It's a busy week on the corporate front, with a number of companies releasing quarterly updates for investors to sink their teeth into. Coming to ‘black gold’, British energy major BP plc BP kicked off the quarterly results season for the top global integrated oil firms with some good news – a profit surprise, sustained dividend payout, and progress on its cost-cutting drive – for the sector’s beleaguered investors.One of the world’s largest investor-controlled oil and gas groups, BP, also reassured investors that it could lower costs further by restricting total organic capital expenditure for 2016 to around $17 billion.Sector investors have been worried after oil’s horror show threatened the industry’s creditworthiness by hurting cash flows, drying up liquidity and narrowing profit margins. Moreover, weak realizations are restricting the companies' internally generated cash flow amid high capital spending and dividend payments (if any). What’s more, the outlook remains grim too, with fundamentals suggesting that the odds are firmly stacked against a sustained crude rally.Outlook for ‘Big Oil’ EarningsThough BP’s results were ahead of forecasts and oil has clawed its way back over $40 a barrel since falling to a 12-year low in mid February, the outlook for supermajors remains bleak to say the least with analysts expecting sharp fall in top and bottom lines. Another round of spending cuts can’t be ruled out amid the majors’ efforts to step up efficiency and improve cash flows. Importantly, there are signs of unexpected weakness in the refining business, suggesting that the units – which had saved them when crude prices plunged – could now be a drag.Among the integrated stocks slated to report this week, let’s take a sneak peek at two of the biggest domestic energy behemoths to see how things are shaping up for the upcoming quarterly results.The largest U.S. oil company by market value, Exxon Mobil Corp. XOM is set to release its first-quarter 2016 results before the opening bell on Friday, Apr 29. With crude prices being low, Exxon Mobil’s upstream division has been able to extract less value for its products. This has stressed the group’s profit margins. Exxon Mobil is also suffering from marginal or falling returns, reflecting its struggle to replace reserves, as access to new energy resources becomes more difficult. Given the large base, achieving growth in oil and natural gas production has anyway been a challenge for the company over the last many years.For the quarter to be reported, Exxon Mobil has an Earnings ESP of -3.57%. It carries a Zacks Rank #3 (Hold) (Read more: Will Lower Realizations Hit Exxon Mobil Q1 Earnings?).Chevron Corp. CVX – the No. 2 U.S. energy producer – will also come up with first-quarter results before the opening bell on Friday, Apr 29. The commodity price rout has brutalized Chevron’s upstream business segment revenues and earnings. In order to survive the cataclysmic energy-price scenario, the integrated major – long considered a safe harbor with a strong balance sheet and substantial dividend – is being forced to offload assets. Moreover, the company’s still relatively high level of capital spending may result in reduced returns going forward. For the first quarter of 2016, this Zacks Rank #3 stock has an Earnings ESP of -38.89%. (Read more: What's in the Cards for Chevron this Earnings Season?)Stay tuned! Check later on our full write-up on earnings releases of these stocks.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report BP PLC (BP): Free Stock Analysis Report CHEVRON CORP (CVX): Free Stock Analysis Report EXXON MOBIL CRP (XOM): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research