Abstract

Solar Enhanced Oil Recovery: Application to Kuwait's Heavy Oil Fields

Thermal enhanced oil recovery (EOR) is poised to make a large contribution to Kuwait's oil production and reserves. Over 12 billion barrels of heavy oil in shallow sandstone are known in the Lower Fars in North Kuwait (Oskui et al 2009), and the first phase of thermal EOR targeting 60,000 bopd is now in engineering and construction, with targets established of 270 M bopd and above (Sanyal 2009). Large resources in carbonate formations at the Wafra field in the PZ have responded favorably to pilot thermal EOR (Barge et al 2009, Meddaugh et al 2012), and large scale production has been planned with first phase of thermal EOR targeting 80,000 bopd (Chevron 2015).

Thermal EOR creates huge demands for fuel to make steam, and the cost and availability of that fuel has a very strong impact on the economic viability of the production operation. Kuwait currently experiences gas shortages that are driving LNG imports, and power generation requirements are forecast to rise faster than new domestic gas production. The energy required for these new thermal EOR operations adds greatly to requirements for new fuel supplies in Kuwait

Solar steam generation has emerged as a promising large-scale source of energy for thermal EOR operations, with several successful pilot projects now operating in California and the Middle East, and full-field commercial facilities in construction in Oman. Solar EOR replaces gas-fired steam with solar-generated steam, eliminating up to 80% of fuel use. Solar EOR offers large opportunities for reduced production costs and expanded reserves in Kuwait's fields. Kuwait enjoys year-round high levels of solar radiation, allowing solar energy to deliver large reductions in gas used for EOR. Long term solar steam supply without fuel costs will defer "shut-in," extend the economic life and increase ultimate recovery. This creates a triple prize for the Kuwait oil industry: lowered current production costs, expanded current production levels, and increased proven reserves.

The Kuwait desert environment poses unique challenges for solar energy systems, however, with levels of wind, sand, dust and heat beyond the experience and capabilities of many existing solar technologies. Special care must be taken in specifying and planning systems for Kuwait oilfield operation. This paper reviews available data on these subjects and the field experience of solar systems operating in harsh environments.

We review the technical requirements for successful integration of solar energy into these heavy oil developments, and the key technical challenges. Based on these technical requirements the fraction of solar energy is calculated for various scenarios. The results show that solar EOR can economically replace 75% of the gas required for thermal recovery in Kuwait. All of the 75% savings are delivered by direct solar steam generation, which is the simplest and least-cost approach. The results show that "thermal energy storage" – the molten salt systems which have been used in solar electric power generation is not required and adds additional costs and technical risk.

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