"While the price of crude oil remains low, it may become increasingly difficult for energy upstream companies to service debt," Market Realist's Alex Chamberlin said over the weekend in answer to his own question of whether US oil and gas companies had "leveraged themselves out".
"Those who have recently incurred huge debts will be more vulnerable since lower crude oil prices affect revenues and cash flows negatively."
From Q4 2009 to Q4 2014, Australia Pacific LNG upstream operator ConocoPhillips' total long-term borrowing decreased 17%, Chamberlin said.
Long-term borrowings are those repaid over more than one year.
However, the company recently increased its debt burden. From Q4 2013 to Q4 2014, ConocoPhillips' net debt, or long-term and short-term debt less cash reserves, increased 16% to $US17.5 billion ($A22.63 billion).
"The company's debt-to-capitalisation currently stands at about 30% and has remained little changed from 31% in Q4 2009," Chamberlin said.
Total capital includes the company's debt and shareholders' equity.
ConocoPhillips is a Houston-based explorer, producer and marketer of crude oil, natural gas, natural gas liquids, LNG and bitumen, operating primarily in North America, Europe, Asia and Australia.
ExxonMobil's debt load has also increased, having sold $8 billion in debt on March 3 in what was one of the highest debts raised by energy companies since July 2014.
Proceeds from the bond sale may be used to fund general corporate purposes, including acquisitions, capital expenditures, and refinancing.
From Q4 2009 to Q4 2014, Exxon's total long-term borrowing increased 63%. Long-term borrowings are repaid over more than one year.
From Q4 2013 to Q4 2014, the super major's net debt, or long-term and short-term debt less cash reserves, increased 36% to $24.5 billion.
Exxon's debt-to-capitalisation currently stands at about 14%, an increase from 7.6% five years ago.
Chevron has also raised significant debt in recent times, most recently selling $6 billion of bonds last month, which was the biggest offering by the super major since the price of crude oil halved since July.
"Chevron is a reminder that all energy companies aren't created equal," Scott Carmack, a money manager at Portland, Oregon-based Leader Capital, which oversees $1.5 billion in fixed-income assets, told Bloomberg when the deal occurred.
"They are a behemoth of a company that is built for the long haul. Investors have no problem lending to them."
