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BEÅ CHÖÙA Baøi taäp Chöông 2 THE RESERVOIR TAÀNG CHÖÙA SECTION 01 Caâu 1 a Sketch the three basic types of pore structure which contribute to the total porosity of a rock Haõy veõ ba loaïi cô baûn cuû[.]
Bài tập Chương 2: THE RESERVOIR: TẦNG CHỨA SECTION 01 Caâu 1: a Sketch the three basic types of pore structure which contribute to the total porosity of a rock … Hãy vẽ ba loại cấu trúc lỗ rỗng tạo nên độ rỗng tổng loại đá b Which type(s) contribute to effective porosity? Loại tạo độ rỗng hiệu dụng? Câu 2: In each numbered box fill in the name(s) of the kinds of common pores associated with the origin given: Hãy điền vào khung bên tên loại lỗ rỗng thường liên quan đến nguồn gốc cho TYPES PRIMARY 1) 2) SECONDAR Y 3) ORIGIN AT TIME OF DEPOSITION REPLACEMENT 4) 5) 6) SOLUTION TECTONICS, etc Caâu 3: What two factors effect the rate of flow of a fluid through a rock? Hai nhân tố có ảnh hưởng đến dòng chảy chất lưu qua đất đá? Chua Caâu 4: What effect does grain size have on porosity? Kích thước hạt có ảnh hưởng đến độ rỗng? Câu 5: What effect does grain size have on permeability? Kích thước hạt có ảnh hưởng đến độ thấm? Câu 6: What effect does sorting have on permeability? Porosity? Độ chọn lọc hạt có ảnh hưởng độ thấm? Độ rỗng? Câu 7: The current which deposited the block of sandstone moved from left to right In which direction would permeability be highest? And lowest? Dòng chảy trình trầm tích đá cát kết có chiều từ trái sang phải Theo phương có độ thấm lớn nhất? Và nhỏ nhất? Câu 8: Draw porosity/depth gradients for: a A clean quartz sand; an arkosic sand; and a volcaniclasstic sand b An arkose in areas of high and low geothermal gradients c What two factors can help preserve porosity at depth? Hãy vẽ gradient độ rỗng - chiều sâu cho: a Cát thạch anh tinh khiết; cát arkosic; cát vụn núi lửa b Đá arkose nằm vùng có gradient địa nhiệt cao thấp c Hai yếu tố giúp việc bảo tồn độ rỗng xuống sâu? Câu 9: Draw on this graph the distribution of porosity: permeability data which may be expected for a sandstone formation which is cemented by kaolin in one area, and illite in another Vẽ biểu đồ phân bố độ rỗng: số liệu độ thấm có thành hệ cát kết, bị ximăng hoá kaolin khoảnh illite khoảnh khác Câu 10: What are the petrophysical difference commonly found between primary and secondary dolomite? Giữa dolomit nguyên sinh dolomit thứ sinh nhìn chung có điểm khác đặc tính thạch học? Câu 11: In what way(s) can basement rocks become reservoirs? Đá gốc trở thành đá chứa nguyên gì? Câu 12: On this graph show the position of: Shale A fractured granite A vuggy limestone (with vugs isolated), (vugs connected) An uncemented sand A chalk Từ hình bên xác định vị trí của: Đá phiến sét Đá granite nứt nẻ Đá vôi hang hốc (hang hốc không liên thông, liên thông) Cát ximăng Đá phấn Câu 13: The reservoir of this oil field consists of an upper barrier bar sand sequence interbedded with shales, and a lower part of interbedded shales and channel sands They were deposited on a westerly sloping shoreline a In which direction in the optimum reservoir continuity likely to be in zones A, B, C, and D? b How and why might the porosity in zone B differ from D? Một tầng chứa dầu bao gồm phần doi cát dạng phân nhịp, bao quanh đá sét, phần bên bao quanh sét cát lòng sông Tầng chứa lắng đọng nghiêng theo hướng tây đường bờ a Theo hướng bể chứa có liên thông tốt đới A, B, C, D? b Như có khác độ rỗng đới B D? Câu 14: Why carbonate reservoirs frequently present more development problems than sandstone ones? Tại phát triển mỏ tầng chứa carbonat thường xuất nhiều vấn đề tầng cát kết? SECTION 02 I Rock properties Self Assessment 1 porosity is formed when a sediment is deposited (A) Primary (B) Secondary (C) Tertiary 2 Intergranular porosity is more typical of _ (A) Limestones (B) Sandstones (C) Dolomites 3 As a secondary porosity type, porosity is developed where there is a gap in the rock framework larger than the normal grain-supported pore spaces (A) Fracture (B) Fenestral (C) Intercrystalline (D) Moldic 4 The unit of permeability is: (A) Cubic meters (B) Centipoise (C) Darcy (D) Barrels/day 5 Which of these rock properties are generally unaffected by grain size? (A) Permeability (B) Porosity (C) Permeability and porosity 6 What type of sand is most likely to have relatively high porosity and permeability? (A) Well sorted sand (B) Poorly sorted sand (C) Grain sorting is unrelated to porosity and permeability 7 Most quartz grains are: (A) spherical (B) cubical (C) slightly elongated (D) hexagonal II Diagenesis Self Assessment 1 With other factors equal, for which of these geothermal gradients would you expect to see the greatest rate of porosity reduction with depth? (A) Geothermal gradient = 3.3 deg C per 100 m (B) Geothermal gradient = 3.0 deg C per 100 m (C) Geothermal gradient = 2.7 deg C per 100 m 2 Which of the following minerals provides the major intergranular cementation? (A) Calcite (B) Kaolonite (C) Illite (D) Silica 3 Which of these processes in NOT generally involved in the creation of secondary porosity in sandstones? (A) Destruction of quartz material through tectonic activity (B) Leaching of carbonate cements and grains (C) Leaching of unstable detrital materials 4 What is a typical porosity range of sand at the time of deposition? (A) 40-50 percent (B) 25-35 percent (C) 15-25 percent 5 is a mixture of calcium and magnesium carbonate (A) Aragonite (B) Montmorillonite (C) Dolomite (D) Calcite 6 Lime sands and skeletal carbonates have initial porosities of: (A) to 10 percent (B) 15 to 25 percent (C) 30 to 40 percent (D) 45 to 50 percent 7 Which one of these statments is TRUE? (A) Dolomites are only formed by 'dolomitization', the replacement of pre-existing calcium carbonate deposits (B) Secondary dolomites are often coarsely crystalline, and have intercrystalline porosity that may exceed 30% (C) When dolomite replaces calcite, there is an increase in the rock's bulk volume 8 Which of the following can NOT be a reservoir rock? (A) Dolomite (B) Granite (C) Salt (D) Shale Submit Your Answers III Reservoir continuity Self Assessment 1 In general, where most oil accumulations occur? (A) Heterogeneous reservoirs with permeability barriers (B) Laterally continuous reservoirs with uniform porosity and permeability distributions (C) Reservoirs in which the gross and net pay thicknesses are roughly equal 2 Fluvial and deltaic sands trend to form type reservoirs (A) sheet (B) belt (C) dendroid (D) ribbon (E) isolated pods 3 In isolated sand bodies, oil entrapment _ (A) can only be structural (B) can only be stratigraphic (C) can be structural or stratigraphic