#oilwire Oil explorers reduced rigs #drilling in U . S . oilfields this week , fueling optimism that a shale slowdown and OPEC production cuts will be enough to deflate a glut and strengthen crude prices . Shares of major shale producers , including #Pioneer #Natural #Resources Co . and EOG Resources Inc . , tumbled this week as investors began to lose confidence in the prolific #Permian basin . As the prod . . .