Natural Gas Geoscience ›› 2022, Vol. 33 ›› Issue (5): 708-719.doi: 10.11764/j.issn.1672-1926.2022.01.001

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Characteristics of hydrocarbon accumulation and its controlling factors in Jurassic Sangonghe Formation in the east slope of Well Pen-1 Western Depression in Junggar Basin

Liying FEI1(),Shili WANG1,Chang SU1,Yu LIU2,Zuqiang JIANG1,Mengyun YANG1,Yongguang LI1,Haijun PENG1   

  1. 1.Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China
    2.Well Testing Company,Xibu Drilling Engineering Company Limited,CNPC,Karamay 834000,China
  • Received:2021-10-08 Revised:2021-12-13 Online:2022-05-10 Published:2022-05-12
  • Supported by:
    The Major Science and Technology Projects of China National Petroleum Corporation(2017E-0403)

Abstract:

High production of industrial gas in the Jurassic Sangonghe Formation has been obtained in Well Qianshao 2 in the east slope of Well Pen-1 Western Depression, which opens an efficient field of natural gas exploration of slope area. To further determine the main controlling factors and the law of hydrocarbon enrichment, and to deepen the oil and gas exploration of Sangonghe Formation in the region, data from boreholes, cores, experimental analysis and seismology were comprehensively applied to analyze the reservoir types, accumulation characteristics and controlling factors. The study shows that the oil and gas of the Sangonghe Formation mainly migrated from the source rock in the Lower Wuerhe Formation of Permian in the Well Pen-1 Western Depression. There are three stages of faults developed in this area, the third stage faults are in the shape of “Y” in the vertical direction and have a good configuration relationship, which provide good transportation conditions for oil and gas migration from deep strata to shallow Jurassic Sangonghe Formation. The large fault zones in Hercynian Period controlled the plane distribution of Jurassic oil and gas. The reservoir types in the study area are structural-lithologic type and lithologic type, which are controlled by paleogeomorphology, sedimentary facies and faults. The model of hydrocarbon reservoir formation is characterized by “source rock supplying hydrocarbon, multi-stage faults relaying transporting, paleogeomorphology controlling belt, groove controlling sand, faults and sand body controlling reservoir”.

Key words: Junggar Basin, The east slope of Well Pen-1 Western Depression, Sangonghe Formation, Accumulation characteristic, Controlling factor

CLC Number: 

  • TE122.1

Fig.1

Structural location(a) and geological column(b) of the east slope of Well Pen-1 Western Depression"

Fig.2

Reservoir types and characteristics of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

Table 1

Characteristic contrast table of reservoir sand body of the second Member of Sangonghe Formation"

区块岩石学特征结构特征物性特征微观特征
粒度岩性岩屑磨圆分选孔隙度/%渗透率 /(10-3 μm2

孔隙

类型

压汞特征

孔喉

类型

莫17

井区

细中粒、

不等粒

长石岩屑砂岩凝灰岩为主

次棱角—

次圆状

中等

(5.0~17.3)

/11.7

(0.022~265)

/3.74

剩余

粒间孔

排驱压力较低,进汞和退汞效率中等—好,具有明显平台

小孔隙、

细喉道

前哨

井区

细粒、

中粒

长石岩屑砂岩凝灰岩为主次圆状中等—好

(5.0~16.2)

/12.7

(0.014~205)

/3.14

粒间孔排驱压力较低,进汞和退汞效率中等—好,具有较明显平台

小孔隙、

细喉道

Fig. 3

Reservoir characteristics of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

Table 2

Contrast table of reservoir characteristics and fluid property of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

区块中部埋深 /m压力 系数油气藏中部压力 /MPa油气藏中部温度/℃原油密度 /(g/cm3原油黏度(50 ℃) /(mPa·s)天然气相对密度甲烷含量 /%

地层水

矿化度 /(mg/L)

水型
莫17井区4 2020.9940.58104.070.860 815.450.641 287.7421 720NaHCO3
前哨井区4 0120.9938.81100.170.771 20.910.632 289.2418 785NaHCO3

Fig.4

Fluid fitting phase diagram of the first sand layer of the second Member of Sangonghe Formation(J1s21) in Qianshao well area"

Table 3

Statistics of geochemical characteristics of natural gas of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

区块天然气组成C7轻烃组成/%天然气碳同位素/‰
N2/%CH4/%干燥系数正庚烷甲基环己烷二甲基环戊烷CH4C2H6C3H8
莫17井区1.9385.610.8843.2244.7812.00-36.73-26.84-25.44
前哨井区1.5490.370.9341.0144.2114.78-37.08-27.05-26.33

Table 4

Statistics of geochemical characteristics of crude oil of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

区块原油密度/(g/cm3Pr/Phδ13C/‰γ蜡烷/C30藿烷萜烷峰型C29αα20S/(20S+20R)C29αβ/∑C29油源
莫17井区0.860 81.36-29.960.18弱上升0.520.57P2w
前哨井区0.771 21.61-29.160.15山峰型0.510.55P2w

Fig.5

Sedimentary profile of the second Member of Sangonghe Formation in wells Mo107-Mo002 (see A-A’ profile position in Fig.1)"

Fig.6

Palaeogeomorphology before sedimentation of the second Member of Sangonghe Formation in the east slope of Well Pen-1 Western Depression"

Fig.7

Plane distribution map of sedimentary facies(J1s21) in the east slope of Well Pen-1 Western Depression"

Fig.8

Profile showing the interpretation result of seismic and geology across wells Qianshao1-Qianshao2-Mo011 (see B-B’ profile position in Fig.1)"

Fig.9

Hydrocarbon enrichment zones in the east slope of Well Pen-1 Western Depression"

Fig.10

Hydrocarbon accumulation models in the east slope of Well Pen-1 Western Depression(see C-C’ profile position in Fig.1)"

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