40 th Anniversary Chemical Characteristics of Geothermal Fluids in Jiaodong Peninsula, Shandong, China. Tingting Zheng Student UNU GTP

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1 40 th Anniversary Chemical Characteristics of Geothermal Fluids in Jiaodong Peninsula, Shandong, China Tingting Zheng Student UNU GTP

2 Contents Geothermal developments in Shandong, China The Shandong area Results Next steps

3 Geothermal developments in Shandong

4 Problems of geothermal resource development Water level decline and temperature changes 0.00 Beijing Shandong Water level depth(m) 2.1/ / / / / / / Water level Temperature Temperature( ) Low to medium temperature: < 150 Over extraction has occurred and induced some corresponding environmental issues, including continuous water level decline, colder water intrusion, temperature drop, etc. Main reasons for issues: Reservoir recharge, runoff and discharge conditions are not clear enough Lack of reinjection or rapid reinjection rate decline Previous calculations of geothermal fields production potential were not based on the restrictions set by water level and temperature drawdown

5 Objectives of study Classification of reservoirs based on renewability Beijing Shandong Ⅲ Heze Reservoir Hebei Dezhou Urban Reservoir Ⅱ Semi-Open Reservoir Ⅲ ClosedReservoir Ⅰ Jiangsu Bohai Sea Ⅰ 0 50km Wenshitang Reservoir Yellow Sea Yellow Sea My study focus on solving these problems and preventing new issues occurring: Build up a classification based on reservoirs renewability Study factors influencing renewability and sustainable utilization Use case studies to show how to assess sustainable yield

6 Materials and Methodology (1) Regional geological and hydrogeological survey (2) Hydro chemical and isotope sampling and analysis of geothermal water (3) Pumping test, reinjection and tracer test (4) Measuring geothermal water level, temperature and quality, together with production rates (5) To understand recharge, runoff and discharge conditions through hydrogeological survey, hydro chemical and isotope analysis, as well as regimes observation and pumping test (6) To find out the potential risk of cooling and clogging of long term reinjection through reinjection and tracer tests and long term monitoring of temperature, water level and chemistry (7) To determine the factors influent sustainability quantitively, and then to evaluate the reservoir s open degree as open, semi open and closed (8) Modeling for sustainable yield and optimize production for Open, Semi open and Closed reservoirs

7 The Shandong area

8 Research area background Geological setting Henan Hebei Liaocheng Heze Q 116 Dezhou Anhui Jining O 微 117 Sandstone reservoir Jinan Ar 山 Arγ Arγ Taian Laiwu 湖 Pt1γ O Pt1γ Binzhou Pzγ Arγ Zibo Pt2γ Zaozhuang P Ar Limestone reservoir Q T K C J N+E O K O Pt3 Granite or metamorphic rocks P K C Linyi Q Q Mzγ Dongying Ar Weifang N+E Pt1γ Arγ Ar Mzγ Pt3 O K Jiangsu K Pt3γ Mzγ Bohai Sea K K Pt1 Pt3γ Rizhao Q Qingdao Huanghai Sea 0 Huanghai Sea N+Q Pt1γ Pt1 Arγ Pt3γ Z 12 Yantai Weihai Arγ 1 K Z Pt Mzγ 11 Pt3γ 5 Pt2ν Arγ Mzγ Ar Pt1γ 3 Mzγ Arγ Arγ 7 6 Pt1 9 Pt3γ Pt1 Pt3γ Pt1 8 4 Mzγ Mzγ Mzγ Pt1 Mzγ Pt1 Mzγ K Mzγ Q N+E K J T P C Huanghai Sea Simplified Geological map of Shandong Province 34km 15 O Pt3 Pt1 Ar Mzγ Pzγ Pt3γ Pt2γ Pt1γ Arγ K Main aquifers: Sandstone(Neogene) Distribution: Northwestern Shandong sedimentary plain, conduction dominated Main aquifers: limestone (Cambrian and Ordovician) Distribution: Southwestern Shandong Plain and middle Shandong uplift, conduction dominated Main aquifers: Granite and metamorphic rocks Distribution: Shandong Peninsula, Controlled by: Neotectonic and large deep faults, convective heat flow Beijing Shandong

Geothermal fields distribution in Shandong Provience 16 hot springs mainly distributed in Shandong

9 Research area background Distribution of geothermal fields Heat Flow map of Shandong Province (mw/m2 Partial data from JIANG G Z, et al Geothermal fields distribution in Shandong Provience 16 hot springs mainly distributed in Shandong Peninsula, with temperatures ranging from 50 to 100 Ԩ. More than 150 geothermal wells have been successfully drilled in Shandong Province, with temperatures between 40 and 100 Ԩ

10 General reservoir characteristics Open reservoir N Hot spring Terrestrial heat flow NW (water-transfer fault) NE (heat-transfer fault) 10km Controlled by: Neotectonic large and deep faults Convective heat flow Main aquifers: Granite and metamorphic rocks Manifestations: Geothermal springs ( o C) Distribution: Shandong Peninsula Ground water age: Most less than 1000a, some can be around 10000a

11 Results

12 Why? Chemical characteristics of geothermal fluids Understanding of the mechanism of reservoir formation, including origin of water, mixing processes, runoff and discharge conditions is not clear enough Reservoir temperatures assumed before are not very credible Water rock interaction processes are mostly ignored in previous studies

Chemical characteristics of geothermal fluids Open reservoirs- Jiaodong Peninsula SO 4 2- + Cl - Ca 2+ + Mg 2+ EXPLANATION hot spring surface water Colder ground water Mixed geothermal water Sea

13 Chemical characteristics of geothermal fluids Open reservoirs- Jiaodong Peninsula SO Cl - Ca 2+ + Mg 2+ EXPLANATION hot spring surface water Colder ground water Mixed geothermal water Sea water Mg 2+ Na + + K + CO HCO 3 - SO 4 2- Ca 2+ Cl - Strata: intrusive rocks, metamorphic rocks, cretaceous sediments, volcanic accumulation and loose deposits of the Quaternary period So far, 16 hot springs were found, all flow out in points formed at the cross positions of the structures The strikes of faults that controlled the formation of hot springs occur in four types: NE, NW, NNE and NNW

14 Chemical characteristics of geothermal fluids Origin of geothermal water Concentration counter map of Cl in geothermal water, Jiaodong Peninsula Variation of B with Cl (in ppm) in surface water, geothermal water and mixed shallow colder water

15 Chemical characteristics of geothermal fluids Origin of geothermal water Open reservoirs mainly recharged by modern atmospheric precipitation mixed with seawater or shallow groundwater Controlled by deep faults with NNE strike and the distributions of Mesozoic intrusive rocks

16 Chemical characteristics of geothermal fluids Mixing of shallow water and secondary minerals formed Mg Variation of SO 4 2 with Cl (in ppm) in surface water, geothermal water and mixed shallow colder water Variation of Mg with Cl (in ppm) in surface water, geothermal water and mixed shallow colder water

17 Chemical characteristics of geothermal fluids Temperature distribution Counter map of SiO 2 in geothermal water, North eastern of Shandong Province

18 Next steps

19 Next steps Organic Rock leaching air Geothermal water Rain Equilibriums, Temperature Origins Other source: seawater, surface water, groundwater, etc. (1) Study equilibria of secondary minerals, estimate reservoir temperature and waterrocks interaction; Deep gas Secondary Minerals (2) Quantify the variable water sources and mixing.

20 Add chemistry information to the conceptual model Recharge Precipitation Surface water Reinjection well Q Production well Q Seawater Depth Shallow water Mixing 150 Reservoir parameters 200 Thermal gradient Reservoir parameters Mixing Water rock interaction Heat flow Sketch map of conceptual model

21 Acknowledgements SDGM Shandong Provincial Bureau of Geology & Mineral Resources

22 Thank you! 谢谢!

THE CHEMICAL CHARACTERISTICS OF GEOTHERMAL FLUIDS IN JIAODONG PENINSULA, SHANDONG, CHINA

Orkustofnun, Grensasvegi 9, 40 th Anniversary Workshop IS-108 Reykjavik, Iceland April 26 2018 THE CHEMICAL CHARACTERISTICS OF GEOTHERMAL FLUIDS IN JIAODONG PENINSULA, SHANDONG, CHINA Tingting Zheng Shandong