2012-12-12_REVISION - P2010026 (3)

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4. Possible changes in the structural strength of the crown due to heating 5. Extent of temperature and pressure front propagation during heating 6. Static geomechanical conditions 7. Heating induced changes in geomechanical conditions. The intervals to be heated were selected to test Shell's heating technology under different subsurface conditions (i.e., kerogen richness, nahcolite and other mineral concentration, and clay content). The goal is to assess the impact of different subsurface environments on heater performance and the temperature variation along the heated section. The top heated section has a crown thickness (distance from dissolution surface) of 180 ft. To minimize production and temperature (and consequent pressure) rise, the heated sections are placed far apart from each other (more than 50 ft) such that there is no temperature superposition between the three heated zones. Nahcolite (NaHCO near the upper most heater will begin to convert above —200 °F to soda ash (Na with water (steam) and CO being released as a result of the mineral decomposition. Initially, kerogen will swell as bitumen is generated during the early, lower temperature phase of pyrolysis. With further heating, kerogen conversion will release water, gas, and liquid hydrocarbons. The volume of nahcolite converted to soda ash along the uppermost heater is estimated to be approximately 1,200 to 1,500 tons. The soda ash will remain in place and could be recovered later. The lower two heaters will be located in intervals with only minor amounts of nahcolite being present. As such, the additional volume of nahcolite converted to soda ash in these intervals is considered to be insignificant. The ELHT predictive reservoir modeling suggests the pyrolysis zone extends to about 2 ft around the individual heaters. Minimal production is expected. The average reservoir pressures in the heated zones will be below the fracture propagation pressure. In addition, the depth of the heaters ( >2,220 ft) provides sufficient crown thickness (180 ft) for containment. Hence crown integrity risks are negligible for the ELHT pilot. 5.53 Production Monitoring The heater wells and the observer /producer well will be instrumented with pressure gauges and temperature sensors. Progress of heating will be monitored by temperature sensors along each heater well. The heater package installed in each heater well consists of MI heater cables attached to an electric cable and instrumentation to measure the temperature along the heater conveyed downhole inside a metal canister. Heaters will be activated and controlled from surface with electrical power supplied via a high voltage substation. During the ELHT oil production is estimated to be small in volume. The observer /producer will be equipped with an artificial lift system to remove accumulated liquids (oil and water). Produced 2 Water in the form of Steam and CO2 will report to the gas phase of the separator at the East RDD, at surface where steam will cool to water and CO2 will be vented. 13