Crude prices almost throughout first-quarter 2016 traded significantly below the $40-per-barrel level. Most importantly, WTI crude fell to the 12-year low mark of below $27 per barrel in mid February. The low levels were owing to plentiful supplies and lackluster demand. This was aptly echoed by the weekly release of Houston-based oilfield services company Baker Hughes Inc. BHI that reported the fifth consecutive record fall in U.S. rig count.What’s more, given the absence of major production cuts from OPEC, the effects of booming shale supplies in North America and a stagnant European economy, we do not expect much upside in the commodity’s prices in the near term. Moreover, Wall Street giant Citigroup Inc. C is apprehensive that Saudi Arabia may raise its output by 0.5 million barrels per day (bpd) to close to the 11 million bpd mark Citigroup feels that the move may stem from the ongoing rivalry with Iran over market share.Oil Refining & Marketing: A Sector Bucking the Downward TrendThe prevailing trend in the oil and energy sector has been well outlined in the Zacks Earnings Trend report. As of Friday, Apr 22, 7.9% of the oil and energy companies reported Q1 earnings. These stocks account for 11.9% of the total market capitalization. Total earnings for these index members plunged 60.9% from the year-ago period on a 30.3% decline in revenues.Nonetheless, investors need not fear or steer clear of oil stocks as there are still a handful of them that are showing strength in this shaky period. In particular, with oil prices cooling off, U.S. downstream (refining and marketing) stocks have been notching up healthy gains. This is apparent in the earnings surprise history of major refiners like Valero Energy Corporation VLO and EnLink Midstream, LLC ENLC which consistently surpassed market expectations in each of the last four quarters. The reason is very simpleThe business of the downstream players is negatively correlated with crude prices. This is because the companies use oil as an input from which they derive refined petroleum products like gasoline – the prime transportation fuel in the U.S. Hence, the lower the oil price, the higher will be their profits.Let’s find out how these players are placed week ahead of their earnings call this week.Marathon Petroleum Corporation MPC is slated to release first-quarter results on Apr 28, before the opening bell. The company has an Earnings ESP of 5.26% and a Zacks Rank #3 (Hold). Our model did not predict an earnings beat earlier, but the current case – positive ESP (+5.26%) combined with a Zacks Rank #3 (Hold) – points to an earnings beat in the to-be-reported quarter.Last quarter, the company posted a positive earnings surprise of 17.91% on the back of higher contribution from the ‘Midstream’ unit following the completion of the MarkWest acquisition. Higher crack spreads and increased merchandise margin also led to the improvement. Coming to earnings surprise history, the company has a mixed record: it surpassed estimates in two of the last four quarters. Let's see what awaits this quarter. (Read more: Is Marathon Petroleum Set to Outperform Again in Q1?) Phillips 66 PSX, an energy manufacturing and logistics company is expected to report first-quarter earnings on Apr 29. The company has an Earnings ESP of 0.00% and Zacks Rank #4 (Sell). While an unfavorable Zacks Rank lowered the predictive power of ESP, the company’s ESP of 0.00% also makes surprise prediction difficult.In the last quarter, the company’s adjusted earnings of $1.31 per share beat the Zacks Consensus Estimate of $1.30. The bottom line, however, deteriorated from the year-ago quarter level of $1.63. Moreover, the company outpaced the Zacks Consensus Estimate each of the last four quarters. (Read more: Will Phillips 66 Disappoint This Earnings Season?) Don’t miss out on our full earnings release articles for these two oil refining stocks, as the actual results might hold some surprises! 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 CITIGROUP INC (C): Free Stock Analysis Report VALERO ENERGY (VLO): Free Stock Analysis Report BAKER-HUGHES (BHI): Free Stock Analysis Report PHILLIPS 66 (PSX): Free Stock Analysis Report MARATHON PETROL (MPC): Free Stock Analysis Report ENLINK MIDS LLC (ENLC): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research