full year of 2012. For the entire company, operating costs for the nine months were $13.64 per barrel, compared to $14.99 for the full year of 2012.
For the third quarter of 2013, daily oil and gas production volumes averaged 767,000 BOE, compared with 766,000 BOE in the third quarter of 2012. Increased domestic production of 7,000 BOE per day was offset by lower Middle East/North Africa production resulting from lower cost recovery barrels. Daily sales volumes were 765,000 BOE for both the third quarter of 2013 and the third quarter of 2012. Sales volumes differed from production volumes due to the timing of liftings in Oxy’s international operations.
Oxy’s realized price for worldwide crude oil increased almost 8 percent to $103.95 per barrel for the third quarter of 2013, compared with $96.62 per barrel for the third quarter of 2012. Domestic crude oil prices increased by over 13 percent in the third quarter of 2013 to $104.30 per barrel, compared to $91.97 per barrel in the third quarter of 2012. Middle East/North Africa crude oil prices and worldwide NGL prices were virtually flat on a year-over-year basis for the third quarter of 2013. Domestic gas prices increased by 32 percent in the third quarter of 2013 to $3.27 per MCF, compared with $2.48 in the third quarter of 2012.
On a sequential quarterly basis, worldwide realized crude oil prices increased 6 percent and worldwide realized NGL prices increased approximately 5 percent. Also on a sequential quarterly basis, domestic crude oil prices increased by about 10 percent, domestic gas prices decreased by over 14 percent and Middle East/North Africa oil prices increased slightly.
Chemical
Chemical earnings for the third quarter of 2013 were $181 million, compared with $162 million in the third quarter of 2012. The improvement in the third quarter 2013 results was primarily due to higher margins in polyvinyl chloride and vinyl chloride monomer.
Midstream, Marketing and Other
Midstream segment earnings were $212 million for the third quarter of 2013, compared with $156 million for the third quarter of 2012. The increase in earnings reflected improved marketing and trading performance and better results in the pipeline, gas processing and power generation businesses.
NINE-MONTH RESULTS
Net income for the nine months of 2013 was $4.3 billion ($5.28 per diluted share), compared with $4.3 billion ($5.25 per diluted share) for the same period in 2012. Year-to-date 2013 core income was $4.2 billion ($5.23 per diluted share), compared with $4.3 billion ($5.26 per diluted share) for the same period in 2012.
Oil and Gas
Oil and gas segment earnings were $6.4 billion for the nine months of 2013, compared with $6.6 billion for the same period of 2012. Higher domestic oil and gas prices, domestic liquids volumes and lower operating costs were more than offset by lower Middle East/North