OK, Halliburton. Ready or Not, Here Come Schlumberger and Weatherford

When Weatherford International ( WFT ) announced that it had named Halliburton ( HAL ) CFO Mark McCollum its new CEO , its shares jumped as some observers contended it increased the odds of an acquisition by the oil-services giant . It looks like they picked the wrong oil-services giant, however, as Weatherford and Schlumberger ( SLB ) announced a joint venture late Friday, one that has sent Weatherford's shares soaring and earned it an upgrade from Wells Fargo analysts Judson Bailey and Coleman Sullivan . They explain why: