Two oil services giants continue to pump out big operating profits. While Schlumberger ( SLB) and Halliburton ( HAL) fell shy of revenue estimates -- and the latter actually posted a net loss -- both companies reported a surge in second-quarter operating profits as business picked up due to high energy prices. Schlumberger saw revenue increase 13% to $2.86 billion, and earnings per share jump an even higher 23% to 48 cents, in the latest period. Still, Wall Street was looking for slightly larger numbers on both the company's top and bottom lines. Thus, Schlumberger's stock slipped 1.4% to $63.38 on Friday morning. But Bob Howard, the author of investment newsletter Positive Patterns, viewed the drop as a fresh buying opportunity. Howard, who recommends the stock to his clients but doesn't own it himself, insists that better times still lie ahead for the oil services giant. "The biggest change will happen when the big boys at Shell ( SC), ExxonMobil ( XOM), etc., are convinced that energy prices are going to stay high," Howard said. "It is happening more and more, but the best is yet to come. That is why you can buy Schlumberger here and still get in at a decent beginning of the upswing." Schlumberger itself was similarly upbeat. "North America pricing moved up satisfactorily in the quarter," CEO Andrew Gould stated. "The growing realization that at current levels of demand, very little spare oil production capacity exists will ensure continued strong growth over the coming quarters." Halliburton posted strong results for its oil services division as well. But Halliburton's controversial KBR unit -- best known for its giant contracts in Iraq -- continued to drag down the company's overall performance. Halliburton reported that second-quarter revenue surged 38% to $5 billion due primarily to its government projects in the Middle East. But it also posted another big charge on a KBR project in Brazil that pushed company-wide results into the red.