3.2 Floating Roofs——【采油专业英语文献阅读】.pdf

1 2.0 Pipeline Types of pipeline Flow line Gathering pipeline Trunk/transmission line Distribution pipeline Flow line system Tank battery LACT, lease automatic custody transfer unit 2 3.1 Storage Facilities Storage facilities are an important element in all pipeline and tanker transportation system Allows for flexibility in operation Minimize the unwanted fluctuation in pipeline throughput and product delivery The capacity of storage varies Covers both aboveground storage and belowground storage 3 3.1.1 Crude Storage At each step in the pipeline gathering and delivery system, varying storage requirement exist. Flow line ----LACT Storage between gathering line and trunk line Storage at the terminal of a trunk line (Refinery or an export terminal) Refinery storage allows the refinery to operate at a relatively constant throughput 4 3.1.1 Crude Storage Refinery storage for feedstock and product Product delivery Refinery complexity Seasonal demand Turnaround According to one resource, a refinery that is supplied by pipeline should have 6 days of crude feedstock storage; if supplied by tanker, 32-35 days of storage is recommended. 5 3.1.1 Crude Storage Tanker terminal storage The amount and type of product handled The number, capacity, and type of tanker berth in the terminal Expected periods of downtime The number and size of ships using the terminal 6 3.1.1 Crude Storage Crude StorageCylinder, Operated at near atmospheric pressure Small lease tank, shop-fabricated Large crude storage tank, built on the site Floating roof or fixed roof Underground storage Underground caverns mined from salt domes or other foundations Strategic oil storage 7 3.1.2 Natural Gas Liquid Storage Natural Gas Liquid Storage Overcome the fluctuation of pipeline throughput Stored in pressurized tanks or vessels Stored in underground cavern 8 3.1.3 Natural Gas Natural Gas Liquid Storage Natural gas storage is needed to meet peak demands that may be much higher than the pipelines average throughput Underground rock or sand reservoir Suitable permeability and porosity Example, depleted oil or gas field 9 3.1.3 Natural Gas Natural gas storage operation Some natural gas in the reservoir must be used as “cushion gas” to allow withdrawal and injection of usable gas Criteria for storage site selection Near consuming center Reservoir conditions 10 3.1.4 LNG LNG storage is a way to compactly store natural gas The volume is reduced to 1/600 Location of LNG storage Base-load plant Terminal plant Peak-shaving plant 11 3.1.4 LNG LNG is stored at low temperature of -260F Insulation is needed for all kinds of LNG storage Frozen earth storage, refrigerant is circulated to freeze the cavity, not commonly used Above ground LNG storage tanks, double walled Above ground LNG storage Used in the majority of LNG peak-shaving and base-load plants Sent to vaporizer to regasifies the natural gas before delivery 12 New Words and Phrases Tankers berth in the terminal Cushion gas Depleted field Suitable permeability and porosity Strategic Petroleum Reserve Underground salt dome 13 2.0 Pipeline Crude trunk line Initial station, booster station Friction, changes in elevation Gas transmission line field-processing facility, dry and clean gas Utilities, take custody of the gas from transmission line and distribute through small pipeline to individual customers Product pipeline Batch operation 14 3.2.1 Tank Classification No universal method for tank classification Classification based on internal pressure Atmospheric tanks Atmospheric pressure psig Low-pressure tanks Atmospheric pressure 15 psig Pressure Vessel 15 psig 15 3.2.2.1 Fixed-roof Tanks Why different types of closure (roof and bottom) are used? The tank builder need to find the shape suitable for pressure containment 16 Pressure Flatdomedomesphere 3.2.2.1 Fixed-roof Tanks Cone-roof tanks 17 Cylindrical Shell Flat bottom Cone roof Roof rafter and support column 18 Cylindrical Shell Flat bottom Shallow cone roof Roof rafter and support column 3.2.2.1 Fixed-roof Tanks Umbrella-roof tanks 19 Cylindrical Shell Umbrella roof Self-supporting structure Segmented section 3.2.2.1 Fixed-roof Tanks Dome-roof tanks 20 Cylindrical Shell Dome roof Approximate a spherical surface 3.2.2.1 Fixed-roof Tanks Geodesic Dome-roof tanks 21 Cylindrical Shell Geodesic Dome roof 3.2.2.2 Floating-roof Tanks A cover that floats on the surface of the liquid. 22 The shell and bottom are similar to those of an fixed-roof tank Internal floating roof tank (IFR) External floating roof tank(EFR) 3.2.2.2 Floating-roof Tanks Internal floating roof tank 23 The IFR tanks can operate at or above atmospheric pressure in the space between the floating roof and the fixed roof 3.2.2.2 Floating-roof Tanks External floating roof tank 24 EFR tanks have no vapor space pressure associated with them and operate strictly at a。