Tar Sands
Transcription
Tar Sands
4/29/2015 Unconventional Resources 2 4 Coal Bed Methane Water/Gas production history Coal is the most abundant fossil fuel Produce Methane adsorbed to coal surfaces Fundamentally different from free gas in pore space Coal stores 6 times more gas than a conventional reservoir by volume Gas content is 100-800 SCf/ton of coal Economic production from 0.5 ft-thick coal is possible Coal bed methane production model Coals has fractures (cleat) Pump out water to lower pressure Gas will desorb Coal Bed Methane Extraction Drill well Pump water out to decrease pressure Produce desorbed gas Water Production 170K bbls/day 1 Million bbls/day 1 4/29/2015 Coal-Bed-Methane Produced Waters Athabaska Tar Sands (or oil sands) Reserves: 1.7 trillion barrels (assuming 10% recovery) Venezuelan Oil Sands: 500 billion barrels The Oil Sand Crude: Bitumen 11 Tar Sands Tar Sands- Strip Mining 12 2 4/29/2015 Canadian Tar Sand Production Tar Sand Extraction method Open Pit Mining Crush Mix with hot water Bitumen floats (60% bitumen, 30%water, 10% solids) 1200 SCF of gas needed to process 1 bbl of bitumen (about 5x energy gain) Upgrading: remove water, sand, impurities, sulfur, catalytic hydrocracking, hydrogenation 16 Bitumen Separation Cell, Alberta Canadian Oil Data Total Production 2,600,000 Barrels/Day Exports to US 2,500,000 Barrels/Day Today, about half is from the Oil Sands #1 foreign supplier for USA Suncor Energy Inc. Steam Assisted Gravity Drainage (SAGD) Proposed Keystone Pipeline Burn some of the oil to extract the rest Japan Canada Oil Sands Limited (JACOS) 15 3 4/29/2015 Oil Shale Kerogen-rich immature shale Heating the shale releases oil by pyrolisis Oil Shale Production Method Mining and crushing Retorting Oil Upgrading Refining Green River Shale- USA Economics Viable at $70 to $95/bbl in USA Energy Produced/Energy Used = 3 to 4 Environmental impact is significant Water usage is a problem Green River Shale Resource Disposal and reclamation Stuart Oil Shale Facility, Queensland, Australia 1.2 to 1.8 trillion barrels in place Recoverable? Global Resource: 2.8 to 3.3 trillion barrels 4 4/29/2015 In-Situ conversion (unproven) Stability Electric heaters in holes 2-3 years heating to 650-700 degrees C www.nrcan.gov Methane Hydrates (Clathrates) Why the Interest in Gas Hydrates? Safety: Hydrates plug flowlines Hydrates can be geohazards for submarine structures Resource: Methane Hydrates are a source of natural gas Environmental: Sensitive Communities use hydrates as food Methane Hydrates can contribute to global warming 29 Impact on Production Facilities Crystal Structures 1 mole methane for 5.75 moles water 1 liter hydrate= 168 liters methane at STP Hydrates Form On Exterior of Subsea Equipment Heat From Buried Pipelines Cause Hydrate Dissociation Hydrates Dissociation Affects Foundation of Surface Facilities? Heat From Production Wells Causes Hydrate Dissociation Modified from Boatman 30 5 4/29/2015 Resource Gas Seeps on the Seafloor Twice the amount found in all fossil fuels How can we produce it? hydrate Bottom-Simulating Reflector (BSR) Off Shore Brazil Sea water BSR Hydrate zone Free Gas zone Take Home Points Coal bead methane (CBM) is adsorbed to coal Disposal of produced water is one of the main challenges for CBM Tar sands require open pit mining and have high energy costs Environmental impact of Tar sands is considerable but reserves are large Oil shale production is technically possible but not economical now Gas hydrates are abundant but we don’t have the technology to produce them efficiently Gas Hydrate Occurrence 6