reservoirs, 2014 , 26(4) : 36 -43 . DOI: 10.3969/j.issn.1673-8926.2014.04.006

References

[1] 蒋凌志,顾家裕,郭彬程.中国含油气盆地碎屑岩低渗透储层的特征及形成机理[J].沉积学报,2004,22(1):13-18.
[2] 曾大乾,李淑贞.中国低渗透砂岩储层类型及地质特征[J].石油学报,1994,15(1):38-46.
[3] 施和生,雷永昌,吴梦霜,等.珠一坳陷深层砂岩储层孔隙演化研究[J].地学前缘,2008,15(1):169-175.
[4] 龙更生,施和生,郑荣才,等.珠江口盆地惠州凹陷深部储层成岩作用与孔隙演化[J].岩石矿物学杂志,2011,30(4):665-673.
[5] 龙更生,施和生,郑荣才,等.珠江口盆地惠州凹陷深部古近系储层特征及发育控制因素[J].海相油气地质,2011,16(3):71-78.
[6] 戴朝强,袁立忠,朱焱辉,等.惠州凹陷A 井区地震相特征及沉积相研究———以古近系文昌组 NA 油组为例[J].石油天然气学报(江汉石油学院学报),2012,34(10):51-54.
[7] 邓宏文,郭建宇,王瑞菊,等.陆相断陷盆地的构造层序地层分析[J].地学前缘,2008,15(2):1-7.
[8] 赵澄林,朱筱敏.沉积岩石学[M] .第3 版.北京:石油工业出版社,2001:102.
[9] 钟大康,朱筱敏,张枝焕,等.东营凹陷古近系砂岩储集层物性控制因素评价[J].石油勘探与开发, 2003,30(3): 95-98.
[10] 朱筱敏,米立军,钟大康,等.济阳坳陷古近系成岩作用及其对储层质量的影响[J].古地理学报,2006,8(3):295-305.
[11] 朱筱敏,潘荣,李盼盼,等.惠民凹陷沙河街组基山三角洲中孔低渗储层成岩作用和有利储层成因[J].岩性油气藏,2013,25(5):1-7.
[12] 朱世发,朱筱敏,刘振宇,等.准噶尔盆地西北缘克-百地区侏罗系成岩作用及其对储层质量的影响[J].高校地质学报,2008,14(2):172-180.
[13] 石油天然气地质勘探专业标准化委员会. SY/T 5477—2003碎屑岩成岩阶段划分[S].北京:石油工业出版社,2003.
[14] 查明,曲江秀,张卫海.异常高压与油气成藏机理[J].石油勘探与开发,2002,29(1):19-23.
[15] 江涛,解习农.莺歌海盆地高温超压环境下储层物性影响因素[J].地球科学,2005,30(2):215-220.
Outlines

/