“Exploring petroleum inside source kitchen”: Connotation and prospects of source rock oil and gas

Zhi YANG,Caineng ZOU

Table 3 Comparison of main parameters of shale gas in China and abroad.

Gas field Geology Geochemistry Fluid Structure Sed. background Formation Depth/ m Area/km2 TOC>2%, shale thickness/m TOC/ % Ro/ % Organic matter Pressure coefficient CH4/ % Gas/ (m3·t-1) Changing Wide and gentle slope, syncline Deep water, shelf Upper Ordovician - Lower Silurian 2 000- 3 000 2 050 33-46 0.3-7.9 2.4-2.8 Type II 1.4-2.0 96-99 1.9-7.8 Weiyuan Wide and gentle slope, syncline Deep water, shelf Upper Ordovician - Lower Silurian 1 600- 2 900 1415 20-60 0.3-8.2 1.8-2.3 Type II 1.4-2.0 96-99 2.8-3.9 Fuling Box anticline, serious slippage pay zone Deep water, shelf Upper Ordovician - Lower Silurian 2 000- 4 500 600 38-44 1.5-6.1 2.2-3.1 Type II 1.5-2.0 96-99 2.0-5.0 Yanchang shale Wide and gentle slope Shallow water, lake basin Upper Triassic 800- 1 600 2 367 21-66 2.0-10.0 0.8-1.2 Type I, type II1 0.7-1.0 50-80 2.0-8.1 Marcellus Foreland depression and slope, serious slippage pay zone Deep water, shelf Middle Devonian 1 300- 2 600 Southwest 7,000, Northeast 6,900 15-61 2.0-10.0 1.1-3.0 Type II, less type Ⅲ 1.0-1.3 >95 1.7-2.8 Gas field Reservoir Resource Production Pore Porosity/ % Matrix porosity/ % Fracture porosity/% Permeability/10-3 μm2 Brittle mineral/ % Recoverable resource/ 108 m3 Abundance/ (108 m3?km-2) Production/ho- rizontal well/ (104 m3·d-1) Cumulative production/ 108 m3 Yearly production/ 108 m3 Changning Matrix pores and less fractures 3.4-8.4 3.4-8.2 0-1.16 0.000 22- 0.001 9 65-98 3 500 4.38 5.55-27.4 0.80-1.00 25 Weiyuan Matrix pores and less fractures 2.5-9.7 3.4-7.9 0.000 11- 0.000 6 55-98 2 300 4.00 2.30-22.80 0.70-1.00 Fuling Matrix pores and fractures 4.6-7.8 3.7-5.2 0.50-3.30 0.05-0.30 55-75 2000 9.92 5.90-54.70 1.13-2.00 60 Yanchang shale Nano-pores 0.5-4.0 < 0.05 30-50 5 318 2.25 0.20-1.60 Marcellus Matrix pores and fractures 6.0-10.0 5 3.50-4.50 0.13- 0.77 50-70 85 000 6.12 7.10-76.50 Southwest 0.60-3.40, northeast 0.60-5.70 1 590