Study of Salinity Evol ution of Geofluids during Syngenesis and Diagenesis Using Composition of Carbonate Minerals

Lu Xiancai; Hu Wenxuan; Fu Qi; Zhang Wenlan; Zhou Guangjia; Hong Zhihua; Chen Zhilin

Sedimentational/syngenetic(SS),diagenetic(DG) and post-diagenetic(PD) carbonate minerals in the im-mature oil source rocks of the upper part of the Shasi member in Dongying Depression were identified undermicroscope and analyzed by EPMA(electronic probe micro-analysis). Three composition change patterns wereproposed as follows:(1) The Mg/Ca atomic ratio deceases from 0. 9 in the SS carbonate to 0. O1 in the DGone;(2)the Mg/Ca ratio keeps high values in the SS and DG ones，but it becomes very low in the PS ones;and(3) the ratio increase largely from the SS carbonate to the DG ones. According to the relationship betweensalinity of pore-fluids and the Mg/Ca ratio of carbonates,the above patterns were considered as the result ofdifferent environmental evolution histories from the SS to DG，then to PS stages. The salinity of diageneticpore-fluid was. proved very high in the center of the depression,which was believed to have been favorable. tothe generation of immature oil in the area. In addition,the research methods in this paper might be useful forsimilar studies in other areas.

1 Department of Earth Sciences Naming University Nanjing 210093;

2 State Key Lab of Metallogenic Mechanism Nanjing University 210093;

3 Institute of Geological Science Shengli Petroleum Administration Shandong Dongying 257015

Received Date: 1997-02-14

Rev Recd Date: 1997-06-17

Publish Date: 1998-03-10

Key words:

Dongying depression /
carbonates generated at different times /
EPMA /
Mg/Ca ratio /
salinity

Abstract: Sedimentational/syngenetic(SS),diagenetic(DG) and post-diagenetic(PD) carbonate minerals in the im-mature oil source rocks of the upper part of the Shasi member in Dongying Depression were identified undermicroscope and analyzed by EPMA(electronic probe micro-analysis). Three composition change patterns wereproposed as follows:(1) The Mg/Ca atomic ratio deceases from 0. 9 in the SS carbonate to 0. O1 in the DGone;(2)the Mg/Ca ratio keeps high values in the SS and DG ones，but it becomes very low in the PS ones;and(3) the ratio increase largely from the SS carbonate to the DG ones. According to the relationship betweensalinity of pore-fluids and the Mg/Ca ratio of carbonates,the above patterns were considered as the result ofdifferent environmental evolution histories from the SS to DG，then to PS stages. The salinity of diageneticpore-fluid was. proved very high in the center of the depression,which was believed to have been favorable. tothe generation of immature oil in the area. In addition,the research methods in this paper might be useful forsimilar studies in other areas.

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[1]

1 Mengo F D,et al. Role of transition-metal catalysis in the formation of natural gas. Nature,1994,368, 536-538

2 Helgeson H C,et al. Petroleum,oil field waters,and authigenic min- eral assemblages, are they in metastable equilibrium in hydrocarbon reservoirs? Geochim Cosmochim. Acta,1993,57:3295-3339

3 吴德云，张国防.盐湖相有机质成烃模拟实验研究.地球化学， 1994,23(增刊):173-181

4 Morrow D W. Diagenesis:Dolomite-partl, The chemistry of dolomitization and dolomite precipitation. Geoscience Canada,1982, 9s5-13

5 Muller G.Wagner F.巴拉顿湖(匈牙利)全新世碳酸盐的演化:对气候和人类影响的反映，见:马特A.塔克ME主编，现代和古代湖泊沉积物.贾振远译.北京:地质出版社。1984,44-63

6 徐其俊，吴必豪.江汉盆地q组含盐系中碳酸盐矿物的研究.中国地质科学院矿床地质研究所刊，北京:地质出版社，1982. 65-71

7 陈瑞君，朱井泉，李任伟等.云南安宁地区晚侏罗纪世含盐系的主要特点及沉积环境.岩石学报，1993,9C1)f94-104

8 Colson J, Isabelle Cojan. Groundwater dolocretes in a lake-marginal environment, an alternative model for dolocrete formation in conti- nental settings. Sedimentology,1996.43(1):175一188

9 周光甲.陆相块断盆地油气生成的地球化学模式.石油天然气地质，1992,13(4):359一370

10 洪志华.未、低熟油的地质地球化学特征.见:中国油气地质理论新进展，北京:石油工业出版社，1995

11 赵澄林，刘孟慧，纪友亮.渤海湾早第三纪断陷盆地含油气岩系沉积学及沉积相的基本特征.石油学报， 1991.12(2):28--32

12 王秉海，钱凯.胜利油区地质研究与勘探实践.山东东营:石油大学出版社，1992. 357

113 Melvin J I.Evaporites petroleum and minerals resources. Amster- dam. Elsevier.1991. 556

14 陈致林李素娟，周光甲.八面河油田低成熟原油的生物标志物特征和油源.石油技术，1989,2:1-" 8

15 Hardie I. A. Perspectives on dolomitization;Critical view of some current views. J Sed Petrol,1987 , 57 ;166一183.

16 Stumn W, Mergan J J. Aquatic Chemistry, Wiley-Interscience, 1981,780

17 Mucci A. Influence of temperature on the composition of magesian calcite overgrowth precipitated from seawater, Geochim Cos- mochim. Acta ,1987 , 51:1977-1984

18 Morse J W , Makenzie F T. Geochemistry of Sedimentary Carbon- ates.New York;Elsevier.1990. 707

19 朱井泉，祝促蓉. Collins L B.西澳大利亚豪特曼群礁复活节岛群全新世珊瑚礁的海底胶结作用.地质科学，1996,31(3):274 286

20 魏新俊，邵长锋，王饵力等.柴达木盆地西部富钾盐湖物质组分、沉积特征及形成条件研究.北京:地质出版社，1993. 197

21 张水昌，黄汝昌.盐湖盆地沉积有机质中的脱经基维生素E.沉积学报，1990.8(1):57-64

Study of Salinity Evol ution of Geofluids during Syngenesis and Diagenesis Using Composition of Carbonate Minerals

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