Fast-track 2D Seismic Processing While Drilling to Ameliorate Foothills Exploration and Optimize Side-track Trajectory

The petroleum exploration in foothills domains remains challenging in terms of positioning a well in an optimal manner to target different objectives in places where there are several mechanical discontinuities in the stratigraphy separating them and inducing often shifted structural tops. In consequence, seismic imaging, as well as a good geological knowledge, is mandatory to predict a well trajectory suited for all the targeted objectives. In Kurdistan Region of Iraq, the mechanical stratigraphy is rather simple but the tightening of the structures often leads to the activation of internal mechanical discontinuities and a shift of the main objectives tops. In consequence, and as in any foothills environment, side-tracked wells have to be carefully planned.

After drilling the first leg of a well, and finding out that we were clearly out of our predictions in terms of structural positioning and in the evidence that the deepest objective cannot be drilled with the first leg, the decision to drill a side-track came quickly. Meanwhile, we performed a fast-track processing on the closest 2D line in order to image the high dips of the drilled formations. The output allowed us to help optimizing the side track trajectory and to ahead with better constraints.