Geophysical Support to a Challenging Horizontal Drilling- A Case History from SE Kuwait

One of the world’s largest on-land oil field Greater Burgan, has been producing oil for over six decades from a massive sandstone reservoir, named ‘Burgan’. Due to such intensive drilling activities, specially horizontal wells, well placement is becoming challenging day by day. Moreover, water encroachment is another issue, which is also putting serious restriction to finding suitable location. Geophysical support is an indispensible part in every horizontal well planning. During planning, every well trajectory is generally safe-guarded from faults except very subtle one and accurately depth-predicted. However in one recently drilled well, a plan has been made to deliberately drill through a major fault, a few hundred feet above the target reservoir, to align horizontally into the reservoir at its crestal part and this has been a major unprecedented success in recent times. The main challenges were, drilling through fault and limited drain hole length of about 1000 ft available between two parallel fault system. Normally, faults are avoided in drilling. However, risk was taken to negotiate the fault of more than 110 ft throw to strike the reservoir top at the other elevated side of the fault block.