Review of Segment Quarterly Performance
Since Duncan Energy Partners consolidates the financial results of its controlled operating subsidiaries, the following discussion of segment results presents gross operating margin and volumes on a 100 percent basis, even though the Partnership owns less than 100 percent of these businesses. Gross operating margin is a non-GAAP financial performance measure that is defined and reconciled later in this press release to its most directly comparable GAAP financial measure, which is operating income.
Natural Gas Pipelines & Services – Gross operating margin for the second quarter of 2011 increased 38 percent to $51.2 million from $37.1 million for the second quarter of 2010. Gross operating margin from the Texas Intrastate System increased $14.4 million due to higher firm capacity reservation revenues and increased throughput volumes and fees. Increased natural gas production volumes from the Eagle Ford Shale supply basin resulted in stronger demand for our natural gas transportation services during the second quarter of 2011 compared to the same quarter last year.
Total natural gas pipeline volumes averaged 4.9 trillion British thermal units per day (“TBtus/d”) in the second quarter of 2011, compared to 4.7 TBtus/d recorded in the second quarter of 2010.NGL Pipelines & Services – Gross operating margin for the second quarter of 2011 was $33.0 million compared to $31.6 million reported for the second quarter of 2010. Excluding operational measurement gains and losses associated with the Partnership’s Mont Belvieu storage complex that are allocated to Enterprise Products Partners L.P. (“Enterprise”) through noncontrolling interest, gross operating margin increased 11 percent to $31.1 million for the second quarter of 2011 from $28.1 million for the second quarter of 2010. Gross operating margin this quarter benefited from increased NGL pipeline and fractionation volumes on the South Texas NGL System. Scheduled downtime for maintenance and facility expansion projects negatively impacted NGL pipeline and fractionation volumes on our South Texas NGL System during the second quarter of 2010. NGL pipeline volumes increased 20 percent to 134 thousand barrels per day (“MBPD”) in the second quarter of 2011 from 112 MBPD in the second quarter of 2010. NGL fractionation volumes increased 27 percent to 84 MBPD this quarter from 66 MBPD in the second quarter last year.