It’s been a good time to be an NGL molecule.

Your output was high enough, your demand was strong enough and, doggone it, energy traders liked you.

Except for you, ethane. You endured more of a compare-and-despair couple of months.

The hypothetical NGL barrel at Mont Belvieu, Texas, climbed above $35 as June began to its highest mark since mid-October 2014—a 43-month stretch. Isobutane was exceptionally strong, leaping to $1.41 per gallon (gal), its highest price since mid-February 2015, or 51 months.

But while many NGL have experienced price hikes, ethane has struggled. Its Mont Belvieu price remained static while the price of natural gas rose slightly, squeezing its margin and pulling it below 6 cents/gal before rebounding to 7 cents/gal as May ended.

All this was despite the restart of the Mariner East 1 Pipeline that connects the big Marcellus and Utica plays to Marcus Hook, Pa., outside Philadelphia.

Traders are skittish about ethane demand, in part because Chevron Phillips Chemical Co. LP, experiencing an ethane surplus, announced that it would idle its Sweeny No. 22 cracker, located at the Phillips 66 Co. refinery at Old Ocean, Texas, near Freeport. By itself it’s not a big deal, but it symbolizes the malaise surrounding ethane.

“The ethylene surplus that Chevron Phillips is facing is emblematic of the industry-wide surplus of ethylene facing many U.S. petrochemical producers,” En*Vantage wrote in a second-quarter report.

Sweeny #22 is the smallest and highest-cost cracker that Chevron Phillips operates, but its closing means that ethane cracking demand is diminished at a time when low natural gas prices are spurring higher ethane extraction in the Permian Basin, Rockies and Midcontinent, En*Vantage added.

Given that other ethane crackers ran at full tilt and ethane exports from Enterprise Products Partners’ Morgan’s Point ethane terminal on the Houston Ship Channel are strong, the drop in prices signals a market overreaction, the analysts concluded. Traders also failed to take into account the near-term demand boost from ExxonMobil Corp.’s 3.3 billion pound-per-year ethane cracker in Baytown, Texas, on track to be operational by the middle of 2018.

Meanwhile, the strong isobutane prices could indicate an outage of a splitting tower at Mont Belvieu, En*Vantage speculated. The analysts also noted reports of fractionator shutdowns for planned maintenance at the large NGL hub east of Houston.

Joseph Markman can be reached at or 713-260-5208.