Characterization of Low Molecular Weight Hydrocarbons in Jingbian Gas Field and its Application to Gas Sources Identification

Abstract

Chemical and isotopic compositions of C₆-C₇ low molecular weight hydrocarbons (LMWHs) were used to determine the origin of gas in the Ordovician weathered crust (O1m5) reservoir of Jingbian gas field in Ordos Basin, China. GC quantification of LMWHs for 55 gas samples [20 of them from the Xiashihezi Formation (P1x) and Shanxi Formation (P1s) reservoirs, and the rest from the O1m5 reservoir] were conducted. The compound specific stable carbon isotopes of LMWHs for 24 gas samples (five gas samples from the P1s reservoir) were analyzed with GC-C-IRMS. The results show that cycloalkanes are abundant components and their concentrations range from 23.8–52.5% with an average of 41.1% among LMWHs. Methylcyclohexane (MCH) is the most abundant one among normal heptane (n-C₇), MCH and dimethylcyclopentane (DMCP), ranging from 50.1–81.4% with an average value of 71.6%. A¹³C enrichment for nine compounds of C₆-C₇ fraction was observed, and the δ¹³C values range from −25.4–16.3%. Based on the correlation of the Mango parameters (K1 and K2), the relationship of n-C₇, MCH and DMCP and compound specific carbon isotope of C₆-C₇ compounds, the gas in the O1m5 reservoir shares the same origin with that in the P1x, P1s reservoirs, the natural gas in Ordovician weathered crust reservoir and Permian sandstone reservoir sourced from coal measures in Carboniferous and Permian.

Keywords

Low molecular weight hydrocarbon Compound specific isotope Jingbian gas field Gas origin

References

Cai

C.F.

J.F.

and Wu

Y.S.

, 2005. Geochemical characteristics and origin of natural gas and thermochemical sulphate reduction in Ordovician carbonates in the Ordos Basin, China. Journal of Petroleum Science and Engineering 48(3–4), 209–226.

Cai

C.F.

Worden

R.H.

Bottrell

S.H.

Wang

L.S.

and Yang

C.C.

, 2003. Thermochemical sulphate reduction and the generation of hydrogen sulphide and thiols (mercaptans) in Triassic carbonate reservoirs from the Sichuan Basin, China. Chemical Geology 202, 39–57.

Cai

C.F.

Xie

Z.Y.

Worden

R.H.

G.Y.

Wang

L.S.

and He

, 2004. Methane-dominated thermochemical sulphate reduction in the Triassic Feixianguan Formation East Sichuan Basin, China: Towards prediction of fatal H₂S concentrations. Marine and Petroleum Geology 21, 1265–1279.

Chang

C.T.

Lee

M.R.

Lin

L.H.

and Kuo

C.L.

, 2007. Application of C₇ hydrocarbons technique to oil and condensate from type III organic matter in Northwestern Taiwan. International Journal of Coal Geology 71(1), 103–114.

Chen

, 1994. Origin and migration of natural gas in Ordovician reservoir in Shan Gan Ning basin Central gas field. Acta Petrolei Sinica 15(2), 1–10 (in Chinese with English abstract).

Chen

Zhang

and Xu

, 1993. Isotope characteristics and its application of products from hydrocarbon generating thermal simulation experiments on sedimentary rock. Science in China (Series B) 23(2), 209–217 (in Chinese with English abstract).

Chung

H.M.

Rooney

M.A.

, and Claypool

G.E.

, 1991. Thermal maturity of oils. In: Manning

(Ed.), Organic Geochemistry Advances and Applications in Energy and the Natural Environment, Organic Geochemistry, 15th Meeting of the European Association of Organic Geochemists Poster Abstracts, pp. 143–146.

Chung

H.M.

Walters

C.C.

and Buck

, 1998. Mixed singals of the source and thermal maturity for petroleum accumulations from light hydrocarbons: An example of the Beryl field. Organic Geochemistry 29(1–3), 381–396.

Dai

Chen

Zhong

Pang

and Qin

, 2003. Giant Gas Fields in China and Their Genesis. Science Press, Beijing, pp. 93–136 (in Chinese).

10.

Dai

and Xia

, 2000. Research on source rock correlation of the Ordovician reservoir, Changqing gasfield. Earth Science Frontiers 6, 195–203 (in Chinese with English abstract).

11.

Dai

J.X.

, 1992. Identification of different alkane gas. Science in China, Ser.B. 22(2), 185–193.

12.

Dai

J.X.

, 1993. Identification of coal formed gas and oil type gas by light hydrocarbons. Petroleum Exploration and Development 20(5), 26–32 (in Chinese with English abstract).

13.

Dai

J.X.

Luo

Zhang

W.Z.

G.Y.

C.H.

Guo

J.M.

and Ge

S.G.

, 2005. Stable carbon isotope compositions and source rock geochemistry of the giant gas accumulations in the Ordos Basin, China. Organic Geochemistry 36, 1617–1635.

14.

Dai

J.X.

H.F.

and Wang

S.C.

, 2001. Geochemistry of Coal-measure Oil-Gas in China, Reservoiring Conditions and Resource Evaluation of Coal-derived Gas. Petroleum Industry Press, Beijing, pp. 1–159 (in Chinese).

15.

G.Y.

and Li

, 2008. Preliminary study on the origin identification of natural gas by parameters of light hydrocarbon. Science in China Series D: Earth Sciences 51(Suppl.), 131–139.

16.

G.Y.

Shan

X.Q.

and Han

Z.X.

, 2010. The origin of natural gas and the hydrocarbon charging history of the Yulin gas fieldin the Ordos Basin, China. International Journal of Coal Geology 81, 381–391.

17.

T.L.

B.X.

and Zhang

Y.G.

, 1990. The development and application of fingerprint parameters for hydrocarbons absorbed by source rocks and light hydrocarbon in natural gas. Petroleum Exploration and Development 12(4), 375–379 (in Chinese with English abstract).

18.

Huang

Xiong

and Yang

, 1996. Gas source discrimination and natural gas genetic types of Central Gas Field in Ordos Basin. Natural Gas Industry 16, 1–5 (in Chinese with English abstract).

19.

Zhang

W.Z.

Luo

and Hu

G.Y.

, 2008. Paleokarst reservoirs and gas accumulation in the Jingbian field, Ordos Basin. Marine and Petroleum Geology 25, 401–415.

20.

K.Q.

, 1992. Petroleum Geology of China, Vol.12. Petroleum Industry Press, Beijing, pp. 55–76 (in Chinese).

21.

X.Q.

G.Y.

Zhang

A.Y.

and Li

, 2002. The sources of Lower Paleozoic natural gases in central gas field in Ordos. Geoscience 16(2), 191–198 (in Chinese with English abstract).

22.

Liu

Q.Y.

Chen

M.J.

Liu

W.H.

Han

P.L.

and Guo

Y.R.

, 2009a. Origin of natural gas from the Ordovician paleo-weathering crust and gas-filling model in Jingbian gas field, Ordos basin, China. Journal of Asian Earth Sciences 35, 74–88.

23.

Liu

C.Y.

Zhao

H.G.

and Sun

Y.Z.

, 2009b. Tectonic background of Ordos Basin and its controlling role for basin evolution and energy mineral deposits. Energy Exploration & Exploitation 27(1), 15–27.

24.

Mango

F.D.

, 1987. An invariance in the isoheptanes of petroleum. Science 273, 514–517.

25.

Mango

F.D.

, 1990. The origin of light cycloalkanes in petroleum. Geochimica et Cosmochimica Acta 54, 1315–1323.

26.

Mango

F.D.

, 1992. Transition metal catalysis in the generation of petroleum and natural gas. Geochim et Cosmochim Acta 56, 553–555.

27.

Mango

F.D.

, 1994. The origin of light hydrocarbons in petroleum ring preference in the closure of carbocyclic rings. Geochimica et Cosmochimica Acta 58, 895–901.

28.

Mango

F.D.

, 1997. The light hydrocarbons in petroleum: A critical review. Organic Geochemistry 26(7–8), 417–440.

29.

Obermajer

Osadetz

K.G.

Martin

and Snowdon

L.R.

, 2000. Light hydrocarbon (gasoline range) parameter refinement of biomarker-based oil–oil correlation studies: An example from Williston Basin. Organic Geochemistry 31(10), 959–976.

30.

Rooney

M.A.

Claypool

G.E.

and Chung

H.M.

, 1995. Modeling thermogenic gas generation using carbon isotope ratios of natural gas hydrocarbons. Chemical Geology 126(3–4), 219–232.

31.

Rooney

M.A.

Vuletich

A.K.

and Griffith

C.E.

, 1998. Compound-specific isotope analysis as a tool for characterizing mixed oils: An example from the west of Shetlands area. Organic Geochemistry 29, 241–254.

32.

Snowdon

L.R.

and Powell

T.G.

, 1982. Immature oil and condensate-Modification of hydrocarbon generation model for terrestrial organic matter. AAPG 66(6), 775–788.

33.

Sun

Y.Z.

Liu

C.Y.

Lin

M.Y.

Y.H.

and Qin

, 2009. Geochemical evidences of natural gas migration and releasing in the Ordos Basin, China. Energy Exploration & Exploitation 27(1), 1–13.

34.

Ten Haven

H.L.

, 1996. Application and limitations of Mango's light hydrocarbon parameters in petroleum correlation studies. Organic Geochemistry 24, 957–976.

35.

Whiticar

M.J.

and Snowdon

L.R.

, 1999. Geochemical characterization of selected Western Canada oils by C₅–C₈ Compound Specific Isotope Correlation (CSIC). Organic Geochemistry 30(9), 1127–1161.

36.

Yang

J.J.

, 2002. Structural Evolution and Oil-gas Distribution in Ordos Basin. Petroleum Industry Press, Beijing, pp. 130–162 (in Chinese).

37.

Zhang

S.T.

Zhao

H.J.

and Zhang

, 2005. Applications of Mango's light hydrocarbon parameters to petroleum from Tarim basin, NW China. Applied Geochemistry 20, 545–551.

38.

Zou

Y.R.

Cai

Y.L.

Zhang

C.C.

Zhang

X.Z.

and Peng

P.A.

, 2007. Variations of natural gas carbon isotope-type curves and their interpretation – A case study. Organic Geochemistry 38, 1398–1415.